knonfs

"Chimikui" 20B NA + lots of Nitrous

http://www.worldsfastestcompacts.com/view_...0d42dabeb8e46bb



"Bam Bam" 13B NA miata + Nitrous

http://www.worldsfastestcompacts.com/view_...55c2ff05b4d542c

Trots*88TII-AE*

I don't agree with injecting Nitrous/fuel pre-turbo for 2 reasons:



1) The air pre-turbo has not been heated yet, meaning the effectiveness of the temperature drop won't be as high as if you were to inject it post-turbo (It would be like putting an intercooler before the turbo, if the air isn't heated yet, it won't drop as much in temperature)



2) Because it's before the throttlebody, as soon as you get off the throttle/boost, your BOV will drop it out to the atmosphere. I don't know about anyone else, but I'd rather not have misted gasoline mixed with Nitrous floating around my engine bay, especially near that 1000+ degree manifold... Meth mixed with water isn't as volatile, and I could see someone running one injector pre-turbo, and one post turbo for the best of both worlds.

heretic

But if the air is denser pre-turbo, that effectively makes the turbo larger, since you can fit more mass flow through it. It's like running on a really, *really* cold day. It's not about cooling the charge, that is what intercoolers are for. It's about making the air denser so the turbo can grab more of it and cram more of it into the engine.



For (2), don't run a blowoff valve. Simple.



Methanol wouldn't give the same effect since it isn't extremely below freezing when it is misted out of the injector, unless you're adding dry ice to your methanol tank (did I say that out loud?).

Trots*88TII-AE*

I think everyone running their cars on the street should have a BOV, it eliminates compressor surge/damage to your turbo. You can go ahead and run without one, but I wouldn't.





Really? You should check out BDC's alky injection on his street 13bt on teamfc3s.org and Howard Coleman's FJO meth setup on his REW at rx7club.com, both are getting IAT's down to or below ambient temp, and BDC was doing this with a stock intercooler at 23+ psi. And this is with Meth being used as an auxiliary injection as a substitute of roughly 25-30% of the fuel, the guys running straight Meth do get well below 0 degrees without an intercooler.

heretic

I don't think it is clicking.



By making the air denser PRE turbo, you effectively increase the mass flow of your turbocharger. This is something completely different than dealing with temperatures after the fact.







None of my turbo cars had a blowoff valve and I never suffered from turbo problems. Lots of other problems, yes, but never a problem with the turbo itself.



The compressor surge that happens during off-throttle is much different than the reverse flow that happens with an intake backfire, which IS damaging to the turbo.

Trots*88TII-AE*

I never said that you did. But, you're saying that compressor surge as a result of an abrupt closing of the throttle (and therefore creating an extremely high pressure ratio with minimal airflow) is not bad for the turbo? Don't know about that one chief.



Anyways, I'm new here, not looking to start arguments on turbocharging/heat transfer principles, so if you don't agree with me on all this, we can just leave it at that.