My chassis set up

84gt347 · 09-10-2002, 12:41 PM

I recently bought a steeda drag pac for my car. Drag springs, air bag, drag struts and drag shocks. I have steeda's double adjustable control arms and aluminum lower control arms. I have a 347 and a 100 shot of no2. i dont launch on the bottle. 1.9 60 ft times are killing me. 12.20 @ 120 et. I havent determined my pinion angle yet. I measured from center bolt to center bolt on my convertible and it it 9.25 inches on the uppers. They are aftermarket nonadjustable. My adjustable control arms are 8.75 long. The vert hooks better and transfers better. I was told that if my pinion angle is too far down that my 60 ft should still be better than it is . My tires are et streets @ 13psi 26/10.5-15. I need a low 1.7 maby a 1.6. If my pinion angle is out, i believe it will be to far down. My tokico are set to 5. Maby i was supposed to set them to 1?

Eric4Nitrous · 09-10-2002, 01:24 PM

chassis's are the most important thing in a race car. It can make or break you. Try setting your pinion angle to 1 and post your results from the track.

andy669 · 09-10-2002, 03:05 PM

What bushings are in your control arms? Flexible bushings (i.e. rubber or urethane) require a little more negative pinion angle than solids. Also, what is happening to the tires? Are you blowing them off? I would assume so with a 120mph trap speed! hehe

If you are using all solid bushings and the air bag, I would suggest a pinion angle of -1 to -2. With rubber bushings you might have to go as low as -4.

Andy

Eric4Nitrous · 09-10-2002, 04:27 PM

-4 for rubber bushings?? I wouldn't go but as low as -2 if you are indeed using a rubber bushing. You don't need to set it that low.

andy669 · 09-10-2002, 05:19 PM

The softer the bushings, the more the housing will rotate during launch. Resulting in a need for more negative pinion angle.
1-2 with solids
2-4 with stock type bushings

Andy

Jeff Chambers · 09-11-2002, 06:39 AM

I don't know if any others have found the same, but my car seems to be pretty immune to the pinion angle setting (within reason). I've been everywhere this year, from +2 to -5 degrees and it doesn't amount to a hill of beans in my 60' times. My car runs at 2930#, with 365 rwhp on a 26x8.5-15 slick. I've got Megabite Jrs, Lakewood 90/10 & 50/50, CE pinion snubber, and 4-cyl springs on all corners (which have been chopped about 2 coils).

When my car was making less HP and still had a more stock suspension, the pinion angle seemed to make a little difference, but never a night & day difference.

Nowadays, I've been setting the pinion angle at about -2 degrees, just trying to get the DS near a neutral setting under load as opposed to trying to force extra bite with the rear by going steeper.

Just my $1.95 (inflation you know).

andy669 · 09-11-2002, 06:14 PM

I agree Jeff, adjusting your pinion angle is not going to turn your tireburner in to a instant hooking machine.

The way I understand it is this: During launch, the rearend housing will rotate up. Your pinion angle should be set to where you could draw a straight line through the pinion, driveshaft, and output shaft of the trans during the launch. This would result in the u-joints being completely square with the driveshaft, which is were you will get the most efficient power transfer.

Andy

84gt347 · 09-13-2002, 09:21 AM

Thanks fellas. My car definatly is a tire burner. I loosened up my front struts, and took my pinion angle to -4. My bushings are the polyurethane type. The car seems to be transferring better. Tonight i am going to a local test and tune, barring any rain. I will post results.

09-10-2002, 12:41 PM	#1
84gt347 Registered Member Join Date: Mar 2002 Location: sherwood Forest Posts: 291	My chassis set up I recently bought a steeda drag pac for my car. Drag springs, air bag, drag struts and drag shocks. I have steeda's double adjustable control arms and aluminum lower control arms. I have a 347 and a 100 shot of no2. i dont launch on the bottle. 1.9 60 ft times are killing me. 12.20 @ 120 et. I havent determined my pinion angle yet. I measured from center bolt to center bolt on my convertible and it it 9.25 inches on the uppers. They are aftermarket nonadjustable. My adjustable control arms are 8.75 long. The vert hooks better and transfers better. I was told that if my pinion angle is too far down that my 60 ft should still be better than it is . My tires are et streets @ 13psi 26/10.5-15. I need a low 1.7 maby a 1.6. If my pinion angle is out, i believe it will be to far down. My tokico are set to 5. Maby i was supposed to set them to 1? __________________ 84 gt350 89 lx vert 92 lincoln lsc. All Forced ( one way or another)

09-10-2002, 01:24 PM	#2
Eric4Nitrous Registered Member Join Date: Jan 2002 Location: Va Posts: 1,122	chassis's are the most important thing in a race car. It can make or break you. Try setting your pinion angle to 1 and post your results from the track. __________________ 68 Camaro Gene Fulton 632ci Two stages of Jug 8.41 164mph Rockingham 1-26-03

09-10-2002, 03:05 PM	#3
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	What bushings are in your control arms? Flexible bushings (i.e. rubber or urethane) require a little more negative pinion angle than solids. Also, what is happening to the tires? Are you blowing them off? I would assume so with a 120mph trap speed! hehe If you are using all solid bushings and the air bag, I would suggest a pinion angle of -1 to -2. With rubber bushings you might have to go as low as -4. Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

09-10-2002, 04:27 PM	#4
Eric4Nitrous Registered Member Join Date: Jan 2002 Location: Va Posts: 1,122	-4 for rubber bushings?? I wouldn't go but as low as -2 if you are indeed using a rubber bushing. You don't need to set it that low. __________________ 68 Camaro Gene Fulton 632ci Two stages of Jug 8.41 164mph Rockingham 1-26-03

09-10-2002, 05:19 PM	#5
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	The softer the bushings, the more the housing will rotate during launch. Resulting in a need for more negative pinion angle. 1-2 with solids 2-4 with stock type bushings Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

09-11-2002, 06:39 AM	#6
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	I don't know if any others have found the same, but my car seems to be pretty immune to the pinion angle setting (within reason). I've been everywhere this year, from +2 to -5 degrees and it doesn't amount to a hill of beans in my 60' times. My car runs at 2930#, with 365 rwhp on a 26x8.5-15 slick. I've got Megabite Jrs, Lakewood 90/10 & 50/50, CE pinion snubber, and 4-cyl springs on all corners (which have been chopped about 2 coils). When my car was making less HP and still had a more stock suspension, the pinion angle seemed to make a little difference, but never a night & day difference. Nowadays, I've been setting the pinion angle at about -2 degrees, just trying to get the DS near a neutral setting under load as opposed to trying to force extra bite with the rear by going steeper. Just my $1.95 (inflation you know). __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

09-11-2002, 06:14 PM	#7
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	I agree Jeff, adjusting your pinion angle is not going to turn your tireburner in to a instant hooking machine. The way I understand it is this: During launch, the rearend housing will rotate up. Your pinion angle should be set to where you could draw a straight line through the pinion, driveshaft, and output shaft of the trans during the launch. This would result in the u-joints being completely square with the driveshaft, which is were you will get the most efficient power transfer. Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

09-13-2002, 09:21 AM	#8
84gt347 Registered Member Join Date: Mar 2002 Location: sherwood Forest Posts: 291	Thanks fellas. My car definatly is a tire burner. I loosened up my front struts, and took my pinion angle to -4. My bushings are the polyurethane type. The car seems to be transferring better. Tonight i am going to a local test and tune, barring any rain. I will post results. __________________ 84 gt350 89 lx vert 92 lincoln lsc. All Forced ( one way or another)

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