Launch question/Going left

Ed Carpenter · 03-28-2010, 10:43 PM

Looking for some causes for my car starting to go dead left at the hit. It was fine and now 3 straight passes in a row I let the clutch out and it went left. And I mean left. The last run I think I could of reached out and touched the tree as I went by. We have touched nothing on the car on the rear. We have limited the front end travel to prevent eccessive wheel stand. I broke the pinion gear fri night so i have the rear apart and found nothing to cause the left hand turn. Nothing is broke on the suspension. The shocks are ok(ive had that problem in the past) On another note. My daughter videotaped the car fri night and when i did the burnout the right tire was spinning but no smoke on the burnout. The left tire had smoke pouring off of it. the axles are fine. I'm not sure what is going on here. Thanks. Ed

Darrin Christen · 03-28-2010, 11:14 PM

Not sure why one tire was smoking and not the other, but if that was indeed the case I could see where more heat in one tire versus the other would make the car launch to one side or the other. How was the water in the burnout box?

Jeff Lee · 03-28-2010, 11:53 PM

That's what my AMX was doing. I checked EVERYTHING I could. I adjusted EVERYTHING to compensate. Nothing. In the end it was the driver side floor had moved up an inch and a half.
I know another racer that had the same problem. All sorts of 4-link pre-load to straighten it out. In the end...bad front spring.

Ed Carpenter · 03-29-2010, 03:39 AM

I guess I should have added it's a ladder bar car. Darrin nothing unusual at the water box. Did it the last two runs at Crandall and the 1st pass in San Antonio so that probably isn't it. I don't have video of the Crandall runs but even on DRC they mention how far left I went out to the wall before I had to real it back in. Ed

I have the run from behind in San Antonio. I just don't know how to get it from my video camera to here for you guys to see it. Ed

al wisniewski · 03-29-2010, 04:29 AM

Ed,did you check your axle tubes? bent or twisted? Usually when a car starts doing funny things all of a sudden ,it could be a dead spring or bad shock. The preload went away so look close at the bars. Stretched rod end? And square the car up to make sure something hasn't settled .

Tom Goldman · 03-29-2010, 07:59 AM

Assuming no one else has issues with the track, Everything Al stated in the previous post is a possibility . ..............I would start with the axle brackets ,stringline the rear to see if it's straight in the car . .................If the rear is straight ,I'd check the shocks to see if one is bound up , probably the left rear .............................I just re read your post and the part about the burn out reminded me of a friends car . ....It had a set of axles that looked ok, but had actually stripped the splines in the spool just enough to spin under load..........Don't overlook anything. .......Tom

Wade Mahaffey · 03-29-2010, 08:02 AM

Check the ladder bar brackets on the rear housing. Sometimes the holes will enlongate (oval) from a loose bolt condition. This will allow the preload to change at the "hit". If this is the case, simply make some sleves about 3/8" long that fit the bolt fairly tight with about a .250 wall thickness. Weld (TIG) them to the ladder bar brackets (one for each hole, 8 total). Take the time to determine the correct location of the sleves to be welded in place. You can use the undamaged bracket to comfirm the proper hole location. Use a pair of dividers (dividers: as in a device/tool used to draw a circle, only using the points to determine location instead of a tape measure). After the fix, reset the preload and confirm at the track (compare tire temps after the burnout).
There could be a shock issue, or a tire issue but these things usually will cause a slight drift in one direction and not a consistant hard move. However, you will need to make shock adjustments a few times each season. This will compensate for normal wear of the shock, most of which happens in the trailer during transport.

