Do you by chance have pics or links of any setups that have worked well?

I don't have any datalogs from PPIHC this year. I put out an email to see if anyone else from our group might've caputured that.

Dave

 

Jeff, baro and fuel trims, remember.

 

Holes are for ALS?

 

Correct. I had AMS add 2 bungs to the manifold. I also have some of the JDM antilag parts, but never got around to fabbing it all up because the ECU I am running doesn't support rally style antilag. Hopefully I can find the $ to step up to an ECU that will this year.

Dave

 

love the swain coating good luck dave!

cb

 

I also got the JDM stuff for stock manifold...
wanted to try with an USDM Evo ECU, but seems can't run properly with Us spec...

I want to get a ALS close to the Gr.N for Tarmac use.

 

No I am all over the place. But I will be back for this for sure.

Mitch

 

So, some of you guys might've noticed a thread on rear mounted radiators. Its not a new idea, but its not something you see very often on cars in the US. Its immensly popular with the guys running in the Euro RallyCross series, and those cars have power outputs closer to my hillclimb Evo than most traditional rally cars. I'm not 100% sold on entering the rallycross events later this year, but I am searching for a way to solve my overheating problems.

After a marathon session of looking at Euro RallCross cars for inspriation, I think I'm going to make the jump. Hard to argue with making room in the engine bay (see first attached pic), and the other thing I'm noticing is that not all cars are using ducting in the rear quarter panels, which leads me to believe that its the ducting after the radiator (and a leaky interior) that's most important.

Dave

 

use the rear windows as air duc directing flow directly on the radiator and let the hot air exit by the stock venting flap!

 

Don't be lead to believe. You should create proper ducting coming in and out. Do it right if you do it. You need clear airflow paths.

 

I guess I mis-spoke just a little bit. I do plan on ducting on both sides of the radiator, but after looking at several cars with rear radiators, I've noticed that some duct on both sides, and some just on the back side. My largest hurdle in deciding to go this route was "can I get enough air back there" but cars simply running with their windows down are able to make it work, so adding ducting should mean a system will work even better.

With my roll cage design, I'm not sure if I'll end up pulling air from the window area, or if I'll cut into the door. The advantage to the door skin is that the rear fender arch flares out just a bit, so a NACA duct placed there will naturally have a "lip" built into the trailing edge of the duct. I know that NACA ducts don't need this to function...but I'm wondering if that'll screw things up, or make the duct function more as a scoop?

Dave

 

Don't add a lip, the NACA ducts function as-is. They are not scoops for a reason!

 

David do you know Stefan Verdier from rallying? (sure you do). He rear mounted his radiators in his drift Subaru and he was shocked how well it all worked and how much cooler the car ran with zero issues. I can put you in touch with him if you need contact info.

 

It was actually Stephan that deserves credit for really putting this idea into my head. We were working a Bridgestone Blizzak tire launch and were talking about overheating cars over dinner. He sent me a bunch of pics last week of his subie. His vents out the bottom of the car, but I think I'll probably vent out the trunk lid so I can leave room for a larger diffuser since the PPIHC rules allow it. To me, the biggest surprise about his setup was the fact that he didn't need to add an additional water pump to make it work.

Dave

 

I see a new EvoM trend starting