SS gets squirelly under WOT

[Synner]

The giant sticky up top has all the numbers you need from hotchkis, pedders, or pfadt. Print one and take it to the alignment shop as they say exactly what caster, camber and toe to do which you're off on all of them. Also take it to a place that will take the time to make it even left and right more so than a range.

Cradle and differential bushings would probably help too.

[TornadoSS]

Originally Posted by Synner

The giant sticky up top has all the numbers you need from hotchkis, pedders, or pfadt. Print one and take it to the alignment shop as they say exactly what caster, camber and toe to do which you're off on all of them. Also take it to a place that will take the time to make it even left and right more so than a range.

Cradle and differential bushings would probably help too.

Thanks, those numbers I used are from that sticky, I have been through a decent range if them. Already have diff bushings with the 9 inch kit. I think I will try less camber and zero toe next.

[Parag]

less rear camber will help as the camber increases negative value as the suspension drops during load.
dont try for zero rear toe, it is too risky if you get off a little and have toe out at all. with any rear toe out it will be very twitchy. i go between 1/4 and 1/8 inch total toe in, 1/4 for raceday, 1/8 for drag and street. I did the math backwards and you are less than 1/32" total now.
So i recommend more toe IN

the front alignment will only help for cornering,
I thought stock caster was 7 degrees? am i wrong there? more caster will help once you get sideways, it will pull the steering wheel to hold the car from spinning out.
I always have as much negative camber as possible(isnt much) and a slight toe out(1/8" total toe)

I am still interested in the effects of the suspension drop during launch, if you have it up on the alignment rack, you should throw some weight in the trunk to see.
you still might have the entire rear subframe moving. the stock mounts allow almost an inch of movement!!! the best is to get the pfadt subframe mounts, but around $650 and a bitch to install
I was going to recommend the hotchkis chassis brace, but it looks like you already have it.
the hotchkis brace holds really well for straight line accel, but i am so abusive to my car, i need more lateral support, so i made my own, works really well at the track, totally feel the difference

you should stick a gopro down there to see if anything is moving

[TornadoSS]

Originally Posted by Parag

less rear camber will help as the camber increases negative value as the suspension drops during load.
dont try for zero rear toe, it is too risky if you get off a little and have toe out at all. with any rear toe out it will be very twitchy. i go between 1/4 and 1/8 inch total toe in, 1/4 for raceday, 1/8 for drag and street. I did the math backwards and you are less than 1/32" total now.
So i recommend more toe IN

the front alignment will only help for cornering,
I thought stock caster was 7 degrees? am i wrong there? more caster will help once you get sideways, it will pull the steering wheel to hold the car from spinning out.
I always have as much negative camber as possible(isnt much) and a slight toe out(1/8" total toe)

I am still interested in the effects of the suspension drop during launch, if you have it up on the alignment rack, you should throw some weight in the trunk to see.
you still might have the entire rear subframe moving. the stock mounts allow almost an inch of movement!!! the best is to get the pfadt subframe mounts, but around $650 and a bitch to install
I was going to recommend the hotchkis chassis brace, but it looks like you already have it.
the hotchkis brace holds really well for straight line accel, but i am so abusive to my car, i need more lateral support, so i made my own, works really well at the track, totally feel the difference

Thanks Parag! Yeah stock caster is around 7 degrees, except mine, lol. Damn wide range of factory tolerances! I will shoot for less camber on rear, at least half of front. I have some ideas for the solid rear sub frame bushings later.