Wade Mahaffey

03-28-2010, 10:43 PM	#1
Ed Carpenter Live Reporter Join Date: May 2006 Location: Dripping Springs, Tx Posts: 2,709 Likes: 186 Liked 520 Times in 132 Posts	Launch question/Going left Looking for some causes for my car starting to go dead left at the hit. It was fine and now 3 straight passes in a row I let the clutch out and it went left. And I mean left. The last run I think I could of reached out and touched the tree as I went by. We have touched nothing on the car on the rear. We have limited the front end travel to prevent eccessive wheel stand. I broke the pinion gear fri night so i have the rear apart and found nothing to cause the left hand turn. Nothing is broke on the suspension. The shocks are ok(ive had that problem in the past) On another note. My daughter videotaped the car fri night and when i did the burnout the right tire was spinning but no smoke on the burnout. The left tire had smoke pouring off of it. the axles are fine. I'm not sure what is going on here. Thanks. Ed __________________ Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development

03-28-2010, 11:14 PM	#2
Darrin Christen Member Join Date: Mar 2007 Location: Des Allemands, LA Posts: 365 Likes: 8 Liked 1 Time in 1 Post	Re: Launch question/Going left Not sure why one tire was smoking and not the other, but if that was indeed the case I could see where more heat in one tire versus the other would make the car launch to one side or the other. How was the water in the burnout box? __________________ 4878 SS/GA 66CHEVY II

03-28-2010, 11:53 PM	#3
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: Launch question/Going left That's what my AMX was doing. I checked EVERYTHING I could. I adjusted EVERYTHING to compensate. Nothing. In the end it was the driver side floor had moved up an inch and a half. I know another racer that had the same problem. All sorts of 4-link pre-load to straighten it out. In the end...bad front spring. __________________ Jeff Lee 7494 D/S '70 AMX

03-29-2010, 03:39 AM	#4
Ed Carpenter Live Reporter Join Date: May 2006 Location: Dripping Springs, Tx Posts: 2,709 Likes: 186 Liked 520 Times in 132 Posts	Re: Launch question/Going left I guess I should have added it's a ladder bar car. Darrin nothing unusual at the water box. Did it the last two runs at Crandall and the 1st pass in San Antonio so that probably isn't it. I don't have video of the Crandall runs but even on DRC they mention how far left I went out to the wall before I had to real it back in. Ed I have the run from behind in San Antonio. I just don't know how to get it from my video camera to here for you guys to see it. Ed __________________ Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development

03-29-2010, 04:29 AM	#5
al wisniewski Junior Member Join Date: Nov 2003 Location: auburn,mi. Posts: 56 Likes: 1 Liked 0 Times in 0 Posts	Re: Launch question/Going left Ed,did you check your axle tubes? bent or twisted? Usually when a car starts doing funny things all of a sudden ,it could be a dead spring or bad shock. The preload went away so look close at the bars. Stretched rod end? And square the car up to make sure something hasn't settled .

03-29-2010, 07:59 AM	#6
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,473 Likes: 881 Liked 858 Times in 234 Posts	Re: Launch question/Going left Assuming no one else has issues with the track, Everything Al stated in the previous post is a possibility . ..............I would start with the axle brackets ,stringline the rear to see if it's straight in the car . .................If the rear is straight ,I'd check the shocks to see if one is bound up , probably the left rear .............................I just re read your post and the part about the burn out reminded me of a friends car . ....It had a set of axles that looked ok, but had actually stripped the splines in the spool just enough to spin under load..........Don't overlook anything. .......Tom __________________ Tom Goldman 1500 SG , 1506 STK Last edited by Tom Goldman; 03-29-2010 at 08:04 AM.

03-29-2010, 08:02 AM	#7
Wade Mahaffey Senior Member Join Date: Apr 2007 Posts: 581 Likes: 0 Liked 17 Times in 7 Posts	Re: Launch question/Going left Check the ladder bar brackets on the rear housing. Sometimes the holes will enlongate (oval) from a loose bolt condition. This will allow the preload to change at the "hit". If this is the case, simply make some sleves about 3/8" long that fit the bolt fairly tight with about a .250 wall thickness. Weld (TIG) them to the ladder bar brackets (one for each hole, 8 total). Take the time to determine the correct location of the sleves to be welded in place. You can use the undamaged bracket to comfirm the proper hole location. Use a pair of dividers (dividers: as in a device/tool used to draw a circle, only using the points to determine location instead of a tape measure). After the fix, reset the preload and confirm at the track (compare tire temps after the burnout). There could be a shock issue, or a tire issue but these things usually will cause a slight drift in one direction and not a consistant hard move. However, you will need to make shock adjustments a few times each season. This will compensate for normal wear of the shock, most of which happens in the trailer during transport. Wade Mahaffey