For the past two months I've been trying to pick out an intercooler. I don't like any off-the-shelf options offered for our cars (ETS, VSRF, PR), so I've decided to go custom. Through research, I found the big names in core suppliers are Garrett, ETS, Bell, Precision, and Treadstone. Of course, everyone on the internet has an opinion and I've seen all of these cores rated anywhere from the best to the worst, but I have consistently seen the Garrett praised above others, although it does utilize a high density core that blocks more airflow to the radiator than other cores. Evo's have no problem with this, being designed from the factory for a fmic, but DSM's have supposedly had overheating issues due to this in the past. This is the reason that ETS has a lower fpi count to allow more air to the radiator, but the cooling of the charge air is (debatably) inferior.

I feel with proper ducting (including a path for air to bypass over fmic and straight to radiator) there won't be a high likelihood of overheating, but of course it remains a concern. Even still, I think a Garrett core is the best choice for my car. The car is used for street, drag, autox, and road racing. I'm currently on a t25 but a 68HTA is waiting to be installed, and will likely satisfy my power goals for a long time. I can see a point in the future where I might upgrade again, but honestly can't see myself going with a huge turbo (let's just say a 500hp max).

I never like to upgrade parts twice if I don't have to, but it is inevitable sometimes when trying to build an efficient and matched car. If I followed the never-upgrade-twice route, I'd just throw a 4" core on and be done with it. But there's no need for that on the little turbo I'll be running.

Considering all the spatial and power requirements, this is the constraints I have determined:
Length: 24" to 26"
Height: 9" to 10.5"
Width: 3" to 3.5"

Like I said before, I don't like the off-the-shelf options (mostly due to end tank design), so a suitable core must be found to meet these requirements. Garrett offers the following sizes that meet the requirements:
24x10.5x3.5
24x12.1x3 (which I would cut the height of to whatever I want)

These are the suitable end tanks I have found to work with the core choices:
12" Tall x 3.5" Thick, 2.5" Outlet Cast Aluminum End Tank : atpturbo.com
(can be cut down to make 11x3, and modified further to fit whatever height I need)





TR11 Intercooler 560HP- TREADSTONE PERFORMANCE
(if sold separately, needs modified some for shorter height)



Treadstone E1053 Intercooler Endtank- TREADSTONE PERFORMANCE
(3.5" thick, very nice design IMO, 3" inlet/outlet however)



3.5" thick:
Cons:
Harder to fit in bumper / with tow bar
Blocks more airflow to radiator
Perhaps not as matched to small turbo as 3"

Pros:
Really like end tank for 10.5x3.5 core
It seems like any "big boy" fmic upgrade is 3.5"
Superior charge air cooling

3" thick:
Cons:
Potentially not good enough for power goals? (Doubt it.)
More work/money to make end tanks work and don't like end tanks as much

Pros:
Easier to fit in bumper/with tow bar
Better flow to radiator
Can cut down shorter to 10" to get more airflow to radiator and make packaging easier



I've been unable to make my mind up for months, so I'm looking for any advice and constructive criticism that can help me decide I'm leaning towards a 24x10x3 Garrett core with the Treadstone TR11 end tanks (with a baffle on the inlet tank), but I'm open to any opinions and discussions. And if anyone knows other sources for end tanks that would fit the constraints, please share.

A friend of mine made a custom FMIC for his Supra with the treadstone 1235/1245 end tanks. They are very nice pieces, I like the fact they divert air to the entire core.

I built an awesome top to bottom flow intercooler for my dsm. Used a spearco core and it was cheaper than even the vfsr and other cheap ass kits. Sadly I sold the car it was in but it outperformed my eta kit as far as intake temps and I never had a problem with keeping the car cool. I would have temp as low as 10-11 degrees over ambient. Btw this was on a 20g trying to hold 32-33 psi, so it was making a lot of heat vs. a large turbo. Iirc it was spearco 221 core. Going top to bottom leaves you with short piping too. Only about 2 feet total in the system over a smic setup-which is pretty short piping.

It u look at the fastest and most powerful turbo cars in the world- a lot of pro 5.0 racers and such, they almost all run top to bottom cores. The only reason I have an ets race on my car right now is because it was sitting in my garage. The top to bottom more effectively uses the cores frontal area and does not force all the air to make a 90 degree non tubular bend.s. I'm not saying the traditional kits aren't any good btw.