yikes, hope you get that solved.

 

I COULDNT AGREE MORE!

 

Rim is 8 or 8.5" wide, tire is 10.5" which is within recommended specs. I double checked all tire pressures btw, so thats not the reason for the pull. I am not running tubes, I never did before. From what I understand-maybe coach can correct me if Im wrong, tubes only help stability slightly, they are more for running more consistent tire pressures. Its funny in that video on my 2-3 shifts the camera skipped and didnt record/see my arm shift lol, I am def happy the tranny gave me no issues!

 

btw-on my second run, my first 1/8 sucked so bad it was on par with my TN trap, but the car picked up 35mph the second half with a slow short shift to 4th gear, I want a clean run!!!

 

Bert You need a 2step like really bad. You were launching almost at red line. I was launching at 4500 with the two step and got wheel spin hard I'll post the video right now. As far as your floating... Well you got me, I am stumped. If and when you hook her up I think we'll see some 10's in low boost. I have no doubt. Have you considerd just running DR's (in low boost)? I know you can hit a 1.6 with DR and as long as they stick in 1st your golden.

 

Being smooth and using minimum steering input is key in any from of motorsport racing (if you want to go fast). Man handling the shifter may make you feel like you are getting the most out of the car, but it actually opens the door for you to make more errors and is unnecessary. Large sudden throttle changes should also be avoided. Proper chassis setup, and seat time will work wonders. The in car cam is a great tool. Was this your first time on a bias ply tire?

 

forcefed-Ive run the Z 30+ times on slicks, from NA to FI-ino the 11's with the TN set-up. I have already calmed down my shifting, I'll work on keeping steering input to a minimum, no offense to anybody but I dont want to shift slowly and keep it straight and run on par with everybody else's times.

Luie-Id have to order new wheels for dr's. I dont need a 2 step right now car is overpower tires already...

 

that was scary especially the 1st run!!

Does everyones tach peg out like yours when you shift? Just wondering.

What did you change from your 1st run with your TT months ago and did you have the same wobble at the time?

I don't know if it's possible to change back to your old slicks and suspension since you probably won't have enough seat time for the 21st with your new set-up.

Good luck with fixing your problem. What times did you run we all know these were crappy runs so share your times.

If you still ran mid-low 11's I consider that good even though you were all over the place imagine a clean run!!

 

Also are you boosting at the line since you have that module from KP.

 

It was pegging in 1st from the spinning, if you shift initially at redline it will bog in 2nd, it kinda did in my second run. I have another set of 26: slicks, but that would lead to issues with me hitting 5th, which is why I went with a taller gear/tire. Changing over to another suspension would throw my alignment off, and Id need to do that again, its awesome right now. I didnt have the wobble nearly this bad with the 11.5" slicks, stock gearing, JIC suspension with more negative camber, 1" taller sidewall may be part to blame. I wont share my times/traps yet, I'll share a "bad" run when Im 100 WOT down the track, otherwise no point.

 

Hey bert you can use my old 18,s with 245,s on the front if you need to.

 

Alberto,

Had another thought: you can induce additional understeer by modifying your sway bar settings (stiffer up front, less in rear). It may add some additional straight line stability.

EDIT: Actually while I'm at it, might as well provide the complete list to increase understeer...

Lower front tire pressure.
Raise rear tire pressure.
Stiffen front shocks.
Soften rear shocks.
Raise front end.
Lower rear end.
Reduce rear track.
Install taller front tires.
Install shorter rear tires.
Install narrower front tires.
Install wider rear tires.
Stiffen front sway bar.
Soften rear sway bar.
More front toe in.
Increase rear toe in.
Reduce front negative camber.
Reduce positive caster.
Stiffen front springs.
Soften rear springs.
Install wider rear wheels.
Use harder front compound if possible.
Use softer rear compound if possible.
Add weight to front of vehicle.
Remove weight from rear of vehicle.
Raise front and rear tire pressures slightly.
Roll centers may be too high.
Lower vehicle.
Widen track front & rear.

 

An 8 or 8.5 inch wheel is pretty narrow for a 10.5 inch real slick. The lack of wheel support could lead to induced sway in the back of the car... plus the rear tire will be flatter and get better bite with a wider wheel.

It's possible that the slicks are slipping on the rear wheels. It's unlikely, but it's worth marking the rear wheels and tires to make sure it isn't happening. Don't worry about this if you're running tubes, because the wheel would rip the valve stem out of a tube if it was slipping.

Like some of the people in this thread have said, launching a car with a lot of power and slicks makes the front of the car lighter. That makes the rear wheels steer the car. It's important that the rear tires have exactly the same pressure. You might need a more accurate gauge.

The plan is to have as little steering input as possible during a run. Steering loads the outside tire and makes the swaying worse. Your car is different now, it might take some practice to get used to driving it again.

 

this is why we run skinnies . radials in front and slicks/big DRs are a no no...

i about hit the wall and went into the other lane a few times, there is nothing you can do about it at these speeds.


WHAT did you run?? is my 11.2 guess on high boost looking about right...

 

you want the car to squat 1-3 inches and stay there..... whatever that takes

 

now you see why we take our power steering out and run skinnies.


that only happened a few times before i started making sure i did things to fix it, you really DONT need to be going down the track like that.


problem is more in your front tires, believe me , i know. the slicks are pushing your front tires out because of the traction, they are probably pretty wide so they grip well when they push them out.


those runs look very dangerous to me, i hope you get it all straightened out soon..!! (no pun intended there)

 

Jeremy, what would you suggest for front skinnies? I need 17" wheels to fit over my Brembos!! Anybody have any ideas? Id rather run the bias play slicks than step down to drag radials in the rear...I didnt have issues with my old setup on the short run I had previously done, Im going to look into my rear toe settings as well compared to my old alignment.

 

I didn't know you had Brembos...skinnies won't fit over Brembos so you'll have to go with the smallest radial that fits your wheels and fits over Brembos. I was talking with JT this morning and you might want to try a 225 or something close to that.

 

I can tell you by what the car is trapping in LOW boost your way off on this one