Team Chevelle banner

Status
Not open for further replies.
61 - 80 of 108 Posts

·
Registered
Joined
·
171 Posts
They have an adjustable length, right?
Absolutely. I wasn't implying that having the proper pinion angle isn't important. Sure it is. But it isn't what gives you better traction off the starting line. Having the correct IC location as well as a free moving front suspension, (preferably with at least 5" of upward front suspension travel) is what gets your car to hook. You'll also need to dial in some good shock settings too, and of course taller/lighter front coil springs help out a lot.
Lowers plus 1/4” non adjustable
Uppers double adjustable.
All greasable delrin/urethane bushed.
Has rubber in ears on rear as per moser.
They said it’s better that way.
 

·
Registered
Joined
·
171 Posts
With these cars you need to know how far you want to go. I’ve reached my limits for now. Don’t want to cut or weld anymore if I don’t have to.
So slow down to 10.0 for index and pro dial.
 

·
Registered
Joined
·
171 Posts
They have an adjustable length, right?
Absolutely. I wasn't implying that having the proper pinion angle isn't important. Sure it is. But it isn't what gives you better traction off the starting line. Having the correct IC location as well as a free moving front suspension, (preferably with at least 5" of upward front suspension travel) is what gets your car to hook. You'll also need to dial in some good shock settings too, and of course taller/lighter front coil springs help out a lot.
I shortened my front suspension travel too to 3”.
Using Gm springs and afco 80/20 front shocks.
 

·
Registered
Joined
·
540 Posts
Along with I/C location, chassis stiffing (in one form or another) and controlling body roll are essential.
For those not wanting to go roll bar/cage for chassis stiffing Summit, Hellwig, and others make kits for this.
I opted to fab up my own and save 500+ bucks, along with mine supports the control arm mounting points.
thumbnail_image1.jpg

DSC_0064.JPG

Crossmember w/exhaust clearance.
DSC_0065.JPG

When I swapped the 12 bolt out for the Moser M9, the upper arms interfered with the ARB due to the taller upper mounting points of the M9.
The ARB's new home along with correcting shock alignment and reinforcement.

DSC_0061.JPG

DSC_0060.JPG
 

·
Premium Member
Joined
·
13,873 Posts
I shortened my front suspension travel too to 3”.
Using Gm springs and afco 80/20 front shocks.
And have you raced the car since you made those changes to the front end? ( I mean since you shortened the front travel to 3")??? I think in many cases it depends on the front/rear weight bias of the car in question. For full weight BB GM A-body cars with stock steel bodies, iron blocks full interiors, etc, they're so nose-heavy that you usually need the extra travel in your front suspension to take full advantage of the "stored energy" in the front coil springs for the added weight transfer during the launch. Now for cars with glass hoods, front bumpers, light weight radiators, removed heater cores, and heater ducts, etc., etc,... it's a whole lot easier to still hook good with only 3" of front suspension travel. But the whole vehicle combination is what matters.

For instance, adding Ladder bars, and back halving the car, along with wheel tubs obviously changes the game.
 

·
Premium Member
Joined
·
13,873 Posts
Along with I/C location, chassis stiffing (in one form or another) and controlling body roll are essential.
For those not wanting to go roll bar/cage for chassis stiffing Summit, Hellwig, and others make kits for this.
I opted to fab up my own and save 500+ bucks, along with mine supports the control arm mounting points.
View attachment 705121

View attachment 705122

Crossmember w/exhaust clearance.
View attachment 705123

When I swapped the 12 bolt out for the Moser M9, the upper arms interfered with the ARB due to the taller upper mounting points of the M9.
The ARB's new home along with correcting shock alignment and reinforcement.

View attachment 705124

View attachment 705125
I really like what you did there. That looks like really nice work. However for drag racing in the 10 second and 9 second neighborhoods,(and beyond) not only will the tech inspectors still require you to have a roll cage, but even the amount of impressive work that you did still won't take the place of a roll cage for stiffening up the car, and preventing chassis flex. I'm not saying that the work you did won't add to the stability and stiffness of the chassis, ( of course it has) but a roll cage would stiffen it more.

Again, I'm not discounting the work that you did. I'm merely saying that aside from getting it past drag strip tech inspectors, if you want to get serious about drag racing the car and making it launch consistent, instead of your tires going up in smoke, then you would have to take your work further by adding a roll bar or roll cage depending on how fast you want to go, and what power level you're at.

