Traction issues

Posted By: Dave_S

Traction issues - 07/24/10 10:37 PM

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

Posted By: MR_P_BODY

Re: Traction issues - 07/24/10 11:47 PM

Raise the launch rpm to hit the tire harder... go up
a fair amount

Posted By: dc426

Re: Traction issues - 07/24/10 11:50 PM

what shocks? and what are they set at? I'm in the same boat and can only launch at 3200. Then is spins after that. My Ranchos are set at #2 with one full turn of Pre load.

Posted By: Dave_S

Re: Traction issues - 07/24/10 11:59 PM

I've tried with the shocks set from 0 up to 7 (ran out of time to go any higher)

Posted By: MR_P_BODY

Re: Traction issues - 07/25/10 12:02 AM

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

Posted By: sixpackgut

Re: Traction issues - 07/25/10 12:06 AM

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

Posted By: 602heavy

Re: Traction issues - 07/25/10 12:19 AM

Having the same issues with same set up as your's , blowing the tyres away on launch , next time out i'm gonna change front shock to 70/30 , maybe the front end is coming up to fast & not allowing the rear end to work hard enough , bit like the guy on the scales holding a 20ft scaffold board with his mate supporting the other end , when he tries to lift the board on his own the scales read his weight plus the board , when his mate helps him lift the board the weight on scales does'nt alter much........i read this somewhere before so it stuck in my mind , the guy was talking about higher hp motors sometimes need a slower rebounding shock on fronts.

Posted By: cbarracuda

Re: Traction issues - 07/25/10 12:50 AM

I have the same problem with my car. everybody in this forum talk so well about Cal tracks, but in a marginal track I don�t think it works the way everyone�s saying it does. I personally went back to my SS springs, they work better for me

Posted By: dc426

Re: Traction issues - 07/25/10 01:09 AM

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?

Posted By: 68shifter

Re: Traction issues - 07/25/10 01:23 AM

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

Posted By: cbarracuda

Re: Traction issues - 07/25/10 03:50 AM

15x10.5x33 10 pounds seem to work best for me because of the poor traction

Posted By: Twin Turbo Mower

Re: Traction issues - 07/25/10 04:21 AM

If you have the money buy a set of afco double adjustable shocks for the rear. I run them and qa1's up front with cal-tracs. I also have my dart lowered in the back 2 inches to aid in weight transfere.

Posted By: 540DUSTER

Re: Traction issues - 07/25/10 09:17 AM

Whats the angle of the rear shackels?

Posted By: Quicktree

Re: Traction issues - 07/25/10 10:40 AM

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.

Posted By: sshemi

Re: Traction issues - 07/25/10 11:28 AM

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.

Posted By: Quicktree

Re: Traction issues - 07/25/10 11:33 AM

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.

Posted By: Dave_S

Re: Traction issues - 07/25/10 02:02 PM

thanks for the tip guys.
The tires are M/T 29.5x10.5 x15. I've tried tire pressures from 12 to 14 psi.

Posted By: Dodgem

Re: Traction issues - 07/25/10 02:29 PM

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!!)

Posted By: Quicktree

Re: Traction issues - 07/25/10 02:52 PM

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

Posted By: dc426

Re: Traction issues - 07/25/10 03:13 PM

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

Posted By: BradH

Re: Traction issues - 07/25/10 03:27 PM

Are your CalTracs using the top or bottom front mount hole? If currently in the top, try them in the bottom.