That is why I ask the question, People with different performance goals are going to have different thresholds where they believe the effect is worth the cost and effort. One thing I can do is find the formulas to give estimates on horsepower based on temperature drop. I will get them and post it. That info should be useful to have for other reasons.

I've already got SS piping. I'll probably use some of my upper IC piping and stick with SS for my new setup this winter, although if I was starting from scratch, I still think I'd switch to aluminum unless there was a measurable difference, on the order of 5 horserpower or more on my setup. It would probably take a decent difference in intake temp to lose that horsepower.

Alright,
All of you guys have been very helpful with all your information, I think that SS might be the way for me. I don't think I will be going into th 9s anytime soon (at least not with this car) Just looking for somthing that can support me in the upwards or 500+ hp. Like i said earlier in the post I might be going up to maybe a 50-56 trim for a turbo later, so somthing that will support that.
I think that I will call QPR to see about their prices for IC and piping and maybe a couple of others
Thank you all for the advise
If anyone else has any more info, feel free to post :D

You can call or come down anytime you like, there are a lot of options as far as pricing and what we can do. Just make sure you ask for Mike.

Well after digging and questioning a bunch of auto engineers, I can't find a better equasion to determine the benefit of reduced intake charge exactly. The old standby of 1% power increase for every reduction of 10 degrees was confirmed by several engineers for me at least for a N/A application they said if anything it was a bit conservative. We actually stand to benefit more from it from a standpoint of being able to run more boost with less knock so the gains should be a bit higher than 1%. I am still harrassing them for more info and getting their viewpoints on the piping, I will post that info when it is all settled.

Don't you think if it is 1% @ 1 bar that at 2bar it would be more like 2% or even 3% .. and at 3bar it would go higher than 3%...

If he was talking about NA which is going to be non compressed, less dense.. that if you drop the temp of denser air by 10degrees it would make bigger difference than non compressed air.

-E

I am thinking that intake temp may effect a boosted car less than an N/A car if you go on a straight degree-by-degree basis since the intake temps are already so much higher. My personal opinion is that it should be looked at as such: A X% drop/rise in intake temp will yield a gain/loss of Y% hp.

It will definately have a larger effect on higher boost levels, how much is hard to figure exactly. Some vary carefull testing will need to be done to get accurate info. The truely telling tests will have to wait till spring at the trac since that is where the performance gains are desired and under those conditions. I am bugging the engineering groups into telling me their opinions on the effect in our situation considering the speed of the charge etc as well. By the time this is done, we should all be a little smarter.

Since it is already a percent, I don't think it is going to drasticly rise with more boost. It might go up or down some, but I don't think it is going to double or triple. I don't see big HP changes on the dyno when my intake air temps are 10 degrees higher, not anything like a 3%(20whp) change at 3 bar absolute if the temp is 10 degrees different. I would like to try some drastic cooling of the intercooler with nitrous or CO2, but it would be hard to get 100% factual results with the CO2 or nitrous contaminating the surround intake air. I guess, if you can get a big HP gain with CO2 then you know it's working, since sucking in CO2 should kill HP. Jason Siebels, the guy who designed the Pro-EFI and AEM EMS standalone doesn't even run an air intake temp sensor on his turbo MKIV Supra. He thinks it is not nearly as important on a turbo car compared to an NA car. I don't know why.

If I remember right, Corky Bell's turbo book has the formula in it for boosted applications. I don't have it here in front of me, but that's probably a better place to start than all of our guesses.

Once we get some more solid info, this post should definitely go in the Good Stuff forum. Sorry anuindlight for the post getting jacked. ;)

Alright, I got a n00b question to ask. I plan on running a 14b/16g sized turbo sometime in the near future, and I have a chance to pick up an Evo8 FMIC. Would you guys reccomend this Front mount for that turbo size? I'm not shooting for 11s or anything, at least yet. Sorry if this totally screws this thread.

This thread was screwed long ago haha. Mods should cut it up and make a new topic out of all the theory talk.

At a certain point in a balls out application I think it is easier to pick up 2, 3, or 5 hp compared to the difficulty of dropping even a couple pounds. For something the size of an intake manifold especially, I would want aluminum.


Another thing I have to add is that aluminum is much better than SS at transfering heat, thats what all this discussion is about. But consider that it works both ways. Heat may be transferring out of your intake charge. When I touch my IC pipes after a run, they are often hotter than the ambient engine bay air. I assume the engine bay air is probably cooler yet when moving at 100+mph. Of course, the better your IC is the less you have to take this into consideration.

Re: buying an Intercooler
 

I can see it both ways, but after thinking about this, I'd bet the difference in charge temp between SS and AL piping would be a small fraction of a degree, due to the relatively small amount of inner surface area of the piping.I recently bought a bunch of various temp sensors to put in a number of different locations including IC inlet/outlet, turbo outlet/inlet, TB and to measure ambient temps in various locations.These are going on my new car/engine/setup, and I have a generic logger that will log all info and graph the results.I suspect in most setups, the intake charge will on average be hotter than ambient around the piping anyway.I also suspect the thermal insulation qualities(or lack of thermal insulation qualities) of piping material will effect flow, via different inner/outer viscosities of the layers of the intake charge, more than it will effect mean charge temp.

Re: buying an Intercooler
 

This theads theory talk is pointless now. Testing is obviously the only real answer to solving the mystery and it sounds like I won't be the only one doing it. The numbers will tell the tail.