I'm in the process or rebuiling my rear suspension and am asking for some advice. I want my car to have no wheel hop and to have a good launch but kinda unsure on what to do. My two options are either getting polyurethane bushings and no hops bars or just buying all new tubular control arms w/ polyurethane bushing w/out no hop bars. Anybody have any recommendations? Since I'm on a budget, I can only afford one of the two options. Thanks!!

[This message has been edited by KaiserLT1 (edited 02-22-2000).]

i just did my rear end. i boxed my own arms.original parts group sells the parts you need for 37 dollars

www.globalwest.net (http://www.globalwest.net)

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Lowered '67 Elcamino
ZZ430HP / 4L60
"Canyon Carver"

Anyone have any more ideas? I'm getting anxious to do this but still am debating on what to do.

The problem with wheel-hop on a four-link rear suspension like the A-bodies is that the instant roll-center is to far forward. The easiest way to correct this is to change the suspension geometry. To accomplish this you can either use hop-stop bars (i.e. move the roll center back and down) or those Lakewood lower bars, but those tend to raise the roll center along with moving it back.

Use the poly bushings and Edelbrocks no hop bars. (Lakewood makes them but nore expensive) I've used them on my 71 ss454 and now on my ss69 402 both 4 speeds. Also on my friends HO455 69 GTO They work!!
Your car launches like a dart with no wheel hop. Good luck

I am a big fan of the tubular control arms. If the car is set up properly front to rear it will launch hard with no wheel hop. Check out the pictures on my web page. That's fun!

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hometown.aol.com/mkrauser/gmracing/gmracing.htm (http://hometown.aol.com/mkrauser/gmracing/gmracing.htm)


70 Chevelle Fathom Blue
70 Malibu Convertible Midnight Regatta Blue

Chicago - Suburbs

i installed aftermarket boxed upper and lower arms with poly bushings. i still had a bunch of wheel hop. i installed the no-hop bars ($90 from jegs) and the problem. if you decide to use the bars try and cut a deal with whomever you buy your bushings from because you don't use bushings on top of the differential. it's a pretty big job on your back in the garage, ps be sure to support the front of the diff. housing, they're front heavy and might tip foward and crush somthing. (like your body) have a good project. john

I really am at a loss. I've installed newer GM-made boxed lower control arms and all new RUBBER bushings and I've never had any wheel hop problems. I have an L79 (350hp/327) so it's not like I'm running a weak engine.

The most important thing you can do and do cheaply is box the lower arms (buy new boxed ones, they come with bushing already in) and replace all four upper bushings. Make sure to replace all the mounting bolts too as they can become weak after years of abuse.

If you mess with the axle geometry (no-hop bars) you will make it ride like a truck. Adding a rear anti-sway bar if you don't already have one can really help overall handling and launch capabilities too.

No need to spend a million bucks to make it work. Full blown (EXPENSIVE) replacement parts (tube arms, spherical joints, urethane bushings, no-hop bars) can make modest improvements but there is always a price to pay (ride quality, increased maintenance, etc.).

If your car does not already have them you can add a set of brackets GM introduced in mid-1965 that connects the front upper control arm mount to the front lower control arm mount. These brackets were introduced to all hi-perf four-speed cars to help tie the suspension points together and make it all stronger. Earlier cars had been breaking the control arm mounts. These brackets were included in most performance Chevelle chassis' through 72 but most got lost or broken (they are kind of in the way of the mufflers if the mufflers are larger than stock). GM issued a tech memo suggesting these brackets to be retrofitted to older hi-perf a-bodies, especially those with manual trasmissions.

Repro brackets are available from most resto parts vendors.

If you want to see the bracket I'm talking about go here: http://www.geocities.com/motorcity/flats/8627/rearaxle.jpg The bracket in question starts in the right center of the picture and runs, mostly obscured by the driveshaft, to the lower right of the picture.

I put a lot of credit in these simple brackets but they simply work and it's cheap. Chances are if your car was not originally an SS it won't have them.
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Rich's 1965 Malibu SS Restoration Project Progress Page (http://www.geocities.com/motorcity/flats/8627/)
1:18 scale diecast car Detailing by Scooter (http://www.amhost.com/scooter/)

[This message has been edited by Rich-L79 (edited 02-24-2000).]

I have no wheel hop either out of my 410HP/500Ft.lb 383 or my last motor 330HP/400ft.lb 350. I just boxed the arms myself for $6 (the price for flat bar) and then just welded them, and I did change the bushing to poly, but this has never been a problem in my car, are you running different tires, low pressure or something?

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383 69 Chevelle
Citrus Heights, CA
http://www.x86Racing.com (Daves Pics)

I bought my whole rear suspension from this company. The rear control arm are zinc plated Gold. Very haevy duty at a reasonable price.. check it out.
http://www.performancesuspension.com/

ps if using a twelve bolt rear, on of the upper arms has to be trimmed (for clearence).
This does not effect the intgegrity of the arms..

I've heard that the use of No-Hop bars like Lakewood's can create a pinion angle problem which creates vibrations at cruising road speeds.

Is this true? Will adjustable upper control arms help this problem? (Cure one problem, have to fix two more...)

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??michael j Team Chevelle Gold #77
70 Chevelle SS396 4sp, Fathom Blue/White Stripes - Canadian built

Installing No-Hop Bars is NOT going to make any car ride like a truck. They raise the mounting point of the upper control arms, which if anything is a distinct improvement over the inferior factory design. This does not affect ride quality. Pinion angle may change slightly, but more than likely not enough to cause driveline vibration. At least they never have for me or any of the people I know using them.