As I'm sure you already know, chassis flex will KILL and prevent any launch consistency, since the flexing will be a little different during every individual launch, and therefore it becomes difficult to dial in shock settings that will be effective. You'll be like a puppy dog running in circles chasing his tail.
 

·
Registered
Joined
·
540 Posts
I really like what you did there. That looks like really nice work. However for drag racing in the 10 second and 9 second neighborhoods,(and beyond) not only will the tech inspectors still require you to have a roll cage, but even the amount of impressive work that you did still won't take the place of a roll cage for stiffening up the car, and preventing chassis flex. I'm not saying that the work you did won't add to the stability and stiffness of the chassis, ( of course it has) but a roll cage would stiffen it more.

Again, I'm not discounting the work that you did. I'm merely saying that aside from getting it past drag strip tech inspectors, if you want to get serious about drag racing the car and making it launch consistent, instead of your tires going up in smoke, then you would have to take your work further by adding a roll bar or roll cage depending on how fast you want to go, and what power level you're at.

As I'm sure you already know, chassis flex will KILL and prevent any launch consistency, since the flexing will be a little different during every individual launch, and therefore it becomes difficult to dial in shock settings that will be effective. You'll be like a puppy dog running in circles chasing his tail.
Thank you.
I agree with you about the roll bar/cage.
I started with the roll bar (NHRA ET. rules ), then decades later to a full cage, and now lastly the underside reinforcement, adjustable control arm mounts and window net for 8.50 chassis certification
I even added an X brace, and other bars between the main hoop and the backside of the rear upper control arm mounts.
DSC_0067.JPG

I posted it as more a fuel for thought thing for those not wanting/concerned with racing and a roll bar/cage to stiffen up the chassis some.
Every bit helps.
 

·
Premium Member
Joined
·
13,873 Posts
Thank you.
I agree with you about the roll bar/cage.
I started with the roll bar (NHRA ET. rules ), then decades later to a full cage, and now lastly the underside reinforcement, adjustable control arm mounts and window net for 8.50 chassis certification
I even added an X brace, and other bars between the main hoop and the backside of the rear upper control arm mounts.
View attachment 705160

I posted it as more a fuel for thought thing for those not wanting/concerned with racing and a roll bar/cage to stiffen up the chassis some.
Every bit helps.
Oh yes, I had forgotten about that X-brace that you told me about that you've added to the cage. Nice!
 

·
Registered
Joined
·
4,320 Posts
I agree with the guy earlier in this topic that said to add brackets to the top of the rear and use hiem joints. I fabricated and added these brackets to the top of my Strange Engineering 9". I used the old ears as a guide.


705166

20190119_104022.jpg


705162


705164
 

·
Premium Member
Joined
·
13,873 Posts
I agree with the guy earlier in this topic that said to add brackets to the top of the rear and use hiem joints. I fabricated and added these brackets to the top of my Strange Engineering 9". I used the old ears as a guide.


View attachment 705166
View attachment 705165

View attachment 705162

View attachment 705164
That looks like it came out real nice Rick. Thanks for the pics. How thick are the steel pieces you used for those brackets? .125"? .250"? And did you cut them out with a plasma cutter?
 

·
Registered
Joined
·
1,129 Posts
Along with I/C location, chassis stiffing (in one form or another) and controlling body roll are essential.
For those not wanting to go roll bar/cage for chassis stiffing Summit, Hellwig, and others make kits for this.
I opted to fab up my own and save 500+ bucks, along with mine supports the control arm mounting points.
View attachment 705121

View attachment 705122

Crossmember w/exhaust clearance.
View attachment 705123

When I swapped the 12 bolt out for the Moser M9, the upper arms interfered with the ARB due to the taller upper mounting points of the M9.
The ARB's new home along with correcting shock alignment and reinforcement.

View attachment 705124

View attachment 705125

looks good but the biggest improvement i seen was adding additional body mounts to your extra bracing. This will have a very similar effect as to adding a roll cage. all those floor braces, tie those into the chassis with mounts.

I did on mine with some polyurethane bushings... its doesn't move at all anymore.

check out post 85 in the boosted beaumont thread for a couple pictures of what i am talking about
 

·
Premium Member
Joined
·
13,873 Posts
looks good but the biggest improvement i seen was adding additional body mounts to your extra bracing. This will have a very similar effect as to adding a roll cage.
Adding more body mounts will only tie the body to the frame more. How can that prevent the frame itself from flexing? Because in addition to being for personal safety, a roll cage stiffens the frame itself, and reduces or prevents frame flexing. Are you saying that the sheet metal of the body is going to reduce frame flex like a roll cage does?