[TornadoSS]

Originally Posted by Parag

less rear camber will help as the camber increases negative value as the suspension drops during load.
dont try for zero rear toe, it is too risky if you get off a little and have toe out at all. with any rear toe out it will be very twitchy. i go between 1/4 and 1/8 inch total toe in, 1/4 for raceday, 1/8 for drag and street. I did the math backwards and you are less than 1/32" total now.
So i recommend more toe IN

the front alignment will only help for cornering,
I thought stock caster was 7 degrees? am i wrong there? more caster will help once you get sideways, it will pull the steering wheel to hold the car from spinning out.
I always have as much negative camber as possible(isnt much) and a slight toe out(1/8" total toe)

I am still interested in the effects of the suspension drop during launch, if you have it up on the alignment rack, you should throw some weight in the trunk to see.
you still might have the entire rear subframe moving. the stock mounts allow almost an inch of movement!!! the best is to get the pfadt subframe mounts, but around $650 and a bitch to install
I was going to recommend the hotchkis chassis brace, but it looks like you already have it.
the hotchkis brace holds really well for straight line accel, but i am so abusive to my car, i need more lateral support, so i made my own, works really well at the track, totally feel the difference

you should stick a gopro down there to see if anything is moving

And that is a badass sub frame brace you made!

[JusticePete]

Originally Posted by TornadoSS

Since the rear has been apart several times recently for the 9 inch conversion with an S trac posi (mechanical) I am trying to get my alignment dialed in again, Hopefully some of the alignment gurus can help me out here.

The SS has Spohn trailing arms and toe rods and BMR bushings on the spindle side of the trailing arm. Hotchkis chassis max brace on subframe and Hotchkis 1" lowering springs.

The car is wiggling (not violently) very tightly back and forth side to side under hard acceleration (WOT all gears), most notably at the strip, but does this on the street too. It only became apparent after the 9 inch conversion and the much faster/aggressive acceleration now.

The old numbers were

Front Left Right
Camber -.8 -1.0
Caster 5.9 5.8
Toe in .09 .11
Total Toe .20 Steer ahead -.01
Rear
Camber -.3 -.4
Toe in .10 .09
Total Toe .18 Thrust angle 0.01
NEW current Numbers -

Front Left Right
Camber -.8 -1.1
Caster 5.8 5.9
Toe In .05 .05
Total Toe .10 Steer ahead 0.00
Rear
Camber -.8 -.8
Toe In .07 .07
Total toe .14 Thrust angle 0.00

Can someone give me some advice for which direction I should go with the numbers? Since the new alignment the car did get better with less wiggling but it still has some movement. I am guessing it wants the rear toe and camber closer to 0? It did pretty well with the rear camber near -.3 or -.4 on the stock diff. I have checked all the subframe bolts and hotchkis attaching points.
I am shooting for a happy medium between aggressive street and drag settings on street tires (Invos), I run the car on the drag strip several times a month but mostly street driving. Sorry for the long winded post. Thanks!

A few quick questions please.

1. What are the rear ride heights measured Pedders style in mm?

[IMG][/IMG]

2. You are on OEM coils and struts?

3. The sub-frame bushes are still OEM?

4. What is your tire and wheel package?

[TornadoSS]

Originally Posted by JusticePete

A few quick questions please.

1. What are the rear ride heights measured Pedders style in mm?

[IMG][/IMG]

2. You are on OEM coils and struts?

3. The sub-frame bushes are still OEM?

4. What is your tire and wheel package?

I won't have car back until friday evening, so I don't have ride height measurement. Its 1" lower than stock.
It rides on Hotchkis sport springs 1" drop with stock struts. Stock subframe bushings with Hotchkis under car max brace. The wheel are 9" x 20 front and 11 x 20 rear forgstar f14's wrapped with Invo 275/40 front and 315/35 rear. Thanks!

[JusticePete]

Originally Posted by TornadoSS

I won't have car back until friday evening, so I don't have ride height measurement. Its 1" lower than stock.
It rides on Hotchkis sport springs 1" drop with stock struts. Stock subframe bushings with Hotchkis under car max brace. The wheel are 9" x 20 front and 11 x 20 rear forgstar f14's wrapped with Invo 275/40 front and 315/35 rear. Thanks!

One more question. Have you timed your rear lower control arm bushes?


Bush Timing

Step 1. Lift the car on a two post lift and raise it.

