WRX experts

[Jammin]

I am going to build one of these cars. I was planning on building a locost car, but after seeing this car I am sold. Problem is I know nothing about these cars. It looks like the donor years are from 2002-2007. Which is the best year to use as a donor. I have seen mention of 5 speeds and 6 speeds, which is best. Engines are they all the same in all models hatch, sedans ect. Of course I would need to upgrade the hp, what is the best and most reliable way to do that on these engines. Can the axles handle more hp or do those need to be upgraded as well. Total newbee on these cars so any help would be great.

[Jmcd]

Engines are the same in sedan/wagon, 2006 plus are 2.5 liter, 5 speed is what ffr are making the kit around-should be decent for holding power in 2wd, they are also using a sedan-longer axles and control arms.

Cobb tuning rates their accessport stage 1 at 285 hp with 93 octane, that is a plug in computer along with a turbo back exhaust! The stock turbos can relatively easily reach about 230-250 awhp(maybe 320-350 crank) with header+catless uppipe/intake/exhaust(guess this would come with the kit?)/tune/upgraded top mount intercooler, bolt on a bigger turbo with fuel, and 300 awhp(maybe 400 crank) is a safe conservative number on the stock block, 2.5 will produce more power/torque.

Front axles are really beefy, I would say no worries there on stock motors/trans.

[crobin4]

The best year to use as a donor is what they are using, 2006-2007 WRX. Wagons and Sedan are the "same" except axles and control arms. 2002-2005 donors will require some creativity with the throttle cable. Not to difficult I imagine. I'll be drawing from Porsche/VW for inspiration.
Cobb Tuning is probably the best way to start adding power. They have reliable maps that add more than a little power.
Anyone one with specific questions is free to PM me. I'm no expert, but I stayed at a Holiday Inn Express last night.

[MDRex]

The brakes are also upgraded on the 06-07. I would go for an 06-07 myself. I like the bigger engine and the upgraded brakes. I would upgrade to a larger top mount intercooler(actually have one in my basement right now), better intake and piping(got that too), larger injectors, better fuel pump and something like a vf34 turbo. The vf34 is a little bigger than stock, so it will give more power without sacrificing too much lag. Everything else on the tranny and axles I would just keep stock. I really don't think any of that will need to be upgraded for such a small RWD car. I think you could do all the above mods for about $1500, depending on the deals you score. Plus you'll need a custom tune, which you could do free with OpenECU software or pay a Subaru shop which is about $500-1000.

[crobin4]

The brakes are also upgraded on the 06-07. I would go for an 06-07 myself. I like the bigger engine and the upgraded brakes. I would upgrade to a larger top mount intercooler(actually have one in my basement right now), better intake and piping(got that too), larger injectors, better fuel pump and something like a vf34 turbo. The vf34 is a little bigger than stock, so it will give more power without sacrificing too much lag. Everything else on the tranny and axles I would just keep stock. I really don't think any of that will need to be upgraded for such a small RWD car. I think you could do all the above mods for about $1500, depending on the deals you score. Plus you'll need a custom tune, which you could do free with OpenECU software or pay a Subaru shop which is about $500-1000.

VF34 excellent choice for this car and that engine, you won't really need injectors ,unless you switch to a different fuel. You may also want think about a water to air intercooler, instead.

[BrandonDrums]

There's quite a bit of info already shelled out on this forum but a lot of it has gotten buried with top/no top talk so I'll take a stab at it. Sorry in advance for the book.

2002-2005 used the same 2.0l H4 engine with a small but quick spooling TD04 Turbo and essentially the same exact 5 speed manual transmission with 50/50 torque split.
In the 2nd half of 03, Subaru beefed up the 5-speed a bit more and again in 05.

02-05 use a traditional mechanical cable controlled throttle
02-05 use 16bit ecu's and a drive-by-wire throttle

06-07 have 32 bit ECU's (more resolution and control than 16 bits) which allows you to do more fine tuning to fueling, boost, timing etc. 16 bit ecus work fine but there larger "gaps" in the tuning tables that result in compromises in the tune, especially with boost control. Engine Management systems get around these gaps i.e. cobb accessport.

06-07 have 17'' wheels standard and the fantastic 4-pot/2-pot brakes as standard.
02-05 have 16'' wheels (nicer ones for 05) and smaller more base-model style brakes (h6 rear rotor upgrade brings the gap down compared to 06-07 in capability)

2006' have aluminum front lower control arms which save a lot of weight over the other years (02-05 and 07)'s standard steel control arm. That's probably the only suspension component of consequence out of all of the model-years that will have any impact on this kit. Perhaps the sway-bars will also be used in which case sedan-versions of all donor years will have the better option. Wagons come with smaller rear sway bars than the sedan. Aftermarket sways can be purchased for just over 100 bucks and endlinks for just under 100 (i reccommend just getting used STI endlinks)

In short, 06-07 wrx's (hatch and sedan) are probably the best donors as a stand-alone oem donor. Stronger transmission, bigger engine, bigger brakes, better ECU. But they will be more expensive and harder to find.

On the flip side, 02-05 are also great, the 2.0L engine has a few advantages over the 2.5 in durability and fuel economy and mechanical balance. They are more sensitive to oiling issues as their rod-bearings don't self-oil as well as later 2.5L models. However, assuming you have good oil and aren't low they are actually more durable than the 2.5's since they have a more optimal bore and stroke than the 2.5's which are over-square engines. Over-Square meaning bore and stroke are nearly equal which puts rod-angles at an extreme placing undue stress on the piston rings by shoving them against the cylindar wall causing ring-land failures.

Aside from piston issues, the 2.5's can make better power and torque than the 2.0 with equal upgrades. The 2.5's are less reliable in the sense their weak-point: ring lands, will fail as a result of power upgrades and aggressive driving. Upgrading the 2.5 puts it at risk. The 2.0 can handle more power and not have their weak-point fail (rod bearings) assuming you have good oil and keep the oil full and changed regularly. You can prevent a 2.0 from failing after upgrades with added maintenance. A 2.5 on the other hand is just at risk, but that risk is smaller than a 2.0L's if you let maintenance fall behind. It's a trade-off.

The cheapest and most-reliable way to make power on a wrx, 02-05 or 06-07 is to upgrade the turbo to an STI oem turbo, sti or better TMIC, upgrade the fuel pump and injectors (injectors are the same between wrx and sti in 06/07) and get a professional tune.

You can spend a little more and get a bigger aftermarket turbo and get the stock injectors modified by http://www.deatschwerks.com/ or http://www.witchhunter.com/ and make huge power with a good tune, there are less "off the shelf" maps available for more custom setups requiring professional tuning services which cost more.

Cobb accessports are great but are also expensive. If your concerned about cost I recommend opensource tuning. www.openecu.com has all the info on that. Many vendors offer remote tuning services or pre-made maps to re-flash your car for common upgrade combonations.

I used an XPT stage 2 map on my 05 wrx for over 60k miles with no problems making around 220hp at the wheels (just under 300 crank hp) on a stock turbo, upgraded downpipe and catback exhaust.
http://www.xpttuning.com

The kit will obviously use aftermarket exhaust components since the engine will be at the back. You probably won't have to purchase any aftermarket exhaust parts to go "stage 2" aside from removing the cat in the up-pipe (the pipe before the turbo) or buying an sti or aftermarket up-pipe which is less than 100 bucks.

You can learn just about everything you need to know about Subarus on the following sites.

www.nasioc.com
www.iwsti.com
www.clubwrx.net
www.scoobymods.com

Again, to summarize. Get an 06-07 sedan or wagon if you can find one at a good price for the best overall oem donor. Getting an 02-05 will potentially save you enough money vs. buying an 06-07 that you can use the extra cash to upgrade nearly all the components that make the 06-07 a 'better' car.

You can't go wrong. Which donor is "best" depends on how much you want to rely on an OEM donor vs. aftermarket parts. I can assume all donors will cost similar amounts to achive the same numbers when accounting for all costs.

[Jammin]

All good info, thanks

[thebeerbaron]

02-05 use a traditional mechanical cable controlled throttle
02-05 use 16bit ecu's and a drive-by-wire throttle

Great info, can you clear up this inconsistency? Is DBW/cable split depending on model year, or turbo/NA?

Also - I'm very much wondering if the larger brakes on the later models will be necessary in such a light car. Smaller = lighter = better. Can you speak to whether there are more choices in brake pads or rotors with either setup? Is one setup easier to swap pads on?

[Dave Smith]

... and just when I was about to get a tad annoyed at our dear friend Brandon- "raging top debate"- Drums... Wow! Thanks for the great info. Seriously, the strength, passionate and knowledgable support of the Subie aftermarket was one of the major decisions behind this running gear on the car. Perfect.

[sonicrex]

Front rotors from 02-07 are the same. I think 06-07 rear rotors are slightly larger but I don't know the specifics so someone will have to double check that.

06-07 front 4 pot calipers are cast iron so I don't think there are any weight savings. Rear 2 pots are aluminum so you might shed some there. 06-07 use the same pads as the 300zx so because of that I would assume that you would have more pad choices.

02-03 pads are a bit funky. You can have early fronts/early rears, early fronts/late rears, late fronts/early rears, or late fronts/late rears. :mad: More info with pictures here: http://www.knsbrakes.com/staticWRXPADSHAPE.php

[PhyrraM]

..... can you clear up this inconsistency? Is DBW/cable split depending on model year, or turbo/NA?


2.0 Has 16 bit ECU and throttle cable. '02-'05
2.5 Has 32 bit ECU and drive by wire. '06-'07

[PhyrraM]

Front rotors from 02-07 are the same. I think 06-07 rear rotors are slightly larger ...

06-07 front 4 pot calipers are steel .... Rear 2 pots are aluminum .... .



Correct, all front WRX rotors are the same. Correct, '06-'07 have larger diameter, but the same swept area and IIRC, vented.

Edit.....Foot in mouth......

[crobin4]

Correct, all front WRX rotors are the same. Correct, '06-'07 have larger diameter, but the same swept area.

Wrong...all '06-'07 calipers are aluminum. Front and rear.

Wrong .... '06-07 WRX calipers are Cast Iron, that is why Racing Brake has a market with Aluminum calipers to fit stock rotors.
They save unsprung weight and dissipate heat faster.

[Jammin]

Do all WRX cars have the STI engine or was that a option

[PhyrraM]

Do all WRX cars have the STI engine or was that a option

The STI was a submodel of the WRX. AKA: "Subaru Impreza WRX STI".

WRXs are 227 HP (2.0 and 2.5), 5 speed (or auto), optional small wing.
STIs are 300HP 2.5 liter, 6-speed, Brembo brakes, and huge wing.

[PhyrraM]

Wrong .... '06-07 WRX calipers are Cast Iron, that is why Racing Brake has a market with Aluminum calipers to fit stock rotors.
They save unsprung weight and dissipate heat faster.

Not going to draw this out, but some reading is in order.

[sonicrex]

Oops they are definitely cast iron, not steel or aluminum.

[MDRex]

It's the STi Brembos that are aluminum.

[BrandonDrums]

... and just when I was about to get a tad annoyed at our dear friend Brandon- "raging top debate"- Drums... Wow! Thanks for the great info. Seriously, the strength, passionate and knowledgable support of the Subie aftermarket was one of the major decisions behind this running gear on the car. Perfect.

I was wondering when you were going to call me out on that, that took you too long...:p I've more recently been trying to put the top debate to rest...no such luck though.

Sorry for any stress-related nerve damage I might have caused you guys. After 10 years doing rain-dances and Celtic (for St. Patties day!) prayer ceremonies for a FFR Subaru Based-kit, I might have been a bit Zealous on the forums I admit.

This car is going to explode for FFR in a good way (i'm not aware of any fueling issues on 02-07 models). We can't wait.

Many thanks Dave!

[crobin4]

Do all WRX cars have the STI engine or was that a option

STi engines have stronger/better internals: crossdrilled cranks, forged rods, stronger cast pistons, more aggressive cams, higher flowing intake manifold, larger turbo, better uppipe, better down pipe, larger dia. exhaust, larger top mount intercooler, the block is a stronger design as well.

The WRX/Forester XT 2.5L are built along the way as 2.0L turbo engines. They are not as strong but no slouches either.

[crobin4]

It's the STi Brembos that are aluminum.

That is correct.

[mn_vette]

Now what about using a base impreza 5speed for a donor and purchasing an STI engine/controller???? Are there majore differences in the Base vs the WRX in alot of the basic suspension/brake/etc areas?

[Oppenheimer]

Now what about using a base impreza 5speed for a donor and purchasing an STI engine/controller???? Are there majore differences in the Base vs the WRX in alot of the basic suspension/brake/etc areas?

Brakes, yes. Suspension, doesn't matter much, the 818 is going to use fabricated control arms, aftermarket shocks & springs. Other big differences that you wouldn't use in 818.

Your approach would work, but I think the for the cost of an STi engine it would be cheaper to locate a wrecked STi, then sell of all the STi stuff you weren't going to use to a WRX guy.

[Evan78]

From what I found, front 06/07 calipers are cast iron and the rears are aluminum. I'll be pulling a full set off my car as early as this weekend, so I should find out first hand.

[forced4]

I've never had brake fade with my 02 stock calipers during track days. I do have autox-ish pads, SS brake lines and the "H6" rear upgrade FWIW. I'd think with this lighter car, the stock brakes will be just fine.

[PhyrraM]

Yup, I stand corrected. USDM WRX 4-pots are cast iron. I was getting confused with the 300Z calipers which went from aluminum to cast iron, and are the same basic casting/design as the WRX calipers.

