Intake temperature

[tmoretta]

Okay, I have installed an intake temperature gauge in my air to air intercooler. I have improved/sealed the two intake air tracts on top of the engine cover, and modified the subie hood scoop seal to use in my 818S. Now, what temp. numbers should I be looking at? What temp. indicates a possible melt down? During my one road test so far, I have seen gauge temps. at 80 to 98 degrees F. with ambient air about 60 degrees.

[ssssly]

The ECU will start pulling timing at anything above 104f.

I set my intercooler auto water spray to kick on at anything above 87.

But it all really depends on your timing map. At stock timing, temps above 105 start getting really dicey.

If you have a tuned car with more aggressive timing, it starts to get dangerous much earlier unless you are running race gas or e85.

I myself don't like pushing boost much over WG pressure if the IAT is above 95. And I would highly suggest not down shifting or flat footing with IATs above that level.

If there is air running over the IC, the IATs should be far lower. At stock boost levels, the STI TMIC is about 85% efficient. So at 60 degree ambient temps, if there were air flowing over it, you should have IATs in the low 70s.

[Bob_n_Cincy]

My air intake at the MAF is between 100-120 with a 60 ambient. Stock tune.
This is first lap after a pit stop so the 120 was some heat soaking. But only dropped to 100 at race speeds.
Please let me know what you see in this chart. This is new to me.
Should I be seeing more than 10psi boost?
Bob

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[Rasmus]

Should I be seeing more than 10psi boost?

Yes. On a stock tune boost pressures should max at

15.9 PSI max 2015+ WRX
13.3 PSI max 2009-2014 WRX
11.9 PSI max 2008 WRX
11.6 PSI max 2006/2007 WRX
13.5 PSI max 2001-2005 WRX
14.5 PSI max STi

[Bob_n_Cincy]

Thanks Rasmus,
Nice to have you back. I missed seeing all your gram saving ideas. While you were gone the state made me add front and rear 60" x 4" bumpers. About 50 lbs each. Sorry.

My donor is a MY04 2.5L FXT TD04 turbo. I'm guessing 11.6 PSI stock tune.
What would be holding me down?

I had it dyno tested October 2014 by TIC in go kart configuration.
It was getting up close to 12 PSI then. see attached.

52833

Biggest engine change since then was rebuilt turbo and TMIC to AWIC conversion.
Thanks for your advice.
Bob

[tmoretta]

So raising the octane of the fuel will help? I used to use Amsoil Octane Boost in my M3 engine BMW 2002 track car years back. Also I am considering adding a pair of scoops to top of engine cover air inlets, but, I thought I remembered FFR saying that larger scoops did not increase air flow in the wind tunnel.

[RM1SepEx]

Bob, I dynoed mine at 220 hp on a dynocom 150,000. It maxed at 10 psi, when I clocked the turbo I extended the vac line and deleted the little $2.00 brass pill that slows down the wastegate operation. You rotated your turbo, is the pill where it should be? I've replaced it but not dynoed yet, he's upgrading to 4wd as we speak https://www.facebook.com/christopher.moberg?fref=ts

I added in and out temp gage to my side mount IC, I expect to have some data soon

[Bob_n_Cincy]

If I move (replace) my AIT sensor with a post intercooler AIT, do I need to reprogram anything?

[ssssly]

So raising the octane of the fuel will help? I used to use Amsoil Octane Boost in my M3 engine BMW 2002 track car years back. Also I am considering adding a pair of scoops to top of engine cover air inlets, but, I thought I remembered FFR saying that larger scoops did not increase air flow in the wind tunnel.

Raising the octane will help with the engine running into detonation problems caused by the high IATs, but the underlying problem of high IATs still needs to be addressed. Routine IATs over 100 degrees put the engine in a perilous situation where the cooling systems is always stressed to keep cylinder and lube temps within safe parameters. And leads to premature engine failure.


Bob, I dynoed mine at 220 hp on a dynocom 150,000. It maxed at 10 psi, when I clocked the turbo I extended the vac line and deleted the little $2.00 brass pill that slows down the wastegate operation. You rotated your turbo, is the pill where it should be? I've replaced it but not dynoed yet, he's upgrading to 4wd as we speak https://www.facebook.com/christopher.moberg?fref=ts

I added in and out temp gage to my side mount IC, I expect to have some data soon

The brass pill isn't there to slow WG operation. It is there to provide increased pressure. Without the pill the ECU needs to be retuned since the readings passed to the ECU will always be off (it is expecting vac to be at one pressure, you have changed that pressure).

