Bigger radiator for a 91 turbo legacy

[LucyFord]

I am looking for a stock-looking larger radiator swap into our 91 legacy turbo. Would something like a STi radiator work? I would prefer to not have to buy aftermarker fans ethier. I did I quick search on this (on both NASIOC and here) and the only thing i found was some bliggy aftermarket solutions.


Thanks in advance

[dscoobydoo]

Sorry, but stick with stock. Many of us bought the koyo radiator as it was bigger, but ALL of them had serious failures. ( even my Koyo, after 2-3 years, finally took a crap.)

[asotwavb]

Stick with stock! My aftermarket started leaking too

[wtdash]

Hi, Why do you need larger?

I ran my '90 Legacy turbo swap (535cc/TD05-16G) on the stock NA radiator (smaller than SS) for 3 years and never had an overheating issue....that includes Auto-X sessions in 90° heat.

Td

[kleinkid]

My Koyo radiator is fine, probably six years old. There are others that are sized like Koyo.

http://www.mishimoto.com/mishimoto-suba ... turbo.html

[LucyFord]

The vehicle is going to be used for endurance racing. I understand that it's a slight overkill but rather overkill it on the cooling side when it comes to this type of racing. I have been burned by running a "undersized" radiator before and haven't gotten the taste out of my mouth.

The koyo is too bliggy. I need something more "stock" looking that wont bring attention.

[evolutionmovement]

You could paint it black. Can you duct airflow through the radiator? That could increase efficiency without changing size.

[Legacy777]

There really is nothing that is between stock and the larger koyo. The newer style radiators from the WRX/STi will not work.

For what it's worth, the cooling system on these cars are extremely over designed IMO. I too had been running a non-turbo radiator with a turbo motor that was making close to 300 chp, and it provided excellent cooling, even in the Texas heat. The one thing I would recommend and probably has helped me is running something like Redline water wetter. It helps get rid of some of the surface tension between the engine/radiator surfaces and the water. This improves heat transfer.

Short of getting something custom made for your car, I would also suggest sticking with the stock radiator. If you want a little extra cooling, add some Redline Water Wetter.

[LucyFord]

Well i got the car to overheat during a race. I am not a fan of the Mishimoto's price or the rep of the Koyo. Looks like I will try to wedge a STi one in.

[jefferson]

Something I would do is make sure all the air that goes in has to go through the radiator. I made a cooling plate for the top of mine and used some of that stick on foam tape for the sides. I don't endurance race mine though. I may be wrong, but I think the 100,000 km record setting cars had stock radiators.

I second what Josh mentioned about the redline water wetter. If the car isn't going to be in freezing conditions use distilled water with the water wetter. Water will cool the car better than an antifreeze mix.

Jeff

[Legacy777]

How old was the stock radiator?

What was your water/antifreeze percentage?

When did the engine overheat? Can you provide some details as to whether it was a gradual climb due to increased engine use/load or did it go up rather suddenly?

[LucyFord]

100% water per the rules

Engine overheated about 6hrs into the race when ambient temps rose to 95+. The car really starts overheating in the draft. I don't have these issues when its ~70 outside.

Radiator fins/finish looks suburb. I already have a cooling plate on top of the radiator. Not on the sides thought (pretty hard to package).

[Legacy777]

Was the overheating a gradual increase or ramp up quickly? If you got some fresh air to the front of the radiator did the temps come back down?

What sort of engine rpm and load/boost are you running when you're in the draft?

Have you thought about adding some ducting on the side of the bumpers to bring high pressure air in towards the radiator?

[LucyFord]

Well i don't have a data logger so this data is pretty hard to obtain. It would quickly ramp up in the draft. But it was a gradual thing (6 hrs into the race). If we got out of the draft we would be slightly above the half way mark on the gauge (stupid C-H gauges) . But honestly it seemed to be bad everywhere but the worst at ~5500 RPM at 0.1mpa (maybe that just because it were there was time to look). Yeah, changed around some stuff to allow more air flow which helped but didnt solve the issues.

Moral of the story i need a bigger radiator.

[jefferson]

I should have known you were running straight water as sanctioning bodies don't allow antifreeze. I don't know what I was thinking. The foam sealing tape was real easy to do on the sides. I think I did it with just leaning the radiator back, but you might have to move the bottom too, I just don't remember. It was so easy I couldn't believe it wasn't done at the factory.

Jeff