Traction issues
#756916
07/24/10 06:37 PM
07/24/10 06:37 PM
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Joined: Jan 2003
Posts: 344 Burlington, Ontario Canada
Dave_S
OP
enthusiast
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OP
enthusiast
Joined: Jan 2003
Posts: 344
Burlington, Ontario Canada
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My new found power is making my life miserable! My sixty foot times are worse with the 512 than they were last year with my 440. The best I can do is 1.43 Cant seem to hook up. I've adjusted the caltracs and shocks from one extreme to the other. I even tried another set of tires just to rule them out. The car seems to hook then unload the tires. In the video you can see it bouncing a few times. Any suggestions? 3200 lbs 512 727 trans brake. Launch off two step @ 3400 Caltracs, mono-leafs, Ranchos in back , calvert 90/10's in front and 5.5 inches of front end travel Video http://www.youtube.com/watch?v=VD5xWIbtcfI
Dave Stillie '73 Swinger 5.7 Hemi, 88mm turbo, powerglide, cal-tracs & 8 3/4 Mega-Squirt EFI [email]8.93@149 [/email]
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Re: Traction issues
[Re: dc426]
#756919
07/24/10 07:59 PM
07/24/10 07:59 PM
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Joined: Jan 2003
Posts: 344 Burlington, Ontario Canada
Dave_S
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enthusiast
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OP
enthusiast
Joined: Jan 2003
Posts: 344
Burlington, Ontario Canada
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I've tried with the shocks set from 0 up to 7 (ran out of time to go any higher)
Dave Stillie '73 Swinger 5.7 Hemi, 88mm turbo, powerglide, cal-tracs & 8 3/4 Mega-Squirt EFI [email]8.93@149 [/email]
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Re: Traction issues
[Re: Dave_S]
#756920
07/24/10 08:02 PM
07/24/10 08:02 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
I've tried with the shocks set from 0 up to 7 (ran out of time to go any higher)
Turn them all the way up
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Re: Traction issues
[Re: dc426]
#756921
07/24/10 08:06 PM
07/24/10 08:06 PM
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Joined: Jun 2003
Posts: 9,225 Charleston
sixpackgut
Drag Week Mod Champion
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Drag Week Mod Champion
Joined: Jun 2003
Posts: 9,225
Charleston
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i have encountered that bouncing issue once. thats when i listened to someone slower than me.
how are your caltracs adjusted?
mine touch on the driver side without me in it and 6 flats of preload on the passenger side. think you need a stiffer shock setting too
Gen 3 power 6.22@110, 9.85@135 Follow @g3hemiswap on instagram
performance only racing, CRT, ultimate converter, superior design concepts, ThumperCarbs
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Re: Traction issues
[Re: cbarracuda]
#756924
07/24/10 09:09 PM
07/24/10 09:09 PM
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Joined: Aug 2003
Posts: 5,000 Tampa Florida
dc426
gotta keep'm separated
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gotta keep'm separated
Joined: Aug 2003
Posts: 5,000
Tampa Florida
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General consensus and Calvert advises to go down on shock settings when using a T-brake. Foot braking I have to be on 9, T-brake 2. Seems to work for me. BTW, tire pressure is critical. What size tires and what pressure are you running?
Last edited by dc426; 07/24/10 09:11 PM.
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Re: Traction issues
[Re: dc426]
#756925
07/24/10 09:23 PM
07/24/10 09:23 PM
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Joined: Jan 2007
Posts: 1,169 MI
68shifter
super stock
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super stock
Joined: Jan 2007
Posts: 1,169
MI
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I had a similar issue as well. They called it porpoising (sp?). I dealt a good deal with Scott and John at Calvert. They were adamant about leaving the front loose for transfer and unlimited and stiff shocks on the rear. Also they also stuck firm to half turn preload with driver. At one point I was trying three different sets of rear shocks and was/am using double adj on the front. Once I got the car consistent any change in track or weather and back to square one. I got rid of the mono=leafs and went back to SS springs. Not saying it can't be done - but call Calvert get them some video and just be ready to really work it out. Just my experience Good luck
68' Barracuda (4 speed)
64' Savoy (4 speed)
65' Satellite (girl tranny)
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Re: Traction issues
[Re: Dave_S]
#756929
07/25/10 06:40 AM
07/25/10 06:40 AM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
I've tried with the shocks set from 0 up to 7 (ran out of time to go any higher)
time to upgrade the shocks and check the front end.
