Launch rpm for F/S. 396 ,325hp ? - Page 2

mcashman · 10-16-2014, 09:12 PM

Update I lowered caltrac bar to lower hole no pre load, switched to 90-10 on fronts and lowered launch to 4200 then 4400 went 1.72 then 1.66 60 foots. Both dead hooked.not fast but much better. I will figure out what clutch stuff I got. Thanks for info.

69Cobra · 10-16-2014, 09:58 PM

IMO If you've got it dead hooking keep raising the launch RPM's until you get about 1 full revolution of the tire. Then tire making adjustments to the clutch, chassis, tires, shocks etc... to get it to dead hook again at your new launch RPM once you get that then keep raising the launch RPM again until you get your 1 revolution back. Obviously the time slip (60') will be your guide. Just my .02

Mike Taylor 3601 · 10-17-2014, 12:59 PM

Quote:

Originally Posted by 69Cobra

IMO If you've got it dead hooking keep raising the launch RPM's until you get about 1 full revolution of the tire. Then tire making adjustments to the clutch, chassis, tires, shocks etc... to get it to dead hook again at your new launch RPM once you get that then keep raising the launch RPM again until you get your 1 revolution back. Obviously the time slip (60') will be your guide. Just my .02

Mike Taylor 3601

Rory McNeil · 10-17-2014, 01:46 PM

Quote:

Originally Posted by 69Cobra

IMO If you've got it dead hooking keep raising the launch RPM's until you get about 1 full revolution of the tire. Then tire making adjustments to the clutch, chassis, tires, shocks etc... to get it to dead hook again at your new launch RPM once you get that then keep raising the launch RPM again until you get your 1 revolution back. Obviously the time slip (60') will be your guide. Just my .02

If he is still running radial slicks, it will be very difficult to get only 1 revolution of the slicks. I have used both the M/T 9x29.5 3056STs, as well as the Hoosier 9x29 D07s, both worked great, although the M/Ts seem to not "go away" as severely when they reach the end of their life. On my car, when fresh, the Hoosiers are a tick better on 60foots.

69Cobra · 10-17-2014, 09:16 PM

Quote:

Originally Posted by Rory McNeil

If he is still running radial slicks, it will be very difficult to get only 1 revolution of the slicks. I have used both the M/T 9x29.5 3056STs, as well as the Hoosier 9x29 D07s, both worked great, although the M/Ts seem to not "go away" as severely when they reach the end of their life. On my car, when fresh, the Hoosiers are a tick better on 60foots.

My experiences have been the same as yours Roy and yes I don't know if he's going to have any luck with the radial I've never tried them myself.

Doug Domm · 10-17-2014, 10:11 PM

Ok, the 3056st is a stick tire but what effect would that tire have with an automatic car?
What is the build difference of the 3056st to the 3056? Is it just compound or constructed different as well?

Rory McNeil · 10-17-2014, 10:28 PM

Quote:

Originally Posted by Doug Domm

Ok, the 3056st is a stick tire but what effect would that tire have with an automatic car?
What is the build difference of the 3056st to the 3056? Is it just compound or constructed different as well?

The sidewalls, although not really a stiff sidewall, are stiffer than a normal slick. I also believe that the tread compound is a bit harder.

Doug Domm · 10-17-2014, 10:45 PM

Quote:

Originally Posted by Rory McNeil

The sidewalls, although not really a stiff sidewall, are stiffer than a normal slick. I also believe that the tread compound is a bit harder.

That is what I have understood as well. That being said, if you have an automatic car that hooks with the st tire would the stiffer sidewall help with reaction and performance? Will the st still grow as much as the non st?

mcashman · 10-18-2014, 08:13 PM

Next time will be in 2 weeks I will defiantly try to get the 1 revolution and see how it pays off. I have rear shocks set second softest setting I was thinking of stiffing them think it would help 60 ft times?

james schaechter · 10-19-2014, 06:45 AM

We have been testing off an on with a clutch set up that we can run radials. In the right conditions it can be good. The cool track and whatever led you to dead hook can be reason it works now. If you race on normal summer conditions be prepared for disappointment if you think it will work when the track gets hot or you just have too much hit to hold it. It is a very very fine line. When the radials start to spin you can go from a 1.40 60 foot to 1.70. 😁

I think that radials can be faster someday. I have gone 10.70's in E stick with them. But I don't have a big enough tuning window with them to leave them on all the time. Too easy to roast them on the line for me anyway.

Let us know how it goes and take video if you can.

10-16-2014, 09:12 PM	#11
mcashman Junior Member Join Date: Oct 2007 Location: Westminster MD Posts: 80 Likes: 16 Liked 5 Times in 2 Posts	Re: Launch rpm for F/S. 396 ,325hp ? Update I lowered caltrac bar to lower hole no pre load, switched to 90-10 on fronts and lowered launch to 4200 then 4400 went 1.72 then 1.66 60 foots. Both dead hooked.not fast but much better. I will figure out what clutch stuff I got. Thanks for info.

10-16-2014, 09:58 PM	#12
69Cobra Senior Member Join Date: Aug 2007 Location: California, Ky Posts: 667 Likes: 28 Liked 1 Time in 1 Post	Re: Launch rpm for F/S. 396 ,325hp ? IMO If you've got it dead hooking keep raising the launch RPM's until you get about 1 full revolution of the tire. Then tire making adjustments to the clutch, chassis, tires, shocks etc... to get it to dead hook again at your new launch RPM once you get that then keep raising the launch RPM again until you get your 1 revolution back. Obviously the time slip (60') will be your guide. Just my .02 __________________ Kris Rachford 69 Cobra 428CJ 4 Speed C/S 3032 Last edited by 69Cobra; 10-16-2014 at 10:00 PM.

10-17-2014, 10:11 PM	#16
Doug Domm Member Join Date: Apr 2006 Location: canada Posts: 244 Likes: 26 Liked 40 Times in 19 Posts	Re: Launch rpm for F/S. 396 ,325hp ? Ok, the 3056st is a stick tire but what effect would that tire have with an automatic car? What is the build difference of the 3056st to the 3056? Is it just compound or constructed different as well?

10-18-2014, 08:13 PM	#19
mcashman Junior Member Join Date: Oct 2007 Location: Westminster MD Posts: 80 Likes: 16 Liked 5 Times in 2 Posts	Re: Launch rpm for F/S. 396 ,325hp ? Next time will be in 2 weeks I will defiantly try to get the 1 revolution and see how it pays off. I have rear shocks set second softest setting I was thinking of stiffing them think it would help 60 ft times?

10-19-2014, 06:45 AM	#20
james schaechter VIP Member Join Date: Dec 2004 Location: Cumming GA Posts: 1,928 Likes: 1,070 Liked 1,212 Times in 249 Posts	Re: Launch rpm for F/S. 396 ,325hp ? We have been testing off an on with a clutch set up that we can run radials. In the right conditions it can be good. The cool track and whatever led you to dead hook can be reason it works now. If you race on normal summer conditions be prepared for disappointment if you think it will work when the track gets hot or you just have too much hit to hold it. It is a very very fine line. When the radials start to spin you can go from a 1.40 60 foot to 1.70. 😁 I think that radials can be faster someday. I have gone 10.70's in E stick with them. But I don't have a big enough tuning window with them to leave them on all the time. Too easy to roast them on the line for me anyway. Let us know how it goes and take video if you can. __________________ James Schaechter 3163 STK Last edited by james schaechter; 10-19-2014 at 06:49 AM.