F Body suspension questions

[LS14gezr]

On a points day prepped track my car is very consistent (thousandths) for incremental and split times. It's when the track is less than good I have issues. Also it doesn't take much to provoke wheelspin downtrack on a suspect track. After having the same car as mine go by me on the bumper during time trials I thought it might be a good idea to seek guidance/info from S/SS racers. First my combo: 2001 camaro LS1, mid 12 second bracket car,t400,ati mrt 8" converter, 3200 stall(not optimized to my combo. Ati says it's as tight as they can make it.). Moser 9" w/4:10 w/locker. S&W sfc, adj tq arm, bmr anti roll bar, bmr rear lower control arm relocating brackets, tubular panhard bar and tubular lower control arms w/rod ends. LCA located in bottom hole(only 2 holes are available),8 pt. roll bar, Afco DA rear shocks w/V6 springs, QA1 SA front shocks(full soft) w/QA1 300# front springs. I have some preload on front springs. 53% frt / 47% rear weight distribution. M&H 26x12x15 slicks. 3650# w/driver. A modest effort, still street legal but I've had success (pts championship,runner up following year, 2012 NED 1 Bracket Finals Pro - 5 rounds w/bye).

My questions are chassis/suspension related. I am looking for a real, working suspension.

1. my pinion angle may be too negative. At 60 mph there is a vibration at light cruise/decel. Goes away on accel. What affect would a too negative pinion angle have related to drag racing?

2. While bringing up launch rpm, the car rises about 3" in rear. It's quite noticeable. I believe this relates to the rear lower control arm bottom mounting position but w/low hp I thought a high
instant center would be best. But aren't I transferring weight to the front? I' m getting good chassis separation though.

3. Front suspension: stock except for above. Using the search here I see bushings and such need upgrade. Recommendations?

4. 1.80 60'. Pretty slow. Car has never 60 footed.

5. Does the fact that I have a low hp car affect the workings of the suspension? I sometimes think that on launch the car pitches back but doesn't have enough power to keep from pitching back forward again. Afco rear DA are set: full soft extension ( have been 8 clicks up
from full soft) 16 clicks from full stiff compression.

6. My converter was setup for a bbc 468/550 hp and a lot more torque than I have.I felt that a converter that didn't hit the tire hard would provide a softer launch and make for more consistent times. Opinions?

7. The camshaft provides a very flat torque curve. 30,40 ft/lbs tops from 2500 to 6000 rpm. 371 rwtq / 354 rwhp.

I want to compete at different tracks and for instance at the bracket finals last year the track conditions deteriorated over the event. I was .1 off my 60' at the end but dialable. With a low hp combo I feel I should never have a traction issue.

I have many different chassis/suspension books for drag racing. If you need to
reference something I may have it.

I've gone on long enough. Just wanted you to have as much info as possible. Thank you in advance for any insight, recommendations, info you can provide.

E103 Ed Knodler

[Coach]

If you want your car to work call Madman 409-792-9744.

IMO-your convert is way to tight.

Coach

[Dragsinger]

LS Racer,

In my opinion, your first step is to forget about the street legal deal.

*Do everything reasonable to remove weight, doing so will help the car in every way.
*Remove the 400 trans and install a powerglide with properly matched 8" converter. The powerglide will be a superior package especially as you remove weight.
*keep a close eye on the tires and consider the tire options. About 200 runs is the reasonable upper limit, maybe less.
*keep good records and experiment, experiment, experiment.
*have fun

[gbur]

Originally Posted by LS14gezr

On a points day prepped track my car is very consistent (thousandths) for incremental and split times. It's when the track is less than good I have issues. Also it doesn't take much to provoke wheelspin downtrack on a suspect track. After having the same car as mine go by me on the bumper during time trials I thought it might be a good idea to seek guidance/info from S/SS racers. First my combo: 2001 camaro LS1, mid 12 second bracket car,t400,ati mrt 8" converter, 3200 stall(not optimized to my combo. Ati says it's as tight as they can make it.). Moser 9" w/4:10 w/locker. S&W sfc, adj tq arm, bmr anti roll bar, bmr rear lower control arm relocating brackets, tubular panhard bar and tubular lower control arms w/rod ends. LCA located in bottom hole(only 2 holes are available),8 pt. roll bar, Afco DA rear shocks w/V6 springs, QA1 SA front shocks(full soft) w/QA1 300# front springs. I have some preload on front springs. 53% frt / 47% rear weight distribution. M&H 26x12x15 slicks. 3650# w/driver. A modest effort, still street legal but I've had success (pts championship,runner up following year, 2012 NED 1 Bracket Finals Pro - 5 rounds w/bye).

