I am running MT Slicks 26 X 8.5 X 15
Seems like at the top of 3rd. (around 100 MPH), it becomes unstable. So much that it scares the crap out of me!
Ssomebody mentioned it is because I am running radials on the front and bias ply on the back.
Anybody know anything about this?

 

Don't run radials with bias ply.

 

Even if you run a drag style tire up front, your car will still be wander all over the track. And people say it's not hard driving in a straight line


Get used to it man, it's normal.

 

Great! I see other cars that don't have that problem. Wonder if it's the way the rear suspension is setup???

 

To the unaccustomed the rear end may feel floaty and like it's not following the front, especially with the low tire pressures run in the rear. Mostly it's not as bad as you think, it just feels disconcerting.

 

Every car that I've driven with ET streets wander. You can't see it when watching but you can feel it when driving.

 

try running more tire air pressure.. what are you running for tire pressure currently , before and after a run?

 

yea check your psi my bmw liked 6.5 psi any more and it spun them and any less and it got a good wobbel on

 

yeah when I ran on my slicks the car would move around in 3rd in 4th

make some more passes takes a while to get used to it.

what kinda times did you run? what was your air pressure?

 

yeah I have to agree with that

 

I was running 20 PSI in them!! I was afraid to lower the pressure after that. Only got one run in with them. I'm thinking, I might have been rubbing on my struts.....will check again this year at Test-N-Tune.
This is my run. I lifted at the end. Should have been well over 115 MPH and high 11's with this run. Oh well...shoulda, coulda, woulda!!!
http://www.idahorotary.com/3amigos.wmv
BTW...I'm the first car...Black FC

 

WTF MUSIC

I run around 12psi in my ET Streets.

 

yeah you need to run 12 - 14 psi in them

 

nice vid!!

 

The same thing would also happen to me. I changed from a 11.5 to a 10.5 on a 16inch rim and that helped.

I felt the most comfortable when I removed the power steering. The issue was only going from 3rd into 4th.

I would run like 13psi cold and when it was warm it would be around 14-15psi.

I've tried different tires up front but will try skinnes and see if that helps.

If you get the new MT ET Street Radial, you will have no issues whatsoever. They are the same compound as the MT ET Streets but with a tough radial ply tire and a very stiff sidewall.

I tested them this past weekend, turned the boost down to about 500HP and this is what happened..... I am going back to the Et Streets and just get used to the swaying up top.

Anthony

 

Ouch.......... you broke both axles? Same pass?

 

Yes, same pass.

The event before this last one I destroyed the 4.33 gears but the Kaaz has held up perfectly.

After talking a few friends on here, I think its a combination of high HP, puck clutch, launching too hard on the limiter and the radial ply sidewall.

I then launched earlier and easier and the same thing happened. Im going back to the ET streets that I used prior with no issues.

Anthony

 

Yeah, I was always told that ET Streets or Slicks were always gentler on the drivetrain than Drag Radials......

Good thing I never have to worry about breaking rear-end components.

 

Built like a FORD! Mine is going in late this summer.

 

too bad you'll have a pos irs

 

Can you post some pics of your rear from the bottom?

Also, did you consider going with an independant rear instead of the solid?

Thanks,

Anthony

 

I'll post pics tommorow. Why would I go with a IRS? How many drag cars do you see running IRS?

 

It depends on why you are building your car. If you just want to run down the quarter mile on a test and tune, then use a solid axle rear but if you build your car to compete in an NHRA class at NHRA events, you cannot use a solid in the class you will be competive in.

As for drag cars running IRS, just look at 99% of the drag cars in the Sport RWD NHRA class, they run IRS.

Post the pics when you get a chance, sorry to hijack your thread.

Anthony

 

Those cars run IRS because the rules say they have to. What do you think they would be running if solid axles were allowed

Lets get real now, how many of realistically plan on being competitive? I'm not interested in that......... I just get a kick out of beating up on the locals

These pictures are old so they might look funny.

 

I guess IRS is bad for autocross and road racing.......... right.

My car is a street car, not a full out drag car like yours. That is why I opted for the 8.8 IRS.