Have you tried & air bag in the passenger side
rear spring with about 8lbs of air, it helped
my car alot. I have a 69 chevelle weighs 3770
with me in it & I run 1.55 60's.
Larry

 

Larry - I forgot those in the list... Yes I have air bags, I've tried many different combinations of air pressure, it never seemed to help any.

Lee

 

I went through the same problems. In the last 2 years my traction was an issue so i'll list what i did.

First phase:
Air bag, adjustable upper control arms
-set one air bag in pass side, adjusted pressure til car launched evenly
-the pinion angle is total 4 degrees
-summit shocks (next upgrade will be better shocks) set at 50/50
-no front sway bar

Second Phase:
Front suspension rebuild
-New busings all around
-new front springs (Small block ac springs)
-new idler arms
-new shocks (summits but like the rears, next upgrades will be better shocks) set at 90/10

Third Phase:
Body Bushings

I have a 502 in a 3850 70 chevelle (me in it) and race at bandimere speedway (mile high elevation). I get 1.7x 60's and run about 12.50s.

Each stuff progressively helped and burnout procedure, tire pressure, staging procedure helped as well.

 

I am curious on how your are changing the pinion angle? I thought the Hotchkis arms are non adjustable. Also have played around with the instant center? As in rasing the upper control arm mounts or lowering the bottom ones on the rear end. Can be done with no hop bars or SM Lower control arms.

Steve

 

Here's my current suspension setup:

Front
=====
Global West upper/lower control arms
Custom QA1 coilover (SBC tapared springs) Promastar shocks set 2 clicks from full soft
front sway bar removed
Alignment with as much positive caster as possible (would need to look at alignment sheet but I think it's ~5.5*)
Hoosier 15" skinnies with 44lbs

Rear
====
Hotchkis adjustable upper control arms
Hotchkis lower control arms
Hotchkis triangulation braces
Edelbrock no-hop bars
-4* pinion angle
QA1 Stocker Star shocks set 1 click from full soft
Air Lift air bags (16psi passenger, 5-8psi driver)
1.125" rear sway bar
Factory replacement rear springs with 1/2 coil removed
MT ET Drags 14-15lbs depending on track temp

The best suspension improvements I've made (in order) are:

- stiff sidewall slick (3055S MT ET Drag)
- Edelbrock no hop bars
- Quality adjustable shocks front and rear

The front coil over is a "nice to have" but not necessary item. I got tired of installing/cutting different OEM springs. I never did try a 6 cylinder spring and wish that I had as the coil over setup is $$$. My next planned change is likey an anti roll bar to replace my rear sway bar. I'm eying the HRPartsNStuff piece. Best 60' in sig. Normal 60's in the 1.49-1.51 range on a decent track.

 

hotchkis has both adjust and non adjust uppers

 

I guess it's been so long since I've done all the upgrades that I missed a few things:

I do have SSM lower bars, hotchkis adjustable uppers. The rear is a currie Ford 9" and I was told the upper brackets have been relocated up a bit from stock.

kjett- you make a ton more power then I do so I would expect more traction problems then me yet your hooking well.

Now, and I'm a little embarrassed to admit this, but the body bushings are stock and most likely original and I have no roll cage. How much will this effect me? I hated to cut up the car for a cage but I'm finally ready to do it, I also have energy suspension body mounts. Maybe this is the whole answere to my problems....

Lee

 

Lee,

I don't know anyone else running at the elevation that you're running at so I can't say how much of what you're experiencing is related to the air (or lack there of). The worst air I run in is 4,000' in the dead of summer. My 60' times will slow .03-.04 from 4,000' air to 2,000' air. I ran my car quite a bit before adding a roll bar. It went 10.79@124 and change with a 1.52 60' without the roll bar. My roll bar has a swing out on the drivers side so the chassis is likely not as rigid as a roll bar without the swing out arms. IMO, I don't think a roll bar will be a cure all for your 60' times. You might see a slight improvement. As for body bushings, again maybe a minor improvement. I have replaced all the body bushings on my car (except for one that I couldn't get out) with OEM replacement rubber.