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Re: Traction issues
[Re: Quicktree]
#756930
07/25/10 07:28 AM
07/25/10 07:28 AM
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Joined: Aug 2004
Posts: 2,128 sweden
sshemi
top fuel
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top fuel
Joined: Aug 2004
Posts: 2,128
sweden
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You should have adjustable front shocks also. 90/10 works good for lower hp cars but when the hit gets violent you need to slow the front end down a little bit. dubble adjustable for the rear is almost a must when useing a t-break. Im not saying everybody will need them but my experience says its a good investment. If it first hooks then spinn i would use tyhe hardest setting on the rear shocks and if that doesnt work get yourself adj front shocks to slw the front down and if that doesnt work time for dub adj rears.
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Re: Traction issues
[Re: sshemi]
#756931
07/25/10 07:33 AM
07/25/10 07:33 AM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
You should have adjustable front shocks also. 90/10 works good for lower hp cars but when the hit gets violent you need to slow the front end down a little bit. dubble adjustable for the rear is almost a must when useing a t-break. Im not saying everybody will need them but my experience says its a good investment. If it first hooks then spinn i would use tyhe hardest setting on the rear shocks and if that doesnt work get yourself adj front shocks to slw the front down and if that doesnt work time for dub adj rears.
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Re: Traction issues
[Re: Quicktree]
#756932
07/25/10 10:02 AM
07/25/10 10:02 AM
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Joined: Jan 2003
Posts: 344 Burlington, Ontario Canada
Dave_S
OP
enthusiast
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OP
enthusiast
Joined: Jan 2003
Posts: 344
Burlington, Ontario Canada
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thanks for the tip guys. The tires are M/T 29.5x10.5 x15. I've tried tire pressures from 12 to 14 psi.
Dave Stillie '73 Swinger 5.7 Hemi, 88mm turbo, powerglide, cal-tracs & 8 3/4 Mega-Squirt EFI [email]8.93@149 [/email]
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Re: Traction issues
[Re: Dave_S]
#756933
07/25/10 10:29 AM
07/25/10 10:29 AM
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Joined: Mar 2008
Posts: 5,746 Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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You may want to give it a try with shocks at 9 and at least 2 full turns of negative pre load. When I went from a 452 to my 542 RIP I had to do that after trying everything. I put an air shock over the pass wheel with 65 lb in it and just kept backing the bars off till it launched nice and smooth. Went from 1 1/4 turn pre load to 2 1/4 negative and walla that was the ticket. Course that was foot braking and it went 1.400 short in my 3620 GTX then after the 542 went to Big block heaven went back to a 452 and back to about 1 1/4 turns pre load still using the air shock keeps it even leaving and can set bars the same no need for extra flats pass rear. now I went from a 4000 stall to a 5000 stall and it's a bit different again kinda chasing it a bit still? Yours almost looks like it hits and kicks back instead of lifting front good and that is what my 542 did only even more dramatic. You may have to set it so you can get in the top hole if your not on an A body. ( I have one air shock left?? LOL!!)
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Re: Traction issues
[Re: Dodgem]
#756934
07/25/10 10:52 AM
07/25/10 10:52 AM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
You may want to give it a try with shocks at 9 and at least 2 full turns of negative pre load. When I went from a 452 to my 542 RIP I had to do that after trying everything. I put an air shock over the pass wheel with 65 lb in it and just kept backing the bars off till it launched nice and smooth. Went from 1 1/4 turn pre load to 2 1/4 negative and walla that was the ticket. Course that was foot braking and it went 1.400 short in my 3620 GTX then after the 542 went to Big block heaven went back to a 452 and back to about 1 1/4 turns pre load still using the air shock keeps it even leaving and can set bars the same no need for extra flats pass rear. now I went from a 4000 stall to a 5000 stall and it's a bit different again kinda chasing it a bit still? Yours almost looks like it hits and kicks back instead of lifting front good and that is what my 542 did only even more dramatic. You may have to set it so you can get in the top hole if your not on an A body.
( I have one air shock left?? LOL!!)
air shock
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Re: Traction issues
[Re: Quicktree]
#756935
07/25/10 11:13 AM
07/25/10 11:13 AM
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Joined: Aug 2003
Posts: 5,000 Tampa Florida
dc426
gotta keep'm separated
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gotta keep'm separated
Joined: Aug 2003
Posts: 5,000
Tampa Florida
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I'm starting to think you have too much air in the tires. I run Hoosier 10.5X30. Foot braking I run 14.5 pounds. T-braking I run anywhere from 10-11 depending on the track. Foot braking I run a 1/4 turn of PL and T-braking one full turn. Here's a vid of my last outing. 3200 RPM, 10.5 pounds in the tires with 1 full turn of pre load. Ranchos set at 2. http://www.youtube.com/watch?v=-ejlLfrdf8I
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