[crobin4]

Yup, I stand corrected. USDM WRX 4-pots are cast iron. I was getting confused with the 300Z calipers which went from aluminum to cast iron, and are the same basic casting/design as the WRX calipers.

you,were half right the rears are aluminum.:D

[BrandonDrums]

STi engines have stronger/better internals: crossdrilled cranks, forged rods, stronger cast pistons, more aggressive cams, higher flowing intake manifold, larger turbo, better uppipe, better down pipe, larger dia. exhaust, larger top mount intercooler, the block is a stronger design as well.

The WRX/Forester XT 2.5L are built along the way as 2.0L turbo engines. They are not as strong but no slouches either.

Subaru denotes the STI 2.5 as the EJ257 and the WRX/Forrester as the EJ255. The only difference that Subaru themselves note is a slightly different domed piston design and the valve material in the heads in the Ej255 vs EJ257.

Actual differences are surprisingly a matter of debate. Tiny variations in head combustion chamber size, piston design and materials have been documented by individuals but never confirmed or denied by Subaru http://forums.nasioc.com/forums/showthread.php?t=1667168

Power output potential is identical, the VE equations are identical, they are the same engine but ever so slight variations in alloys and component designs that suggest there might be some engineered differences. It's probably more likely that the STI engine is manufactured in a separate facility or in separate manufacturing sequences than the WRX and have slightly different machine equipment between the 2 factories or different tooling durations set for the manufacturing cycle that call for some design trade-offs. The differences are so minute that there's no clear performance gain or loss between the 2, they just are slightly different for no apparent reason.

Both have AVLS (active valve-lift system), identical blocks, identical heads with identical cam-lobe profiles. For all intensive purposes, you can probably treat them as the same engine and disregard the comparisons. There are variations but again, it's up for debate in what the practical differences in reliability and output are. The best guess I have is again, the manufacturing process and not performance enhancing.

[crobin4]

Subaru denotes the STI 2.5 as the EJ257 and the WRX/Forrester as the EJ255. The only difference that Subaru themselves note is a slightly different domed piston design and the valve material in the heads in the Ej255 vs EJ257.

Actual differences are surprisingly a matter of debate. Tiny variations in head combustion chamber size, piston design and materials have been documented by individuals but never confirmed or denied by Subaru http://forums.nasioc.com/forums/showthread.php?t=1667168

Power output potential is identical, the VE equations are identical, they are the same engine but ever so slight variations in alloys and component designs that suggest there might be some engineered differences. It's probably more likely that the STI engine is manufactured in a separate facility or in separate manufacturing sequences than the WRX and have slightly different machine equipment between the 2 factories or different tooling durations set for the manufacturing cycle that call for some design trade-offs. The differences are so minute that there's no clear performance gain or loss between the 2, they just are slightly different for no apparent reason.

Both have AVLS (active valve-lift system), identical blocks, identical heads with identical cam-lobe profiles. For all intensive purposes, you can probably treat them as the same engine and disregard the comparisons. There are variations but again, it's up for debate in what the practical differences in reliability and output are. The best guess I have is again, the manufacturing process and not performance enhancing.

Hmmm.... I wasn't aware that ej255 got the Semi-closed deck block, forged rods, and hypereutectic pistons. It's been my understanding that only Stis and the 2.5gt legacy got those. Are you you sure you are not referring to the 08+ cars?

[PhyrraM]

IIRC, Up until the '05 Legacy GT was released the '04 STI, '04 Forester XT and the '04 Baja Turbo all had the same part number for a replacement shortblock.

When the '06 2.5 WRX was released the Forester and Baja part numbers migrated to the Legacy GT part number, along with the WRX. Leaving the '06+ STI as a seperate part number with the differences still debated.

All turbo 2.5s are semiclosed decks with HyperU pistons.

All 2.5 turbos use the same part number for a replacement BARE block. (except maybe the '08+ STI)

[Jammin]

So if I understand everything, the best donor would be a 2007 WRX STI, but I would need to switch out the trans. to a 5 speed. The 5 speed will bolt up with no problem and no problems with the engine computer and the 5 speed. Will the alxes bolt up to the 5 speed.

[crobin4]

So if I understand everything, the best donor would be a 2007 WRX STI, but I would need to switch out the trans. to a 5 speed. The 5 speed will bolt up with no problem and no problems with the engine computer and the 5 speed. Will the alxes bolt up to the 5 speed.

I wounldn't take my word for it at this point. I have obviously forgotten/confused a large amount of stuff since I boned up on my StreetMod auto-x build a couple of years ago.
If I were to use an STi donor I would be looking at an '04-'05.
'06-'07s integrated pitch/yaw and steering input sensors into the center diff control. The center diff control (DCCD) is controlled by a separate computer. However, I'm not sure how much of DCCD the is integrated into the ECU on the '06-07s.
I wouldn't buy one until those questions were resolved.
There may also be an issue with FFR control arm fitment on the '05-'07 front spindles. Some thing else to find some answers to.

[BrandonDrums]

Hmmm.... I wasn't aware that ej255 got the Semi-closed deck block, forged rods, and hypereutectic pistons. It's been my understanding that only Stis and the 2.5gt legacy got those. Are you you sure you are not referring to the 08+ cars?

I don't know about the forged rods but the block is the same and basically every car made right now has hypereutectic pistons, it's a fancy way of saying cast pistons. Every Turbo model in the past has a semi-closed deck, even the 2.0L found on the 02-05 wrx.

In researching more, the main difference is actually with the heads, the EJ255 has a slightly higher compression ratio and lower cam profile since it's designed for lower boost. http://forums.nasioc.com/forums/showthread.php?t=1594587 I still can't find a solid source really laying out the specific and identifiable differences. Subaru, as I said before, only acknowledge different valves in the heads and pistons as the 2 only separate components between the 2 engines...

But again, for the purposes of this discussion, they might as well be the same exact engine. The "Best" overall donor car will be a 2006 wrx; it has the 5MT, 2.5L engine, 4/2pot red calipers and aluminum front lower control arms (which if this FFR uses the same basic donor components as other FFR's, that will be used).

[BrandonDrums]

I don't know about the forged rods but the block is the same and basically every car made right now has hypereutectic pistons, it's a fancy way of saying cast pistons. Every Turbo model in the past has a semi-closed deck, even the 2.0L found on the 02-05 wrx.

In researching more, the main difference is actually with the heads, the EJ255 has a slightly higher compression ratio and lower cam profile since it's designed for lower boost. http://forums.nasioc.com/forums/showthread.php?t=1594587 I still can't find a solid source really laying out the specific and identifiable differences. Subaru, as I said before, only acknowledge different valves in the heads and pistons as the 2 only separate components between the 2 engines...

But again, for the purposes of this discussion, they might as well be the same exact engine. The "Best" overall donor car will be a 2006 wrx; it has the 5MT, 2.5L engine, 4/2pot red calipers and aluminum front lower control arms (which if this FFR uses the same basic donor components as other FFR's, that will be used).

I think my nerdiness might have killed this thread...

[thebeerbaron]

Well, maybe your nerdiness can help me: this is probably a better venue than in the Subaru Tidbits thread where I posted it, but what do you know about Subaru steering racks?

I'd like to know the lock-to-lock turns (everyone seems to report these in the far less useful gear ratio format) and if there's a standardized way to depower them.

For example, since I'm a Miata dork, when I get around to depowering my Miata rack, I'll use this guide (http://flyinmiata.com/tech/depower.php?x=1). I assume the Subie method is similar, but if you know of an exact guide, that'd be awesome.

[BrandonDrums]

Well, maybe your nerdiness can help me: this is probably a better venue than in the Subaru Tidbits thread where I posted it, but what do you know about Subaru steering racks?

I'd like to know the lock-to-lock turns (everyone seems to report these in the far less useful gear ratio format) and if there's a standardized way to depower them.

For example, since I'm a Miata dork, when I get around to depowering my Miata rack, I'll use this guide (http://flyinmiata.com/tech/depower.php?x=1). I assume the Subie method is similar, but if you know of an exact guide, that'd be awesome.

Ahh yes, I forgot about that stuff.

Cars 101 gives all the steering ratio info from year to year which is where I got this info

2002-2003 WRX have 3.0 turns to lock and 16.5:1 steering ratio
2004-2007 WRX have 2.7 turns to lock and 16.5:1 steering ratio
2004-2007 STI have 2.6 turns to lock and 15.0:1 steering ratio

There's no real step-by step FAQ on de-powering these racks since it's less common in a heavier AWD car. The best post I've been able to find on the topic is at the bottom of this post.

Lastly, 02-04(might just be 03) the steering rack have horrible "soft" mounting points. 2 rubber bushings with a metal bracket going around the rack, not through it which allows the rack to move back and fourth a bit. You'd 100% want to and need to upgrade the steering rack bushings for those year donors.

http://www.scoobymods.com/steering-rack-bushings-t5.html?t=5&highlight=rack+bushings

The newer style has 2 bolt holes milled directly in the rack so the bolts go through the rack directly into the chassis which solves the problem. No real need to upgrade bushings for 05+ You can kinda see the difference in this pic. The bottom is the 05-07 version which is the better one.
http://img534.imageshack.us/img534/4819/img2233m.jpg

---------
http://forums.nasioc.com/forums/archive/index.php/t-132810.html
How to get a manual rack in ANY car for $100 or less:

If you want manual steering in a performance oriented car it's better to just modify your power rack. I'm not talking about just taking of the power steering belt. The easiest solution is to make a new hardline that directly connects the right and left sides of the rack. This also is so easy it can be done temporarily if you want to just try it out. This solution is not a true 100% conversion as you are still pushing around a tiny bit of PS fluid. But to anyone that isn't picky you will happy with it, it's a simple diy mod, it can be done without removing the rack, and it's almost free!

If you want to do the conversion 100% you need to take out the rack and bring it to a power steering rebuild shop and have them rebuild it and leave out the center seal on the inner shaft. This makes it into a true manual rack. From there you just plug up the hydraulic fittings, which you can later use to grease it once every few years. Kit car people have to have this sort of thing done all the time. I've done twice both for chevy v8 converted 240sx's, it was around $100-125 both times (which also includes a fresh rack rebuild). If anyone wants more details let me know.

Yes a manual power steering rack will give you some extra steering feel. However personally I don't think the improvement is worth the extra effort. The other problem with manual racks is the steering ratio is much slower, so if you have a section with a lot of transitions or a slalom you're going to be moving the wheel much more. When you de-power a power steering rack you keep the faster ratio with no power.

de-powered power steering rack > manual rack

-----------------------

[bbjones121]

Now what about using a base impreza 5speed for a donor and purchasing an STI engine/controller???? Are there majore differences in the Base vs the WRX in alot of the basic suspension/brake/etc areas?

I don't know if I would use the impreza 5 speed with the power of a turbo 2.5.

[bbjones121]

The 6 speed on these engines is overkill, but they are stronger. Good for high speed (70+mph) mpg, but at the drag strip they would be even. If you have a choice on engines, get the latest sti version with the Nitride crank. Honestly though, the engine I have already been eyeing to replace my 450+hp corn fed stocker in my Legacy GT if it ever craps out is a built RalliSpec block. Go to their website, I think the prices are pretty reasonable for a built subaru block. So I could see just getting a junked out 06+ WRX, sell off parts that you don't need on one of the many subaru forum sites and just purchase a shortblock from Rallispec when the funds become available.

I don't know if anyone has mentioned this or not, but there are different intercooler/turbo mounting on 08+ WRX's. Same with the 05+ LegacyGT. These turbos have a flange connection straight to the intercooler. There are not as many options when it comes to aftermarket turbos for these intercoolers. Trust me, I have researched this a lot. It wasn't until the WRX went to the Legacy style that we Legacy owners started to see some better turbo options (BNR is one of the best) to keep the top mount intercooler.

Anyways, another thing that I don't know if it is mentioned here or not is that you will most likely not ever see more than 350-400 hp out of this engine (250-300whp) without upgrading the fuel system. If you want to go north of this number, plan on bigger injectors and fuel pump(not very much money, maybe $200-$500 total if you can find these used)

Another thing, most tuners will be able to tune the engine for E-85 (flexfuel) and get you a significant amount more power. With a Cobb Accessport device, you can switch your fuel maps on the fly so you don't have to worry about not finding an E-85 station. If you ever plan to go that route in the future, pick the largest injectors, at least 800's you can find, a 255lph walbro fuel pump should suffice. You will need to pass more fuel with E-85, but it will help to spool the turbo quicker with the extra exhaust volume.

Lastly, I am running a quarter mile equal to that of the 500hp corvette Z06 at this elevation, so I am probably north of 450hp at the crank on stock Legacy GT engine. It is my daily driver and I have put over 30,000 miles on the car this way. I have not spent more than $4k on my upgrades including tune. There are others that have had no reliability issues running at these power levels on a Legacy GT engine longer than I have, but it is is very important that you get a good tune. Lastly, many of us pass Colorado sniffing emissions at these levels as well, don't know if this is an issue for kit cars.

Kinda went off on a tangent, but anyways, there you go on my thoughts.

[BrandonDrums]

The 6 speed on these engines is overkill, but they are stronger. Good for high speed (70+mph) mpg, but at the drag strip they would be even. If you have a choice on engines, get the latest sti version with the Nitride crank. Honestly though, the engine I have already been eyeing to replace my 450+hp corn fed stocker in my Legacy GT if it ever craps out is a built RalliSpec block. Go to their website, I think the prices are pretty reasonable for a built subaru block. So I could see just getting a junked out 06+ WRX, sell off parts that you don't need on one of the many subaru forum sites and just purchase a shortblock from Rallispec when the funds become available.