Something you said about your setup concerns me. The fact that the currie rear end has the raised ears coupled with the SSM bars may have a negative impact on your cars instant center. Typically people do one or the other; either lower the rear mounting point (ala SSM bars) or raise the upper rear mounting point (ala no hop bars). Since you've essentially done both the instant center may be too short and causing the tires to be hit too hard. If you have access to a set of boxed stock lower control arms it may be worth swapping out the SSMs to see if this is the problem. You should be able to get your 60' times down to the mid-low 1.5x (or better) range with basically stock bolt on suspension upgrades and a good set of shocks front/rear. I'm not familiar with the Hoosier QTP tires, but I can tell you that the Hoosier D05 compund tires never worked on my car. I saw an improvement of nearly .08 in 60' just switching to the stiff sidewall MT ET Drag tires. I don't want to make these tires sound like a cure all but that's what they did for my car. BIll Burke (BillsCamino) was also running the Hoosier tires two weeks ago behind his 540ci monster and the best 60' times he could muster was 1.80. I gave him an old set of 3055S MT ET Drags (91 passes on them) to try and with no other changes (a little better air) his 60' dropped to 1.599. Something to think about.

The other advice I will offer, and possibly the best I have to offer, is to get someone to video tape the rear tires of your car at launch. If you have access to a digital cam corder this is an invaluable tuning aid. I video taped my car (or rather my wife) over the course of a few months. I would then transfer the videos to my PC and play them back frame by frame. My cheapo Sony cam corder has a frame by frame slow motion replay that I can control through the firewire connection. This allowed me to see exactly what my car was doing. You want to have some separation at the rear wheel (planting the tires), but not too much. My guess is that if you were to video your car now you would see a lot of separation just before the car spins. If you get too much separation in the rear you can top out the spring/shock travel and that will cause the rear tires to unload. Not knowing where you are at in the suspension tuning process you may need to start with the front end. If the front wheel(s) are lifting at all I would focus my attention on the rear suspension. Once the front tires are off the ground all the weight is on the rear and it's largely up to the rear suspension to keep the car going forward/up.
HTH.

 

Ken - thanks for the replies. I had the same problem when I had the hotchkis lowers, then I tried the SSM and there was absolutely no difference. Also, currie said it was only a slight increase with the mounts. I've also ran drag radials and to my surprise the best 60's have been with the drag radials but it was so violent when it lauched by hooking-spinning-hooking and very inconsistent.

On my wifes camaro the hoosiers have always done better then M/T so that's why I went with them.

I can tell you that there is none to very little separation on the rear when I launch. It doesnt squat either! The front end rises and just rotates on the rear axle (does that make sense?). If you watch the video it just goes forward with little excitement or body pitch, it's actually quit boring... The Yank converter does flash to about 4400 on the launch and it's the second one I've tried. I've have also tried 3.70 and 4.30 gears with absolutley not change in any incremental times!

Lee

 

Originally posted by 70_chevelle:
Ken - thanks for the replies. I had the same problem when I had the hotchkis lowers, then I tried the SSM and there was absolutely no difference. Also, currie said it was only a slight increase with the mounts. I've also ran drag radials and to my surprise the best 60's have been with the drag radials but it was so violent when it lauched by hooking-spinning-hooking and very inconsistent.

On my wifes camaro the hoosiers have always done better then M/T so that's why I went with them.

I can tell you that there is none to very little separation on the rear when I launch. It doesnt squat either! The front end rises and just rotates on the rear axle (does that make sense?). If you watch the video it just goes forward with little excitement or body pitch, it's actually quit boring... The Yank converter does flash to about 4400 on the launch and it's the second one I've tried. I've have also tried 3.70 and 4.30 gears with absolutley not change in any incremental times!

Lee

Lee,

I understand what you're saying, but the Chevelle is a much different animal to hook than a 1st gen Camaro (nice one, BTW). The Chevelle has a longer wheel base and quite a bit more weight over the rear wheels, and it's also a nose heavy pig! The things that work on her car almost assuredly won't work on your A body. The converter sounds pretty close. My 8" ATI brake stalls to 5,000RPM and flashes to 5,300 between shifts. Start with the rear shocks set on the softest setting possible. I know others will tell you to use a 50/50 valving, but that's a relative statement isn't it? The QA1 shocks I use have killer valving. I know for sure that a QA1 Stocker Star set on full soft has as much (or more) valving than a KYB GasAdjust shock; I've tried both

 

This weekend I tried the softest all the way to the hardest and the softest was certainly the best! I have 9 way adjustable on the front and rear. I also have the fronts on the softest setting too.

So, if I'm reading you right, there's not anything apparently wrong with my setup other then you would suggest M/T's? That's depressing...

