Max boost without cooling

[Brent 930]

What is the max psi you can run without cooling the air intake? I'm SC'd and running 6psi right now.

Thanks

[5mall5nail5]

Its not really a question of boost, but when does your compressor start heating the air up big time.

6 psi I'd say you're fine - you'll prob heatsoak over time. 9 psi you want to think about charge cooling (and will suffer the pressure drop as well) to make more power.

You can run a hot as hell charge, you just need to have very mild timing and low horsepower figures.

[BigM62]

Run 9-10 psi with WI.

[Brent 930]

Yeah it isn't just about psi numbers yet running the right pressure with the SC and motor, etc. for the most efficience/lower charged air possible. From what I have seen (just wanted to be sure) if I wanted to run another 2 psi or > I would need WI. I was hoping just another 2 psi would be OK without WI.

[5mall5nail5]

I wouldn't - the tune you have is for the air you're flowing. Adding more air without tune can spell disaster. If you must bump the boost, spend the $400 and get a decent WI kit to protect your investment. You'll actually have potential to make more power as well.

[black318i]

I ran a DASC at 10 psi with nothing for cooling, but there was a big power difference when driving around in 90+ degree weather vs 60 and below.

[Brent 930]

Looks like a Snow Performance Stage II would be the ticket if I want to up the boost. It's only money, right?

[5mall5nail5]

Its only money man - just make sure the parts dont sit on your table ;)


Nah, snow stage 2 is a good kit grab one!

[LazyFox]

I'm considering to switch from 6psi to 8psi after adding SnowPerformance WI kit together with SafeInjection controller.

In my country we have quite poor fuel quality- 91PON only (no 93 or anything with higher octane), therefore I can't switch to 8psi without WI just because of high detonation.

[paul e]

Its not really a question of boost, but when does your compressor start heating the air up big time.

6 psi I'd say you're fine - you'll prob heatsoak over time. 9 psi you want to think about charge cooling (and will suffer the pressure drop as well) to make more power.

You can run a hot as hell charge, you just need to have very mild timing and low horsepower figures.

Snail... I did a lot of IAT instrumenting as I progressed from the 8 psi out of the box Dinan kit, to 11 psi with same kit augmented only by WI, and onto aftercooled setup. The problem is that, without an aftercooler, ie, with no intake cooling, or with pressure triggered WI kits, the IATs measured WITHOUT EVEN USING ANY BOOST, ramped up to AMBIENT plus 100 degrees. It has to be realized that on 80 degree days, your IATs on a fully warmed engine, ie, one thats been driven even easily for more than 15 minutes, will produce IATs of 180 degrees.. I dont have to tell you how more than doubling the ambient temps at your IAT sensor will make your bmw feel like quite a slug. Of course, if you have WI that triggers at say 4 psi, as soon as you get into the boost on the way to a redline pull, if youre monitoring your IAT sensor, youll see that youre removing over 50 degrees of heat up near redline.. And thats great. But, for most people who's car is their daily driver, not just their racetrack or dragstrip vehicle, the slug it turns into just cruising around on hot summer days is a real killjoy.. Thats why aftercooling is the only answer Ive seen that will address this issue.

As for the pressure drop you talk about, I trust you realize thats a much bigger problem with Air to Air intercoolers than with the water to air units most of us with Vortech units have... We lose what.. maybe 1/3 psi if that even. Hardly palpable on these setups.

[Brent 930]

I'm considering to switch from 6psi to 8psi after adding SnowPerformance WI kit together with SafeInjection controller.

In my country we have quite poor fuel quality- 91PON only (no 93 or anything with higher octane), therefore I can't switch to 8psi without WI just because of high detonation.

91 is the min., and the most offered around where I live. BUT, that isn't really the reason you can't go from 6 to 8psi. You will pull timing if need be based on the gas.

Sounds like WI isn't that big of a deal, I mean 50 deg. drop isn't bad but I would be looking for a 100 deg. drop if possible.

[GG///M3]

I wouldn't - the tune you have is for the air you're flowing. Adding more air without tune can spell disaster. If you must bump the boost, spend the $400 and get a decent WI kit to protect your investment. You'll actually have potential to make more power as well.

+1, and try and find a aftercooler

[LazyFox]

91 is the min., and the most offered around where I live. BUT, that isn't really the reason you can't go from 6 to 8psi. You will pull timing if need be based on the gas.

Sounds like WI isn't that big of a deal, I mean 50 deg. drop isn't bad but I would be looking for a 100 deg. drop if possible.

91 is a label, but it is actaully lower- detonation is killing.
W/I not only drop a temp, it does more

[Brent 930]

WI will also richen up the mixture, but only if you need it. I do agree the octane ratings are at the pump are probably a little lower.