My questions are chassis/suspension related. I am looking for a real, working suspension.

1. my pinion angle may be too negative. At 60 mph there is a vibration at light cruise/decel. Goes away on accel. What affect would a too negative pinion angle have related to drag racing?

2. While bringing up launch rpm, the car rises about 3" in rear. It's quite noticeable. I believe this relates to the rear lower control arm bottom mounting position but w/low hp I thought a high
instant center would be best. But aren't I transferring weight to the front? I' m getting good chassis separation though.

3. Front suspension: stock except for above. Using the search here I see bushings and such need upgrade. Recommendations?

4. 1.80 60'. Pretty slow. Car has never 60 footed.

5. Does the fact that I have a low hp car affect the workings of the suspension? I sometimes think that on launch the car pitches back but doesn't have enough power to keep from pitching back forward again. Afco rear DA are set: full soft extension ( have been 8 clicks up
from full soft) 16 clicks from full stiff compression.

6. My converter was setup for a bbc 468/550 hp and a lot more torque than I have.I felt that a converter that didn't hit the tire hard would provide a softer launch and make for more consistent times. Opinions?

7. The camshaft provides a very flat torque curve. 30,40 ft/lbs tops from 2500 to 6000 rpm. 371 rwtq / 354 rwhp.

I want to compete at different tracks and for instance at the bracket finals last year the track conditions deteriorated over the event. I was .1 off my 60' at the end but dialable. With a low hp combo I feel I should never have a traction issue.

I have many different chassis/suspension books for drag racing. If you need to
reference something I may have it.

I've gone on long enough. Just wanted you to have as much info as possible. Thank you in advance for any insight, recommendations, info you can provide.

E103 Ed Knodler

26 in tire is to short, try 28 s.Short tire will not recover.

[LS14gezr]

Found the problem. The design of the aftermarket torque arm, from a well respected manufacturer, put the rear suspension into severe bind. So I made my own based on a slider link. First time out yesterday with this setup - 3 passes 60' foot within .003. Finally a working suspension. My confidence going into the points season is high.

Ed Knodler E103

[Ed Wright]

Your front springs are too stiff also.
And, a lot of rear separation is "so fifteen years ago".
You might want to go to an NHRA race and watch the faster Stock Eliminator F body cars. Ask to look under them, and talk to them. Probably won't hear the same things you read on F body message boards. :-)

[Lee Valentine]

How do you make a 3rd or 4th gen not hook?

[Ed Wright]

Originally Posted by Lee Valentine

How do you make a 3rd or 4th gen not hook?

Good question. LOL

[Ed Wright]

Originally Posted by gbur

26 in tire is to short, try 28 s.Short tire will not recover.

I missed the 26" tires. If he had his rear fender openings re-radiused for & changed to 30" tires he would think he had a whole new car. Taller makes more difference than wider.
You don't want a powerglide either. That is a band aid for a car that won't hook.

[LS14gezr]

Originally Posted by Ed Wright

Good question. LOL

Where were you two guys when I was asking for help?

I have asked 4th gen S/SS racers about their setups and pretty much received the brush off. I don't search for info on f body message boards. No real racers, which is why I posted here. As my sign on name implies, I'm not a kid. Just don't have 35 years experience.

30" inch tires, radius wheel wells, more gear for tires, converter. Based on the results from this past weekend, I believe I achieved my goal for about $300 in parts. Thankfully, I don't have to chase an ever descending index to remain competitive.

If chassis separation is an outmoded concept, then what is the current thinking for stock suspended cars?

Ed Knodler E103