I don't know if anyone has mentioned this or not, but there are different intercooler/turbo mounting on 08+ WRX's. Same with the 05+ LegacyGT. These turbos have a flange connection straight to the intercooler. There are not as many options when it comes to aftermarket turbos for these intercoolers. Trust me, I have researched this a lot. It wasn't until the WRX went to the Legacy style that we Legacy owners started to see some better turbo options (BNR is one of the best) to keep the top mount intercooler.

Anyways, another thing that I don't know if it is mentioned here or not is that you will most likely not ever see more than 350-400 hp out of this engine (250-300whp) without upgrading the fuel system. If you want to go north of this number, plan on bigger injectors and fuel pump(not very much money, maybe $200-$500 total if you can find these used)

Another thing, most tuners will be able to tune the engine for E-85 (flexfuel) and get you a significant amount more power. With a Cobb Accessport device, you can switch your fuel maps on the fly so you don't have to worry about not finding an E-85 station. If you ever plan to go that route in the future, pick the largest injectors, at least 800's you can find, a 255lph walbro fuel pump should suffice. You will need to pass more fuel with E-85, but it will help to spool the turbo quicker with the extra exhaust volume.

Lastly, I am running a quarter mile equal to that of the 500hp corvette Z06 at this elevation, so I am probably north of 450hp at the crank on stock Legacy GT engine. It is my daily driver and I have put over 30,000 miles on the car this way. I have not spent more than $4k on my upgrades including tune. There are others that have had no reliability issues running at these power levels on a Legacy GT engine longer than I have, but it is is very important that you get a good tune. Lastly, many of us pass Colorado sniffing emissions at these levels as well, don't know if this is an issue for kit cars.

Kinda went off on a tangent, but anyways, there you go on my thoughts.


And yes, I didn't mention fuel mods here but that's pretty much small-potata's. A walboro fuel pump can be had for 80-100 bucks and you can just have the stock injectors modded by http://www.witchhunter.com/ which bumps WRX injectors to around 810cc and STI to 870cc for 100 bucks+shipping. That would give enough go-juice for over 400hp. The big expense is the turbo, fuel mods are cheap unless you go with some brand new aftermarket top of the line squirters.

[Kasmodean]

Lastly, 02-04(might just be 03) the steering rack have horrible "soft" mounting points. 2 rubber bushings with a metal bracket going around the rack, not through it which allows the rack to move back and fourth a bit. You'd 100% want to and need to upgrade the steering rack bushings for those year donors.

http://www.scoobymods.com/steering-rack-bushings-t5.html?t=5&highlight=rack+bushings

The newer style has 2 bolt holes milled directly in the rack so the bolts go through the rack directly into the chassis which solves the problem. No real need to upgrade bushings for 05+ You can kinda see the difference in this pic. The bottom is the 05-07 version which is the better one.
http://img534.imageshack.us/img534/4819/img2233m.jpg

-----------------------

Are you sure the bottom one is the better one? From what you describe, it looks like it is the bottom one with the rubber bushings and the top one with the bolt holes. Just asking though, I could be looking at it wrong.

[BrandonDrums]

Great info, can you clear up this inconsistency? Is DBW/cable split depending on model year, or turbo/NA?

Also - I'm very much wondering if the larger brakes on the later models will be necessary in such a light car. Smaller = lighter = better. Can you speak to whether there are more choices in brake pads or rotors with either setup? Is one setup easier to swap pads on?

.....aaaand I miss this one too.

The larger brakes probably aren't needed that much. However, the brake pedal feel on the 02-05 was natoriously squishy feeling which the 06-07 brakes really help out with.

Rotor and pad choices are wwiiiiide open. www.knsbrakes.com for example (they are performance oriented pads and rotors)

With a 02-05, I'd recommend keeping the stock brakes, just doing the H6 rear rotor conversion. It uses the same caliper but a different mount and a larger dia. rotor. That puts more rear brake bias (not through hydraulics, but through braking torque) which really helps solidify the pedal feel and improve braking. With the weight more towards the back in the 818, you'd really benefit from this, and it's cheap.

The 06-07 have the larger rear rotor stock.

Brembo's are great but they are expensive with pads, expensive with rotors. They limit wheel choices and are much more valuable on a 3300lb wrx than an 818 I would assume.

[bbjones121]

And yes, I didn't mention fuel mods here but that's pretty much small-potata's. A walboro fuel pump can be had for 80-100 bucks and you can just have the stock injectors modded by http://www.witchhunter.com/ which bumps WRX injectors to around 810cc and STI to 870cc for 100 bucks+shipping. That would give enough go-juice for over 400hp. The big expense is the turbo, fuel mods are cheap unless you go with some brand new aftermarket top of the line squirters.

I agree with you, but still an expense I thought I should mention.

[Doc_FFR]

Is there a clear winner among the 02-05 WRX's? Does one stand out as the better year?

[BrandonDrums]

I agree with you, but still an expense I thought I should mention.

Oh yes, you're absolutely right. Fuel upgrades are a MUST for more boost and in some cases, modding stock injectors aren't going to be the best option.



Is there a clear winner among the 02-05 WRX's? Does one stand out as the better year?

My vote is for the 05. It has the most upgraded gears among the 02-05 5MT tranny, The direct bolting steering rack, a few more tweakable ECU parameters and if it matters, the Interior is slightly better looking (more modern steering wheel, cooler looking seats) however the 02-04 dash's have a cup holder on it. In 05 it switches to having both cup holders in the center console. I doubt the center console will be used but it's possible the dash might make it in the kit.

Umm, on the other hand, I might also point out that in 05, Subaru put a non-serviceable PCV valve AND a non-serviceable, single In-Tank fuel filter. Before 05 you had a generic, easy to replace PCV on the MAF, and 2 fuel filters; one in-tank and easy to replace but designed as a permanent unit, the other in the engine bay which pops right out and you can buy new ones at your corner auto store. That's a huge plus once you start pushing high HP numbers, you want to keep the fuel system clean and make sure you're not lowering your octane with excessive oil blow-by.

The 05+ in-tank unit requires purchase of the entire in-tank Fuel Pump/Fuel Filter/Fuel level sensor which is well over 100 bucks if I remember correctly. You can mod the unit to accept the older in-tank filter but that wasn't designed to be a single filter but part of a combo.

The 05+ PCV system CAN be worked around IF you can unscrew the PCV valve from the plastic t-fitting it's in without breaking the plastic. That's nearly impossible though...I recommend just spraying it clean with carb or brake cleaner every 15k and keeping an eye on the amount of oil use and oil build up in the crank case vent hoses. Those attach to the black metal pipe/hose thingy on the front of the inter-cooler. Too many WRX/STI guys don't keep an eye out for that and find that the crank case vent hoses are 100% clogged.

http://farm4.static.flickr.com/3069/3046885039_1a4ef410e0.jpg

...I THINK that's everything really to be considered though.

[Hondaslayer]

Are you sure the bottom one is the better one? From what you describe, it looks like it is the bottom one with the rubber bushings and the top one with the bolt holes. Just asking though, I could be looking at it wrong.

Yes, you are looking at it wrong.

The top one has a metal bracket that goes around a larger rubber bushing which allows the rack to move side to side while turning hard. There are upgrades available to those bushings though they will eventually wear out. The bottom one is a cast mounting point with pressed in bushings that allow a much smaller amount of movement (think flex vs sliding) However to use the bottom steering rack you will need to us a subframe from the same car. Hopefully FFR takes that into consideration.

If there are any typing errors I apologize as I am typing with a broken finger :mad:

[BrandonDrums]

Yes, you are looking at it wrong.

The top one has a metal bracket that goes around a larger rubber bushing which allows the rack to move side to side while turning hard. There are upgrades available to those bushings though they will eventually wear out. The bottom one is a cast mounting point with pressed in bushings that allow a much smaller amount of movement (think flex vs sliding) However to use the bottom steering rack you will need to us a subframe from the same car. Hopefully FFR takes that into consideration.

If there are any typing errors I apologize as I am typing with a broken finger :mad:

I could be wrong but I believe the bolt-holes for both steering racks line up to the same points on the chassis. Therefore 02-04 WRX's could directly swap in a 05+ rack with no modifications to the chassis because the cast mounting points line up the same as the bracket for the earlier models.

[PhyrraM]

The original donor was a '06 WRX, so that's the rack I would expect the chassis to accept. After reading these posts, I'm sure Jim is hard at work sourcing an earlier rack to compare to. ;)

[Gollum]

This thread is pretty well covered, so I just want to say Please Skip Cobb Tuning Products. They're way over priced and from what I've seen most people just use the premade maps which leave a LOT of power on the table for any given boost level. You're MUCH better off going with an open source tuning option. It will save you money and teach you how to tune an EFI system, which I find much easier than tuning carbs. Tuning EFI is like solving a rubik's cube, it takes time but with an instruction sheet anyone can get it done with patience. Carb tuning is like a wizard turning a stone into a toad. Some guy out there might be able to do it, but the rest of us are just banging rocks together.

Overall I think many guys don't create their own maps for their tune for all the wrong reasons. Then there's people that ruin their motors because they failed to read anything...

[MDRex]

I'll argue that an AccessPort is a great tool if you can get it cheap. I have used them on 3 cars now with base maps and have been happy, but I have gotten them used for really cheap. Obtained cheaply, I think they are great, but a custom tune is still far better. Open source tuning tools have come a long way for Subarus.

[BrandonDrums]

This thread is pretty well covered, so I just want to say Please Skip Cobb Tuning Products. They're way over priced and from what I've seen most people just use the premade maps which leave a LOT of power on the table for any given boost level. You're MUCH better off going with an open source tuning option. It will save you money and teach you how to tune an EFI system, which I find much easier than tuning carbs. Tuning EFI is like solving a rubik's cube, it takes time but with an instruction sheet anyone can get it done with patience. Carb tuning is like a wizard turning a stone into a toad. Some guy out there might be able to do it, but the rest of us are just banging rocks together.

Overall I think many guys don't create their own maps for their tune for all the wrong reasons. Then there's people that ruin their motors because they failed to read anything...

Pretty much true! Read this guide to get started, it's great for learning the basics of EFI tuning on a subaru.
https://sites.google.com/site/asubienewbietuningguide/ver-1-0

It's also good for understanding enough to keep a professional tuner accountable. I've had some horrible experiences with reputable tuners who just didn't have the time to finish the job. If I didn't have at least a basic understanding I wouldn't have been able to call them out.

[Evan78]

Comparing a custom open source tune to a Cobb off the shelf map is not really an apples to apples comparison. A relatively small percentage of people are going to do their own tuning, so the important thing for most people is selecting a good tuner. Some tuners will work with open source, some won't. There are certainly advantages of being able to use an AccessPort instead of openECU.

[snakeboost]

05 up Stis are DBW /wrx to 06 is cable 06 up dbw

[Gollum]

A relatively small percentage of people are going to do their own tuning,

That's exactly the problem I was trying to help address with my post. Back in the carb'ed days just about every guy out there knew how to adjust a carb and any real gear head knew how to select jets and such and had no quarrels with tuning their own carb.

EFI is EASIER to tune, yet the art is being lost because people are too scared to get their feet wet. My point with my post is that the information is so there and available that I think anyone willing to BUILD THEIR OWN CAR should take the time to TUNE their own car. Most guys that build a FFR would be willing to paint their own car, but either don't have the time for it, but more likely don't have the tools to do it well/right. Tuning a Subaru motor WELL just takes time and a few cheap tools (likely worth more than your laptop even!)

[Evan78]

I guess where we differ is if people SHOULD do their own tuning. I say yes, if they have the desire and ability to do so. I have the ability, but not the desire with so many other demands on my time. If I had tons of free time, then yes, I'd love to go through the process. When I have a very experienced tuner available, I'd rather pay the money to get a good, reliable tune than put in the many, many hours it would take me. Tuning mistakes can end up being very costly. I'm sure AccessPort (AP) vs open source has been debated endlessly, but I certainly prefer plugging in my little AP to do some logging or load a different map a lot more than plugging in a comparatively bulky laptop and waiting for it to boot. Everyone has different needs. I haven't kept up with recent developments, but Cobb also has a AccessTuner Race version of that allows people to tune their own car. I don't think it's available for all ECU's however. But, I don't see why someone couldn't run just about any turbo Subaru ECU with any turbo Subaru motor. Obviously, there's functional caveats such as variable timing on intake, exhaust, etc.

[Evan78]

I don't really know anything about carbs, but is part of the reason that (by your estimation) more guys knew how to tune their carb than people know how to tune EFI due to the need? My impression is that carbs are more likely to need adjusting than an EFI system that adapts to changing conditions, elevation, etc better than a carb.

[Gollum]

I don't really know anything about carbs, but is part of the reason that (by your estimation) more guys knew how to tune their carb than people know how to tune EFI due to the need? My impression is that carbs are more likely to need adjusting than an EFI system that adapts to changing conditions, elevation, etc better than a carb.

That's actually a very true reality. EFI is "set it and forget it" and if anything just needs new sensors from time to time to make it happy. Many OEM EFI system can even support as much as 50% more power over stock without ruining anything. The same could NEVER be said for a carb. Carb's definitely required more adjustments for more reasons. The nice thing about carbs though is that they where much harder to blow an engine up with for the average user. Much of their fuel curve was impossible to change, you could only move the curve or raise/lower it, not change it dramatically. This is where EFI can really be hazardous to tune, even on a NA engine. You have the ability to really move things around and dramatically change fuel curves. This can quickly lead you into dangerous territory.