Removing the pill also creates problems with part throttle full boost situations. Such as going up a moderate incline at mid RPM ranges. Because the ECU sees the wrong pressure, it initiates a boost runaway because it can't average the WGDC properly for full boost in open loop fueling, resulting in a blown engine.

Removing the restrictor pill with the stock boost control solenoid is not advised unless you are tuning the car specifically for it and driving the car only on tracks with limited elevation change and limited track portions where you require long periods of mid range throttle manipulation.


Thanks Rasmus,
Nice to have you back. I missed seeing all your gram saving ideas. While you were gone the state made me add front and rear 60" x 4" bumpers. About 50 lbs each. Sorry.

My donor is a MY04 2.5L FXT TD04 turbo. I'm guessing 11.6 PSI stock tune.
What would be holding me down?

I had it dyno tested October 2014 by TIC in go kart configuration.
It was getting up close to 12 PSI then. see attached.

52833

Biggest engine change since then was rebuilt turbo and TMIC to AWIC conversion.
Thanks for your advice.
Bob

The most likely reason your boost is low is the high IATs.

With IATs that high the ECU not only pulls timing, it also adds a (-) boost multiplayer per gear and adds fuel to base AFR to help stave off detonation.

You could have a small vacuum leak. But with IATs that high I would resolve that problem first no matter what. Since you don't want higher boost at those IATs.

If you have the log files, I'll take a look at them and see if there is anything else of note. I prefer to look at the raw logs, graphs are too messy and not precise enough.


If I move (replace) my AIT sensor with a post intercooler AIT, do I need to reprogram anything?

The stock IAT is the MAF which cannot be easily relocated unless you go to a speed density tune. If you go to speed density you can have the IAT wherever you want.

The other option is to go to one of the 16 bit JDM ECUs (and harness) that allows for multiple IATs (spec C, RAR, S202/3).

[Bob_n_Cincy]

The most likely reason your boost is low is the high IATs.
With IATs that high the ECU not only pulls timing, it also adds a (-) boost multiplayer per gear and adds fuel to base AFR to help stave off detonation.
You could have a small vacuum leak. But with IATs that high I would resolve that problem first no matter what. Since you don't want higher boost at those IATs.
If you have the log files, I'll take a look at them and see if there is anything else of note. I prefer to look at the raw logs, graphs are too messy and not precise enough.
The stock IAT is the MAF which cannot be easily relocated unless you go to a speed density tune. If you go to speed density you can have the IAT wherever you want.
The other option is to go to one of the 16 bit JDM ECUs (and harness) that allows for multiple IATs (spec C, RAR, S202/3).

Thank ssssly for the advice.
The reason for my high IAT temp is because I am pulling air from the engine bay.
I was running a rear radiator that had 2 16" fans pulling hot air out of the engine bay. I moved my radiator to the front and now I have no forced cooling.

I have zero knocks in my 4 hours of track time. I suspect my AWIC is doing it job to reduce the air temp into the engine.

I will hook up my post intercooler temp sensor to a spare ecu input, just for monitoring purposes.
My dash software allows me to set off alarms on any ECU value.

To fix my AIT temp problem. I will run a snorkel pipe from my air filter to the side sail vent.

I will also add back in an engine compartment fan.
Thanks
Bob

[tmoretta]

If goal is to lower the IAT, am I better off attempting to install a pusher fan on top of the intercooler or going to water injection over the intercooler? There is little room below the intercooler for a puller fan.

[Hindsight]

To fix my AIT temp problem. I will run a snorkel pipe from my air filter to the side sail vent.

That's what I was going to suggest. I would suggest boxing it in. I remember Tamra and Andrew and/or Chad did some tests and found that having the air filter right behind the side sail vent wasn't enough - intake temps were still quite high. The only thing that worked was to actually build a box that sealed-off the area behind the intake vent completely and have the air filter located inside, sealed around the intake pipe. This is what I plan on doing when I finally get there.

