Impreza Track Preparation

Martin B · Post by **Martin B** » Wed Sep 17, 2008 9:52 am

I took my Impreza to the Nurburgring recently and there are a few issues I would like to resolve before the next Ring trip.
The car is a 2004 UK STI with 23k miles. It is running approx 330 bhp with an exhaust, fuel pump, air filter and remap.

Oil temps were hitting just over 120'C on one lap runs. I would like to get this lower, as I didn't want to take it on back to back laps without letting it cool first. Oil cooler should sort this.

Oil useage. On the road it uses no oil. On track it used 2/3L in 7 laps. I think it's getting through the breathers, so a catch can should sort this.

Wheel Bearings. Had quite a bit of pad knock off, and NSF was making a faint whirring sound on fast right handers. Plan to replace both front bearings as a precaution.

Tyres. Using Goodyear F1 Aysmmetric which are a good all rounder on the road. I would like something more track focussed. I think I've sourced some 17" wheels. The obvious contenders are Bridgestone RE070, Toyo 888 and Yoko A048's. Any recommendations appreciated, decent life preferable over saving tenths of a second.

Fire Extinguisher mounted by passenger seat. Just in case.

Obviously I can spend more money on losing weight & more power but at the moment the car is fast enough, handles predictably and the brakes are awesome. I want to cut the lap times by better driving instead of a bigger turbo.

Is there anything else I should consider to make the car more durable on track. I want to get the essentials right to protect the car from track use. It is my everyday transport, so fully stripped and caged is not an option!

Cheers,

Martin

duncan · Post by **duncan** » Wed Sep 17, 2008 10:10 am

Been there, done that

(all in my project thread/s if you can wade through them)

Oil Cooler - yes it works

Oil Catch Can will solve the breathing issue

Wheel Bearings - they are a weakness on 100 pcd imprezas. Just have to accept that they dont last long I am afraid.

Tyres - RE070 are the perfect tyre for the ring IMO. 888's and you will create other issues.

Extinguisher - good idea. Would be a shame to lose a car for the sake of

Martin B · Post by **Martin B** » Wed Sep 17, 2008 10:36 am

Thanks once again Dunk. Your threads are what got me thinking about all this. What are the issues created with 888s?

Swirl pot is a good call, I kept the tank above 1/2 full at all times on the Ring, as below that I even get fuel issues on the way to work.

Cheers

duncan · Post by **duncan** » Wed Sep 17, 2008 11:06 am

No worries

888's and you will get oil surge and starve the bearings and you dont want to go there.

Martin B · Post by **Martin B** » Wed Sep 17, 2008 12:32 pm

Right, that's the 888s off the list then.

Andy916 · Post by **Andy916** » Wed Sep 17, 2008 4:01 pm

duncan wrote:888's and you will get oil surge and starve the bearings and you dont want to go there.

?

I'd like to see figures before believing that oil surge on a standard-sumped Impreza happens at the max cornering force attainable by 888s but not RE070s! And, what happens if/when you spin on either tyre and generate an even greater lateral force?

I ran Avon radial slicks on a standard-engine classic scoob for a couple of trackdays, generating much higher lateral forces than on road tyres, and it had no bearing issues.

There's oil surge irrespective of tyre, the uncertainty is simply the point at which the oil-pickup suffers starvation. Better to address the issue rather than assume safety on a particular tyre IMO. That said, I've still got a standard sump on my latest Impreza.

duncan · Post by **duncan** » Wed Sep 17, 2008 4:19 pm

Agreed Andy, but track rubber will make it worse.

You were lucky or not driving fast enough

I have dealt with oil surge with the 06 twin scroll narrow sump and baffle plate (for the time being anyway)