[Oppenheimer]

This is where EFI can really be hazardous to tune, even on a NA engine. You have the ability to really move things around and dramatically change fuel curves. This can quickly lead you into dangerous territory.

Which is why I'm hoping one of the tuners offers an ECU re-flash tuned for the 818. Something that takes advantage of the added lightness, whatever exhaust the 818 ends up with, and produces reasonable gains, while remaining very street friendly and responsive. Even just taking a stock WRX, with such a mild tune, should produce very impressive acceleration figures with such a light car.

For those looking for a track-monster, they will want to have a real pro tune or roll their own. Same deal for the guys looking for the most outrageous power/weight ratio. But for the guy that just wants to build an awesome street car, and doesn't have the time to invest in learning how to tune (or the desire to deal with the pain of the learning curve), paying a couple of bucks for something off the shelf, that just flat works out of the box (even if its leaving something on the table), that you won't need to be fiddling with, would be well worth it.

Anyone out there want to step into this role?

[Gollum]

Anyone out there want to step into this role?

This is where having such a quality community could really offer something usually unheard of.

On my main Z forum - hybridz - we even have tool loan programs and the tools float around from member to member so that we all save money and get the job done. I see no reason one of the more experienced tuners could get a tune working with open source tuning tools and then loan out the tools to flash their stock ECU with a modified map that works for the 818. If someone was willing to do it, it could save everyone a lot of money, even over a used access port.

[PhyrraM]

Where there is a need, someone will step in to fill it.

If the 818 really needs a custom tune (a stock WRX is pig rich for warrenty purposes), then I have no doubt that FFR and/or a 3rd party will develop some type of program. Exchange program, send and flash, rebranded "FFR" Accessport, even a preprogrammed device like the Diablo or such.

Much like a WRX, I still feel that most who drive one stock first will likely be satisfied. This leaves the tuning to the (very vocal) minority.

[Evan78]

There's numerous Subaru tuners that are doing mail order tunes that could get the job done. It's an iterative process just like doing the tuning yourself, except it goes like:


Load a tune
Log
Email log to tuner
Get new map (tune) from tuner
Repeat

Naturally you have to have an AccessPort or open source software.

AccessPorts are shipped with preloaded maps, no reason why a FFR map couldn't come preloaded, if it existed. Unfortunately, AccessPort is the only unit of this kind for Subarus as far as I know (no Diablo, etc).

A tuner that's spent a lot of time with turbo EJ motors in sandrails will probably get closest to a good tune in the shortest time. Those can be of similar weight and exhaust config to what the 818 will end up with. I wonder how much of a stock load map doesn't get used when weight is decreased by this much.

[Oppenheimer]

It's an iterative process just like doing the tuning yourself, except it goes like:


Load a tune
Log
Email log to tuner
Get new map (tune) from tuner
Repeat

Naturally you have to have an AccessPort or open source software.



While this works for those looking to get the most out of their mods, its more hassle than I personally want to go through. I'm envisioning a one-size-fits-all approach, that works for a 'stock' WRX motor (it will have a non-stock exhaust to fit the 818), that optimizes the parameters for the lighter weight, different exhaust, etc. Perhaps it assumes (or even includes) a few small 'typical' mods, such as a freer flowing downpipe, etc. A plug-and-play, hassle-free ECU upgrade.

Perhaps that leaves some performance on the table, but I imagine it would also cost a lot less than the tuner having to tweak my tune a couple times based on logs. For me, such a trade-off would be well worth it, as the extra performance a solid tune for my unique setup could yield over a generic tune would be way overkill. I'd rather put that extra cost into something else in my build. Yes, I could just leave the tune stock, but its a bang-for-buck thing I'm thinking of here.

For a little buck, I get all the bang I'd want. Wait, that didn't quite sound right...

[Evan78]

I think you're looking at $100-$300 depending on tuner and how custom the map is. I think for $200-$300 you can get a custom map from a few different people using the process I described. Personally, I'd get a custom tune that includes dyno time. The engine tune is not where I want to save a few hundred bucks.

[Gollum]

Many might not get a tune at all, so if you're in the camp that thinks "saving a few hundred on a tune isn't where I'd skimp" then you'll most likely end up with a custm tune anyways.

The solution I'm talking about could be done for less than $50 to each individual. It would only cost $25 tops to ship everything from person to person, and the other $25 could go into a paypal account or something to cover the cost for the parts and labor. It would only take a good 20 guys to get close to breaking even, including the time the tuner donated.

If that $50 you spent gave you even as little as 15 peak HP gain, but smoothed out the lower RPM levels for good 20-30hp gain bellow the curve, and got better gas mileage to boot... well, you can imagine that more than just a few people that wouldn't otherwise get a tune done might really consider it. Overall, oppenheimer's idea is a good one and wouldn't be difficult to implement.

[Brian Apple]

Also keep in mind as people are thinking about the possibility of racing and or self service, ALL wrx's and 04 STI are a 5x100 bolt pattern. STI 05 and later are 5x114. WRX's and 04 STI are smaller strut mount point at the hub carrier with a closer bolt mount point (two bolts holding the strut to carrier are closer together). And the wheel bearing must be pressed out to be replaced. 05 to 07 STI Has a thicker strut mount point with wider bolt spacing for strut and a bolt in wheel bearing (all four wheels).
Tranny is switchable between base wrx and STI with cradle switched at the same time.(I assume FF will not use the cradle though).
Wiring is tricky when switching from STI to WRX. Keep in mind some of the WRX's (earlier) are cable throttle and later ones are wire. All STI are wire.
This list could go on and on because in addition to these and other differences, Japenese Domestic cars came with their own set of rules and they get stuff before us so compatible years go bace to earlier than 02.....

[thebeerbaron]

I haven't personally seen the front suspension of a Roadster yet, but from what I can see of the pics, the strut mount point gets an adapter that provides a connection point for an upper A-arm.* If the STi has different uprights (as evidenced by hub and mounting point differences), they will require a different adapter. Whether such an adapter is available immediately (or ever) is a good question.

Is it possible to use an STi hub on a WRX upright? Am I wrong in thinking that 5x114.3 is a much more common bolt circle?




*this is assuming that the 818 does something similar.

[PhyrraM]

Is it possible to use an STi hub on a WRX upright?


Nope, completely different bearing design.

But, all hope is not lost. The SVX hub *may* press into a WRX knuckle. A google seach of WRX and SVX bearing numbers may turn up something...

[Brian Apple]

No on the hub, and yes 114 is more common on the bolt pattern. At least when it comes to wheels produced for performance based cars with wider sizing. The Mitsubishi Evolution and Subaru STI can interchange wheels for instance. Not so for the WRX base.
Also keep in mind (I forgot above) that IF you use the STI hub carrier, the CV axle and trans all have a different number of splines than the WRX hub carrier and trans switches from female to male CV input at the trans... Ahem, more confusion to work with.

[MDRex]

The 114.3 is also the size that Mustangs and Z's use, so you have even more options in wheels from those.

[wjfawb0]

I would prefer a WRX vs STI 2.5 engine in this car from a street car standpoint. I'd rather have 9+:1 compression than 8.5:1 for fuel economy alone. If I remember correctly the STI heads in the early STI years had sodium filled exhaust valves. The lower compression and head features probably would be beneficial for a track car, though. Whatever kit I build will be mainly street driven.

[Brian Apple]

Both the STI and the base WRX are built from the same basic block design and are the same size(outside). The STI was build around higher compression ability and stronger internals. You can however use the STI block and the WRX heads for a larger displacement engine with some minor internal work to get various compression ratios. Piston swap alone will do it for you. Besides the STI pistons are the weak point. They fail around the ringlands when going for high horsepower. If you want a bigger turbo without crazy lag, a stroker kit(2.0 to 2.1 or 2.5to 2.6 or 2.7)will make for faster spool and more torque to boot. The aftermarket has made options endless.
As a word of warning, Subaru is different than other Japenese cars. Increasing boost without aftermarket air/fuel control will destroy the engine quick. Mitsubishi motors get away with it but this motor will not. Their electronics will not compensate for the boost over stock.

[GS guy]

Tire Rack lists the STI wheel bolt pattern (as mentioned in several posts) as 114mm. Not the same as the "Ford" pattern 114.3mm (4.5")! That's too bad because you'd have almost unlimited wheel choices, sizes and widths with the 114.3 pattern (except for maybe the hub-centric fitment).

[forced4]

It's 114.3 x 5 for 2005+ STi. Trust us.

[MDRex]

Yeah, don't look for wheels at the tire rack. Use Wheel Dude to see what there is for this car. STi 05+ is 114.3 x 5, which is the same as the Ford 4.5 x 5.

[Brian Apple]

You need to make sure the wheels you pick will clear the brembo STI brakes fi you are going to use them. Many wheels will fit the bolt pattern but not clear the brakes on the perimeter or face of the caliper.

[Evan78]

Many might not get a tune at all, so if you're in the camp that thinks "saving a few hundred on a tune isn't where I'd skimp" then you'll most likely end up with a custm tune anyways.

The solution I'm talking about could be done for less than $50 to each individual. It would only cost $25 tops to ship everything from person to person, and the other $25 could go into a paypal account or something to cover the cost for the parts and labor. It would only take a good 20 guys to get close to breaking even, including the time the tuner donated.

If that $50 you spent gave you even as little as 15 peak HP gain, but smoothed out the lower RPM levels for good 20-30hp gain bellow the curve, and got better gas mileage to boot... well, you can imagine that more than just a few people that wouldn't otherwise get a tune done might really consider it. Overall, oppenheimer's idea is a good one and wouldn't be difficult to implement.Are you talking about sharing a Tactrix cable? I can only think of 3 methods for reflashing a Subaru ECU:


Cobb AccessPort - can't be shared among different vehicles
EcuTek - requires onsite tuner with EcuTek hardware or shipping ECU to tuner (i.e. they don't have a portable solution like a AccessPort and all the other handheld reflash units available for other makes
RomRaider - uses a Tactrix cable ($200 or less, depending on version and new/used) and freely available software on a Windows or Linux computer, presumably a laptop.

[Gollum]

Yes, I was referring to a Tactrix cable with free tuning software. Quite an affordable solution and perfectly usable by any pro tuner.

[MDRex]

Could you also use the Cobb AP dongle and a USB cable? Or does the Cobb dongle only work with an AP?

[Monkey Tricycle Flip]

This thread is pretty well covered, so I just want to say Please Skip Cobb Tuning Products. They're way over priced and from what I've seen most people just use the premade maps which leave a LOT of power on the table for any given boost level. You're MUCH better off going with an open source tuning option. ...
I disagree in part. The Cobb AccessPort is an easy way to get a lot more power out of a stock setup (stage 1) or a mildly upgrade exhaust (stage 2). It's neither the cheapest nor the most effective, but it's certainly the easiest. The AccessPort is also handy for checking CEL codes, engine parameters like intake temp, boost, etc., etc. and logging the data without having to hook it up to a laptop.

Very few people will actually tune their own ECUs; it's not trivial, and the results can be disastrous. A few more will seek out a local tuner to do an open source tune. Given the target market for the 818 (which I think will be 10-20 years older than the average WRX driver), I suspect that many people are going to go for the plug and play solution that Cobb offers. And there's nothing wrong with that.

Cobb also makes the best catted downpipes in the business, though something tells me they're not going to fit the 818.

[Monkey Tricycle Flip]

Increasing boost without aftermarket air/fuel control will destroy the engine quick. Mitsubishi motors get away with it but this motor will not. Their electronics will not compensate for the boost over stock.
This needs to be repeated. Salvage yards are littered with blown 02-03 WRX engines. Back then, the car was new in the US and people didn't know what they were doing. Untamed boost will cause knock, and knock will destroy a Subaru motor in no time.

[Monkey Tricycle Flip]

While this works for those looking to get the most out of their mods, its more hassle than I personally want to go through. I'm envisioning a one-size-fits-all approach, that works for a 'stock' WRX motor (it will have a non-stock exhaust to fit the 818), that optimizes the parameters for the lighter weight, different exhaust, etc. Perhaps it assumes (or even includes) a few small 'typical' mods, such as a freer flowing downpipe, etc. A plug-and-play, hassle-free ECU upgrade.
These engines usually don't work like that. Identical engines with the same history will behave differently with the same tune. It's one of the reasons that Cobb's OTS (Off the Shelf) maps for common configurations usually don't make as much power as custom tunes: they're one size-fits-all solutions and extra conservative as a result.

[bbjones121]

This thread is pretty well covered, so I just want to say Please Skip Cobb Tuning Products. ....

I also disagree in most part to this one. The Cobb Accessport is extremely easy to use. It becomes a necesity if you are going to be running any e-85 through your car (which if you have available in your area, you would be crazy not to take advantage of the extra power). You will need to be able to switch maps on the fly if you can't get to your local e-85 station to fill up.

Code reader and reset is extremely handy on the road too. I have even read codes for an old lady with an outback at the store who couldn't start her car.

[Monkey Tricycle Flip]

Unless I missed it, there's hasn't been a clarification about the stock fuel injectors. 06-07 WRX's have a stock fueling system that has a lot of room to accept a bigger turbo. 02-05 WRX's require bigger injectors and a bigger fuel pump if you plan on going above stage 2. Lots of 02-05 guys will use 06-07 injectors, or have their stock ones modified by DeatschWerks or WitchHunter.

While we're talking about things I haven't seen on this thread:

Boost control: I'm not a huge fan of the factory boost control as it can be difficult to achieve and hold the boost target when running higher PSI than stock. There are tons of electronic aftermarket boost controllers available (I'm partial to GrimmSpeed's). Of course, all boost control mods require an updated tune.