Step 2. Loosen the following bolts/nuts:
Front:
---Inner Control Arm Bushing
---Inner Radius Rod
Rear:
---Trailing Arm Bushings (both ends)
---Toe Rod Bushings (both ends)
---Lower Control Arm Bushings (Inner)
---Upper Control Arm Bushings (Rearward)
---Lower Strut Bushings

Step 3.
Lower the car and drive it around the parking lot SLOWLY and on to the alignment lift.

Step 4.
With the weight of the car on the wheels tighten all of the nuts/bolts to spec.

Step 5.
Align the car at the new ride height.

[jdenotter]

Originally Posted by JusticePete

One more question. Have you timed your rear lower control arm bushes?


Bush Timing

Step 1. Lift the car on a two post lift and raise it.

Step 2. Loosen the following bolts/nuts:
Front:
---Inner Control Arm Bushing
---Inner Radius Rod
Rear:
---Trailing Arm Bushings (both ends)
---Toe Rod Bushings (both ends)
---Lower Control Arm Bushings (Inner)
---Upper Control Arm Bushings (Rearward)
---Lower Strut Bushings

Step 3.
Lower the car and drive it around the parking lot SLOWLY and on to the alignment lift.

Step 4.
With the weight of the car on the wheels tighten all of the nuts/bolts to spec.

Step 5.
Align the car at the new ride height.

deleted post...nvm

[TornadoSS]

Originally Posted by JusticePete

One more question. Have you timed your rear lower control arm bushes?


Bush Timing

Step 1. Lift the car on a two post lift and raise it.

Step 2. Loosen the following bolts/nuts:
Front:
---Inner Control Arm Bushing
---Inner Radius Rod
Rear:
---Trailing Arm Bushings (both ends)
---Toe Rod Bushings (both ends)
---Lower Control Arm Bushings (Inner)
---Upper Control Arm Bushings (Rearward)
---Lower Strut Bushings

Step 3.
Lower the car and drive it around the parking lot SLOWLY and on to the alignment lift.

Step 4.
With the weight of the car on the wheels tighten all of the nuts/bolts to spec.

Step 5.
Align the car at the new ride height.

I have timed the rear bushings that have not already been switched out to poly.

[JusticePete]

There isn't much left to look at.

The guys with the corner weights are on to something and it ties into ride height. The lowest rear ride height wheel will have the least amount of weight. The The tallest, longest will carry more weight. Using corner weighting scales you will be able to get and even load across the two rear wheels which will help keep them straight. I know you are on coils and not coilovers, but you can shim the upper strut mount plate Getting a good accurate rear ride height measurement is a good place to start.

The root cause of your IRS instability will eventually be traced back to the OEM sub-frame bushes. Brace or no brace they are still moving. Switch them out to Pedders EP1201HDs and bolt your brace back in place. Run a few tests. If they are not better I will refund your purchase price and you can keep the bushes. I am able to make an offer like this for two reasons. First, I have a vague idea that it will work and two, most of the people here on C5 are true enthusiasts and I can depend on their integrity.

Even with the EP1201HDs installed, we still want to corner weight and adjust the alignment after to squeeze out every 10th and there might be one or two more tricks we can apply to your car.

[TornadoSS]

Originally Posted by JusticePete

There isn't much left to look at.

The guys with the corner weights are on to something and it ties into ride height. The lowest rear ride height wheel will have the least amount of weight. The The tallest, longest will carry more weight. Using corner weighting scales you will be able to get and even load across the two rear wheels which will help keep them straight. I know you are on coils and not coilovers, but you can shim the upper strut mount plate Getting a good accurate rear ride height measurement is a good place to start.

The root cause of your IRS instability will eventually be traced back to the OEM sub-frame bushes. Brace or no brace they are still moving. Switch them out to Pedders EP1201HDs and bolt your brace back in place. Run a few tests. If they are not better I will refund your purchase price and you can keep the bushes. I am able to make an offer like this for two reasons. First, I have a vague idea that it will work and two, most of the people here on C5 are true enthusiasts and I can depend on their integrity.

