Shifting heavy S/St car on Stop.....

cujo3116 · 05-25-2011, 11:23 PM

I'm looking to see if anyone else has suggestions or comments on shifting a super street car on time. I have a friend I'm helping with his combo and its being inconsistant on the stop, he cant confirm 100% but believes its climbing rpm on stop.

Cruisn RPM is at 4400 right now with a 1.72 60 foot. to go 10.90 in about 2400 DA hes on the stopat .050 and runs it for 2.5 seconds and goes 10.90ish at 138 mph. (7.20 104 in the 1/8th)

If i set the rpm lower though I know it will be to much and when he switchs to 1/8th mile (the super street series we run also stops at a 1/8th mile track) and I worry in the thick summer air his stop time will be less then his 60 foot and we wont be able to get any good 60 foot numbers.

SO I'm thinking of shifting on time about 1 second into the pass to help keep the rpm from climbing but I wasnt sure how successful this would be with a 2980 lbs car?

Thanks,

Andrew

Chris Williams · 05-26-2011, 09:34 AM

I'm always a fan of shifting on the stop. We had a climbing problem, moved from shifting at 1.0sec to 0.5sec and it fixed it.

65Shoebox · 06-02-2011, 04:36 PM

I had to move my shift point out for the same reason. I go on the stop at .500 and shift at 1.0. Works well in a simialar combo to that you reference.

GaryGoFast · 06-24-2011, 04:20 PM

i have my 2835lb s/st car going on at .005, clears the tree, doesnt slam the tires and lights are more consistent. Originally had it at .05 but found that with an air stop you can have the time at 000 and by the time it reacts you still clear the tree. Shift at .75, agree that running the track in second gear is most consistent.

sst7250 · 08-30-2011, 11:58 PM

My 2895lb car we shift at .50, on the stop at .000 off at somewhere around 4.6-4.7. I also agree getting the car into high gear as soon as you can is key.

CBS jr · 09-01-2011, 11:50 AM

Quote:

Originally Posted by sst7250

my 2895lb car we shift at .50, on the stop at .000 off at somewhere around 4.6-4.7. I also agree getting the car into high gear as soon as you can is key.

really?

sst7250 · 09-02-2011, 01:33 AM

Quote:

Originally Posted by sst7250

My 2895lb car we shift at .50, on the stop at .000 off at somewhere around 4.6-4.7. I also agree getting the car into high gear as soon as you can is key.

really?

Jeff saw you out there last weekend. That had to be brutal between the heat and sitting around that much. I think I'll pass for sure on that one. We were thinkoing of racing out there this weekend but I think I'll pass again. I did run the PSCA B1 deal in July, managed to win that deal but everyone gets lucky.

As for the stop, yep that is the dealio. I have not run the car at 10.90 in the heat yet. This 5000'+ DA stuff is for the birds. IIRC in July we saw 5800', just dumb. I put one of those fancy disc stops on and need to get out and see how that goes. But we both know I have no idea what I'm doing

Oh yeah having a non climate controlled shop out here is also for the birds....

CBS jr · 09-02-2011, 12:17 PM

I went outside and got a couple of nuts for you out of the bolt ben.
It wasn't that hot. What moparts can't run in the heat or 5000 plus feet.

sst7250 · 09-02-2011, 06:37 PM

We were racing too

I did not see a reason to go out and get any data at 5000' + of air. Cant see it as real useful but maybe I am wrong. We both know I have no clue what I'm doing anyway.

85transam · 09-21-2011, 09:17 AM

Trying to figure out running a throttle stop and have a couple questions hopefully you guys can answer. We have a heavy car (3500) that will run 10.30s. From what I have read I figure we should have the stop on very early ( .3-.5?). My main question comes from the fact that we have a three speed tranny. When is it best to shift into second gear, and I assume we should do both shifts on time? Thanks for all the help in advance.