Up-Pipes: The up-pipe goes from the exhaust manifolds to the turbo. The 02-05 have a catalytic converter while 06+ does not. The catalytic converter dramatically slows the spool of the turbo. they've also been known to disintegrate, taking the turbos with them. Aftermarket catless up-pipes are widely considered an absolute must on an 02-05 engine.

Intakes: The stock intake is a monstrous plastic thing with something called a "snorkus" that's meant to quiet the sound of the turbo. I suspect that FFR is already planning an alternative. There are very few aftermarket intakes that do not require a custom tune: Subaru's SPT, Cobb's Short Ram, K&N's Typhoon and maybe a few others.

Intercoolers: The stock WRX intercooler is OK but it's pretty puny. The much larger 04-07 STi intercoolers will fit WRX engines with the appropriate hose kit. You'll likely see references to TMICs (Top Mount Intercoolers) and FMICs (Front Mount Intercoolers). All WRX and STis use TMICs from the factory while FMICs are a popular aftermarket option. I can only guess that the 818 will retain the stock TMIC. Upgrading to an STi intercooler also requires the use of a STi splitter - a scoop within the hood scoop that "splits" the incoming are to ensure the whole intercooler gets air passing through it.

Clutches: On a comparatively heavy AWD car with sticky tires like most modified WRXs have, the conventional wisdom it to let the clutch be the "weak link" in drivetrain. Even people running tons of power tend to retain the stock clutch lest they break their transmission gears. In a light RWD car like the 818, I think that concern will no longer apply, or at least be less of an issue.

EJ205: The WRX's engine from 02-05 is mostly good but often suffer from spun rod bearings at high horsepower.

EJ255: Same as above but for 06+. 2009 was a bad year for this motor with many spinning bearings off the showroom floor! I also seem to recall cracked ring lands being common on the aft passenger cylinder when heavily modified.

EJ207: This is the standard engine in non-North American STis and is widely regarded to be the best engine Subaru has ever made. They are available from importers but they are not cheap.

Oil: Subaru engines like some oils more than others. German Castrol and Shell Rotella-T are very popular options. Mobil 1 is roundly criticized as a poor choice, whether for good reason or not. If you post about a spun bearing on a Subaru forum, the first reply is likely to be, "Where you using Mobil 1?". It's a bit of a joke, but many think there is something to it.

Shifters: The stock WRX shifter has a very long throw so a short-throw is virtually a must. I'm interested to see how FFR routes the shift cables.

Radiators: The stock WRX radiator has a weak point where the copper (I think?) is crimped around the plastic top. They all fail eventually, some with well under 100K miles. Mishimoto makes an excellent and relatively cheap aluminum replacement.

[Oppenheimer]

These engines usually don't work like that. Identical engines with the same history will behave differently with the same tune. It's one of the reasons that Cobb's OTS (Off the Shelf) maps for common configurations usually don't make as much power as custom tunes: they're one size-fits-all solutions and extra conservative as a result.

You must not have read my whole post. I know an off the shelf tune will leave performance on the table. I'm saying I don't mind. In a car this light, that I will be using primarily on the street, utlimate HP is not my goal. To me, its not worth the hassle, or the risk, of trying to tune it myself or even bringing it to a 'pro' for a custom tune. I actually WANT something that leaves margins for safety, just not quite as conservative as stock.

[Monkey Tricycle Flip]

You must not have read my whole post. I know an off the shelf tune will leave performance on the table. I'm saying I don't mind. In a car this light, that I will be using primarily on the street, utlimate HP is not my goal. To me, its not worth the hassle, or the risk, of trying to tune it myself or even bringing it to a 'pro' for a custom tune. I actually WANT something that leaves margins for safety, just not quite as conservative as stock.
I read it all, and my post still stands. If you want something cheap that leaves margin for safety, your best route will probably be an OTS open source tune. None exist yet, of course, but I'm sure there will be plenty of them floating around before long. Your cost will be the cost of a Tactrix cable. That said, you'll be trusting the integrity of your motor to some kid on the internet.

I can't emphasize this enough: turbocharged EJ motors blow up on a regular basis. It's not just because somebody is trying to get every last horsepower out of them.

Based on my experience of owning 5 Subarus, any OTS solution is risky. Cobb's AccessPort maps are less so as they test the hell out of them and are adamant about what mods the car must have to run a given map.

Tactrix cables cost about $200. For $200-$300 you can get a custom tune that will be safer (and more powerful) than any one-size-fits-all solution. I strongly recommend that people seriously consider this, and I expect the other WRX veterans here will agree.

[Twinspool]

Thanks Monkey Tricycle Flip for the info!

Have builders had success chamfering or cross drilling the crank to improve oiling to the rod ends?

[Monkey Tricycle Flip]

Thanks Monkey Tricycle Flip for the info!
No problem!


Have builders had success chamfering or cross drilling the crank to improve oiling to the rod ends?
Some builders do cross-drill and chamfer the crank. There doesn't seem to be a consensus on what the timing of the holes should be - everybody does it a little differently from what I understand.

[Oppenheimer]

Tactrix cables cost about $200. For $200-$300 you can get a custom tune that will be safer (and more powerful) than any one-size-fits-all solution. I strongly recommend that people seriously consider this, and I expect the other WRX veterans here will agree.

OK, that sounds good, but just who is going to do this 'custom tune', and how do I make sure its 'good' (my motor will last)? If I drive away from the tuner shop, and the car seems to run great, if 30K miles later my motor is dead, as a result of damage that slowly accumulated over time, due to the tune, how would I prove that or even know that was the cause?

I don't want to trust Joe local tuner any more than kid on internet. I want to get a known good, err on the side of conservative (just not as conservative as stock), tune, that endeavors to safely improve performance & drivability all along the torque curve (not just peak power). Something that just works, I don't have to ever fiddle with, and don't have to take tuning 101. How do I get that?

I had assumed that would be an OTS tune from a reputable company. I know those are available already, I just thought it would be good to have one that was based around the lightness of the 818, and was hoping one of these sorts of reputable companys that offer OTS maps would build one just for this car.

[Monkey Tricycle Flip]

OK, that sounds good, but just who is going to do this 'custom tune', and how do I make sure its 'good' (my motor will last)?... Something that just works, I don't have to ever fiddle with, and don't have to take tuning 101. How do I get that?
Here's (http://www.romraider.com/RomRaider/ProfessionalTuners) a list of Open Source tuners. As for making sure you have a good tune, reputation is probably your best bet. WRX guys have no problem sharing their opinions of various tuners on NASIOC.com, etc.

You can also get the cable and software yourself and learn enough about the ECU to notice if there is an issue. Honestly, once a good tuner has done a few hours worth of tweaking on the dyno or via road testing, you're probably good to go for the natural life of the engine. If you want to be super cautious, a knock sensor isn't a bad idea, but I think it's overkill unless you're running huge numbers.

[Gollum]

I also disagree in most part to this one. The Cobb Accessport is extremely easy to use. It becomes a necesity if you are going to be running any e-85 through your car (which if you have available in your area, you would be crazy not to take advantage of the extra power). You will need to be able to switch maps on the fly if you can't get to your local e-85 station to fill up.

Code reader and reset is extremely handy on the road too. I have even read codes for an old lady with an outback at the store who couldn't start her car.

I'd never recommend changing to E85 on the fly anyways. Unless you're going to get under the car and drain the tank, odds are you'll end up with any variant from E60-E80 which will REALLY screw with your tune. You'd either be leaving LOTS of power on the table, running maps basically designed for E50, or you'll be risking your motor every time you don't verify the tank is really empty before putting E85 in.

The Lesson: Either run E85, or don't. Guys that run E85 are usually pretty serious about it and understand the risks involved. If they want to run 91 octane for a road trip for the mileage they'll drain the tank and switch maps. This isn't a slow process no matter what, thus busting out a laptop to switch maps isn't a huge thing to tack on your to-do list. Plus, you can get a tactrix cable and a used laptop for less than a new accessport...




I read it all, and my post still stands. If you want something cheap that leaves margin for safety, your best route will probably be an OTS open source tune. None exist yet, of course, but I'm sure there will be plenty of them floating around before long. Your cost will be the cost of a Tactrix cable. That said, you'll be trusting the integrity of your motor to some kid on the internet.

I can't emphasize this enough: turbocharged EJ motors blow up on a regular basis. It's not just because somebody is trying to get every last horsepower out of them.

Based on my experience of owning 5 Subarus, any OTS solution is risky. Cobb's AccessPort maps are less so as they test the hell out of them and are adamant about what mods the car must have to run a given map.

Tactrix cables cost about $200. For $200-$300 you can get a custom tune that will be safer (and more powerful) than any one-size-fits-all solution. I strongly recommend that people seriously consider this, and I expect the other WRX veterans here will agree.

I wouldn't want my motor trusted to some kid on the internet either. I personally was going to hire a friend of mine to make a tune for the 818 crowd when we get to that point. He's worked for a high profile pro subaru tuning company that will remain nameless for now. He's well trusted and knows what he's doing. Having a map made by him should put people's minds at ease that this tune wasn't just thrown together.

And while I agree that every motor is different and that's why you'll be leaving power on the table with an off the shelf tune, Cobb tuning is more conservative than they really need to be, and this is because they're making sure that there's not even a CHANCE of someone blowing a motor unless they've done something REALLY stupid. I see no reason a quality tuner couldn't get a map that's going to make a good 5% more power through the curve (not just peak) and still be safe enough as long as people understand things like making sure to buy quality gas.

Point being: The 818 crowd is going to be much more hardcore than the average Cobb tuning purchaser. As such I just feel sorry for those who take the easy route and buy the AP.

[Twinspool]

Since California builders are going to have to go through the CARB referee process anyway, it seems like the door would be wide open to a Megasquirt ECU. (No SB100 required for this car right?) If you're running a MS unit it will accept a flex fuel sensor and interpolate between the standard and ethanol blended fuel.

http://www.megamanual.com/flexfuel.htm

Otherwise, get a dang wideband O2 sensor and don't exceed 12:1!

[thebeerbaron]

While we're sort of near the topic, can we have a gentleman's agreement among the 818 builders that we will not describe engine mods by "stage"? It's arbitrary bovine-sourced-fertilizer and makes it sound like we're talking about a video game. It's common on the VW and Subaru sites and as an outsider it irks me to no end.

It may take a few extra words, but how about we agree to just outline the mods we're talking about?

"Hey, I'm at Stage 3.1415, what should I do next?"
"Hey, I've got an intake, up-pipe, and bigger injectors, what's next?"

/end rant :)

[Monkey Tricycle Flip]

Point being: The 818 crowd is going to be much more hardcore than the average Cobb tuning purchaser. As such I just feel sorry for those who take the easy route and buy the AP.
I'll be going with a custom open source tune, but if people want the ease of the Cobb AP as well as its additional features, I understand it. I certainly won't feel bad for them.

[Monkey Tricycle Flip]

While we're sort of near the topic, can we have a gentleman's agreement among the 818 builders that we will not describe engine mods by "stage"? It's arbitrary bovine-sourced-fertilizer and makes it sound like we're talking about a video game.
:D

Yeah, it's a bit silly, really. The stage modifications are typically defined as:

Stage 1: ECU tuning
Stage 2: Stage 1 + turbo-back exhaust including bellmouth downpipe
Stage 2.5: Stage 2 + up-pipe
Stage 3: Stage 2.5 + larger intercooler and supporting mods
Stage 4: Stage 3 + bigger turbo and supporting mods
Stage 5: Stage 4 + internal engine modifications and supporting mods

That said, people and aftermarket companies abuse the loosely defined stages all the time.

[Evan78]

While we're sort of near the topic, can we have a gentleman's agreement among the 818 builders that we will not describe engine mods by "stage"? It's arbitrary bovine-sourced-fertilizer and makes it sound like we're talking about a video game. It's common on the VW and Subaru sites and as an outsider it irks me to no end.

It may take a few extra words, but how about we agree to just outline the mods we're talking about?

"Hey, I'm at Stage 3.1415, what should I do next?"
"Hey, I've got an intake, up-pipe, and bigger injectors, what's next?"

/end rant :)Good point. It always drives me crazy to go on to a forum of a car that I don't know well and have to look up tons of acronyms and "stages", etc. I try to take a couple extra seconds to make my posts as universally understandable as possible.

[PhyrraM]

Considering the target price point for the kit, I actually expect custom tunes to be in the minority - unless FFR decides to include an Accessport type device with the kit or sell them as an option.

I also think we will see almost as many normally asiprated builds as turbo ones.

[mn_vette]

:D

Yeah, it's a bit silly, really. The stage modifications are typically defined as:

Stage 1: ECU tuning
Stage 2: Stage 1 + turbo-back exhaust including bellmouth downpipe
Stage 2.5: Stage 2 + up-pipe
Stage 3: Stage 2.5 + larger intercooler and supporting mods
Stage 4: Stage 3 + bigger turbo and supporting mods
Stage 5: Stage 4 + internal engine modifications and supporting mods

That said, people and aftermarket companies abuse the loosely defined stages all the time.

I wonder what "stage" would be equivalent to a base build given the new cold air intake and exhaust. Would we need a new tune just to be "safe" on a stock build? Not that I'm planning on keeping it stock, but I would like to start there and move up and chart the progress.

[crobin4]

Considering the target price point for the kit, I actually expect custom tunes to be in the minority - unless FFR decides to include an Accessport type device with the kit or sell them as an option.

I also think we will see almost as many normally asiprated builds as turbo ones.

Agree completely.

[Monkey Tricycle Flip]

I wonder what "stage" would be equivalent to a base build given the new cold air intake and exhaust.
Probably stage 2 assuming the new exhaust will utilize a bellmouth downpipe and the appropriate ECU tuning.


