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Discussion Starter #1
Converted over to a quick performance 9" that I should have in the next week or two and I had a couple questions about initial setup. Could you guys share where you have everything set to right now so I have some kind of starting point. One thing the previous owner had on the 12 bolt were the no hop bars attached to the housing. He told me unless I have the ears mounted up higher to mimic the no hop bars that the car won't lift on the hit and will never 60ft properly. Car had a best time of 9.67 before I literally replaced everything in the car to handle the new setup. Any input or base settings (which bolt holes to choose with upper/lower control, pinion angle etc.) arms would be much much appreciated as I am adding additional goodies. Below is the old setup and how I am configuring the new rear end.

12 bolt
Stock upper control arm bushings
No hop bars
Adjustable rear upper control arms
Non adjustable lower control arms with stock mounting brackets
Shocks moved inboard vertically
UMI drag anti roll bar

QP 9"
Spherical aluminum upper control arm bushings
TRZ adjustable rear upper control arms
TRZ double adjustable rear lowers with double adjustable dual rod ends
QP adjustable lower control arm mounts
Shocks moved inboard vertically
TRZ anti roll bar (above axle)


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Compare the heights of the upper ears on both rears. Some aftermarket housing have them raised a little over factory. I think Moser did this. But yes, you are taking hit out of the rear by dropping the rear of the upper bar.
 
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Discussion Starter #3
Compare the heights of the upper ears on both rears. Some aftermarket housing have them raised a little over factory. I think Moser did this. But yes, you are taking hit out of the rear by dropping the rear of the upper bar.
Is there any way to duplicate this with all the new adjustable arms and mounts? Obviously anyone running a 9" can't utilize these no hop bars.
 

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Yes Sir the QP 9" upper control arm ears are higher when compared to a stock 12bolt. Not by much though, and not close to the Anti Hops. I'm remembering 5/8" I think. My rear is lowered 3-4" as well (will be 5" this weekend), so that helps put a better angel on the uppers in relation to their forward mount but not as much leverage. I run full UMI roto-joints on the entire rear so no rubber/poly.

There is no set standard for driveshaft/pinion angle for ALL. It is what it is. Install the rear and set the pinion angle with all the weight on the car. Trans and pinion should be within 1-3* equal and opposite with a more favorable 1* down angle on the pinion side to allow the pinion to rise under acceleration.

My lower control arm is on the third hole from the bottom on the rear axle mount. That is one hole down from being parallel for me. But again my car is lowered. If I was to go with the track I would put it on the bottom hole.

Don't know the rear shocks and springs you are running. Mine are double adjustable Vikings and I started in the directions on my settings. Found this on the blackweb.

OIP (1).jpg


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Correct me if I'm wrong but I think that the upper control arms attaching point should be set higher on top of the rear axle (and point downwards towards the front of the car)
and
the lower control arms' attaching point should be even lower below the rear axle (and point upwards towards the front of the car)...

As for the sway bar settings I don't know but right now, I think my car would launch better without one... (maybe launch crooked but harder)

Right?

Claude.
 

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Yes Sir.
 

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Discussion Starter #7
Yes Sir the QP 9" upper control arm ears are higher when compared to a stock 12bolt. Not by much though, and not close to the Anti Hops. I'm remembering 5/8" I think. My rear is lowered 3-4" as well (will be 5" this weekend), so that helps put a better angel on the uppers in relation to their forward mount but not as much leverage. I run full UMI roto-joints on the entire rear so no rubber/poly.

There is no set standard for driveshaft/pinion angle for ALL. It is what it is. Install the rear and set the pinion angle with all the weight on the car. Trans and pinion should be within 1-3* equal and opposite with a more favorable 1* down angle on the pinion side to allow the pinion to rise under acceleration.

My lower control arm is on the third hole from the bottom on the rear axle mount. That is one hole down from being parallel for me. But again my car is lowered. If I was to go with the track I would put it on the bottom hole.

Don't know the rear shocks and springs you are running. Mine are double adjustable Vikings and I started in the directions on my settings. Found this on the blackweb.

