Best PSI for 305/35/18 MT DR's at the track???

[cobrasvtcoupe25]

What up,

I'm running Mickey Thompson ET Street Radials II - 305/35-18.

Mickey Thompson ET Street Radial II Mustang Tire - 305/35-18 3785R - Free Shipping 3785R


What PSI should I run at the track?


I can't wait because my cobra is finally tuned :rolling:

Thanks,
Mike

 

[cobrasvtcoupe25]

I was thinking 18 PSI btw...

 

[vortek01gt]

I was running from 16-18 psi when i had mine. They were the same size and i was able to get a 1.70 60ft.

 

[cobrasvtcoupe25]

I was running from 16-18 psi when i had mine. They were the same size and i was able to get a 1.70 60ft.

Cool, so I'm close.. I'm going to Sac raceway this Saturday. You going out there?

 

[vortek01gt]

Cool, so I'm close.. I'm going to Sac raceway this Saturday. You going out there?

No. I wish i was going, but I have to work. good luck man!

 

[Shadow Grey 03]

Try 15-18 and check between runs. Good luck!

 

[cobrasvtcoupe25]

No. I wish i was going, but I have to work. good luck man!

Thanks!

Try 15-18 and check between runs. Good luck!

Good idea, I'll look at the PSI in-between runs.

 

[DaleM]

Drag racing the 18 psi sounds like a good starting point.

On a road course you could run 10-15% higher, especially if you are going over 120mph.

 

[vortek01gt]

So what did it run?

 

[cobrasvtcoupe25]

1.910 was my best 60ft :nonono:

I need slicks!

 

[vortek01gt]

Thats sucks. How many miles are on them? Cuz when mine were brand new they didnt hook very well. It wasnt until like the secone trip to the track that they started to grab. What was you psi, launch technique, rpm?

 

[sam92lx]

I had good luck at 17-18psi cut a 1.67 60ft.

 

[mrlrd1]

18psi works well for me. If you're getting a 1.9x you don't need slicks, you need help with driving or chassis setup. I've gone 1.47-1.49 on them several times.

 

[cobrasvtcoupe25]

I had them at 16/17 PSI

I need more practice. This was my first time out on 18 DR's. I think it's going to take a little bit of technique. I feel like the MT DR's are just barely broken in.

Here's a vid:

In car Vid of 4.56 Bolt On NA 1999 Cobra - 300+ RWHP - YouTube

-Mike

 

[mrlrd1]

I need more practice.

You CANNOT just drop the clutch on a drag radial, especially a stiff short sidewall. More RPM and clutch modulation will drop that 60' even on stock suspension.

 

[vortek01gt]

Ya slipping the clutch will help out alot

 

[cobrasvtcoupe25]

Got a 1.863 60ft yesterday on the 305 MT DR's. Little bit of improvement, but now I think I have a little bit of drivetrain vibration I need to check out before I go back out again. :fm:

This 28" DR is not as good as 26" DR would be for my set up(300 RWHP). My next tire will be a 26".

 

[vortek01gt]

Got a 1.863 60ft yesterday on the 305 MT DR's. Little bit of improvement, but now I think I have a little bit of drivetrain vibration I need to check out before I go back out again. :fm:

This 28" DR is not as good as 26" DR would be for my set up(300 RWHP). My next tire will be a 26".

IIRC it is a 26" tire. The 305/45r18s are a 28" tire. Just give it some more practice man

 

[500hp04cobra]

16-18 is where I ran them and cut high 1.5s low 1.6s