I wonder what "stage" would be equivalent to a base build given the new cold air intake and exhaust. Would we need a new tune just to be "safe" on a stock build? Not that I'm planning on keeping it stock, but I would like to start there and move up and chart the progress.
A new tune is a must with any type of cold air intake system on an EJ motor, even if the rest of the engine is completely stock. The MAF sensor is in the intake and is dramatically impacted by the geometry of the intake as a result.

[bbjones121]

I am sorry, but you are extremely mistaken on the little bit of flexibility that an engines ecu adapts to.
What do you think they blend into premium gas to give it a higher octane rating? You are correct, never switch between e-85 and 91/93 half tank. I didn't even think that would be considered by anyone with a bit of sense?


I'd never recommend changing to E85 on the fly anyways. Unless you're going to get under the car and drain the tank, odds are you'll end up with any variant from E60-E80 which will REALLY screw with your tune. You'd either be leaving LOTS of power on the table, running maps basically designed for E50, or you'll be risking your motor every time you don't verify the tank is really empty before putting E85 in.

The Lesson: Either run E85, or don't. Guys that run E85 are usually pretty serious about it and understand the risks involved. If they want to run 91 octane for a road trip for the mileage they'll drain the tank and switch maps. This isn't a slow process no matter what, thus busting out a laptop to switch maps isn't a huge thing to tack on your to-do list. Plus, you can get a tactrix cable and a used laptop for less than a new accessport...





I wouldn't want my motor trusted to some kid on the internet either. I personally was going to hire a friend of mine to make a tune for the 818 crowd when we get to that point. He's worked for a high profile pro subaru tuning company that will remain nameless for now. He's well trusted and knows what he's doing. Having a map made by him should put people's minds at ease that this tune wasn't just thrown together.

And while I agree that every motor is different and that's why you'll be leaving power on the table with an off the shelf tune, Cobb tuning is more conservative than they really need to be, and this is because they're making sure that there's not even a CHANCE of someone blowing a motor unless they've done something REALLY stupid. I see no reason a quality tuner couldn't get a map that's going to make a good 5% more power through the curve (not just peak) and still be safe enough as long as people understand things like making sure to buy quality gas.

Point being: The 818 crowd is going to be much more hardcore than the average Cobb tuning purchaser. As such I just feel sorry for those who take the easy route and buy the AP.

[crobin4]

Dave hit the nail on the head didn't he, we are VERY passionate.:D

[bbjones121]

I get the feeling you might own an evo now, Monkey Tricycle Flip. Why scare all these people about the few blown Subaru engines where someone didn't know what they were doing or ran a bad tune? There are far more ej motors running reliable numbers than the blown engine stories. People reading this: THE EJ MOTOR WILL HANDLE OVER 400 HP EASILY WITHOUT WORRY OF DESTROYING IT.

A Cobb AP can be uploaded with your professional Protuned certified shop's maps. You can have just as professional/dyno tuned map as any other option. I have never used the off the shelf maps that were preinstalled on the AP, only custom built maps.



I read it all, and my post still stands. If you want something cheap that leaves margin for safety, your best route will probably be an OTS open source tune. None exist yet, of course, but I'm sure there will be plenty of them floating around before long. Your cost will be the cost of a Tactrix cable. That said, you'll be trusting the integrity of your motor to some kid on the internet.

I can't emphasize this enough: turbocharged EJ motors blow up on a regular basis. It's not just because somebody is trying to get every last horsepower out of them.

Based on my experience of owning 5 Subarus, any OTS solution is risky. Cobb's AccessPort maps are less so as they test the hell out of them and are adamant about what mods the car must have to run a given map.

Tactrix cables cost about $200. For $200-$300 you can get a custom tune that will be safer (and more powerful) than any one-size-fits-all solution. I strongly recommend that people seriously consider this, and I expect the other WRX veterans here will agree.

[Evan78]

Boost control: I'm not a huge fan of the factory boost control as it can be difficult to achieve and hold the boost target when running higher PSI than stock. There are tons of electronic aftermarket boost controllers available (I'm partial to GrimmSpeed's). Of course, all boost control mods require an updated tune.Are you referring to the factory boost control solenoid or really talking about running an independent manual or electronic boost controller?

[wjfawb0]

I used accessports on the two subarus I owned, but I also had a dyno tune performed by a reputable tuner. It would definitely be cheaper to get the tactrix cable and learn the open source software. Regardless, any car I tinker with gets a dyno tune that suits how the car is driven. I would imagine FFR could work out a deal with Cobb or another tuner to flash ECUs for those who purchase the kit.

[bbjones121]

Are you referring to the factory boost control solenoid or really talking about running an independent manual or electronic boost controller?

Yes I think he is. Replace the factory unit and Get an EBCS, you can get a Grimmspeed for pretty reasonable. I would image that this <2000lb car will need an extremely precise way of controlling the turbine speed.

[Evan78]

I just want to clarify that you can replace the OEM boost control solenoid with a GM solenoid or any number of aftermarket solenoids and still control them with the factory ECU. It is not necessary to use an independent manual or electronic boost controller that operates outside of the control of the ECU.

[Gollum]

I am sorry, but you are extremely mistaken on the little bit of flexibility that an engines ecu adapts to.
What do you think they blend into premium gas to give it a higher octane rating? You are correct, never switch between e-85 and 91/93 half tank. I didn't even think that would be considered by anyone with a bit of sense?

The reality I was getting at is that to properly switch between E85 and petroleum based gasoline you really SHOULD empty the tank. You're not just going to wait until the gas light turns on and then go get the gas you prefer. This means it's not going to be a short ordeal, thus the argument that using an AP is more convenient option for map switching is almost a moot point. You're already going out of your way to make sure your tank is as close to empty as practically possible, what's the extra effort of booting up a laptop? So unless you're going to buy a GM flex fuel vehicle's fuel content sensor with display unit, mixing fuels isn't "convenient" and we're now talking about a person that has to take their car and motorsports very seriously. They're usually not a Cobb AP buyer.

And those thinking that most 818 builders will be "budget minded" thus not get a tune at all, I can understand the thought process with that. But even the cheapest of builds will still be more expensive than the average WRX hoped up on ebay go-fast parts, and lots of those guys are still getting their cars dynotuned... I think we might be surprised how many guys are wanting to get their car custom tuned for their specific setup.

Now, my suggestion for having some 818 specific tunes for an off the shelf option isn't something I'd strongly encourage, but I'd recommend it over everybody going out and spending the money for an AP that is overkill in features for most people, and usually not worth it. Custom, engine specific, tunes are always the way to go AP or Open Source.

[Monkey Tricycle Flip]

I am sorry, but you are extremely mistaken on the little bit of flexibility that an engines ecu adapts to.
Who are you talking to?

[bbjones121]

Good points, but keeping a device(cobb AP) that will fit in your pocket or concealed in the car somewhere is far from equal to keeping a laptop in your car all the time. Wouldn't you at least agree to that? It is extremely user friendly unlike most other options.


The reality I was getting at is that to properly switch between E85 and petroleum based gasoline you really SHOULD empty the tank. You're not just going to wait until the gas light turns on and then go get the gas you prefer. This means it's not going to be a short ordeal, thus the argument that using an AP is more convenient option for map switching is almost a moot point. You're already going out of your way to make sure your tank is as close to empty as practically possible, what's the extra effort of booting up a laptop? So unless you're going to buy a GM flex fuel vehicle's fuel content sensor with display unit, mixing fuels isn't "convenient" and we're now talking about a person that has to take their car and motorsports very seriously. They're usually not a Cobb AP buyer.

And those thinking that most 818 builders will be "budget minded" thus not get a tune at all, I can understand the thought process with that. But even the cheapest of builds will still be more expensive than the average WRX hoped up on ebay go-fast parts, and lots of those guys are still getting their cars dynotuned... I think we might be surprised how many guys are wanting to get their car custom tuned for their specific setup.

Now, my suggestion for having some 818 specific tunes for an off the shelf option isn't something I'd strongly encourage, but I'd recommend it over everybody going out and spending the money for an AP that is overkill in features for most people, and usually not worth it. Custom, engine specific, tunes are always the way to go AP or Open Source.

[bbjones121]

Gollum, I thought I qouted him. Sry if it didn't show.

[Monkey Tricycle Flip]

I get the feeling you might own an evo now, Monkey Tricycle Flip.
I do not now nor have I ever owned an Evo (not that I wouldn't).


Why scare all these people about the few blown Subaru engines where someone didn't know what they were doing or ran a bad tune?
Because it's the truth. I love EJs. I've had 5 Subarus. I'm a fanboy, but I will not wax apologetic about a real weakness in the EJ motor. They spin bearings at a rate which should give one pause. That's a simple fact. It's an inherent design problem which has been compounded by people who don't know what they're doing.


There are far more ej motors running reliable numbers than the blown engine stories.
I totally agree. Most people will be fine and never experience and issue.


THE EJ MOTOR WILL HANDLE OVER 400 HP EASILY WITHOUT WORRY OF DESTROYING IT.
USUALLY, YES. Oops, seems my caps lock was stuck. Usually, yes. EJs still spin bearings at lower horsepower ratings much more often than they should. The 2009s were spinning bearings on test drives! OK, that was a bit of hyperbole, but not much. In 2009 the issue was identified as out of spec bearings from a supplier. It simply compounded an existing issue with the EJ205/EJ255, however.

Any doubters need only read the threads on NASIOC or go to YouTube and search "WRX spun bearing":

NASIOC: 2009 Impreza WRX motor issues (4,743 posts!) (http://forums.nasioc.com/forums/showthread.php?t=1648372&highlight=2009+spun+bearing)
NASIOC: 2009 WRX engine failure VIN/build date owner list (http://forums.nasioc.com/forums/showthread.php?t=1695936&highlight=2009+spun+bearing)

The lesson: EJs are quirky little engines. Make sure to do the job right the first time or it could go south really quick.

[Kasmodean]

It becomes a necesity if you are going to be running any e-85 through your car (which if you have available in your area, you would be crazy not to take advantage of the extra power)

E85 has an actual octane of ~95, while I can get sunaco gasoline with 94 octane. How much extra boost can an engine run because of 1 octane? Is it 4% more? Regular gasoline can do what 20 PSI? So E85 has to do (14.4+20)*.04 -14.4= 21.4 PSI.

I ask this because E85 has 4% less energy density than gasoline. So unless you can run enough boost to get more then 4% more fuel into (and burn in) the engine than there is no added power by using E85.

If you do a conservative tune (by conservative, I mean anything that is not maximizing boost to the edge) then E85 is definitely not making more power than gasoline. But this all depends on how much difference 1 octane does which I can only guess would be different for differents car/setups.

[Gollum]

Good points, but keeping a device(cobb AP) that will fit in your pocket or concealed in the car somewhere is far from equal to keeping a laptop in your car all the time. Wouldn't you at least agree to that? It is extremely user friendly unlike most other options.

I agree the Cobb can be very user friendly. Where I really start to dislike the Cobb alltogether is when considering the fact I've seen endless people buy them that just don't understand engines at all. They load a map and then go change something on their car and don't change maps. Or they don't know what they're doing and end up with a worse tune than off the shelf or even ruining their motor. There's too many blown motors out there not from too aggressive of a tune, but people modifying their cars AFTER having a good dynotune done thinking it'll be fine.

I think people would be better off if the Cobb wasn't even an option. If you can't sit down to read and understand the articles out there on open source tuning and how to properly tune a vehicle, then you should just take your Subie to a real tuner and spend the money to have them do an open source tune with their own tools. It'd be money better spent.

All of the convenience the AP could give will normally only apply to the more serious user, and the more serious user usually doesn't mind keeping a laptop around. The Cobb AP has a market, it's just a sliver of what they actually own.

[Gollum]

E85 has an actual octane of ~95, while I can get sunaco gasoline with 94 octane. How much extra boost can an engine run because of 1 octane? Is it 4% more? Regular gasoline can do what 20 PSI? So E85 has to do (14.4+20)*.04 -14.4= 21.4 PSI.

I ask this because E85 has 4% less energy density than gasoline. So unless you can run enough boost to get more then 4% more fuel into (and burn in) the engine than there is no added power by using E85.

If you do a conservative tune (by conservative, I mean anything that is not maximizing boost to the edge) then E85 is definitely not making more power than gasoline. But this all depends on how much difference 1 octane does which I can only guess would be different for differents car/setups.

It's about a heck of a lot more than octane rating!!! (not trying to yell at you, just in excitment of this topic for me ;-) )

Ethanol requires more fuel to actually run at much "richer" lambda stoichiometric level, meaning to reach rich or lean mean best torque, will be using a lot more fuel, thus creating MORE power, despite it having less power per volume.

Ethanol also absorbs a LOT more heat than any petroleum based gasoline, meaning you can get away with a smaller or no intercooler, or go into higher boost levels off your compressors efficiency island and not deal with as much knock threshold issues.

A 350wheel hp STI on gasoline will be running as much as 10 degrees LESS timing on top than a 400 wheel hp E85 powered STI.... Food for thought...

[bbjones121]

E-85 octane is actually north of 100. Let dyno numbers and equal quality tunes speak for themselves. You will have closer to 10% power boost and quicker spool with e-85 on a properly tuned FI vehicle.


E85 has an actual octane of ~95, while I can get sunaco gasoline with 94 octane. How much extra boost can an engine run because of 1 octane? Is it 4% more? Regular gasoline can do what 20 PSI? So E85 has to do (14.4+20)*.04 -14.4= 21.4 PSI.

