BEST Intercooler and intake temp location??!!!????

Discussion pertaining to positive pressure E28s.
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5timesturbo
Posts: 307
Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

BEST Intercooler and intake temp location??!!!????

Post by 5timesturbo »

So I had an interesting conversation today concerning my horsepower goals and the placement of my air to water intercooler. My intercooler system says it can flow enough CFMs to support 600hp. I’m shooting for 500. I’m installing mega squirt now. I’m running a tcd manifold and a turbo that should take me to 500…. I forget what it is. I’m also waiting for delivery of 9:1 turbo pistons. I’m being told that because my air to water intercooler is above my exhaust manifold there is no real amount of cooling I can do to get intake temps to support that horse power before I get detonation from high intake temps. I’m trying to see if anyone is making over 400 with air to water intercooler placed near the exhaust manifold or 400+ with no intercooler…..safely. ???? Lol. Any input is appreciated. Thanks.

P.S…. Another part to this question would be….where is the best place to place the air temp sensor being used by the MS so that it gets a good read. Is it a good idea to place it in the main charge pipe close to the idle control valve?? Or is that too far up?? Some ppl have it located BEFORE the turbo…..is THAT best?? Again….ANY advice is appreaciated!

It’s kinda tight…..is placing the IAT for the mega squirt two inches from the ICV to close??
tschultz
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Re: BEST Intercooler and intake temp location??!!!????

Post by tschultz »

Best bet would be to put after turbo as close to the intake if the engine as possible.
I have mine a ways before the idle valve so it's always having some air moving past the probe.The problem is that heat from the engine can cause heatsoak which gives dome people heat soak issues on hot restart.

There are megasquirt settings for that and I haven't had too many issues. Still some people put it post intercooler so you have some temps close to realistic but less prone to heat soak. For reference I drove my car in winter 30f temps and without an intercooler temps jumped to 120f in a single 3rd gear pull. With the intercooler I can stay closer to 20f above ambient, even with 100f ambient temps. So this translates into more power.

Watercooled is better in the sense that it will remove more heat from the air and in a single pull it should be more consistent in cooling the charge. I wasnt sure i liked water cooled because of complexity of pumps, heat exchangers and the water system required. If the system gets heated up from long pulls or multiple runs, it may be harder to shed the heat from the water system. For that spirited driving and reduced complexity, I have stayed air to air
turbodan
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Re: BEST Intercooler and intake temp location??!!!????

Post by turbodan »

You're really going with the high compression pistons. Good luck.

IAT can be anywhere between the intercooler outlet and intake manifold. Preferably closer to the manifold. Locating before the turbo would be really dumb.

You intercooler may be able to flow a certain amount of volume through the core but that doesn't mean it's going to be able to maintain reasonable IAT's while doing so. It's primary function is heat exchange and high boost requires a lot of area.

You won't get close to 400 without intercooling. Probably won't get close to 300. Heat is the primary cause of detonation, which is the primary cause of engine damage in forced induction engines. You have two main sources of heat, first one is adiabatic heating which relates directly to your compression ratio, which you have already chosen to increase. I think I recommended against that in your other thread. The other main source of heat is from the compressor, turbos add a substantial amount of heat during compression and whatever gets through the intercooler will elevate temps in the combustion chamber. I used to run two A-A intercoolers in series which kept IAT's to within ten degrees of ambient. This requires a lot of core area, so much that it is hard to fit it all in the front of the car. Water to air improves the packaging in some ways, you can put the heat exchangers anywhere you want, but you will be looking at a bit of a situation with the circulating pump and plumbing. Just like air to air, you will need to make sure you have enough heat exchanging capacity to support steady state operation under boost.

The thing with the M30 is the intake manifold. It doesn't like to build power past 5000 RPM. It peaks early and will maintain power to 5500 or so before falling off. It's trying hard to make torque in the midrange which is great until you try to turn the boost up and it starts detonating. A short runner intake will alleviate the cylinder pressures through the midrange and move the torque curve upward where horsepower is made and detonation is less likely. If you're chasing numbers that's what you'll need. If you want buttloads of usable torque and you can settle for "only" 350-400 rwhp the stock intake has a certain appeal. You just have to be careful with the tune and make sure it's not pinging.
Dirtym30
Posts: 75
Joined: Jan 12, 2020 5:30 PM
Location: Toronto, Canada

Re: BEST Intercooler and intake temp location??!!!????

Post by Dirtym30 »

This is a noob question but where does the sensor wire into?

Running a PNP2
5timesturbo
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Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

Re: BEST Intercooler and intake temp location??!!!????

Post by 5timesturbo »

Dirtym30 the IAT sensor connects to the 1 and 4 pin in the MAF sensor harness connector.
Dirtym30
Posts: 75
Joined: Jan 12, 2020 5:30 PM
Location: Toronto, Canada

Re: BEST Intercooler and intake temp location??!!!????

Post by Dirtym30 »

Thank you 5times!
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