Turbo options

[bompus]

I know.. I know.. This thread will get out of control.

I'm debating whether to keep my stock 2005 WRX TD04 turbo ( as-is used or get it rebuilt? ) or upgrade to something else. I figure if I am going to pay to have it rebuilt ( $450+ ) , I could just get something a tad better? What is out there that is reliable and a direct fit. I've read tons of info over at Nabisco, but there are quite a few options. I'm just looking for advice on whether to just stick with what I have used, get the TD04 rebuilt, or replace it with something "better" that is reliable.

Let the fun begin :)

[RM1SepEx]

How many miles/what is the condition of your turbo?

[bompus]

The donor had around 90k on the car, not sure if turbo was ever serviced or not. It doesn't look horrible and my simple test of feeling it didn't seem to have any play in it, but I have no idea what I am looking for. I was just concerned because there was a pool of oil sitting in the bottom of the intake manifold but I wasn't sure if that came from the turbo or just normal blow-by. It seemed a bit odd to have a decent amount of oil just sitting in the manifold so not sure what to make of that.

I don't necessarily want to replace the turbo, but was thinking about rebuilding it just to be safe. That got me thinking about other options and here I am.

[Jvalgardson]

I know.. I know.. This thread will get out of control.

I'm debating whether to keep my stock 2005 WRX TD04 turbo ( as-is used or get it rebuilt? ) or upgrade to something else. I figure if I am going to pay to have it rebuilt ( $450+ ) , I could just get something a tad better? What is out there that is reliable and a direct fit. I've read tons of info over at Nabisco, but there are quite a few options. I'm just looking for advice on whether to just stick with what I have used, get the TD04 rebuilt, or replace it with something "better" that is reliable.

Let the fun begin :)

I am curious about this too

[Goldwing]

With the turbo swap, I had chosen to upgrade to a VF48 with the goal of keeping the low end power range, while expanding the top. Due to my perceived nature of the 818 (nimble tossable car) I felt the low end was going to be really important to me. Someone else is using that turbo in their build and ran across some interference at the rear shock brace. So far, I'm sticking with stock, but ask me tomorrow, lol. All that said, you'll get more tailored, to you, recommendations for turbo upgrades if you also state your goals with your build. E.g.: where do you want to develop power? How much power? How quickly, etc. In my searches, it seems 300hp is where you start losing the bottom end to expand the top end of the power band. It's also where the 5 speed starts to grind teeth without building for strength there too. So, near 300hp seemed a natural goal for me, but everyone has their own goals and ideas of what they want their 818 to do.

There are a few turbo comparison lists out there. Here's one:

http://forums.nasioc.com/forums/showthread.php?t=1141476

[Westview]

Unfortunately its pretty common to have a small amount of oil in the intercooler/manifold on these motors with the stock crankcase ventilation system. So you can't jump to the conclusion that the turbo is leaking. I still occasionally got oil in my intercooler/manifold even after installing an AOS. I have methanol injection now, so I don't see it anymore. It gets washed out. I don't know how to verify whether the turbo is leaking. If there's no shaft play, I think I'd just install it and see how it goes. I have a VF-48 Turbo sitting on my shelf, but I'm going to install the stock turbo off my 2006 donor and see how the car performs. Then I'll decide whether I think an upgrade is in order.

[mikeb75]

Also doing a VF STI takeoff. Cheap(ish), simple(ish), and should get my 2.0L to ~ 300HP after tune. I believe most other turbo options are going to have huge expense relative to finding a decent STI takeoff, either in the turbo itself (for direct fit) or in new headers/uppipe/downpipe and intake for rotated & twinscroll setups.

I found my VF39 for less than you will pay for rebuild as an example.

[DMC7492]

Hi guys I was in the same situation.and as Subaru engines go, I am not the most experienced. Therefore I called Blouche performance turbos and explained the 818 for street applications and the first question he asked was what is your HP goal!
mine was the capacity for 325 HP to the ground,seems like a lot for this car but like I always say, you don't have to use it all, but J I C it is there waiting.
They suggested the following turbo on the 2.0 liter 2005 WRX. Stock location mount with the 8mm housing.
i also am going with the External waste Gate.
The TD05- 20 was getting too big for the 2.0 and pushing the power even higher in the RPMs and sacrificing low end.
The 18 was mentioned to bring on the power more gradually than the 16 to broaden the power band.
I do not have the engine together yet,and my kit is said to be here in the next week or so depending on Stuarts schedule,and the Huntington Beach show truck drivers for FFR.

