Intercooler size

[obi_waynne]

Any tips pointers or rules of thumb when choosing the size of an intercooler?

I'm guessing there is an optimum flow rate for each power level you tune for. Heat soak also comes into it.

Bigger is not always better but does that apply to intercoolers?

 

[old-git]

Well.... I have this piece of string in my pocket, all you have to do is guess its length

So many variables; engine power, available air flow, ambient to underbody temp difference, available budget, pipe lengths, available space, etc

A quick google search found this:

http://horsepowercalculators.net/intercooler-calculator/intercooler-calculator

Unless you are building a car that a lot of others have done, you have to rely on expert advice coupled with your budget and the space available.

Yes, you can go too big. The more air you have to move the more lag is likely. However, this isn't quite the case when drag racing. Once boost is built up the whole race is done under full throttle so the turbo is kept at full tilt reducing the chances of lag.

 

[HDi fun]

Space is likely to be the biggest constraint; there is rarely room to fit an intercooler that is too large.

 

[TCJBOLDIE]

Interesting site. I see my Aussie cooling guru ARE is mentioned

 

[griffindai]

I think you can go too big but have always fitted the biggest I can without too many hardware changes. On the 9000 I fitted a Chinese ebay 3" IC with decent results. Miles better than the more expensive Abbott Racing one I had in there but this was with a GT3076R running around 480hp, so the AR IC got heat soaked pretty bad at this stage (was fine up to 300ish though) 2 WOT pulls and it's done, the Ebay one could get 6/7/8 continuous hard 60-100 & 70-120 pulls and still be ok, made a hell of a difference tbh, no extra lag just off like a rocket
Just needed a few extra pipes to fit and all in cost around £130.

I've bought another one for this car but the Chinese evo style as its almost a drop in fit, this ones 90mm thick so should be fine for my power level.

I'd price/size up some of the ebay ones and see what you think

 

[old-git]

The Chinese ICs are OK as long as you aren't looking for optimum performance.

 

[hairy]

I think you can go too big but have always fitted the biggest I can without too many hardware changes. On the 9000 I fitted a Chinese ebay 3" IC with decent results. Miles better than the more expensive Abbott Racing one I had in there but this was with a GT3076R running around 480hp, so the AR IC got heat soaked pretty bad at this stage (was fine up to 300ish though) 2 WOT pulls and it's done, the Ebay one could get 6/7/8 continuous hard 60-100 & 70-120 pulls and still be ok, made a hell of a difference tbh, no extra lag just off like a rocket
Just needed a few extra pipes to fit and all in cost around £130.

I've bought another one for this car but the Chinese evo style as its almost a drop in fit, this ones 90mm thick so should be fine for my power level.

I'd price/size up some of the ebay ones and see what you think

hello there if i may ask a question. did you have the car retuned? after installing the bigger intercooler? or just fit the new i/c

 

[griffindai]

No probs. It's been a while now but I think it dynod 416bhp a few weeks after it was fitted, then remapped again a few months later plus changed the forge actuator spring from blue to red and got 450bhp. Still the same, no heat soak after a load of continuous wot runs.

We didn't dyno with the Abbott IC but the difference on the road was night & day.

I'm not sold on these expensive IC's anymore. Plenty of the guys in Saabland have fitted these chinese ones now and haven't heard anything bad, some pushing around 500hp

 

[hairy]

No probs. It's been a while now but I think it dynod 416bhp a few weeks after it was fitted, then remapped again a few months later plus changed the forge actuator spring from blue to red and got 450bhp. Still the same, no heat soak after a load of continuous wot runs.

We didn't dyno with the Abbott IC but the difference on the road was night & day.

I'm not sold on these expensive IC's anymore. Plenty of the guys in Saabland have fitted these chinese ones now and haven't heard anything bad, some pushing around 500hp

hello there so for it to be able to be succesful to instal the intercooler without a tune am i correct that the computer will automatically adjust to compensate for the new intercooler

 

[SLEEPER]

Some ecus certainly can change the air fuel ratio and ignition on the fly but none can change the amount or air any turbo moves at any given rpm.
You may well be able to keep the mixture and ignition right but you can't change physics . A bigger ic will take longer to spool up because the turbo has to shift more air to get the same boost level because the system is bigger. This must take longer if you are off full boost.
This may not notice on some road cars with relatively small turbos but it will be evident driving a highly tuned motor where you cannot keep the boost level up. As og said drag racing is different because you can stay on full boost for 10 seconds( ish) when going in a straight line.
I fitted a bigger ic to the stagea as was told it would help and the result was more lag. The link ecu keeps keeps the afr ratio the same ( I have an afr gauge to confirm this ) so the cars runs as smooth but there is more lag.
Conclusion the ic is too big and the ecu can't compensate