I'm in the process of adding E-brocks no-hop bars to the rear of my 72. I was under the impression that these could be added to stock arms and pinion angle would not be effected. WRONG! No-hop bars shortened upper arm C-C approximately 1 inch. So I ordered the adjustable uppers from Edelbrock. They are nice, but I have to run the adjustment all the way in for holes to align. Has anyone had a similar experience. I know rearend has not moved because the righthand side is still assembled (stock arms and w/o no-hop bar.) If I later wanted to add a little negative pinion angle, I would not have the adjustment to do so. I would like to have a sleeve about .5" shorter. I don't think I want to do any grinding on these new sleeves. If anyone can give me some advice, I would appreciate it. I'm waiting for E-brock's tech service to open this morning. Thanks.

Danny

Danny, they should not shorten the length any. Have used the no hops on several cars for years with no changes. Have them on my 67 now along with the adjustable upper control arms. Only reason I have the adjustable arms on it is because of the change to tko600 5 speed which changed the length of the driveshaft making the angle off.

OK Jerry. Since I've posted this I have talked to 'Ron' at tech service and he told me he's never had an issue like what I described. So I'll wait until I get the other side up and see where I'm at. He said when they're installed I should be able to move between 4 degrees - to 2 degrees +. But I know nothing has moved on this rearend since I started. I'm leaving tomorrow morning and will be gone a week. I'll get back on it when I return. I'll have an angle gauge and know more the next time I post. The fact that hardly anyone has replied tells me most think I'm an idiot and they may be right. But thanks for your input.

Danny

Are you certain you installed the no-hop correctly? I've never used them, but I would think it would be possible to install it off just a bit which would put the upper control arm mounting point in the wrong place.

Rich, there's really only one way. They are marked left from right, but I double checked that. That would only move the upper bushing from side to side. I did have to grind a little as per instructions to get the bar to drop back in the web far enough to pin it. From Jerry's thread and what the tech man at E- brock told me, I'm sure I'm wrong. I'll get the other side up and then see. It'll work. Hell, I know my Chevelle isn't different from ten million others. Thanks.

Danny

Are the bushings good in the existing stock arms? bum bushings affect angles and effective length.

I know it's probably a pointless post, but you said they are clearly marked right and left. Now, I know that it can get confusing at first when you crawl under the car as to which side is really right in left, but you do have them installed as left for drivers side, and right as passenger side, correct?

Yes, Tom the bushings in the stock arms are polyeurothane or however you spell it, installed 2 years ago. Thanks.
Jake I appreciate the suggestion, but no question about the correct bar. And again, if it was wrong, it would only move the upper bushing left or right. It wouldn't affect the CC length.
Thanks everyone. I don't see how changing out the other side as Edelbrock suggested this morning is gonna cause me to have to lengthen the left, but I won't say anything else until I get back in town and try that. If others have changed these out and kept the stock uppers without a pinion angle issue, then I'm squealing for nothing. We'll see.

Danny

The Eddy control arms comes pre-adjusted to the length of the stock control arms, so if the stock arms were short, so will these.

Dan, what's happening to you is suppose to happen: pinion angle gets screwed up when installing these. I think most people dont know any better and just do what it takes to make the connection w/o regard to the pinion angle. As I stated in the last thread, some suspension outfits wont see you no-hops unless you buy adjustable uppers...just b/c of this. I dont know why Eddy doesnt make this clear, guess there afraid of lost sales b/c people dont wanna spend the $$$ or deal with angles.

Do what it takes to make the conenction (rotate the rear up or down) then set the rear via upper arms and be done. For all you know, your pinion angle could of been screwed up to begin with. Now you have the opportunity to CONFIRM the angles. Its not hard at all.

Block the car up EVENLY on all its wheels. Measure the angle of the driveline with a $10.00 angle finder from sears or Home Depot. Then rotate the rear up to that angle. Thats it!!! Now, a racer may wanna run some negative angle to compensate for "wind-up". Most guys here suggest running the pinion down 1-1.5* (depending on power level) to the drive line. So if your driveline is -2* down, bring the pinion up to +.5* to +1*. For a street car just go to +2* for smooth operation. Thats it!!!

