Farm Truck ran 1/4-Need Help!!!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JReynolds · 08-13-2002, 06:28 PM

Those of you who have been on the board for a while might remember seeing pictures of the "Farm Truck."
I finally went to New England Dragway, and I could only muster a 15.29, but the top speed was at 98 mph.
My wife was watching from the lights, and she said the rearend came off the ground "several inches". I made another pass, and the same thing happened. I've done plenty of burnouts on the street, and have gotton a bit of wheel hop coming out of them, but nothing like this. Guys at the track couldn't believe the speed verses the time, normally that would be a mid 14 second speed. My question is, what can I do about the wheel hop?
The truck has coil spring rear susp. with new KYB gas shocks.
3.07 rearend, 4 speed. The springs are original-heavy duty coil springs. Any help would be great. Thanks>>>>>

68racer · 08-13-2002, 06:40 PM

There is nothing wrong with the suspension, you need more weight on the rear or slicks. A rear fuel tank really helps or tractor ballast. That trap speed should put you in the 13's, these trucks don't run as fast as cars at the top end because of the lack of aerodynamics.

JReynolds · 08-13-2002, 06:48 PM

I have a 3.73 rearend that I bought from CPNE. It is ready to go in, I think I am going to try that to see what happens. My theory being that maybe with the harder launches the rearend might want to stay on the ground better. I don't want to move the tank, and the bed is finished so nicely I really dont want to put anything in it. My other thought was to replace the springs with lighter duty ones. I dont want to go to far with it because I really only go to Epping once or twice a year. What you say about times is encouraging though. I know that on the street I have surprised a few late models!

68racer · 08-13-2002, 06:59 PM

I use suburban rear springs and get 1.9 second 60' times (with slicks and a 3.73). I think the springs are 3/4 ton, I guess it's the progressive wind just lets it sit back a bit and then no more. What were your 60' times? Check out the girlfriend/burnout post for pic of truck.

JReynolds · 08-13-2002, 07:16 PM

I threw my slips away when I got home, so I can't give you my 60' time, but I'm certain that the first 100' or so were pretty pathetic. If I get the same sort of problem after changing the rearend, I'll just try to lauch without any wheel spin at all. I get so amped up at the lights though, it's easier said than done. I dont think slicks would really help me, as the tires werent really spinning, just bouncing....On the street, I can absolutely bake the tires, and come to think of it, maybe I should try one pass doing just that. I remember I was trying not to lose a lot of time spinning, so maybe I was just stuck in between, and should go one way or the other, either all out, or just feather it off the line.

68racer · 08-13-2002, 07:27 PM

I'd go for the feather approach, but your problem is traction can you borrow slicks? Stud pattern may be a problem. You could fabricate a ballast box to go where the spare wheel should be. It's alot more fun when you can nail it off the line. Deeper gears will make wheelspin worse.

mooneyes · 08-13-2002, 08:59 PM

i think the 3:73 rear would help greatly..ive had a 4 speed ,..now 3 speed with 3:07 and there a bit tall with a 4 gear it takes off like a mut once your rolling but from a dead stop its pretty harsh

**smitty62** · 08-13-2002, 09:44 PM

I'm not that sharp when it comes to drag racing, but it would seem to me that some experimenting with tire pressure is called for?

08-13-2002, 06:28 PM	#1
JReynolds Registered User Join Date: Jan 2001 Posts: 44	Farm Truck ran 1/4-Need Help!!!!! Those of you who have been on the board for a while might remember seeing pictures of the "Farm Truck." I finally went to New England Dragway, and I could only muster a 15.29, but the top speed was at 98 mph. My wife was watching from the lights, and she said the rearend came off the ground "several inches". I made another pass, and the same thing happened. I've done plenty of burnouts on the street, and have gotton a bit of wheel hop coming out of them, but nothing like this. Guys at the track couldn't believe the speed verses the time, normally that would be a mid 14 second speed. My question is, what can I do about the wheel hop? The truck has coil spring rear susp. with new KYB gas shocks. 3.07 rearend, 4 speed. The springs are original-heavy duty coil springs. Any help would be great. Thanks>>>>> Attached Images __________________ 1969 SWB Stepside. 350 w/Vortec heads, 380 H.P., 450 ft/lb dyno proven.