Lee

 

Lee,

YGM. Take a look at this video:

http://bellsouthpwp.net/k/_/k_jett/Images/Videos/ken1slow.wmv

You can see my car pull both front tires on launch and then immediately unload the rear tires. The car finally settles down about 65'-70' out. I was able to fix this with nothing but front/rear shock valving. Note the rear sway bar being forced into the ground as the suspension separates from the car.

 

Originally posted by kjett:
BIll Burke (BillsCamino) was also running the Hoosier tires two weeks ago behind his 540ci monster and the best 60' times he could muster was 1.80. I gave him an old set of 3055S MT ET Drags (91 passes on them) to try and with no other changes (a little better air) his 60' dropped to 1.599.

What Kenny doesn't know because we haven't yet compared notes face to face is...
Right off the trailer last Friday with the same shock settings and air pressures as the previous weekend and with ONLY the change of slicks (from Hoosier to Kenny's M/T stiffs), my 60' dropped to 1.63X. As the night went on, I fine tune adjusted the QA1 and air bag pressures down to a best of 1.599 . Still much more room for improvements.
Ended up with the right rear shock @ 6 clicks, left rear @ 2 clicks, left bag @ 5 lbs, and right bag @ 17 lbs. This keeps the left front tire only about 3" off the ground at launch but the car still rises crooked.
Ordered the HR parts sway bar/anti roll setup today. Hopefully ,it will help cure this.

 

Originally posted by BillsCamino:
</font><blockquote>quote:</font><hr />Originally posted by kjett:
BIll Burke (BillsCamino) was also running the Hoosier tires two weeks ago behind his 540ci monster and the best 60' times he could muster was 1.80. I gave him an old set of 3055S MT ET Drags (91 passes on them) to try and with no other changes (a little better air) his 60' dropped to 1.599.

What Kenny doesn't know because we haven't yet compared notes face to face is...
Right off the trailer last Friday with the same shock settings and air pressures as the previous weekend and with ONLY the change of slicks (from Hoosier to Kenny's M/T stiffs), my 60' dropped to 1.63X. As the night went on, I fine tune adjusted the QA1 and air bag pressures down to a best of 1.599 . Still much more room for improvements.
Ended up with the right rear shock @ 6 clicks, left rear @ 2 clicks, left bag @ 5 lbs, and right bag @ 17 lbs. This keeps the left front tire only about 3" off the ground at launch but the car still rises crooked.
Ordered the HR parts sway bar/anti roll setup today. Hopefully ,it will help cure this. </font>[/QUOTE]Thanks for the clarification, Bill. Still, .17 in 60' ain't bad for a tire change The shocks settings you ended up with are interesting. If anything I would have thought more valving on the drivers side to account for the weight in the front seat

 

Ken, I'm barely raising the front fenders let alone the tires! If I get a minute in the next few days I'll post a small slow motion video of the launch. I cant see anything right off when I'm watching but maybe you guys will see something I'm not. We have a couple of chevelles here that run low 12's pulling a tire, they are gutted shells though.

Thanks for everyones input.

Lee

 

Originally posted by kjett:
If anything I would have thought more valving on the drivers side to account for the weight in the front seat

Hey...I'm STILL on that So. Beach diet!

 

Originally posted by BillsCamino:
</font><blockquote>quote:</font><hr />Originally posted by kjett:
If anything I would have thought more valving on the drivers side to account for the weight in the front seat

Hey...I'm STILL on that So. Beach diet!

</font>[/QUOTE]Oh, I didn't mean it that way. I've spoken with some old time racers before and received that tip. makes sense to run a little more shock valving and maybe even a little more tire pressure on the drivers side when you get down to tuning hundreths or thousandths

 

Originally posted by 70_chevelle:

Now, and I'm a little embarrassed to admit this, but the body bushings are stock and most likely original and I have no roll cage. How much will this effect me?

Lee

Lee, when i swapped from stock 35 yr old bushings to new bushings from p-s-t.com my luanches were more consistent and huge improvement in the 60's. Before it would vary from mid 1.7x to low 1.8x. Now its low 1.7s to mid 1.7s. Do not skip this detail when looking at traction issues.

 

Are you still running the front sway bar?? If so when we pulled it from my bro in law's 69 Chevelle it made a huge difference. He is consistant 1.65's with ssm bars/Hotchis rear springs/Summit rear shocks. The front is Summit 90/10's/Hotchis drop springs/no sway bar. The car lifts HARD . Tires are 28x12.5 ET streets.

Also with that 502 and 3.06 first gear coupled with the steep rear gear to me seems like way to much mech advantage. I say step back to 3.42's and I bet it hooks a bunch better.