View attachment 703741

Mike.
Thanks for the info Mike, much appreciated. The car is lowered about 2-2.5” in moroso drag springs all around. I also just installed Viking shocks all around. From what I understand is that the adjustable lower control arm mounts allow you to drop the arm which essentially does the same as raising the uppers with the no hops. I also read that the uppers should be pointing down and the lowers pointing up to where the two should intersect so that the rear end lifts. I guess I will start from there and see where it leads. TRZ has a decent write up where to set the rear but doesn’t talk about where to set the upper/lower control arms. If you drop to the bottom hole on the lower at the track, won’t that essentially change your pinion angle as well?


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Discussion Starter #8
Correct me if I'm wrong but I think that the upper control arms attaching point should be set higher on top of the rear axle (and point downwards towards the front of the car)
and
the lower control arms' attaching point should be even lower below the rear axle (and point upwards towards the front of the car)...

As for the sway bar settings I don't know but right now, I think my car would launch better without one... (maybe launch crooked but harder)

Right?

Claude.
That is what I read in order to achieve the correct instant center. I’m new to this kind of rear end setup.


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The "NO-HOP" bars put the upper arms at an angle that is good for most 12 second cars, and some 11 second cars too, but places them at the wrong angle for 9 and 10 second cars, (assuming we're speaking of GM A-body cars such as Chevelles, and with anywhere from a 3,000 lb to 4,000 lb vehicle weight). If the car is still capable of getting into the 9 second neighborhood, then your upper and lower control arm angles required will not be accomplished with No-hop bars anyway, (unless they have brackets with more than one adjustment hole like the Art Morrison ones do).

If you want the car to hook then you can't just be guessing at what angle the arms should be at. You need to plot your rear end out with software to find out exactly where the IC, (ie. instant center) is. There are websites on the internet that let you do that for free. If you want, I can help you out. I have software to do that, which also lets you know where you need to move it to based on your vehicles specs. i would simply need you to take four measurements for me. I like helping fellow Chevelle owners out with this because it happens to be a pet peeve of mine that so many drag racers at tracks I've been to say: "Chevelles won't 60 foot like Camaros do...not gonna happen"...and I know they're wrong. But some Chevelle drag racers buy into that crap that Camaros will always run better short times, and that "Chevelles can't hook"....I get tired of hearing that nonsense from both Camaro owner and Mustang guys too. Send me a PM/"conversation" if you want help with that.

Bottom line, axle torque is responsible for 2/3rds of the available "hit" on the rear tire at the starting line, and vehicle weight transfer offers 1/3rd of that hit. So you have to manage the available hit from the axle torque by adjusting the instant center length because where your instant center length location is will effect the tire hit greatly, (as I'm sure you already know). You do that with various rear suspension parts/components. Butyou need to find out where your current IC is and where it needs to be. Software will tell you that. Good luck
 

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The "NO-HOP" bars put the upper arms at an angle that is good for most 12 second cars, and some 11 second cars too, but places them at the wrong angle for 9 and 10 second cars, (assuming we're speaking of GM A-body cars such as Chevelles, and with anywhere from a 3,000 lb to 4,000 lb vehicle weight). If the car is still capable of getting into the 9 second neighborhood, then your upper and lower control arm angles required will not be accomplished with No-hop bars anyway, (unless they have brackets with more than one adjustment hole like the Art Morrison ones do).

If you want the car to hook then you can't just be guessing at what angle the arms should be at. You need to plot your rear end out with software to find out exactly where the IC, (ie. instant center) is. There are websites on the internet that let you do that for free. If you want, I can help you out. I have software to do that, which also lets you know where you need to move it to based on your vehicles specs. i would simply need you to take four measurements for me. I like helping fellow Chevelle owners out with this because it happens to be a pet peeve of mine that so many drag racers at tracks I've been to say: "Chevelles won't 60 foot like Camaros do...not gonna happen"...and I know they're wrong. But some Chevelle drag racers buy into that crap that Camaros will always run better short times, and that "Chevelles can't hook"....I get tired of hearing that nonsense from both Camaro owner and Mustang guys too. Send me a PM/"conversation" if you want help with that.

Bottom line, axle torque is responsible for 2/3rds of the available "hit" on the rear tire at the starting line, and vehicle weight transfer offers 1/3rd of that hit. So you have to manage the available hit from the axle torque by adjusting the instant center length because where your instant center length location is will effect the tire hit greatly, (as I'm sure you already know). You do that with various rear suspension parts/components. Butyou need to find out where your current IC is and where it needs to be. Software will tell you that. Good luck
Chevelles don’t hook.
 

