350+whp intercooler recommedations
 

Hello All,

I'm finishing up my build and the last piece I need to upgrade is my intercooler. I'm running a mostly kraken turbo kit with smaller ebay IC (21x5.5x2.5 inch core) right now and its sufficient for 250whp. Looking for something that will work in the 350-400whp range. I'm planning on maxing out my GBC22-350 and see how that does. Then eventually upgrade to a G25 or GTX2860. The car is just a street car that sees a lot of mountain runs so no track time. Not sure how much bigger intercooler i need for my goals.

Looking at the Treadstone TR6/8 or Fab9 stage 1/2. Which would you suggest?

Also, I'm running a 2" hot pipe and 2.5 cold. Is a 2" hot side going to be too restrictive for my power goals? Thanks again in advance.

Vibrant 12800 and 12810 are the cores fab9 uses and used to be half the price on amazon until recently. The fab9 units are a good buy if you dont want to fab brackets.

Stage 1 would be good for street use but I'd bump to the bigger stage 2 for the heatsoak of hard driving.

On my track car I just purchased the fab9 stage2 vibrant. I did a bunch of research and those cores seem pretty good for the price, a few years ago they updated their cores to have offset turbolators and they got a lot better around that time.

That stage2 core is surprisingly heavy though. Like wow, I could jack up the car using this thing as a jack point heavy. And mounted way in the front. The weight should be worth it though, after all it's a big chunk of aluminum and gives you lots of mass for heat transfer. I've yet to install my stage2, but I'm currently on an ebay FMIC with similar dimensions to yours. It did fine on the track at ~240whp, and OK for street pulls at 300+ whp but my end goal for the car is to have it track reliable at 300+ so it has to go.

I've got the Fab9 Stage1 350hp, it fits easily and you'll doubtfully ever need anything bigger, 300hp in an MX5 is ludicrous for MOST drivers.

The Fab9 Stage 2 is HUUUGE so will be a hassle to fit, is more expensive, is heavier and blocks your radiator completely from receiving ANY non-heated air (REALLY BAD ON A TRACK CAR;) it maxes out to 550hp which is AT LEAST 130hp more than you'll ever get close to using.

I'm not sure why ANYONE would want the Fab9 Stage2 intercooler in an MX5, it makes no sense to me (apologies to Fireindc, who's opinions/thoughts I respect, but I just don't think you thought your decision through enough on this one).

As for the "2" hot pipe and 2.5 cold. Is a 2" hot side going to be too restrictive for my power goals?" question, that's not an issue and is how most people plumb it; there's NOT a lot of space on the hot-side so 2" plumbing on that side is very practical.
Just avoid downsizing the plumbing between the turbo outlet and the TB inlet - continuous upsizing is OK.

I like this discussion!

I went back and forth on this one, and did a bit of research on how vibrant rates the cores. They are rated at crank HP, which is part of what pushed my decision to go with the stage 2 unit. At 310WHP that my car makes, it's already pushing over 350whp at the crank, so I figured I'd go stage 2 for some headroom down the road when I upgrade turbos.

Admittedly after receiving the stage2 core, it's bigger than I thought it would be and I've second guessed if it was the right choice. Comments like Lokiel's also makes me second guess that decision, as I don't disagree with most of the points he made regarding airflow to the radiator. That all said, with good ducting I don't think it will be a problem, especially with an oil cooler on the car.

Fireindc, thanks for receiving my "opinion" constructively. It is just an opinion and I look forward to seeing posts on your "real world" findings, that's what really matters and we all learn from (or not :( ) here on MT.net.

.

Of course, I respect your opinion as well. You've been around for a long time and always have reasonable comments/arguments. Hence my 2nd guessing myself now.

Particularly regarding airflow on a track car. I thought I'd just duct everything through the IC and it would work, but after some research I'm really thinking the rad's gonna need more fresh air than with the stage2 unit. So I might not be running this after-all, we'll see. And you are right that I didn't fully think this one through.

I appreciate all the input guys, after mulling it over, I think I'm going to go with the Treadstone TR6. It's smaller than the Fab9 stage 2 and rated for 400hp. It should be plenty for what I'm doing. It also like it will be a lot easier to install.

That's also what I was thinking about the hot pipe. There really isn't a whole lot of options to go bigger on that side.

Thanks again for the help

I initially used a vibrant 12800 and then when COVID hit and I started getting rich from the US govt I upgraded to a 34x6x3 atp Garrett core fmic. 34" is the most wide you can fit into the nose of an nb and it's not very tall so there is a surprising amount of room left above it for the radiator to get plenty of cool air. I think if you want a bigger fmic going longer not taller is the way to go fwiw.

​​​​​ Also I run 2" on the hot side and 2.5" cold side and I've made as much as 427whp so I don't think you'll see any restrictions there.

We have a track reliable high HP (400+) running the FAB9 stage 2 - highly recommend that one. Did the core support delete - the IC actually becomes that support because it bolts to the tow hook points. Run it extremely hard on 110F Texas summer days session after session with no heating problems. Also using a 21 row oil cooler and very tight air ducting.

Here’s a couple of pics to show how I did the IC and OC:

https://cimg3.ibsrv.net/gimg/www.mia...44bbf70ae.jpeg
https://cimg6.ibsrv.net/gimg/www.mia...9d3e6b873.jpeg

... have a poscat Turbomack, you've demonstrated that my 'opinion' isn't correct with appropriate ducting which is what this forum is all about.
Pictures appreciated..

For additional ducting, I added a diagonal duct from the rear-top of the intercooler to the front-bottom of the radiator so that heated air from the intercooler exits directly under the radiator.
Air entering the mouth of the bumper is highly pressurised and since the intercooler-heated air is no longer reaching the radiator, all air in the cavity between the intercooler and radiator is not pre-heated and is forced through radiator.
See Lokiel's intercooler/radiator ducting
FYI: My oil cooler is mounted in the cold-side wheel-well behind the fog light which is now used as fresh-air source into the DIY oil cooler duct.

I've done the core support delete too and it never occurred to me that "the IC actually becomes that support because it bolts to the tow hook points" so there's bonus points for Fab9 intercoolers just for that.