 

I was just thinking that with a TH700R4 and your gears you are to low in first gear....then noticed that 6D9 said the same thing.
That FI 502 has to make a ton of torque!
And how about moving to where you have some air???Sorry, we at sea level get spoiled....and wouldn't have the first clue what to do where you are.
And as others have said, I don't know about the QTP's, I run regular Hoosier slicks and they work just the same as M/T's or even Goodyears.

Ron

 

One more thing.....is the 9" a locker? Or a Posi?
Sometimes posi's don't......
Ron

 

Buddy - I'm now looking forward to replacing my body bushings!

6D9 - No, I took that off long ago. I also have the hotchkis 1" drop springs, and I've wondered many times if that's hurting the abilty to shift the weight on launch. With the 3.70's I cross the finish line at ~5600 RPM @ ~116, 3.42's would drop it quit a bit! Interestingly, my 60's are near identical with 3.70 and 4.30 gears, it seems that with 4.30's I would spin even more? Plus with cars running in the 10's, wouldnt they have more of a mechanical advantage due to the increased torque they produce? If you were to calculate the axle torque with a 10 second car with 3.42 vs mine I'm sure they are producing far more torque and thus would have worse traction problems.

Ron - I would love some more air, so would our cars! Just going to Boise my wifes camaro drops .4 and picks up 5MPH! I have the detroit locker.

Maybe I'll try some sand bags in the trunk!

With the SSM bars arent I'm supposed to be getting body separation? I get none even with the shocks on 0.

Lee

 

Originally posted by 70_chevelle:
I also have the hotchkis 1" drop springs, and I've wondered many times if that's hurting the abilty to shift the weight on launch...

...With the SSM bars arent I'm supposed to be getting body separation? I get none even with the shocks on 0.

Lee

The spring rate on the Hotchkis lowering springs it way to stiff for what you're trying to do. Been there, done that. Get a factory replacement moog spring front and rear at a minimum. Many folks have had luck running 6 cylinder or SBC front springs on a BBC chevelle. Avoid the Moroso trick springs on the front if you've got over 1,900 or so pounds over the front tires. They will not last. Moroso trick springs would be a pretty good choice for a rear spring, IMO.

 

Lee, My son's '70 Chevelle with a "540 BB" usually cuts low 1.40 sixty foot times and has a Currie 9" Ford rear end with a spool and 31 spline axles. The currie rear end has a nearly stock height on the upper attachment points and is not going to help your lift. I think your transmission has too much first gear multiplication to produce good 60' times. Your front springs might also be contributing to your lack of weight transfer. K Jett's car seems to be porposing and could probably run better with a slightly slower rise of the front end. The aftermarket anti-roll bars work a lot better than a factory anti sway bar on the rear end and we have had very good luck with the Moroso front drag springs. The anti-roll bar located above the rear end housing helped straighten out the front end twist and turning to the right on launch but didn't reduce 60' times. The best so far was when the 482" motor was in the car ( 1.38) in good air. All the local shootout racers go to Powerglides which have about 1.8 first gear ratios and then nitrous the hell out of them to get the torque on the ground and move the cars hard.

 

Originally posted by Harold Sutton:
Lee, My son's '70 Chevelle with a "540 BB" usually cuts low 1.40 sixty foot times and has a Currie 9" Ford rear end with a spool and 31 spline axles. The currie rear end has a nearly stock height on the upper attachment points and is not going to help your lift. I think your transmission has too much first gear multiplication to produce good 60' times. Your front springs might also be contributing to your lack of weight transfer. K Jett's car seems to be porposing and could probably run better with a slightly slower rise of the front end. The aftermarket anti-roll bars work a lot better than a factory anti sway bar on the rear end and we have had very good luck with the Moroso front drag springs. The anti-roll bar located above the rear end housing helped straighten out the front end twist and turning to the right on launch but didn't reduce 60' times. The best so far was when the 482" motor was in the car ( 1.38) in good air. All the local shootout racers go to Powerglides which have about 1.8 first gear ratios and then nitrous the hell out of them to get the torque on the ground and move the cars hard.

Harold,

That video was before I tuned the shocks. I put that up there so that Lee would know what to watch for. My car launches fine now. You're one of the few people I've heard singing the praises of the Moroso trick springs for the front of a nose heavy Chevelle. My car currently has 2,070lbs over the front tires. I'm going to venture a guess that your son's car has been significantly lightened.