Here is a link to the website
http://www.bptstore.com/Subaru-WRXSTi-TD05H-18G-XT_p_11.html


Part Number SUB-TD05H-18G-XT


Application: Subaru WRX/STi
Horsepower: 430HP

The Blouch 18G-XT is a proven performer utilizing the latest in billet compressor aerodynamics combined with genuine Mitsubishi journal bearing technology.

Here's the skinny: 1. Custom Blouch Turbo compressor housing with improved fitment and custom CNC machined at Blouch Turbo for the new 18G-XT aero; 2.closed die forged fully machined billet 18G-XT compressor wheel that is lighter yet stronger with greater flow rate; 3. genuine Mitsubishi center housing with all genuine Mitsubishi parts; 4. Mitsubishi TD05H turbine wheel; 5. options of 7cm2, 8cm2 or 10cm2 turbine housings tailored to your application; 6. option of 3" bell mouth inlet compressor housing; 7. upgrade actuator option and 8. complete drain tube/coolant line package with gaskets for a complete bolt-on package.

So what's the big deal? The 18G-XT spools very quickly, produces great mid-range torque and excellent top end power for its size. If 430 crank horsepower is your goal, this turbo is for you!

[nkw8181]

I am now on this topic, ahead of schedule, because I need a clutch so I need to figure out my power (turbo and mods planned). The turbos I've been recommended for 350, ft-lbs to the ground, are:

GTX 3076R
Bloush 20 G
VF48
SS-20GXR

Now I'm just confused. Thoughts input?

[philly15]

I am now on this topic, ahead of schedule, because I need a clutch so I need to figure out my power (turbo and mods planned). The turbos I've been recommended for 350, ft-lbs to the ground, are:

GTX 3076R
Bloush 20 G
VF48
SS-20GXR

Now I'm just confused. Thoughts input?

are we talking a 2.0L or a 2.5L? im completely unsure of why the vf48 is in any category with the others, but ok.

[nkw8181]

2.5L from 06 Wrx. Will the vf48 not put me in the desired power band?

[Goldwing]

I'll need to go back to review all the turbos to be sure , but if my memory serves me, the VF48 would be a bit smaller than the others, thus the comment above. More of a 300-325 range, while the others will top out higher. Personally, I like the VF48 for the 818. It does not sacrifice much on the bottom end, but expands the top nicely. The others, if they are what I think they are, will sacrifice some bottom end, to push more up top. That's where you need to decide where you want the power to be delivered on your 818. I look at the 818 as a corner carver, nimble, throwable. Not so much a power beast. The 5 speed has historically had some reliability problems above 300 without planning for it. Putting that together, the VF48 stood out to me as a good fit. Utilizes the full reliable potential of the unmodded tranny, spools well at the low end. That said, since mine isn't on the street yet, all of this is still theoretical and hot air, lol. I should point out that the rear strut brace needs a little modification to accommodate the waste gate actuator on the VF48. A notch in the lower main arm and a brace to compensate. I'm not sure about the others, fitment wise.

[Mechie3]

I am now on this topic, ahead of schedule, because I need a clutch so I need to figure out my power (turbo and mods planned). The turbos I've been recommended for 350, ft-lbs to the ground, are:

GTX 3076R
Bloush 20 G
VF48
SS-20GXR

Now I'm just confused. Thoughts input?

My stock TD04 made 351ftlbs to the ground on a stock 2.5L shortblock. Of course, it hit 351 and quickly tapered, but it made 243whp from 3100 to 5100 rpms. Super fun around town and autox but you could feel it running out of steam on the high end.

[ssssly]

$450 for a td04 rebuild is not with it. You could blow up 3 used ones for that price.

Unless you want to spend the money to convert to twin scroll, I would suggest getting a cheap, used vf39 and see what you think. You can get used vf39s all day for under $350.

With proper fuel, a good tune and the conversion to 2wd, a vf39 should get you in the mid to high 300hp range (up to around 5k rpm). And any higher than that and you are going to want to start looking at a built block anyway.

You will also be trying to figure out how to get the power to the ground. Because a 8.5" rear tire won't cut it at those power levels. Based on the road dyno plots of my old spec C (the donor for my 818@430fp) I calculated that I will need to figure out how to get 10.5"s of rubber in the rear to keep it from breaking traction in every gear but 6th. 12" to use first gear.