Not meaning to be a wise guy, but I'm pretty sure that the 5/8" diameter.134" wall thickness steel tubing of roll cages being welded to 8 or 10 points on the frame stiffens it a whole lot more than adding 8 or 10 additional body mounts to the frame would.
 

·
Registered
Joined
·
171 Posts
And have you raced the car since you made those changes to the front end? ( I mean since you shortened the front travel to 3")??? I think in many cases it depends on the front/rear weight bias of the car in question. For full weight BB GM A-body cars with stock steel bodies, iron blocks full interiors, etc, they're so nose-heavy that you usually need the extra travel in your front suspension to take full advantage of the "stored energy" in the front coil springs for the added weight transfer during the launch. Now for cars with glass hoods, front bumpers, light weight radiators, removed heater cores, and heater ducts, etc., etc,... it's a whole lot easier to still hook good with only 3" of front suspension travel. But the whole vehicle combination is what matters.

For instance, adding Ladder bars, and back halving the car, along with wheel tubs obviously changes the game.
Yup. Ran it last 2 years as I’ve said here.
 

·
Registered
Joined
·
171 Posts
Adding more body mounts will only tie the body to the frame more. How can that prevent the frame itself from flexing? Because in addition to being for personal safety, a roll cage stiffens the frame itself, and reduces or prevents frame flexing. Are you saying that the sheet metal of the body is going to reduce frame flex like a roll cage does?

Not meaning to be a wise guy, but I'm pretty sure that the 5/8" diameter.134" wall thickness steel tubing of roll cages being welded to 8 or 10 points on the frame stiffens it a whole lot more than adding 8 or 10 additional body mounts to the frame would.
I would think more body mounts will help. Gm left certain models unbolted in certain places for a more comfortable ride I believe.
It’s like grabbing something with 3 fingers instead of 4.
I could be wrong.
 

·
Registered
Joined
·
1,129 Posts
Adding more body mounts will only tie the body to the frame more. How can that prevent the frame itself from flexing? Because in addition to being for personal safety, a roll cage stiffens the frame itself, and reduces or prevents frame flexing. Are you saying that the sheet metal of the body is going to reduce frame flex like a roll cage does?

Not meaning to be a wise guy, but I'm pretty sure that the 5/8" diameter.134" wall thickness steel tubing of roll cages being welded to 8 or 10 points on the frame stiffens it a whole lot more than adding 8 or 10 additional body mounts to the frame would.
said it was similar... but if you add more fixed points to the frame there is less spacing between mount points for the frame to move. adding additional mounts takes a lot of torsion out of the frame. It is surprising how much the front to back frame rails move, tieing these into the body will eliminate a lot of flex and torsion.

Somewhat hard to explain, all i know is if i jacked the front passenger side up solely to lift the car you'd see a lot of movement in everything and everywhere. Now it flex's maybe 1/2" and lifts. The door and fender gaps remain where they should. Adding an additions 6 mount points will reduce flex and torsions dramatically without the need of a cage. If eliminating is your end goal, there no doubt a cage is the route you should take.

i like this analogy "It’s like grabbing something with 3 fingers instead of 4. " for simple people like me!
 

·
Premium Member
Joined
·
13,873 Posts
I would think more body mounts will help. Gm left certain models unbolted in certain places for a more comfortable ride I believe.
It’s like grabbing something with 3 fingers instead of 4.
I could be wrong.
said it was similar... but if you add more fixed points to the frame there is less spacing between mount points for the frame to move. adding additional mounts takes a lot of torsion out of the frame. It is surprising how much the front to back frame rails move, tieing these into the body will eliminate a lot of flex and torsion.

Somewhat hard to explain, all i know is if i jacked the front passenger side up solely to lift the car you'd see a lot of movement in everything and everywhere. Now it flex's maybe 1/2" and lifts. The door and fender gaps remain where they should. Adding an additions 6 mount points will reduce flex and torsions dramatically without the need of a cage. If eliminating is your end goal, there no doubt a cage is the route you should take.

i like this analogy "It’s like grabbing something with 3 fingers instead of 4. " for simple people like me!
I know what you guys are talking about with the factory frames of our cars, because I too have seen it when I begin raising the floor jack with the saddle placed underneath the front cross member of the frame. With the factory set-up you can raise the floor jack quite a bit before the body and the rest of the car actually begins to raise up. It's actually kinda scarey to see how much that front loop of the frame flexes, because that's the part of the frame that the lower front control arms get attached to via their mounting bolts.