[Hindsight]

If goal is to lower the IAT, am I better off attempting to install a pusher fan on top of the intercooler or going to water injection over the intercooler? There is little room below the intercooler for a puller fan.

So far, no one has reported adequate results with a top mount intercooler, fans or not (a couple have tried and reported their results as being poor - though the setups looked good from an appearance standpoint). Air to Water is where it's at until someone figures out a way to successfully duct the side sails to a side mount Air to Air unit.

[Loring]

So far, no one has reported adequate results with a top mount intercooler, fans or not (a couple have tried and reported their results as being poor - though the setups looked good from an appearance standpoint). Air to Water is where it's at until someone figures out a way to successfully duct the side sails to a side mount Air to Air unit.

What he said ^^

As an aside, I'll be making some phenolic spacers as an extra heat containment measure. I'd highly suggest them even if you aren't having IC efficiency issues.

[tmoretta]

Yes, but even with ambient temp. air entering the air filter, the turbo is ultra heating that air, and the entire engine compartment is very enclosed and hot. I am thinking that the supplied engine cover vents and aluminum tracts to the intercooler, even if improved are just a poor design. I am experimenting with increasing the inlets by adding scoops (cardboard for now), but I am not convinced I will see AIT decreasing. I may have to go to air to water. Don't know if I can install a system without removing a side sail. I am not happy with the results of FFR designs in regards to managing intercooler air temps.

[tmoretta]

So how are you guys cooling the intake?

[ssssly]

Thank ssssly for the advice.
The reason for my high IAT temp is because I am pulling air from the engine bay.
I was running a rear radiator that had 2 16" fans pulling hot air out of the engine bay. I moved my radiator to the front and now I have no forced cooling.

I have zero knocks in my 4 hours of track time. I suspect my AWIC is doing it job to reduce the air temp into the engine.

I will hook up my post intercooler temp sensor to a spare ecu input, just for monitoring purposes.
My dash software allows me to set off alarms on any ECU value.

To fix my AIT temp problem. I will run a snorkel pipe from my air filter to the side sail vent.

I will also add back in an engine compartment fan.
Thanks
Bob

Bob,

The AWIC should keep the actual IAT under control and keep you away from detonation problems.

You will however still have issues maintaining solid boost and timing under real world driving conditions if your MAF is reading high IATs (if you are using the stock ECU or similar IAT tables in an aftermarket ECU).

If you have a way to measure the IAT at the intake manifold and can be sure that they are below 100f, then you could change the table for the IAT in the ECU so it doesn't retard your other engine tables. But I wouldn't exactly call that a best practice. It is legitimately dangerous without a way to verify the actual IAT at the manifold. And it doesn't address the underlying problem that you are using heated engine air in your intake. It would likely solve your low boost problem though.


If goal is to lower the IAT, am I better off attempting to install a pusher fan on top of the intercooler or going to water injection over the intercooler? There is little room below the intercooler for a puller fan.

If you don't have sufficient airflow over the intercooler, water spray will do little help. Without air moving over the wet intercooler, the increased cooling effect of the evaporating water will be minimal. You could always do both. IE mounting the sprayer nozzles to the underside of the pusher fans.

[Bob_n_Cincy]

Bob,

The AWIC should keep the actual IAT under control and keep you away from detonation problems.

You will however still have issues maintaining solid boost and timing under real world driving conditions if your MAF is reading high IATs (if you are using the stock ECU or similar IAT tables in an aftermarket ECU).

If you have a way to measure the IAT at the intake manifold and can be sure that they are below 100f, then you could change the table for the IAT in the ECU so it doesn't retard your other engine tables. But I wouldn't exactly call that a best practice. It is legitimately dangerous without a way to verify the actual IAT at the manifold. And it doesn't address the underlying problem that you are using heated engine air in your intake. It would likely solve your low boost problem though.

ssssly,
Should be a piece of cake to solve my problem. I used the OEM filter box.
This is a picture of my air filter.

52893

I will put the bottom of this box on and pipe it to the side sail vent.

52894

Thanks again,
Bob

[ssssly]

ssssly,
Should be a piece of cake to solve my problem. I used the OEM filter box.
This is a picture of my air filter.

52893

I will put the bottom of this box on and pipe it to the side sail vent.

52894

Thanks again,
Bob

Bob,

Hope that works for you. Looks like a good solution.