I ask this because E85 has 4% less energy density than gasoline. So unless you can run enough boost to get more then 4% more fuel into (and burn in) the engine than there is no added power by using E85.

If you do a conservative tune (by conservative, I mean anything that is not maximizing boost to the edge) then E85 is definitely not making more power than gasoline. But this all depends on how much difference 1 octane does which I can only guess would be different for differents car/setups.

[Kasmodean]

Gollum, thanks for the added info, I assumed ethanol and gas had the same stoichiometric point (or roughly equivalent) that does make a difference. Seems good for performance vehicles.

Only problem is MPG will suffer compared to gasoline even at same hp levels, not that the people in this forum worry much about that :)

[Kasmodean]

E-85 octane is actually north of 100. Let dyno numbers and equal quality tunes speak for themselves. You will have closer to 10% power boost and quicker spool with e-85 on a properly tuned FI vehicle.

Over 100 is an inaccurate measurement. Read here http://en.wikipedia.org/wiki/E85 End of first paragraph under section of Comparison to Gasoline:

"If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests"

Regardless, as Gollum added, I was figuring Octane only, so you are correct in more power.

[bbjones121]

I am saying that it seems you are scaring people about a failure point on these engines that is no more significant than most other engines out there. These EJ engines are great engines and I am glad they chose them as their platform. They are easy to modify and pretty cheap to do so. I don't think this spun bearing issue is as big a deal for most as you make it out to be.

Sry I could figure out how to bold from my android phone so I used caps instead.


I do not now nor have I ever owned an Evo (not that I wouldn't).


Because it's the truth. I love EJs. I've had 5 Subarus. I'm a fanboy, but I will not wax apologetic about a real weakness in the EJ motor. They spin bearings at a rate which should give one pause. That's a simple fact. It's an inherent design problem which has been compounded by people who don't know what they're doing.


I totally agree. Most people will be fine and never experience and issue.


USUALLY, YES. Oops, seems my caps lock was stuck. Usually, yes. EJs still spin bearings at lower horsepower ratings much more often than they should. The 2009s were spinning bearings on test drives! OK, that was a bit of hyperbole, but not much. In 2009 the issue was identified as out of spec bearings from a supplier. It simply compounded an existing issue with the EJ205/EJ255, however.

Any doubters need only read the threads on NASIOC or go to YouTube and search "WRX spun bearing":

NASIOC: 2009 Impreza WRX motor issues (4,743 posts!) (http://forums.nasioc.com/forums/showthread.php?t=1648372&highlight=2009+spun+bearing)
NASIOC: 2009 WRX engine failure VIN/build date owner list (http://forums.nasioc.com/forums/showthread.php?t=1695936&highlight=2009+spun+bearing)

The lesson: EJs are quirky little engines. Make sure to do the job right the first time or it could go south really quick.

[bbjones121]

I figured you got your info from wikipedia. There is a reason you usually can't put it in most profesional citations.


Over 100 is an inaccurate measurement. Read here http://en.wikipedia.org/wiki/E85 End of first paragraph under section of Comparison to Gasoline:

"If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests"

Regardless, as Gollum added, I was figuring Octane only, so you are correct in more power.

[Evan78]

Do you realize that there are references, footnotes, etc on wikipedia? There are often citations to support the information that goes into the articles.

[Monkey Tricycle Flip]

I am saying that it seems you are scaring people about a failure point on these engines that is no more significant than most other engines out there.
We're just gonna have to disagree on that but I think the numbers support my assertion. While the plural of "anecdote" is not "evidence", there are enough posts on the web and enough professional builders who agree. A little caution can be healthy. That's what I'm hoping people take away from this.


IThese EJ engines are great engines and I am glad they chose them as their platform. They are easy to modify and pretty cheap to do so.
I totally agree!


I don't think this spun bearing issue is as big a deal for most as you make it out to be.
But the data...

Some engine builders have even used the spun bearing issue as a marketing tool. MPS advertises "ZERO spun bearings club. Join us! (http://forums.nasioc.com/forums/showthread.php?t=2103960)"


Sry I could figure out how to bold from my android phone so I used caps instead.
:D, I'm just giving you a hard time. Don't sweat it.

[Kasmodean]

I figured you got your info from wikipedia. There is a reason you usually can't put it in most profesional citations.


Do you realize that there are references, footnotes, etc on wikipedia? There are often citations to support the information that goes into the articles.

If you want to say a cited wikipedia fact is wrong, and you are right please provide proof in the form of another source or actual dyno runs. If your proof disagrees with wikipedia and proves wiki wrong, then I would have no problem changing my mind and agreeing with you. Facts are important, not opinions.

[thebeerbaron]

E85 debates are fun and all, but not really germaine to a discussion of ripping the guts out of a WRX and stuffing it into a new lightweight chassis. So how about we go back to discussing important Subie facts, like uh... umm....

What's the deal with this "bellmouth" exhaust business? I assume we're talking about the part of the exhaust that connects to the exhaust side of the turbo. In my world, the hot setup is to have a "stainless steel separated gas downpipe", which is essentially two tubes, one for the exhaust flow from the impeller exit, one for the exhaust flow from the wastegate. The two pipes join together at some optimal point before the cat (or the test-pipe on track cars). I assume that "bellmouth" is some optimization in that region?

[bromikl]

Would you mind taking your private arguments off the public forum? If you think someone is giving inaccurate information, PM him/her. The last thing I want to see when I'm on this website is a rerun of Jerry Springer.

It's just a friendly disagreement. NO harm done, right? Not from where I'm sitting.

FYI, The octane rating of E-85 isn't the only discussion I'm talking about.

Thank you.

</soapbox>

[crobin4]

Yes, this needs toned waayyy down. Its like there is a Subaru expert contest in addition to the design contest. Sheese.

[thebeerbaron]

d'oh, triple post! :)

It's nice to have all this input, really, but let's save the heated debates for important topics, like what Dave is hinting at (http://thefactoryfiveforum.com/showthread.php?1227-The-official-quot-What-is-Dave-hinting-at-quot-thread). :)

[Kasmodean]

Guys, I am not arguing or upset or flaming bbjones. I am just posting a fact and asking for facts. This is revelant to WRXs. It would be awesome if bbjoes has dyno graphs that shows wrxs rock with e85 because typically I though cars ran better with gas. Regardless I'll take it off thread though and stop posting.

[Evan78]

What's the deal with this "bellmouth" exhaust business? I assume we're talking about the part of the exhaust that connects to the exhaust side of the turbo. In my world, the hot setup is to have a "stainless steel separated gas downpipe", which is essentially two tubes, one for the exhaust flow from the impeller exit, one for the exhaust flow from the wastegate. The two pipes join together at some optimal point before the cat (or the test-pipe on track cars). I assume that "bellmouth" is some optimization in that region?What you described is what I would call a "divorced wastegate downpipe". The bellmouth pipes are similar in size, but they don't bother keeping the wastegate flow separated from the turbine exhaust. Here's an example: http://www.cobbforums.com/forums/images/BellMouthDetail.jpg

Everything I've seen indicates there is not enough performance difference between any of the aftermarket downpipe designs to warrant specifying the design when discussing them. Most people just say "I've got a downpipe" and leave it at that. Sometimes they'll say "catted" or "catless".

[thebeerbaron]

Guys, I am not arguing or upset or flaming bbjones. I am just posting a fact and asking for facts. This is revelant to WRXs. It would be awesome if bbjoes has dyno graphs that shows wrxs rock with e85 because typically I though cars ran better with gas. Regardless I'll take it off thread though and stop posting.

None of this is problem in the least, just a bit intense for the general feel of this thread. Hope to see your posts on other subjects soon!

[thebeerbaron]

What you described is what I would call a "divorced wastegate downpipe". The bellmouth pipes are similar in size, but they don't bother keeping the wastegate flow separated from the turbine exhaust. Here's an example: http://www.cobbforums.com/forums/images/BellMouthDetail.jpg

Everything I've seen indicates there is not enough performance difference between any of the aftermarket downpipe designs to warrant specifying the design when discussing them. Most people just say "I've got a downpipe" and leave it at that. Sometimes they'll say "catted" or "catless".

Wow, on that Cobb piece, is that the bung for the O2 sensor? That seems awfully close to the turbine - is that OK because the turbo is so much further away from the head on these cars?

I once knew, but have now forgotten why the separated gasses technique was so wonderful. I want to say it had to do with waste gate performance or efficiency, but I really can't recall. Glad to know there's at least some consensus with these engines.

It's really nice when someone else has already done all this what-works-what-doesn't work for you! :)

[Gollum]

I never meant to clutter up this thread and I'm sure I had my part in it, sorry guys.

Regarding O2 placement, on a turbo car, especially one with as long of a header path as the subie motors, there's quite a bit of data lag on wideband readings. Because of this you want to get the O2 (wide or narrow) as close as practically possible to minimize the delay already inherent to the system.

The only reason I can see with going with a divorced exhaust setup is if you've done radical head work and are flowing a lot more air than stock. In a situation like this you might be routing a large percentage of your exhaust air through the wastegate necessitating better flow. In a situation like there there's plenty of other problems to consider though, one of which is why on earth you're using a stock turbo with an internal wastegate! :-D

Overall, seeing a divorced wastegate on an internal gate setup is more rare than common.

[bbjones121]

Yes, MPG does suffer, but it is cheaper than premium. Comparitive price speaking, it is the same cost around this area to run e-85 instead of premium.


Gollum, thanks for the added info, I assumed ethanol and gas had the same stoichiometric point (or roughly equivalent) that does make a difference. Seems good for performance vehicles.

Only problem is MPG will suffer compared to gasoline even at same hp levels, not that the people in this forum worry much about that :)

[bbjones121]

I think that an open bellmouth pipe would be better for internal wastgate setups. If you are going to run an external wastegate, it would be better to have a divided downpipe. Preferably one that the divider extends up into the hotside of the turbo to prevent any exhaust from going down the wastegate side.

When I was looking to purchase a DP, I couldn't find any performance number really convincing me that one was better than the other. Where I think it may have an impact is the ability to control the boost more precisely rather than performance numbers? A divided channels allow the turbulent combination of the gases further down the pipe instead of right at the turbine blades. Maybe this would help to allow better control of your turbine speed?

In my opinion, a divided bellmouth is an "attempt" to try and get the benefits of an external wastegate without actually having one.



What you described is what I would call a "divorced wastegate downpipe". The bellmouth pipes are similar in size, but they don't bother keeping the wastegate flow separated from the turbine exhaust. Here's an example: http://www.cobbforums.com/forums/images/BellMouthDetail.jpg

Everything I've seen indicates there is not enough performance difference between any of the aftermarket downpipe designs to warrant specifying the design when discussing them. Most people just say "I've got a downpipe" and leave it at that. Sometimes they'll say "catted" or "catless".

[bbjones121]

This may be important if someone is interested in even more power through a tune with the proper fuel system. If you look, you will find many other dyno charts like this showing the difference between the two types of fuel. Here is one of my earlier dyno tunes: both premium and E-85 are shown. This was at 5,450 ft elevation and on a very conservative dyno, so numbers may be different in different situations, but I think the percentage difference between the two should be the same no matter.
1103

[Gollum]

This may be important if someone is interested in even more power through a tune with the proper fuel system. If you look, you will find many other dyno charts like this showing the difference between the two types of fuel. Here is one of my earlier dyno tunes: both premium and E-85 are shown. This was at 5,450 ft elevation and on a very conservative dyno, so numbers may be different in different situations, but I think the percentage difference between the two should be the same no matter.
1103

Just for validation, that's basically what I've seen first hand for the most part too. It's amazing how much extra torque shows up down low, good signs of how much easier the turbo spools too! And it might just be elevation, but it looks like there's still some room in that tune.

[Kasmodean]

Thanks bbjones and gollum and sorry to everyone else. I probably could have asked privately, but then others like me wouldn't have learned anything. These graphs are awesome though. It is crazy that E85 ends up making more power cause when you look at e85 on paper it appears that gas would be much better performance and price wise. We don't have e85 here yet, but now I can't wait for e85.

Back to the regularly tuned program :)

[GS guy]

Speaking of downpipes, I too was concerned about the best way to "exhaust" the turbo, even though it's just a stock WRX unit. I looked at the popular bell-mouth pipes, even considered getting one - but they all went in the wrong direction for my application and I would have ended up just using the bell-mouth piece and cutting off the rest - seemed a lot of $$$ for just the bell-mouth portion! Still, I thought the bell-mouth exhaust was the right direction, opposed to a flat plat with a 2.5" or 3" hole for the exhaust pipe to come out.
Ended up finding a company to make a more universal design. Unfortunately, it seems they only made this one excellent prototype which I got - afterwards the company disappeared. It is a super nice piece - perfect for what I was looking for.

http://i140.photobucket.com/albums/r36/jg_pics/Subaru%20Engine/ZTSTurboFlange4.jpg

http://i140.photobucket.com/albums/r36/jg_pics/Subaru%20Engine/ZTSTurboFlange2.jpg

http://i140.photobucket.com/albums/r36/jg_pics/Subaru%20Engine/DSCN2125.jpg

[BrandonDrums]

No performance gain between divorced dp and bellmouth. I tend to think the bellmouth is the best, if you look at the exhaust 'hatch' for an internally gated turbo, the flap opens at an angle.

If you have a divorced dp, the wastegate gas path experiences a lot more turbulence since the flap just angles into the wall of the dp making it harder to contol boost because the gas might back up requiring higher wgdc to divert enough exhaust to diminish spool.

For this application, just get an eBay bellmouth dp. But the exhaust behind the turbo will probably have to be completely different anyway for the 818.