05-25-2011, 11:23 PM	#1
cujo3116 Junior Member Join Date: Nov 2004 Location: Canada Posts: 53 Likes: 0 Liked 0 Times in 0 Posts	Shifting heavy S/St car on Stop..... I'm looking to see if anyone else has suggestions or comments on shifting a super street car on time. I have a friend I'm helping with his combo and its being inconsistant on the stop, he cant confirm 100% but believes its climbing rpm on stop. Cruisn RPM is at 4400 right now with a 1.72 60 foot. to go 10.90 in about 2400 DA hes on the stopat .050 and runs it for 2.5 seconds and goes 10.90ish at 138 mph. (7.20 104 in the 1/8th) If i set the rpm lower though I know it will be to much and when he switchs to 1/8th mile (the super street series we run also stops at a 1/8th mile track) and I worry in the thick summer air his stop time will be less then his 60 foot and we wont be able to get any good 60 foot numbers. SO I'm thinking of shifting on time about 1 second into the pass to help keep the rpm from climbing but I wasnt sure how successful this would be with a 2980 lbs car? Thanks, Andrew

05-26-2011, 09:34 AM	#2
Chris Williams Member Join Date: Mar 2009 Location: Woodinville, WA Posts: 401 Likes: 0 Liked 0 Times in 0 Posts	Re: Shifting heavy S/St car on Stop..... I'm always a fan of shifting on the stop. We had a climbing problem, moved from shifting at 1.0sec to 0.5sec and it fixed it. __________________ Chris Williams 6304 SC, TD, ET

06-02-2011, 04:36 PM	#3
65Shoebox Junior Member Join Date: Oct 2009 Posts: 32 Likes: 0 Liked 0 Times in 0 Posts	Re: Shifting heavy S/St car on Stop..... I had to move my shift point out for the same reason. I go on the stop at .500 and shift at 1.0. Works well in a simialar combo to that you reference.

06-24-2011, 04:20 PM	#4
GaryGoFast Senior Member Join Date: Nov 2003 Location: New York Posts: 804 Likes: 0 Liked 1 Time in 1 Post	Re: Shifting heavy S/St car on Stop..... i have my 2835lb s/st car going on at .005, clears the tree, doesnt slam the tires and lights are more consistent. Originally had it at .05 but found that with an air stop you can have the time at 000 and by the time it reacts you still clear the tree. Shift at .75, agree that running the track in second gear is most consistent. __________________ Gary Federico S/St, S/G 1814

08-30-2011, 11:58 PM	#5
sst7250 Member Join Date: Jan 2009 Location: Las Vegas, NV Posts: 184 Likes: 9 Liked 45 Times in 32 Posts	Re: Shifting heavy S/St car on Stop..... My 2895lb car we shift at .50, on the stop at .000 off at somewhere around 4.6-4.7. I also agree getting the car into high gear as soon as you can is key.

09-02-2011, 12:17 PM	#8
CBS jr Member Join Date: Jan 2005 Location: who cares Posts: 176 Likes: 0 Liked 0 Times in 0 Posts	Re: Shifting heavy S/St car on Stop..... I went outside and got a couple of nuts for you out of the bolt ben. It wasn't that hot. What moparts can't run in the heat or 5000 plus feet.

09-02-2011, 06:37 PM	#9
sst7250 Member Join Date: Jan 2009 Location: Las Vegas, NV Posts: 184 Likes: 9 Liked 45 Times in 32 Posts	Re: Shifting heavy S/St car on Stop..... We were racing too I did not see a reason to go out and get any data at 5000' + of air. Cant see it as real useful but maybe I am wrong. We both know I have no clue what I'm doing anyway.

09-21-2011, 09:17 AM	#10
85transam Junior Member Join Date: Sep 2010 Posts: 4 Likes: 0 Liked 0 Times in 0 Posts	Re: Shifting heavy S/St car on Stop..... Trying to figure out running a throttle stop and have a couple questions hopefully you guys can answer. We have a heavy car (3500) that will run 10.30s. From what I have read I figure we should have the stop on very early ( .3-.5?). My main question comes from the fact that we have a three speed tranny. When is it best to shift into second gear, and I assume we should do both shifts on time? Thanks for all the help in advance.