I am sure this has been discussed before but a quick search didn't help much.

I am going to keep the stock turbo (don't ask) but do many other bolt-ons (HKS 264s, 3" TBE, MBC) and a flash to get me around 325whp. The car will see lots of extended road-course track use and am I worried about head-soaking the stock FMIC.

My plan was to go to a large FMIC (maybe around 24x12.5x3.5" core) with nice hard pipes all around but I am worried that such a large IC will hurt response and incrase turbo lag with the stock turbo. Is this a vaild concern or will the large IC have no affect on the spool-up time?

How many of you are running stock turbos with big FMICs?

Very Interesting post, I was wondering about that too. I meet an Evo owner in Watkins Glen raceway and he was running the large Buscur Intercooler with the stock turbo. His EGTs were nice and low on pump gas map, but he had a lot of other bolt-on mods too.

I think a lot would depend on the psi drop, but I know nothing about turbo cars that I haven't learned in the last 7 months.

with the bigger I/C the pressure drop would be more pronounced (depending on core size and endtank design) A good fabricator can minimize the amount though.

I don't think it will hurt too bad though.

I have the Buschur kit and they claim less than 1psi pressure drop. I tell you, I have heard the discussions to but all I can say as after the install the car seem to spool better and run harder. Just my 2c.

i have a 'hybrid' intercooler (bar and plate design) that was kinda controversial a while ago because there wasnt much testing done with them on evos(also it was universal 31"x12"x3" with 3"inlet and outlet). they claimed a .8 of a psi drop. i didnt do hard fact tempurature testing on upper ic pipe from before and after. but i did do the hand test(after long hard drives or hard runs touch the upper ic pipe before and after change out). the result was dramatic. after 30 mins of harder driving before the upper pipe was heat soaked (i have aftermarket aluminum ic pipes); with the large ic it was cery cold... like i had put the upper pipe in the refrigerator for 3o mins! the point is it will flow better, and be much more efficient than a stock ic. you will need one.

I bet a well designed aftermarket core with nice hard-pipes won't have anymore pressure drop than the stock FMIC, but the turbo still has more volume to fill before the boost pressure reaches the intake manifold. Am I over-thinking this or can the large FMIC still hurt spool up time?

there's no way ANYTHING under your hood was cold like it had been in the refirgerator for 30 mins, especially after spirited driving

Intercoolers do make a difference in air intake temps. and most good ones have <=1.5psi drop. don't be fooled by obvious exaggerations though.

with some, (buschur, rnr, etc) the hardpipe take a much more direct route from turbo outlet to intake man. this will aid in spoolup counteracting the increased volume

maybe not as cold as 45 degrees or so... but cool to the touch, yes much much much colder than stock. with any ic core if you are sitting it will heat soak. if you have a good ic core with cold air rushing through it and the car is moving, yes it will stay cool.... A*SS

I had pretty dissapointing results with an upgraded fmic on 340whp stock turbo setup. I had hotter intake temps with the big bar/plate intercooler than I did with the stock IC.

IMHO I woudn't upgrade the intercooler untill your about ready to change the turbo. Up untill that point your money is better spent on other parts.

Maybe for drag racing, but he is apparently into track events and for that cooling mods are everything. I run a few track events a year myself and an oil cooler and bigger intercooler are high on my list for longevity and consistancy reasons.

I doubt the upper ic pipe will stay cool to touch because of bigger fmic. The air that travels through it might be close to outside temp but the pipe itself would have heat soaked just like the intake manifold.
Come on the ic pipe is in the engine bay right next to the engine and connected to the throttle body which is pretty hot to touch. If the upper ic pipe was cool to touch than the throttle body and the intake manifold would be cool as well.
But the first bottom half of the upper ic pipe does stay cool since it's away from the hot area of the engine bay and the other half next to the battery will stay warm to hot.

good discussion, I don't really know the answer to this question, but i am enjoying reading what people have to say on this issue.

If I were you I'd get the bigger FMIC. I think it will hurt your spool but on road courses you aren't going to be off boost in the low RPMs much anyway, so it won't make much difference and it might help your top end. I agree that you need all the detonation protection that you can get in that environment.