Front End topping out or Tire Bouncing traction lost

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The tires are Hoosier QTP 27" brand new. Before that was a MT ET Street Bias. The QTP seems to hook better but have a softer wall from what I experienced. It wads more than the MT's using the same launch rpm.

It was your post that I followed trying to get this dialed in. But the thread didn't have a conclusion on what you ended up setting your shocks/struts that finally got it to work.

I guess I didn't want to bore everyone here with every little tweak and adjustment I made along the way. Honestly, what 'works' always changes just a little bit depending on track conditions. I'd say my biggest improvements have come after learning what I want the car to do, learning how to diagnose what it's currently doing, and learning what changes I need to make to fix the problem. Here's a video I found a while back that I found to be really helpful with some of that:


I ended up swapping to a long style sintered iron 'slipper' clutch because every time I dumped the clutch with the RXT I was running it hit the suspension so hard that nothing was acting right. Not to say you can't get a good launch with a more conventional clutch.

In general I've fought the sidewall of the tire balling up on the hit. The stiff wall slicks definitely help here. In the videos I've taken you can actually see it unwind and then spin. After watching your video a few times it looks like you might be on the cusp of that, but I don't think there's enough weight transfer to plant the tire. If you still see a significant sidewall wrinkle after loosening the front shocks I'd consider increasing the tire pressure and/or tightening the rebound of the rear shocks.
 

Lady L

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I guess I didn't want to bore everyone here with every little tweak and adjustment I made along the way. Honestly, what 'works' always changes just a little bit depending on track conditions. I'd say my biggest improvements have come after learning what I want the car to do, learning how to diagnose what it's currently doing, and learning what changes I need to make to fix the problem. Here's a video I found a while back that I found to be really helpful with some of that:


I ended up swapping to a long style sintered iron 'slipper' clutch because every time I dumped the clutch with the RXT I was running it hit the suspension so hard that nothing was acting right. Not to say you can't get a good launch with a more conventional clutch.

In general I've fought the sidewall of the tire balling up on the hit. The stiff wall slicks definitely help here. In the videos I've taken you can actually see it unwind and then spin. After watching your video a few times it looks like you might be on the cusp of that, but I don't think there's enough weight transfer to plant the tire. If you still see a significant sidewall wrinkle after loosening the front shocks I'd consider increasing the tire pressure and/or tightening the rebound of the rear shocks.


yah ... I think I have the same issue you went through. I already have tightened my rebound a couple of times until I got to the point that my hit was lesser and the wadding minimal. That's what on the video. Initially, due to my anti-squat and a looser rebound, it hits the tire so hard and bounced right away. My final rebound adjustment is what is on the video, barely a rear tire separation which helps a bit. But what what bugs me is I still have that tire bounce although it was lesser compared to my initial rebound settings. But the minimal tire bounce still causing the tire to slip. Like what everybody suggested here, I'll try to do it but only one at a time. I just hope that I could get it solved right away before I'm going to break something in the drivetrain. This is the one that worries me the most :pissed1:
 
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Lady L

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Just an update ... was not able to try and do the changes as some of you guys have suggested. The track already closed for the season. I will try my best to update this thread the soon as I can try the changes but that won't be not until April of next year. Thanks for all the help.
 

86GT351

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Just an update ... was not able to try and do the changes as some of you guys have suggested. The track already closed for the season. I will try my best to update this thread the soon as I can try the changes but that won't be not until April of next year. Thanks for all the help.
Need to live in a warm weather state like i do. Racing all year.
 

Flusher

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lucky you ... but this is where I make my living which sadly supports this hobby :headscratch:

It could always be worse. You could live in a car-hating state that is in a hurry to close down all race tracks and develop the property into strip malls and track houses.

I'll tune in next season to see the outcome of this cliffhanger.
 

Lady L

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It could always be worse. You could live in a car-hating state that is in a hurry to close down all race tracks and develop the property into strip malls and track houses.

I'll tune in next season to see the outcome of this cliffhanger.


Pick your poison ... Politicians or Weather :cheers:
 

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