[Monkey Tricycle Flip]

Here's a good comparison of a stock down-pipe (2007 STi on the left/top) and an aftermarket bellmouth unit (Cobb catted on the right/bottom). I took these while installing the latter in my 2005 9-2X Aero:

http://farm3.static.flickr.com/2452/3623630434_4b3c3e7923_z.jpg
http://farm4.static.flickr.com/3321/3622810649_0bde282e43_z.jpg

[NonProfit]

I can't emphasize this enough: turbocharged EJ motors blow up on a regular basis. It's not just because somebody is trying to get every last horsepower out of them.

OK, I've always thought of Subaru as completely bulletproof and now this...If I'm running <250hp, I don't readline it, and I'm not running with a whacked-out custom tune, is engine failure a realistic concern for me?

Also, the cold hard truth is any used WRX is a candidate for having been driven really hard. What should I be looking for to make sure the one I get has a lot of life left in it?

[Evan78]

In the context of his original post, I think he might have been saying that they blow on a regular basis from running a bad custom tune, but its a little hard to tell what he meant exactly.

<250hp is stock power level, so it should go for 200k plus if properly maintained.

[Smythe]

The biggest problem that I have seen is kids putting a manual boost controller on and then just cranking it up. More boost = more power right.

Never addressing the fuel issues, the engine runs lean and blows up. Said kid then blames Mobil 1 oil, Subaru, or some other BS excuse.

[Evan78]

Also, the cold hard truth is any used WRX is a candidate for having been driven really hard. What should I be looking for to make sure the one I get has a lot of life left in it?A compression check is always good for any engine. Maintenance records, modification history, owner knowledge and experience. How hard it was stressed and engine management are the two areas I would scrutinize most. The ideal car would be never modified and used for standard commuting duty, just like any run of the mill sedan. The older the owner, the better. Red flags would be manual boost controllers, upgraded turbos, poor engine management.

[smkn951]

Hello everyone, noob here. i recently ran up on a 01 subaru wrx forrester. salvage title, dealer don't know much about it. would this 01 subaru work?
TIA
Carl.

[NonProfit]

i recently ran up on a 01 subaru wrx forrester. salvage title, dealer don't know much about it. would this 01 subaru work?The official site (http://www.factoryfive.com/kits/project-818/what-you-need/) states you will need "a Subaru Impreza model years 2002-2007 (except STI models)." However, it's understood that parts from many other Subaru could work (the are like Legos), although it's possible you'd need some additional parts not included in whatever is your particular donor might be. Unfortunately until the 818 is released, we're all just guessing.

[smkn951]

thanks. might as well wait till it's release to commit to getting a subie.

[StatGSR]

Hello everyone, noob here. i recently ran up on a 01 subaru wrx forrester. salvage title, dealer don't know much about it. would this 01 subaru work?
TIA
Carl.

I would be worried about a Subaru that doesn't exist....

[Canadian818]

I would be worried about a Subaru that doesn't exist....

Bawhahahaha

[RossLH]

Said kid then blames Mobil 1 oil

The NASIOC hivemind (which is neither good nor considerably educated) has taken on quite the hatred towards M1, but for the most part they don't have any real idea why. Fact of the matter is M1 is not made for turbocharged engines. The published statistics from M1 show that the HTHS is dangerously low for turbochargers (3.0 for their 5W-30 synthetic, last I checked), UOA's show that the 30 weight starts out light, and (unsurprisingly) shears very quickly when run through a turbocharged engine at an otherwise normal oil change interval. Mobil1 is not a bad oil by any means, it simply isn't the right oil for this application.

None of this is to say your engine will blow as soon as you put M1 in your engine, but if you want your engine to last, the most essential factor is to use the right lubrication. A low HTHS mixed with a 150,000RPM bearing that sits next to a 1600°F exhaust housing is a formula for nothing good.

[Evan78]

The published statistics from M1 show that the HTHS is dangerously low for turbochargers (3.0 for their 5W-30 synthetic, last I checked), UOA's show that the 30 weight starts out light, and (unsurprisingly) shears very quickly when run through a turbocharged engine at an otherwise normal oil change interval. Mobil1 is not a bad oil by any means, it simply isn't the right oil for this application.What's a more appropriate/typical HTHS value for this application?

[RossLH]

For turbocharged engines in general, an HTHS of 3.5 is a good rule of thumb.

[Nuul]

For turbocharged engines in general, an HTHS of 3.5 is a good rule of thumb.

Interesting. So is that why the NASIOC is so keen on Rotella?

[Xusia]

Wait... The engine oil also lubricates the turbo?!?

[Nuul]

Yes, and I think it helps cool it to a lesser extent.

[Evan78]

Most (or all?) these days use the engine coolant as the primary cooling method, but oil will carry some heat as well.

[RossLH]

The oil carries a whole lot of heat, which is half of the problem with using low HTHS oils. Engine coolant is really the secondary coolant in a turbocharger.

[apexanimal]

the german castrol syntec 0w30 is pretty highly regarded last i checked as well...

[Zodiac]

so does anyone know what would be different between an impreza and a wrx donor? I plan on getting the FFR brake upgrade a wrx 5 speed tranny and a STI engine (engine, ecu, wiring harness) but of the wrx and the impreza what is different? Are the axles or any other particular parts stronger on the wrx or is it the exact same thing?

[flytosail]

With "tuning", would you have any issues with passing an emission check?

[imnotted]

With "tuning", would you have any issues with passing an emission check?

I think it depends greatly on where you live and how they test. I live in New Mexico in the only county that tests emissions. They plug their machine into the OBD2 plug and run it to 2000rpm to test for codes; to make sure at least 75% of the self-tests have been completed; and to make sure all emissions devices are operating properly - I think the machine is mostly looking for proper voltage shifts on the O2 sensors here. They also test fuel cap seals and visually inspect to see that you haven't circumvented any major emissions devices like the cat. As long as I keep my cat and tune properly , I should have no problem passing emissions here.

If you live in KAHLEEFOAHNIA, though, things might be different. I know they have to deal with CARB cert requirements on aftermarket parts, more aggressive testing, (probably) more knowledgable inspectors...I really don't know the full extent of it. I'm sure it's doable, but you probably have to be slightly more mindful about what you do to your car. Where there's a will, there's a way!

[Mechie3]

I once asked a guy in California how he got past emissions and visual inspection since ANY change that doesn't have a CARB sticker on it makes you fail. He said he had a stock motor in the garage. If he got caught on the street and had to go to the referee within the week or for his 2 year check up he'd swap his modded motor out for the stock one, get inspected, go home, and change it back.

[imnotted]

Yea, I know some people in Austin that do that. I've also seen some people here who run gutted cats and replace them with working ones about a week before they get tested. I'm always a little leary of that, though. I think any officer can impound your vehicle for bypassing or using unapproved emissions devices since it's a violation of the Clean Air Act (federal law). I suppose that all depends on how much the cop wants to hassle you. I'd expect it to be a problem only if your car got impounded for other reasons and they decide to throw the book at you. Still, it's not hard to make sure your car is compliant and forgo the risk.

[Evan78]

With "tuning", would you have any issues with passing an emission check?The changes you make to the ECU should not make your chances of passing emissions any worse than if you left it alone. If anything, you can make changes that improve your chances of passing.

For instance, the ECU will turn on the "check engine" light (CEL) if a sensor is not functioning properly or getting a reading outside a specified range. The typical scenario is that the rear oxygen sensor causes a CEL because a car's catalytic converter(s) have been eliminated or swapped for hi-flow versions. In the ECU, you can effectively turn off the CEL for that particular sensor by widening the allowable range of readings before the light gets turned on so that no matter what the sensor is picking up in the exhaust, the CEL will not turn off and will still register as "ready" to the emissions testing scanner.

The info below applies to my knowledge of production Subarus in California. I don't know how it will play out with the 818 and it will obviously vary by location.

When it comes to what is actually coming out the tailpipe (emissions), the fueling and timing that are set in the ECU will have an effect. So yes, the "tune" will also play a role in your ability to pass. I don't know how many tuners pay attention to this area and make changes with emissions in mind. In California, 2wd cars are put on rollers to create a load that attempts to simulate real world driving conditions. AWD cars don't go through this, presumably because it was determined to be not worth the cost of additional rollers that would accommodate full time AWD vehicles, so they are still subjected to the older test method that measures emissions at idle and approximately 2500rpm.

In practice, many people will essentially pay a bribe to the emissions testing shop to get the car passed, or they'll swap on the parts necessary to pass the test and then put the modified parts back on after passing. As already mentioned, to be 100% compliant, all emissions related equipment must be original equipment or be CARB approved, but in reality, the smog tech may not conduct a visual inspection to determine that all parts are physically compliant and/or some parts are not practical to inspect in cramped engine bays.

[unclebigbad]

In practice, many people will essentially pay a bribe to the emissions testing shop to get the car passed, or they'll swap on the parts necessary to pass the test and then put the modified parts back on after passing?

What The What?

I wouldn't suggest that. If you're going to take the time to build this car why not just build it in compliance to your local laws? Here in California, any specialty built i.e. kit car, must be inspected,tested and passed at a referee station if you ever hope to drive it on the street. And I would never risk my smog license for a couple of bucks. The consequences are too costly.

[Evan78]

In practice, many people will essentially pay a bribe to the emissions testing shop to get the car passed, or they'll swap on the parts necessary to pass the test and then put the modified parts back on after passing?

What The What?

I wouldn't suggest that. If you're going to take the time to build this car why not just build it in compliance to your local laws? Here in California, any specialty built i.e. kit car, must be inspected,tested and passed at a referee station if you ever hope to drive it on the street. And I would never risk my smog license for a couple of bucks. The consequences are too costly.I'm not at all suggesting that. Someone else mentioned that he met someone that keeps a whole spare engine to swap in for smog purposes, I was just elaborating along those lines on what goes on. I guess I should have been more clear that I was referring to normal production vehicles and not kit cars. I'll go back and edit for clarification.

I agree with you, it should be built to comply with California law, or the law of whatever state you're registering it. In reality, it will vary depending on how people get their car registered (will it be eligible for California exemption under SB100?). If the car has to comply with modern emissions (i.e. cats and other emissions equipment in place), I guarantee there will be some people doing the same thing with their 818 that already goes on with production vehicles. Again, I'm not suggesting or condoning it. If I were a smog shop, I wouldn't risk it either, but it is well known that they are out there.

[RM1SepEx]

So this thread started with generic compatability and went to engine tuning etc...

I have a couple generic questions

My ebay steering rack didn't fit... so

does a generic Im,preza power rack have the same ratio as a wrx rack and the same mounting points and input shaft?
Are 02-07 WRX STI aluminum lower control arms the same as 06 aluminum arms and compatable?

Trying to fill out my parts, replace my damaged 05 rack (and depower it) and add aluminum lower front control arms for the kit

[bugeye_fever]

Can't help you with the rack, but there are several different AL LCA's. They are interchangeable, with 04-05's adding the most caster to the Subaru strut suspension geometry, 06-07 still adding castor over the stamped steel wrx partsbut not as much as the earlier model. The 06 Wrx LCA's in there somewhere, but I do not know they're effect on castor.

In another thread remember reading that due to the adjustability af the 818's upper control arm assembly, the LCA may not be as important.

[RM1SepEx]

Thanks! Ordered my aluminum LCAs this AM... 07 STI versions
Now to get the correct rack and depower it, my donor's was destroyed... broken housing, bent inner tie rod, bent outer ball joint. That front corner was hit pretty hard.

[Rarytas]

Thanks! Ordered my aluminum LCAs this AM... 07 STI versions
Now to get the correct rack and depower it, my donor's was destroyed... broken housing, bent inner tie rod, bent outer ball joint. That front corner was hit pretty hard.

yea all STI, WRX control arms have the same dimensions. 2.5RS controll arms have smaller bushings that attach to the crossmember. Thats y i was kinda like :rolleyes: when i read ONLY wrx donor car, & their prototype had STi front LCA's lol

[RM1SepEx]

their donor was an 06 WRX, they also have the aluminum LCA

[Empty Wallet]

Hi Everyone,
New guy here. My son in law and I are planning to buid the 818 when available. He owned a WRX STI and is the resident expert on these cars, I am big block carb guy. I have read through a number of threads and have confused myself. Here is my question? Can a WRX STi be used as a donor car? If not why? After reading the FFR website it calls for a WRX, NOT STI, although the STI seems to be the stronger of the vehicles. Looking forward to learning more from you guys over the next few months. :confused:
THANKS!!!

[wallace18]

Donors are based on the WRX due to cost and availability. STI has some parts that will work and others that won't. There are lot more wrx available and also plain imprezzas will work as donors. You can mix and match parts. But to be a single donar the STI will not work as the kit is offered so far.

[305mouse]

The biggest hang up with the STI seems to be the size of the 6 speed tranny. There are other little issues with some parts, but that's the big one.

[PhyrraM]

The biggest hang up with the STI seems to be the size of the 6 speed tranny. There are other little issues with some parts, but that's the big one.

I would add the Front knuckles as an equally big issue - considering the kit will include upper a-arm adapters that will not fit the STI knuckles.

Half-shafts for the larger rear hub would be a close 3rd.

[Empty Wallet]

Wallace18, 305mouse and Phyrram
Out of pocket a few days dealing with hurricane Isaac! Thanks for the info on the STI! Greatly appreciated.

[RCKSTR]

if someone did get a STI to use they could easily sell off the 6 speed plus a few other bits like the shaft and rear end for anywhere from 3-4 grand. that is a highly looks for upgrade for all of the WRX owners :)