Tip: to make sure you have both control arms adjusted evenly, get a marker and make a dot dead center of the bolts, and measure the distance between the 2.

Good luck and enjoy your new no-hop bars.

Well, it is possible that you have the wrong no-hop bars? If there is a number stamped on them, compare them to the box they came in, and also the catalog/website. Maybe you got some for a G-body or a different year A-body. Don't really know how much difference that would really make, but possible I suppose.

Here is a post from the guy at Eddy who designed the adjustable uppers - pay attention:

http://www.chevelles.com/forums/showthread.php?t=92521&highlight=edelbrock+adjustable+uppers

Let me see if I can help with the decussion here. I am one of the engineers here who did the original design work on the Adjustable Upper Trailing Arms, the resaon for us offering the Adjustable arms were two fold. The first and main reason was to correct pinion angle when using the Edelbrock No-Hop bar #5213 in certain applications. The rear ride height can seriously affect the pinion angle with and without No-Hop bars, we felt that an adjustable arm could be benificial to our customers. The second reason was the application of the Spherical Joint on the frame end, this was to reduce the bind in the stock suspension design, especially with the No-Hop bars. I'm not going lower myself to blasting other companies or indiviual designs, we did what our experience and engineering showed to be best.

The persons involved in the suspension development have over 50 years in suspension and racing. I myself have been setting up these type of cars for over 20 years and have intimate working experience with the angled 4 bar rear suspension. The original design had bind built it to locate the rear end in the vehicle under cornering loads, this was accomplished with the angled upper trailing arms, this design doesn't require the use of a panhard rod or Watts link. The Edelbrock team that designed the upper arm decussed the advantages to using spherical joints in the lower trailing arms at one or both ends along with the adjustable arms. The conclusion that was reached was that one could make the rear of the vehicle too free and cause the rear end to go into a rear steer condition (read very bad) this would be without the use of a laterial locating devise such as a panhard rod. The Lower Trailing arms are in a parellel plane to the centerline of the vehicle so putting heims or a spherical joint in the lower trailing arms conjunction with the upper arms spherical ends would require the use of some sort of laterial locating devise.

We at Edelbrock Suspension felt the use of the poly bushing was the best all around solution for the majority of customers, the use of rubber upper arm bushing would give too much under certain load conditions and a spherical bushing would give unacceptable ride hasrhness and while giving a greater articulation from side to side would cause a very unacceptable rear steer condition.

The testing that has been presented here comparing ploy to rubber to a spherical type bushing is not a very good test. There is a great drag on ploy in the plane of rotation without the side loading than a bearing type joint, think about it, one is like comparing a roller bearing to metal to metal contact. How much travel or rolling does the rear suspension really experience anyway? The sway bar is designed to control rolling of vehicle, I know that some would say that the rear sway bar isn't required just up the spring rate, and yes that will work at the expense of ride quality, along with having to get your own shock developed to control such a spring, this is just beyond the average garage mechanic. Besides the rear sway bar help launch the vehicle straighter in a drag racing situation when air bags aren't installed in the rear springs.

I hope this clears up why the use of the ploy in the Edelbrock Adjustable Trailing Arms.

I will come back from time to time and check this forum to answer questions and take suggestions on existing products or anything you thing we could build to improve the GM A-body.

Here is a post from the guy at Eddy who designed the adjustable uppers - pay attention:

http://www.chevelles.com/forums/showthread.php?t=92521&highlight=edelbrock+adjustable+uppers

Let me see if I can help with the decussion here. I am one of the engineers here who did the original design work on the Adjustable Upper Trailing Arms, the resaon for us offering the Adjustable arms were two fold. The first and main reason was to correct pinion angle when using the Edelbrock No-Hop bar #5213 in certain applications. The rear ride height can seriously affect the pinion angle with and without No-Hop bars, we felt that an adjustable arm could be benificial to our customers. The second reason was the application of the Spherical Joint on the frame end, this was to reduce the bind in the stock suspension design, especially with the No-Hop bars. I'm not going lower myself to blasting other companies or indiviual designs, we did what our experience and engineering showed to be best.