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Discussion Starter #12
BillyGman the car went 9.67 with the old setup but since then I have replaced EVERYTHING but the frame and half the body. Going to be starting from ground zero. Hopefully I'll have the entire car back together in the next couple of months.

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Chevelles don’t hook.
So I called QP and the ears are located 3/4" higher than factory. I asked if they have an option to mount them higher than that and he had to check and said they can but he's gotta get back to me on the price. Is that something I should have done?

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Chevelles don’t hook.
Don't mess with me Ray :mad:o_O ...actually that's funny coming from you
So I called QP and the ears are located 3/4" higher than factory. I asked if they have an option to mount them higher than that and he had to check and said they can but he's gotta get back to me on the price. Is that something I should have done?

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3/4" isn't going to be enough. My Strange S60 Dana 60 rear has upper arm mounting ears that are 1.5" taller than my stock GM 12 bolt rear had, and that still isn't enough unless your car is into the 1,000+ HP neighborhood. In that case, that would might be all you would need to generate enough hit on the rear tires given the increased amount of axle torque. I saw your conversation message that you sent to me, (geez I hate the sound of that....a "conversation"...sounds so politically correct it makes me want to vomit)...I'll get back to you some time today....
 

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GR8WHITE, did you order the rear assembled? I ask because not everyone knows that the QP9 comes disassembled in several boxes. The axles, then the rear, then the 3rd member (assembled), then the brakes. Its super easy to assemble and only takes a few hours taking your time for someone that hasn't done it.

Mike
 

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Discussion Starter #16
Don't mess with me Ray :mad:o_O ...actually that's funny coming from you
3/4" isn't going to be enough. My Strange S60 Dana 60 rear has upper arm mounting ears that are 1.5" taller than my stock GM 12 bolt rear had, and that still isn't enough unless your car is into the 1,000+ HP neighborhood. In that case, that would might be all you would need to generate enough hit on the rear tires given the increased amount of axle torque. I saw your conversation message that you sent to me, (geez I hate the sound of that....a "conversation"...sounds so politically correct it makes me want to vomit)...I'll get back to you some time today....
I am hoping to be at or north of 700 with the new 505 but I will be spraying enough to make 1000+, at least that is the goal until I get a supercharger (not too fond of nitrous) next year.
 

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Discussion Starter #17
GR8WHITE, did you order the rear assembled? I ask because not everyone knows that the QP9 comes disassembled in several boxes. The axles, then the rear, then the 3rd member (assembled), then the brakes. Its super easy to assemble and only takes a few hours taking your time for someone that hasn't done it.

Mike
Yes I am aware it will come in pieces but shouldn't take me long to install everything. I am still going to have to figure out where I am going to mount the relocated shock brackets and TRZ anti roll bar mounts since I ordered the 9" with the back brace installed.
 

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Don't mess with me Ray :mad:o_O ...actually that's funny coming from you
3/4" isn't going to be enough. My Strange S60 Dana 60 rear has upper arm mounting ears that are 1.5" taller than my stock GM 12 bolt rear had, and that still isn't enough unless your car is into the 1,000+ HP neighborhood. In that case, that would might be all you would need to generate enough hit on the rear tires given the increased amount of axle torque. I saw your conversation message that you sent to me, (geez I hate the sound of that....a "conversation"...sounds so politically correct it makes me want to vomit)...I'll get back to you some time today....
Yeah, I don't take much seriously anymore! Too much stress.
 

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Discussion Starter #19
Don't mess with me Ray :mad:o_O ...actually that's funny coming from you
3/4" isn't going to be enough. My Strange S60 Dana 60 rear has upper arm mounting ears that are 1.5" taller than my stock GM 12 bolt rear had, and that still isn't enough unless your car is into the 1,000+ HP neighborhood. In that case, that would might be all you would need to generate enough hit on the rear tires given the increased amount of axle torque. I saw your conversation message that you sent to me, (geez I hate the sound of that....a "conversation"...sounds so politically correct it makes me want to vomit)...I'll get back to you some time today....
So QP got back to me and said they can make the upper mounting ears any height I would like for $50. So the question is how tall do I go? Should I mirror the height of the current no hop bars? Maybe a little less? I am going to measure the height on the no hops tonight when I get home.
 

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If they can make it to your spec, why not have them make mounts with 3 holes double shear & use a heim on that end.
 
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