Even with the EP1201HDs installed, we still want to corner weight and adjust the alignment after to squeeze out every 10th and there might be one or two more tricks we can apply to your car.

Thanks guys! I will double check ride height tonight and post. Question - how do I adjust the suspension when corner balancing? Shims? I am interested in the subframe bushings, just not ready to tear back into it yet. Thanks for all the great info!

[JusticePete]

Originally Posted by TornadoSS

Thanks guys! I will double check ride height tonight and post. Question - how do I adjust the suspension when corner balancing? Shims? I am interested in the subframe bushings, just not ready to tear back into it yet. Thanks for all the great info!

Shims between the upper rear strut mount. Some have cut them out of aluminum.

You could go all in and bolt on 2/10th in the 60'...

http://www.detroitnews.com/article/2...ros-multi-task


Lingenfelter carries out testing of its 5th Gen Camaro Drag Race Suspension Kit, which is designed not only for the drag strip, but also for autocrossing and daily street driving. (Lingenfelter Performance Engineering)



Get 500 people and their late-model Chevrolet Camaros together, and it can be an eye-opening experience, even for someone well-versed in such things.

It was about a year ago that Mike Copeland, operations manager for Lingenfelter Performance Engineering, attended an event in Arizona hosted by Camaro5.com, a website focused on the rebirth of Chevrolet's modern muscle car.

"It was amazing to me to look at the demographics," Copeland said. "There were people there from 22 years of age through 60 years of age and of their 500 Camaros, there couldn't have been more than two that were still stock. Everybody was modifying them."

That is good news for companies such as Lingenfelter. The company has been producing high-performance parts for Camaros, Corvettes and other vehicles for going on 35 years. Based in Decatur, Ind., Lingenfelter Performance Engineering was founded by the late drag racer John Lingenfelter and is now run by his cousin Ken, a Detroit-area businessman and car collector.

"They sell 100,000 Camaros a year," Copeland said. "There's a large number of those people who are willing to modify their cars."

But, he added, where in decades past someone might modify his or her Camaro specifically for autocrossing or drag racing, now those car owners want to be able to do both exercises — and still use their car for daily driving.

To help make that possible, Lingenfelter has launched its 5th Gen Camaro Drag Race Suspension Kit, which is available in two versions. The kit is designed for 2010 or newer Camaros, cars, Copeland said, that their owners aren't ready to or cannot afford to turn into all-out racers.

One version of the suspension kit retails for $4,495 and includes Lingenfelter by Pedders double adjustable drag racing shocks and custom Lingenfelter by Pedders coil springs for front and rear wheels.

The complete package, priced at $6,750, adds several special rear suspension parts: adjustable trailing arms, adjustable forward tie rods, adjustable stabilizer bar end links, a 1-inch tubular adjustable anti-sway bar, differential bushings, aluminum rear cradle bushings, and an underbody chassis brace.

"Typically, when you design a drag race suspension, it's only good for drag racing," said Copeland. "But these are double adjustable so you can still have a good handling street-driving car and go to the autocross one weekend and to the drag strip the next weekend.

"If you were going to do a full-out road-racing car, these are not the shocks for you. But if you want to road race one week and drag race the next week, these are for you."

Yes, he said, engineering such a setup was a lot more work to extend shock travel and fine-tune shock valving. The hardware is designed for standard-weight cars (not for specially lightened, racing-only modified vehicles).

It also enables ride height changes without affecting spring preload or overall shock travel.

Copeland said Lingenfelter equipped its 2010 Camaro "shop car" with all the competitive aftermarket suspension kits. "We were able to make the car two-tenths of a second faster just by changing to our shocks and struts," he said.

"Typically, people with new Camaros focus on one of two things — performance or aesthetics. People who want the look will do a body kit and wheels and tires, and then suspension. People who focus on performance will do engine upgrades — such as superchargers — and then they'll typically go the suspension next."

Either way, he said, Lingenfelter's suspension setup can be part of the package.

See www.lingenfelter.com for details.

