Intercooler Core Size

[gmh747]

Just wondering if a 115mm core intercooler would be too big for a garrett 35r on an rb30? Is more information required to answer this question? If so what information?

cheers

[paulr33]

it sounds plently big enough

i reckon 90 would be fine

theres only so much heat extraction the core can do

[gmh747]

it sounds plently big enough

i reckon 90 would be fine

theres only so much heat extraction the core can do

cheers, would the larger core cause any loss of hp as compared to a smaller cored intercooler or result in noticeably more lag?

[r33_racer]

Nope, the core on our race car which runs a 35r is 115mm thick.

[Ruff Ryda]

You will get slightly more lag. I went from a Hybrid RS Spec cooler which was 600 x 300 x 96 (or something) with 3" piping to a Blitz CS 622 x 265 x 80 and 2.5" piping. In terms of RPM and hitting fool boost, not much, maybe only 100 RPM.

However, on / off throttle response is amazing and noticably improved compared with the Hybrid. Haven't tried it in the summer yet though.

If it's for the the spirited street / odd track day then don't go anymore than 90 for sure, even 80 would be fine if it's an efficient cooler like ARC, Blitz or the Jap likes.

More information would be nice such as your intended use and budget.

[R31Nismoid]

Do you drive the race car around town?

A larger core will increase lag. Wether it's noticeable or not, depends.

If the VLt is auto/stall then it wouldn't be as much of a problem either.

Either way you won't lose HP.

[r33_racer]

His question was if its too big. No, its not too big. Simple answer. No there isnt any horsepower loss and lag difference is not even noticeable. We went from a 600x300x75mm pwr gtr cooler to an A.R.E 600x300x115mm gtr cooler and there is no difference on the dyno and no difference on the track. However, on the street its a slightly different matter, but my guess is it wouldnt even be noticeable there either.

No the race car isnt driven around town.

[gmh747]

cheers for the responses guys.

Cooler is a 600x305x115 and I already purchased it.. was a bit of an impulse buy but oh well... my old 75mm thick, 2 and a half inlet/outlet ARE cooler was starting to reach it's limits at around 23-24 pound - im guessing due to the inlet/outlet size and but mostly due to a quite a few crushed fins from retarded tow truck drivers over the years. As long as the difference in lag is minimal and I can run more boost I will be happy. I will eventually upgrade to a 42r anyway which will probably be more suited to the cooler.

In reference to R31Nismoid's comment, the car currently has a 2speed glide behind it.

I guess all I can do is see when fullboost is with my current cooler and then see what the difference is with the new one and keep you guys posted!

[r33_racer]

what brand is the new item?

[R31Nismoid]

hehe if it's got a glide then dw about it mate

[gmh747]

Fairly certain that it is a 5r Racing intercooler

[sucram]

cringe

[Ruff Ryda]

His question was if its too big. No, its not too big. Simple answer. No there isnt any horsepower loss and lag difference is not even noticeable. We went from a 600x300x75mm pwr gtr cooler to an A.R.E 600x300x115mm gtr cooler and there is no difference on the dyno and no difference on the track. However, on the street its a slightly different matter, but my guess is it wouldnt even be noticeable there either.

No the race car isnt driven around town.

On my SR20 I noticed a difference when going off / on the throttle but not much if any in terms of lag and hitting full boost.

It's important to consider the application for that reason above IMO, but it's not really problem if the core is larger. A larger one will tolerate more PSI anyway so long as the piping diameter matches up efficiently to the core so you're not running 2.5" piping on a 600 x 300 x 150 core when it requires a 3" pipe setup.

[RIPae86]

Core size and piping diameter I think has to match how much pressure your running that's what's affecting response. The larger core and piping will mean a slower velocity getting to the intake manifold and smaller core an piping will mean a faster velocity however, too small will affect power output as it may become a restriction.

Read somewhere that the inlet/outlet size of the turbo should be the base size you should start with determining the piping and intercooler core size for optimal

Don't ask me where I read that as I really don't remember, I read alot.

[r33_racer]

Corky Bell's book explains how to work out what size piping and intercooler to use for what horsepower you want to achieve. I remember it saying you need about 1.5 times the airflow to achieve your desired bhp. So 1000bhp would require about 1500cfm of flow. Also there was something about working out piping size based on keeping air velocity inside the tube under 450ft/sec otherwise drag and friction become too much of a problem past that point. It was something like airflow in cfm/ the internal area of the piping and then convert it to ft per sec.

[RIPae86]

Thats a good book thanks!