High G cornering issue....

[Dr. Apex]

Hey folks, looking for some input from anyone that has autocrossed or road raced their FiST. I just attended my 2nd autocross yesterday and for the 2nd time I had a lap where: While in a long left hand sweeper the car started "Clattering" and "missing", blowing a good amount of black smoke out of the exhaust when this happens and there's a distinct, intermittent loss of power coinciding with the clattering noise.

At no other time have I had this issue but as described. It only seems to happen for about 1 lap though I changed my line to more of a diamond on it to lessen the side load on the car after. It seems to me like a windage issue, possibly the oil in the pan being pulled away from the pickup while cornering which is bad news if it is and many cars over the years have had this issue. My oil level is spot on the full mark, I'm wondering if there's too much/too little oil in the engine?

Anyone else had this issue or have an idea of what might be going on?? The car runs perfectly normal at all other times. I think I got the lap on video but not sure if it can be heard/noticed in it at all, will post up later if it does.

TIA,

Ben

 

[Dr. Apex]

Listen closely at about :48 secs and you'll hear it. https://www.youtube.com/watch?v=Im5ZWvF1mIk&feature=youtu.be

 

[razorlab]

Could be fuel slosh issue. The Evo's get that with high G corners on good tires as well. It's actually a pretty big problem for the track guys and you have to end up getting a secondary pump and fuel reservoir.

Basically all the fuel goes to one side and starves the pick up.

Does it only do this while on throttle? Are you logging the car?

 

[razorlab]

Listen closely at about :48 secs and you'll hear it. https://www.youtube.com/watch?v=Im5ZWvF1mIk&feature=youtu.be

That sounds like detonation. I bet you are going lean from fuel starvation. Do you have the ability to log the car?

What tires are you using? Does this happen with a full tank of fuel?

 

[Dr. Apex]

Yes only on throttle. No logging. Showroom floor stock other than a dash mat. This event was about 3/5 tank, just above half. Last event was less slightly. Going to go full tank next event for sure.

 

[razorlab]

Yes only on throttle. No logging. Showroom floor stock other than a dash mat. This event was about 3/5 tank, just above half. Last event was less slightly. Going to go full tank next event for sure.

Hmm it really shouldn't be getting fuel starvation bone stock since it doesn't have a ton of lateral grip. With sticky tires I can see it but not stock but that really sounds like detonation to me unless you also happened to run over a bunch of pebbles in that section of the course . I would think if it's a fuel tank issue stock it would have been noticed in all the performance reviews and for sure with some of the guys tracking the car.

I would say run a full tank and see if it does it again. You could probably replicate it in a big parking lot if you can find one that won't attract too much attention.

 

[Dr. Apex]

Hmm it really shouldn't be getting fuel starvation bone stock since it doesn't have a ton of lateral grip. With sticky tires I can see it but not stock but that really sounds like detonation to me unless you also happened to run over a bunch of pebbles in that section of the course . I would think if it's a fuel tank issue stock it would have been noticed in all the performance reviews and for sure with some of the guys tracking the car.

I would say run a full tank and see if it does it again. You could probably replicate it in a big parking lot if you can find one that won't attract too much attention.

Agreed, a fuel starve issue with that much in the tank would have been noticed by others by now unless it's just something off in particular with my car. It wasn't pebbles, it made that noise in 3 different places on the track turning left at 2 different events. Though I'm on stock tires it manifests primarily on the banked left hand sweeper, several seconds of lateral load while at or near full throttle.

Very annoying being such an intermittent issue.