And you will be perilously close to out torquing the 5 speed transmission. At about 400 chp (in 4wd configuration), a mis shift will tank it. In 2wd configuration there haven't been any serious power tests yet. And in theory it should hold up a bit better. But it is something to consider when strapping big turbos into one of these.

[Frank818]

Because a 8.5" rear tire won't cut it at those power levels. Based on the road dyno plots of my old spec C (the donor for my 818@430fp) I calculated that I will need to figure out how to get 10.5"s of rubber in the rear to keep it from breaking traction in every gear but 6th. 12" to use first gear.

I am very curious to understand your calculations. I am not questioning what you said, I just want to use your method and see what results I get for me. :)

[metalmaker12]

Blouch 1.5 xtr twinscroll on ej207 with spec c heads and cams here.

[ssssly]

This is the method I use. It is by no means super accurate but has worked pretty well for me. Due to variations in compound and tire pressure I have found trying to come up with a more accurate formula pretty useless.

Tire= (Gear Ratio * 25 * Torque * 1.05) / 3000

[nkw8181]

Where is the weight of the car factored in?

I though the vf48 in to my consideration because it is the newer vf39. I still have a ways to go before I "need" to get a turbo but for me all of this is stimmed from trying to pick a clutch. Looking at a clutch masters stage 4 figuring it will cover anything I might want to do. The vf39 or vf48 would be a much cheaper route. One they are cheaper themselves and 2 I won't need injectors exc, exc

[philly15]

Where is the weight of the car factored in?

I though the vf48 in to my consideration because it is the newer vf39. I still have a ways to go before I "need" to get a turbo but for me all of this is stimmed from trying to pick a clutch. Looking at a clutch masters stage 4 figuring it will cover anything I might want to do. The vf39 or vf48 would be a much cheaper route. One they are cheaper themselves and 2 I won't need injectors exc, exc

vf48 is basically the same as a vf39, slightly different bearing design I think, and stiffer wastegate actuator. Either way, with good tuning ive seen some crazy numbers on the vf39 on a 2.5L, even in an STi. A friend of mine hit 400/400 to the wheels on a vf39, but granted he spent a solid year perfecting every little piece of that tune. I think any more than an 18g would be too much for the 818. I really believe the best motor for the 818 is an ej207, with something like a twin scroll blouch 1.5xtr as metalmaker has, short of spending thousands destroking a 2.5L.

[metalmaker12]

Sssssly, I am unsure your equation will work with the 818. It's so light even in its heaviest area and it will spin and wheel hope no matter the tire width. I think the rubber compound will be the better solution. I feel the 7
818 will be very balanced with a 255-275 rear and 215-235 front with very sticky rubber.

I also feel 300-400whp is all you will ever want in this car. My engine internals will be good for around 5-600, but I am only tuning it to 300-350max. I might tilt it up to see what it can make ( like 450 ish) but only on the dyno. My setup (ej207 with built bottom end and ported spec c heads, awic, with a 2.5 inlet,10cm Blouch xtr twinscroll will spool quickly with the dual avcs aid and hold power up high till 8k. I bet I can run lower boost levels and still break 300whp and it will be very responsive. It will be a tuff car to pass because it will have strong balanced power all over the place. Funny thing is, I am going to baby this car once it's together, because it's just going to be such a blast.

[DMC7492]

" I also feel 300-400whp is all you will ever want in this car. My engine internals will be good for around 5-600, but I am only tuning it to 300-350max. I might tilt it up to see what it can make ( like 450 ish) but only on the dyno."

Curios as to your internals? I have a builder here in Wisconsin that swears by Manley Turbo Tuff rods and forged pistons,are you running something similar?
Here is my pretty engine with a Blouche TD05-18 xt NOT Ball bearing, Blouche guys said with the ball bearings the housing is bigger and spool will suffer. This is on a 2.0, my power goal was 325 wheel horse, they also recommended a bigger pump, 255 or 340 aeromotive and 750 injectors, also the Grimm speed high flow cross pipe and externally waste gated Grimm speed up pipe.
Once I spoke with a tuner,engine builder and Blouche a lot of the answers come out and make sense,but everybody's situation is different, I totally agree that 300-350 WHP will be enough, but you don't have to use it all;)!!
32992

[philly15]

^nice looking motor, who's your builder? even a stock ej207 would hold up fine in the 400-400 range, plus the higher redline, dual avcs, and twin scroll are really nice for this setup. Looking through metalmaker's thread makes me wish I would have built my 818 without a donor, and just went ej207 :/

[DMC7492]

Philly, I have built engines through Baril Engine rebuilding for a lot of years, they are in ashwubenon Green Bay wi
They will do it all or let you do as much as you want, never had any issues with their work! Ask for Larry !