If you are handy with a set of calipers and or 3D design, if you want to shoot me some parameters I can print you some ducting to try out.

Be well,

Brooker

[Bob_n_Cincy]

Bob,
Hope that works for you. Looks like a good solution.
If you are handy with a set of calipers and or 3D design, if you want to shoot me some parameters I can print you some ducting to try out.
Be well,
Brooker

Thanks Brooker,
Let me get the air box in place am I take some pictures.
How big can you print 3d?
Bob

[tmoretta]

And so, for now, you are still using the air to air intercooler?

[Hindsight]

FWIW, on my Air to Water intercooler, I saw no higher than 90 degree intake temps while doing a 4th gear pull on the dyno. Pre-intercooler temps were close to 150 degrees, and this was on ~ 78 degree day.

[Bob_n_Cincy]

And so, for now, you are still using the air to air intercooler?
Tmoretta,
I'm not sure who you are asking, But I'm very successfully running a AWIC.
The high temps I was getting was at the maf sensor. (before turbo and intercooler)

The 120 I was seeing at the maf/iat sensor was with body on at end of 1 minute pit stop on 60 degree ambient day. This is effectively say I was getting +60 degree in my engine bay over ambient. The temp dropped to 100F while on track.


52930

52931

Bob

[ssssly]

Thanks Brooker,
Let me get the air box in place am I take some pictures.
How big can you print 3d?
Bob

Bob,

About 9x6x11 in one solid piece. Practically however, one can print something as large as they want. You just have to do it in pieces with proper joinery and plastic weld the parts together. Holds up as well as a solid part.

Brooker

[Bob_n_Cincy]

Thanks Brooker for your help on this.
We implemented a solution to our temperature issue.

see
http://thefactoryfiveforum.com/showthread.php?12534-MRG-MotorSports-818S-Build&p=235781&viewfull=1#post235781

Let me know what you think.
Bob

[ssssly]

Looks like it should be better.

Interested to see if it gets the IATs close to ambient.

If it does, I may make a insert for the top of the side vent to allow a 3" connection.

[SixStar]

My RMIC works perfect. I've got dozens of logs showing 83-87% efficiency at speed and on the dyno running 20-25psi.

A typical A2A runs in the 60-70% range, A2Ws are in the 75-95% range. I've seen over 100% running ice over a short drag race run.

[Wayne Presley]

My AWIC works great, you also need to feed your air filter with cold non under hood air.

[Joseph]

Has anyone tried running AWIC to supply cooling to the intercooled air and a hose from the 818C roof vent to supply the cool air to the intake. I have no real experience to base this thought on but it would seem to me that air from the roof of an 818C would be ambient temp.

[Wayne Presley]

One of my customers is using the roof scoop to feed fresh air for the intake and another has a cold air box feed from the side vent

[Loring]

I'm planning to use one of the roof scoop outlets for the air intake.

[ssssly]

Bob,

I got my 3d scanner up and running right and if you would like to test it I will mock up and print out an insert for the side vent you can attach that 3" hose to. Should give you a bit more surface area directly in the flow path and clean up the look a bit. I'll straight up trade you parts for temp dimension data.

Be well,

Brooker

[Bob_n_Cincy]

Bob,

I got my 3d scanner up and running right and if you would like to test it I will mock up and print out an insert for the side vent you can attach that 3" hose to. Should give you a bit more surface area directly in the flow path and clean up the look a bit. I'll straight up trade you parts for temp dimension data.

Be well,

Brooker
Hey Booker
I have track days Saturday and Sunday.
Unfortunately the high for the day will only be around 70. I like to see some 90-100 track days to verify cooling systems.
I have a 3" silicon hose 60 degree elbow stuck into the side vent. I will have about 6 hours of data logs. I'll send you a slice.
I'll put together a cad model. Can you work with an acad2k solid model?
I have solidworks but don't now how to use it.
Bob

[ssssly]

I can pretty much work with any file format. I do most of my quick stuff like this in sketchup or onshape. Both of which can import Acad.

As far as dimensional data, would just be looking for the relationship between the flat plane representing the termination of the rear of the vent, and the location of the air box inlet.

Though I plan to initially mock one up that simply terminates at the boundary edge immediately behind the vent.

[ssssly]

Vent modeled.

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