The persons involved in the suspension development have over 50 years in suspension and racing. I myself have been setting up these type of cars for over 20 years and have intimate working experience with the angled 4 bar rear suspension. The original design had bind built it to locate the rear end in the vehicle under cornering loads, this was accomplished with the angled upper trailing arms, this design doesn't require the use of a panhard rod or Watts link. The Edelbrock team that designed the upper arm decussed the advantages to using spherical joints in the lower trailing arms at one or both ends along with the adjustable arms. The conclusion that was reached was that one could make the rear of the vehicle too free and cause the rear end to go into a rear steer condition (read very bad) this would be without the use of a laterial locating devise such as a panhard rod. The Lower Trailing arms are in a parellel plane to the centerline of the vehicle so putting heims or a spherical joint in the lower trailing arms conjunction with the upper arms spherical ends would require the use of some sort of laterial locating devise.

We at Edelbrock Suspension felt the use of the poly bushing was the best all around solution for the majority of customers, the use of rubber upper arm bushing would give too much under certain load conditions and a spherical bushing would give unacceptable ride hasrhness and while giving a greater articulation from side to side would cause a very unacceptable rear steer condition.

The testing that has been presented here comparing ploy to rubber to a spherical type bushing is not a very good test. There is a great drag on ploy in the plane of rotation without the side loading than a bearing type joint, think about it, one is like comparing a roller bearing to metal to metal contact. How much travel or rolling does the rear suspension really experience anyway? The sway bar is designed to control rolling of vehicle, I know that some would say that the rear sway bar isn't required just up the spring rate, and yes that will work at the expense of ride quality, along with having to get your own shock developed to control such a spring, this is just beyond the average garage mechanic. Besides the rear sway bar help launch the vehicle straighter in a drag racing situation when air bags aren't installed in the rear springs.

I hope this clears up why the use of the ploy in the Edelbrock Adjustable Trailing Arms.

I will come back from time to time and check this forum to answer questions and take suggestions on existing products or anything you thing we could build to improve the GM A-body.


This was a good read, thanks for posting Vince!!!!!! :thumbsup:

Danny

Did you get the no-hop bars installed yet? I just installed some on my 70ss today, and the same thing happened to me. I had to rotate the rearend back to get the stock arms to attach. It made my brake hose a little tight. I left it like that, and tightened everything down and took it for a ride. Everything felt ok, and I was finally able to smoke the tires without hopping! I may get the adjustable uppers later. Let me know when you get your uppers installed and tell us how it handles. Thanks for the updates.

Joe

We at Edelbrock Suspension felt the use of the poly bushing was the best all around solution for the majority of customers, the use of rubber upper arm bushing would give too much under certain load conditions and a spherical bushing would give unacceptable ride hasrhness and while giving a greater articulation from side to side would cause a very unacceptable rear steer condition.I'm constantly amazed at the misconceptions that even the guys who design and make some of these parts buy into and perpetuate onto their customers. :sad:

Rear roll-steer is a product of the link arrangement, and has nothing to do with bushing type. :yes:

I've heard several similar comments from more than one manufacturer, which just proves that you, the customer, need to do some research for yourself and don't believe everything the companies tech support tells you. Just because they produce it, doesn't mean they know how it works. :o

I bet the rearend moved, even if slightly. I've taken the upper control arms loose to replace bushings and go to hook the UCA back up and it had moved, just realign and bolt back in place.

Danny

Did you get the no-hop bars installed yet?

Joe

Joe, no not through yet. Just got back in to town Sat. (had to take the wife to the beach), worked on it some Sunday afternoon and had to get the yard back in shape yesterday (sept 3). May finish it up tonight. I'll keep you posted. Thanks.

Danny