I would do another one, no donor, all the parts are being redone any way and selling the spare parts paid for the nice wheels but what a pain selling the spares dealing with people schedule
On the other hand to buy an engine, tranny and a ECM with wiring will run a few thousand so it is a toss up seems if you thrown in a used engine imminent failure will occur as the engine is not accustomed to the treatment of the new running environment and a brand new block and heads will run the same.

[philly15]

Philly, I have built engines through Baril Engine rebuilding for a lot of years, they are in ashwubenon Green Bay wi
They will do it all or let you do as much as you want, never had any issues with their work! Ask for Larry !

I would do another one, no donor, all the parts are being redone any way and selling the spare parts paid for the nice wheels but what a pain selling the spares dealing with people schedule
On the other hand to buy an engine, tranny and a ECM with wiring will run a few thousand so it is a toss up seems if you thrown in a used engine imminent failure will occur as the engine is not accustomed to the treatment of the new running environment and a brand new block and heads will run the same.

nice, good to know! I usually assemble the motor myself, I usually look for new places to get machine work done. It's hard to find a good shop in our area to do good work these days. I wish we had one of the larger Subaru experienced shops around here.

[ssssly]

Sssssly, I am unsure your equation will work with the 818. It's so light even in its heaviest area and it will spin and wheel hope no matter the tire width. I think the rubber compound will be the better solution. I feel the 7
818 will be very balanced with a 255-275 rear and 215-235 front with very sticky rubber.

The formula is dependent on torque at the wheel.Because the car is lighter, the required torque to propel it from a stop will also decrease.

And I agree, tire compound is a huge variable. As is tire pressure. Hence why I simplified it off based on slip% and rolling resistance. Which is where the "25" comes from. Is a factoring of a 7% slip ratio based on ~98 Newtons per 1000kg at a rolling resistance of 0.001.

I certainly wouldn't use it to base any other engineering on. But I think you'd be surprised at how good of a WAG it will give you. Particularly with the number of other variables.

I wouldn't worry too much about the clutch. The stock 5 sp clutch will hold into the 3s. In 2wd configuration even the basic "street" clutches out there should be more that sufficient. And are still center sprung.

Regardless of the turbo you choose, if you turn the boost up at all you will need new injectors and a tune. @ 400hp to the crank (or ~350whp) you will need a minimum of a 750cc injector. And that is at 90% injector duty cycle. You should get at least an 850cc. And I would suggest just getting the ID1000s so that you have headroom, that and they idle better than most of the 850cc injectors out there.

The vf48 is a slightly clocked vf39 with a different WG casting and extended outlet to match the new TMIC location in the 08+ Subarus. The primary advantage is the redesigned casting at the WG opening location. The vf39s are prone to crack around the WG door. Which is why you can buy them for next to nothing. The cracks don't effect performance at all though.

They will both make around the same peak HP around 4700 RPM and then drop like a rock. They aren't big enough to flow enough air to sustain that HP into the higher RPMs. More than enough power for an 818 though.

EJ207s come with stock forged internals. They will run mid 400s with no issue as long as you use good oil.

Seeing as a Caterham puts 320hp to the ground in a 500kg car with almost no downforce and runs as quick as an LFA; with proper aero, once you learned how to launch it, an 818 should be able to use ever bit of 600hp with some simple tuning to keep it out of max torque during shifts. Just delay the AVCS and and retard the timing a bit in that region and it should blast through a shift without you noticing that your torque curve took a .4 second dip.

And seeing as you can program launch control in speed density tunes on a WRX ECU, shouldn't be too difficult to dial that in as well with sufficient rear rubber on the car. Just keep the torque down until full boost and it should fire like a rocket.

When I get mine up, running and tuned, I'll make some MAF based ROMs available to the community.

Long story short, vf39 or 48 will get you the same result.
vf39s are super plentiful and considerably cheaper.
Either way you want bigger injectors.
A beefy clutch isn't required but won't hurt anything other than your left calf.