Larry Edsall is a Phoenix-based freelance writer. You can reach him at ledsall@cox.net.

From The Detroit News: http://www.detroitnews.com/article/2...#ixzz1xsYIfmTx

Posted with the permission of the Detroit News

[TornadoSS]

Originally Posted by JusticePete

Shims between the upper rear strut mount. Some have cut them out of aluminum.

You could go all in and bolt on 2/10th in the 60'...

http://www.detroitnews.com/article/2...ros-multi-task


Lingenfelter carries out testing of its 5th Gen Camaro Drag Race Suspension Kit, which is designed not only for the drag strip, but also for autocrossing and daily street driving. (Lingenfelter Performance Engineering)



Get 500 people and their late-model Chevrolet Camaros together, and it can be an eye-opening experience, even for someone well-versed in such things.

It was about a year ago that Mike Copeland, operations manager for Lingenfelter Performance Engineering, attended an event in Arizona hosted by Camaro5.com, a website focused on the rebirth of Chevrolet's modern muscle car.

"It was amazing to me to look at the demographics," Copeland said. "There were people there from 22 years of age through 60 years of age and of their 500 Camaros, there couldn't have been more than two that were still stock. Everybody was modifying them."

That is good news for companies such as Lingenfelter. The company has been producing high-performance parts for Camaros, Corvettes and other vehicles for going on 35 years. Based in Decatur, Ind., Lingenfelter Performance Engineering was founded by the late drag racer John Lingenfelter and is now run by his cousin Ken, a Detroit-area businessman and car collector.

"They sell 100,000 Camaros a year," Copeland said. "There's a large number of those people who are willing to modify their cars."

But, he added, where in decades past someone might modify his or her Camaro specifically for autocrossing or drag racing, now those car owners want to be able to do both exercises — and still use their car for daily driving.

To help make that possible, Lingenfelter has launched its 5th Gen Camaro Drag Race Suspension Kit, which is available in two versions. The kit is designed for 2010 or newer Camaros, cars, Copeland said, that their owners aren't ready to or cannot afford to turn into all-out racers.

One version of the suspension kit retails for $4,495 and includes Lingenfelter by Pedders double adjustable drag racing shocks and custom Lingenfelter by Pedders coil springs for front and rear wheels.

The complete package, priced at $6,750, adds several special rear suspension parts: adjustable trailing arms, adjustable forward tie rods, adjustable stabilizer bar end links, a 1-inch tubular adjustable anti-sway bar, differential bushings, aluminum rear cradle bushings, and an underbody chassis brace.

"Typically, when you design a drag race suspension, it's only good for drag racing," said Copeland. "But these are double adjustable so you can still have a good handling street-driving car and go to the autocross one weekend and to the drag strip the next weekend.

"If you were going to do a full-out road-racing car, these are not the shocks for you. But if you want to road race one week and drag race the next week, these are for you."

Yes, he said, engineering such a setup was a lot more work to extend shock travel and fine-tune shock valving. The hardware is designed for standard-weight cars (not for specially lightened, racing-only modified vehicles).

It also enables ride height changes without affecting spring preload or overall shock travel.

Copeland said Lingenfelter equipped its 2010 Camaro "shop car" with all the competitive aftermarket suspension kits. "We were able to make the car two-tenths of a second faster just by changing to our shocks and struts," he said.

"Typically, people with new Camaros focus on one of two things — performance or aesthetics. People who want the look will do a body kit and wheels and tires, and then suspension. People who focus on performance will do engine upgrades — such as superchargers — and then they'll typically go the suspension next."

Either way, he said, Lingenfelter's suspension setup can be part of the package.

See www.lingenfelter.com for details.

Larry Edsall is a Phoenix-based freelance writer. You can reach him at ledsall@cox.net.

From The Detroit News: http://www.detroitnews.com/article/2...#ixzz1xsYIfmTx

Posted with the permission of the Detroit News

Nice setup! I think it would cost me a divorce on top of the cost of that lingenfelter kit! Lol! Maybe someday.