Help with 60' times...

[jsta6]

Before:
Stock 87GN rims
265/50/15 street tire (not a DR)
stock upper and lower control arms
stock rear sway bar
no air bags
30-35lbs air pressure
1.7 60' times

After:
17x8" aluminum rims
275/40/17 Nitto 555 DR's
Stock Boxed upper and lower contorl arms
ATR rear sway bar
no air bags
20-25lbs air pressure
2.1 60' times

What gives?

 

[SPOT MY 6]

17" rims with low profile tires (even though they are DR's).

That is your problem.

 

[bwallace]

I agree! No sidewall

 

[jsta6]

Thanks guys!

I am going to switch from 275/40 DR's to 275/50 street tires when my DR's run out.

Any suggestions to help my 60' in the mean time?

 

[ross87t]

Originally posted by jsta6
Any suggestions to help my 60' in the mean time?

Yeah. Lower the tire pressure to 16psi, and heat them up well.

I'm pretty amazed w/ the 1.7's on non drag radials.

 

[jsta6]

I just got a line lock that I haven't installed yet.

I couldn't do burnouts before.

But I am more worried about my street times (with the g-tech) then my track times.

The thing is, I can't do John Force type burnouts on the street.

 

[ross87t]

Originally posted by jsta6
I just got a line lock that I haven't installed yet.

I couldn't do burnouts before.

But I am more worried about my street times (with the g-tech) then my track times.

The thing is, I can't do John Force type burnouts on the street.

Don't forget...your tires are usually a lot warmer on the street, because you have been driving on them. At the track, they need to be heated, because you only drive a 100 yards or so from the pit to the staging lanes. After you have sat in the staging lanes for a few minutes, your tires have cooled down.

Ross

 

[TKGN1]

sidewalls do help, BUT, I've ran 1.7s on 275/40/17 nittos. Drop pressure to about 16 psi and heat them up. Not arguing that a 15 inch tire is not better, just saying that decent 60 foot times are attainable with 17" tires.

 

[jsta6]

Originally posted by TKGN1
sidewalls do help, BUT, I've ran 1.7s on 275/40/17 nittos. Drop pressure to about 16 psi and heat them up. Not arguing that a 15 inch tire is not better, just saying that decent 60 foot times are attainable with 17" tires.

Cool.

Tell us more. What is your combo and suspension mods? Are the 1.7 consistent? How much boost are you leaving with, etc?

 

[TKGN1]

1.7-1.8 is the norm, got the idea from watching LS1 cars pop off 1.6-1.8 60 fts on 17's with regular bolt-ons.
Quit a bit under hood, pt-54, cas v2, 55's, ect. Back end has boxed lowers, air bags, 3:42's. I do have a line lock to keep back brakes from getting hot during burnout, footbraking I launch at 8#. I havn't tryed launching off t-brake with them, don't think they will hold(thats where I think side wall comes into play) I run slicks off the t-brake, 1.5-1.6's off 12# of boost. Honestly, I don't think 17's will get below mid 1.6's, not on my car. I tryed launching at higher boost only to spin out of the hole. I have trapped a higher mph with the 17's, 122 vs 118 with the slicks, but e.t.'s are the opposite!?
Either way, every car is a little different, some can make 17's hook, others can't. IMO

 

[jsta6]

Thanks.

Sounds like I need to get my line lock installed so I can do some burnouts to heat my tires up.

I also need to lower my air pressure some more.