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Discussion Starter #1
Hi all,

Really can’t decide if I should fit an intercooler or charge cooler to my rev 3 and hoping someone can help.

It is a track car with minimal road driving. Yet to have its first track outing with me, purchased a month ago and is currently with rogue.

The pros and cons to a charge cooler, as I see them;

+more resistant to heat soak, pre rad up front with lots of airflow, seems the mr2 should have had CC from factory? I have been advised this is the way to go for 20 min track day sessions, on the limit - no coasting.

- more failure points. Added weight. Not really fit and forget like and intercooler. Would an uprated intercooler suffice? On that point, interested to know what is considered the best, money no object, side mount intercooler solution. Spal fans?


Any help or guidance you can give me is appreciated

Cheers
Tom
(Sorry if this subject has been covered millions of times already, I found lots of contradicting posts)
 

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Discussion Starter #3
I’ve got no idea anymore

So many contradicting thoughts

50% of people - side mount is fine, even stick with stock intercooler and just trick fan to running non stop

The other 50% - water to air is a must for track use. Any side mounted intercooler stock or uprated is useless on track etc

I would ideally like to stay air to air as it’s more simple and less can go wrong

But if I am going to heat soak after 3 pulls then obviously I need a CC

Just don’t know which to commit to :(
 

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Unless you are using an ice canister, the only benefit of an air to water intercooler is access to the forced air stream at the front of the car. It will be impossible to match that with any rear mounted air to air unit without a very ostentatious air scoop. People have done that: Mounted intercoolers up above the cockpit, or sticking out to the side. However, I doubt that any A2A system mounted within the body of the car can match an A2W system in steady state performance, no matter what kind of fans you put on it. So this sounds like a matter of clearly defining your goals and your taste.
 

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A2W doesn't work well on track. There's an additional heat transfer step (boost > water, water > air), so for sustained usage it's hard to keep IATs down. A2W shines in drag racing (ice), and is generally pretty good for street driving.

Best bet is as much A2A intercooler capacity as you can manage, then run water/meth if you want to give yourself a large detonation buffer. But don't tune for the additional octane added by the water/meth injection, as you don't want to explicitly rely on it 100% to keep the engine together.


If this is about my earlier comments on running that much boost on track - I believe you were using a stock tuned ECU or something similar? That's the main issue with high boost on track, and the real reason high HP turbo cars were rare until the mid 2000's. The ECU/sensor tech from the 90s has things flying blind in open loop in boost. It's too easy to have higher IATs or something like that and the knock sensing to not even catch it (typically knock monitoring is turned off at high RPMs due to engine noise and the simplistic knock filters used at the time). The solution of the day was build the engines stout and keep the power output low, so even if you did get a little knock here or there in open loop, the engine was robust enough to shrug it off. Up the power by 40% with a stock turbo, run way higher IATs and higher exhaust back pressure and now you're MUCH more likely to knock under extended hard driving, and when it does knock, the stress to the engine is far greater than it was designed for. It just isn't a recipe for reliability.


FWIW, I tracked a few Nissan SR20DETs of various levels for quite a while. Using everything from a stock ECU tuned by myself, to an AEM Infinity. The stock ECU was fine, but I always had to turn things way down due to the open loop problem. I got in the habit of tracking the car at lower booster as a result, but in testing, the AEM Infinity made things much more robust and I could set the tune up so it'd automatically dial back boost and ignition timing, and add a bit of fuel as things got hot. Now granted, this was with a 24x12x3" huge FMIC, so IATs generally topped out at about 110-115 deg F (probably about 50 C ish?) on a ~95-100 F day (~40C?). By comparison, my SW20 with a FReddy sidemount will hit 150 F on an 85 F day in the course of 3 gears of pulls at 15-16 psi (~1.1 bar). That was with a TD06 which is far more efficient than a CT26 or CT20 at that boost, but even my EFR 6758 which is a step up in efficiency again still has pretty rapid IAT rises with a 7.5" SPAL fan going full blast.

So if you really want to track the car at fairly high boost (i.e. "high boost' for a street car), I'd give serious thought to a modern standalone. You can build in layers of protection that will emulate what's done on modern factory high HP turbo cars (i.e. let the thousands of engineers working on this problem daily give you a good guide on what to do for ultimate reliability). Those cars will alter boost targets, ignition timing, and fueling as needed. Plus you'll always have closed loop fueling control with a wideband which is worth its weight in gold.

I've personally had two hardware issues that would have smoked my engine without a wideband. One was a weak fuel pump, that was dropping pressure towards redline more as time went on. The other was an aftermarket FPR that wore the regulator seat enough that it's "closed" bypass flow went up enough to also drop fuel pressure. The AEM Infinity knew fuel pressure and the AFR due to the wideband, so it automatically compensated by tossing in a huge chunk of injector duty cycle to keep it safe. I didn't even know these problems were manifesting themselves in the car until I was looking at the data and shocked to see my normal ~65-70% IDC on track was more like 85-90% (also never run injectors flat out on a high HP car for this reason). The car ran exactly the same with the standalone, but a stock ECU would have smoked the engine both times unless I was watching the AFR like a hawk in boost.

Going a bit off topic here, but don't just think of the intercooling solution as "the magic bullet" to make a turbo car reliable on track. Take a step back and see what's been done in to high performance factory cars over the past 25+ years to make them reliable.
 

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A lot of variables...
You can be ok with sidemount on small tracks where a lot of corners and almost no straights, but will be overheating on track with a lot of high top speed straights...
I think you can need choose direction (a2w or a2a), fit temp sensors and look what you will think will be optimal for your car on each track you visit. I think it is always very hard on car when you go full throttle all 20 minutes even with upgraded cooler.

As for subject - i went big a2w, and i can say that at least for about 6 years i have no failure problems (it is more comlicated system of course but in terms of creating and fit to the car, but very reliable in action). So reliability not an issue here.
On my 400+ hp car - 2-3 laps and then tems could go up to 70-80 C (180 F) in the end of long straight. At such temps my ecu pull back timing and of course loosing power, but at least it safe for the engine...
I have never tried big a2a, so can't compare.

A2W doesn't work well on track. There's an additional heat transfer step (boost > water, water > air), so for sustained usage it's hard to keep IATs down. A2W shines in drag racing (ice), and is generally pretty good for street driving.
It\s changing with rear engine layout and so without any real direct comparision we can't say it will be same for mr2.
 
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