So I fully understand what you guys are intending to point out. Thanks for explaining that. Now here's the thing.... by adding more body mounts to a flex-happy frame, you might reduce the frame flex a little bit as viewed when you're slowly raising and lowering your car on and off the garage floor. But during a hard launch at the race track, ( particularly when you begin getting close to or well into the 1.3 second 60 foot neighborhood) the frame and body are going through much more intense, and much more violent jarring forces than when you're raising and lowering the vehicle with a hydraulic jack.

I bring that up because during the starting line launch, you're not just talking about the weight of the car trying to flex the chassis/frame, but also the engine torque and the resulting multiplied axle torque. So if you were to reply on those added body mounts alone to "stiffen" of the frame during drag strip use, there's a very good chance that eventually you see certain signs that the body of the car itself is being stressed, and twisted permanently. The areas to look at which can indicate signs, or proof of such twisting damage is right where the roof in the rear meets the quarter panels. If the body if being tweaked you'll often begin to see the paint cracking in that area. If you see that then it's no coincidence. Particularly if/when there are no signs of the paint cracking in any of the surrounding areas.

Now I suppose it's possible to see those cracking signs of paint if the roll cage being used is inadequate, or was poorly installed. But a good roll cage will reduce flex much better than body mounts will since in essence with the latter you're using a big piece of sheet metal to stop the frame from flexing instead of using steel tubing.
 

·
Registered
Joined
·
540 Posts

·
Registered
Joined
·
2,006 Posts
9612804044316148862283
I agree with the guy earlier in this topic that said to add brackets to the top of the rear and use hiem joints. I fabricated and added these brackets to the top of my Strange Engineering 9". I used the old ears as a guide.


View attachment 705166
View attachment 705165

View attachment 705162

View attachment 705164
Looks awesome Rick, have you ran the car with the new upper brackets yet? I thought about doing the same thing to my housing.
 

·
Registered
Joined
·
451 Posts
Well then you either lucked out, and got your instant center in the right place by accident,( that happens sometimes, but not usually) or you went through some trial and error with testing out the results of various mounting point locations of your rear control arms until you got your I.C. location in the right place and you don't even realize it, or a previous owner had the rear suspension set-up correctly. But either way, I'll bet dollars to doughnuts that if I ran your rear suspension measurements through my software, it would show your instant center location as being ideal, or very close to it.

I can assure you that you're NOT running 1.3 second short times merely because you've set the pinion angle correctly. Pinion angle has nothing to do with starting line traction. That's a myth. And for some reason it seems to be a very common myth. Now pinion angle just might indirectly effect the way a leaf spring equipped car hooks. But that definitely does NOT apply to coil sprung cars.

I know a few lucky people, myself included. Never plotted anything, no trick parts, no hop bars, lowered mounts, nothing but stock arms boxed and polyeurathane bushings, a single airbag in RR spring, CE/Summit 3 way shocks, and a OEM rear roll bar. Moroso Trick springs in front and worn out stock springs in the rear. My car was 3650 with me in it at the time and went 1.41 60' with my little 500hp 406 and a 150 shot.
Buddy of mine had a 72, 13:1 468, 200HP Big Shot plate, 3880lbs, full exhaust, etc, same suspension setup. 1.37 60', 9.66 @ 139mph.
All was 20+ years ago, and that was pretty common setup around here at the time. It wasn't perfect or pretty, but it got the job done. Ride height is a factor when it comes to making the stock location stuff work.
705345


705346


I'd highly buying and reading Dave Morgans book, the Door Slammer Chassis. Lots of good information to be applied.
I will disagree with Billy's statement that pinion angle doesn't affect the hit, as would Dave Morgan and plenty of other racers. It is different for a leaf spring car vs a 4 link or ladder car.

Billy, how fast has you car been with the 632 and chassis mods? What does the rest of your suspension setup look like? How does your suspension plot for IC? What does the front/rear percentage look like?
 
61 - 80 of 108 Posts
Status
Not open for further replies.
Top