08-13-2002, 06:48 PM	#3
JReynolds Registered User Join Date: Jan 2001 Posts: 44	I have a 3.73 rearend that I bought from CPNE. It is ready to go in, I think I am going to try that to see what happens. My theory being that maybe with the harder launches the rearend might want to stay on the ground better. I don't want to move the tank, and the bed is finished so nicely I really dont want to put anything in it. My other thought was to replace the springs with lighter duty ones. I dont want to go to far with it because I really only go to Epping once or twice a year. What you say about times is encouraging though. I know that on the street I have surprised a few late models! __________________ 1969 SWB Stepside. 350 w/Vortec heads, 380 H.P., 450 ft/lb dyno proven.

08-13-2002, 07:16 PM	#5
JReynolds Registered User Join Date: Jan 2001 Posts: 44	I threw my slips away when I got home, so I can't give you my 60' time, but I'm certain that the first 100' or so were pretty pathetic. If I get the same sort of problem after changing the rearend, I'll just try to lauch without any wheel spin at all. I get so amped up at the lights though, it's easier said than done. I dont think slicks would really help me, as the tires werent really spinning, just bouncing....On the street, I can absolutely bake the tires, and come to think of it, maybe I should try one pass doing just that. I remember I was trying not to lose a lot of time spinning, so maybe I was just stuck in between, and should go one way or the other, either all out, or just feather it off the line. __________________ 1969 SWB Stepside. 350 w/Vortec heads, 380 H.P., 450 ft/lb dyno proven.

08-13-2002, 08:59 PM	#7
mooneyes Registered User Join Date: Jan 2002 Location: Slippery Rock PA USA Posts: 1,692	i think the 3:73 rear would help greatly..ive had a 4 speed ,..now 3 speed with 3:07 and there a bit tall with a 4 gear it takes off like a mut once your rolling but from a dead stop its pretty harsh __________________ Ken Lyons, Slippery rock pa 68 short step 327 t10 4 gear 72 2wd blazer project 70 lwb 305/700r driver 78 caprice project 02 cavalier D.D ( hate it!!)

08-13-2002, 09:44 PM	#8
smitty62 Registered User Join Date: May 2002 Location: North Carolina Posts: 1,234	I'm not that sharp when it comes to drag racing, but it would seem to me that some experimenting with tire pressure is called for? __________________ Stepsides look like real trucks! Smitty

08-13-2002, 06:40 PM	#2
68racer Yeah baby! Join Date: Feb 2001 Location: United Kingdom Posts: 436	There is nothing wrong with the suspension, you need more weight on the rear or slicks. A rear fuel tank really helps or tractor ballast. That trap speed should put you in the 13's, these trucks don't run as fast as cars at the top end because of the lack of aerodynamics.

08-13-2002, 06:59 PM	#4
68racer Yeah baby! Join Date: Feb 2001 Location: United Kingdom Posts: 436	I use suburban rear springs and get 1.9 second 60' times (with slicks and a 3.73). I think the springs are 3/4 ton, I guess it's the progressive wind just lets it sit back a bit and then no more. What were your 60' times? Check out the girlfriend/burnout post for pic of truck.

08-13-2002, 07:27 PM	#6
68racer Yeah baby! Join Date: Feb 2001 Location: United Kingdom Posts: 436	I'd go for the feather approach, but your problem is traction can you borrow slicks? Stud pattern may be a problem. You could fabricate a ballast box to go where the spare wheel should be. It's alot more fun when you can nail it off the line. Deeper gears will make wheelspin worse.



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