'Instant center' is the point that the upper and lower arms would intersect if you extended imaginary lines out from them. Stock, you will find your upper arms are level, or even point upwards. This is why wheel hop occurs.

By relocating the mounts on the rear housing upwards, you are shortening the instant center. This is the point of effective lift. (email me, or read 'Door Slammers: The Chassis Book' if you want a better explanation)

RH

I guess when I was thinking about the thing ending up riding like a truck I was thinking about solid mount ladder bars mounted in place of the lower arms. My mistake.

I still advocate the box lower arms/heavy duty support brackets approach. Easy, simple, inexpensive and no worry about screwing with pinion angles and u-joint/driveshaft failure.

In lowering my 69 Chevy pickup I found it very important to be keenly aware of pinion angles. Also, to avoid possible u-joint/driveshaft failures when doing any modifications, make sure the u-joint angle at the transmission is the same (measured from the bottom) as the angle at the axle yoke (measured from the top). If the angles are different, each u-joint will try to fold and unfold at different speeds and put undo pressure on the weakest link in the whole drivetrain: the u-joints.

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Rich's 1965 Malibu SS Restoration Project Progress Page (http://www.geocities.com/motorcity/flats/8627/)
1:18 scale diecast car Detailing by Scooter (http://www.amhost.com/scooter/)

Has anybody used the tubalar lower/upper control arms offered from Jegs? Are they good? I can get all 4 for $300, which I don't think is that bad of a deal considering the have poly busings in them.

I had those no-hop bars on my '72 SS-454 El Camino, along with stock-style boxed control arms, polygraphite bushings, and anti-sway bar The ride was terrible. The upper control arms came up and dented the bottom of the bed. I would definitely not recommend them on an El Camino. I took them off and the ride improved dramatically.
And even though I can get a lot of wheel spin, I get no hop at all (with or without the bars).

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Dan Carr
dcarr@chevelles.com
Team Chevelle Gold Member #11, ACES #701
Author of the GMC Sprint, El Camino, and '68-'72 SS Authentication pages.
See my GM A-body fleet at:
www.rmi.net/~dcarr/cars/cars.HTM (http://www.rmi.net/~dcarr/cars/cars.HTM)

from what i heard the bars sold at jegs are pretty good. i did not buy them because there are no holes drilled for the sway bar and i didnt want to do any drilling on those bars..

What exactly is involved in boxing your own control arms?

i have no wheel hop and i am putting 416 lb-ft to the tires....
why do some have this problem and others not??

my setup is a stock resto w/stock arms (nothing even boxed)

stock ss wheels bfg 245r60/14

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Rich
Cocoa Beach, Fla
Team Chevelle #380
46 but feeling like 20 when i'm in my 70 SS 454
wa3men@aol.com
www.chevelles.com/showroom/70_SS_454.jpg (http://www.chevelles.com/showroom/70_SS_454.jpg)

I'm running a 71 w/a built 454, a dual turbo 400 trans and a 12 bolt. I had ALL kinds of trouble w/wheel hop. I ended up buying the Morrison package that included the tubular control arms, adjustable upper tubes, shocks and anti-hop bars. The difference is amazing.

The setup actually improved the geometry and allowed me to set a negative 4 deg of pinion angle (which seems to work best on this car). The uppers can be switched pretty easily at the track to adjust for conditions/tire changes.

If I had to choose, I'd box the existing arms to save enough cash for the anti-hop bars. You won't regret it!

JYD,

Can you give me some tips on the initial setup of the Art Morrison kit? I have installed it, and now my car is at the body shop, so it won't be running for a while.

Do you use the top hole for the shortest instant-center?

Thanks,

RH

Ryan, it's been two years since I installed them. I dug up my notes and
an old article from Chevy High Performance to refresh my memory.

I had some unqiue circumstances that forced me to modify some of
the parts and made the setup a bit more complicated than the
instructions describe.

First off, I have a twin turbo 400 trans. It's basically two turbo
400's stacked end to end to produce a 5 speed trans. The excessive
length of the trans makes for a very short driveshaft and acute
angles at the tailshaft and pinion. Also, the trans gearing allows
me to run 2.73 rear gears and still have a very steep first gear.

Using this package, I can run a motor producing power on the low
end. That allows a stock converter stall speed, lower trans temps
and a very streetable, strip car.

My anti-hop bars came with 3 fingers to engage the webs on the
diff housing. One of those fingers interfered with a boss on the housing
so I chopped off the offending finger on each bar.

I also had to grind on the diff housing ears, as they describe in
the article, so the heim joints would clear on the lowest setting. It
turns out to be the most used position for my situation.

Once the geometry was established, I located the bars and torqued
everything down. I went to the trouble of measuring the body/axle
separation to get the pinion angle set right. This is done by measuring
how much the body and wheel separate when the drivetrain is fully
loaded, like when staging. Measure the distance at the center of the
wheelwell. Then, when you set the pinion angle, jack up the car to
simulate the launch conditions. This will allow for your ride height
change at the line. I needed to adjust the length of the upper bars
to get my angle to read 4 deg negative on the lowest hole setting.
Most important to adjust each bar the same amount!

Another important note is to try and get the lower control arms to
be nearly parallel with the ground. They will still work good if you
have a reasonable positive angle but should never have a negative angle
where the front mount is lower than the rear. I tested a variety of
wheel sizes and spring heights once I had the package installed. Then
you can check your slips to see what improves and what doesn't. It's
all in the experimenting from there. Keep in mind that varying track
conditions have an impact as well so make changes gradually.

As they say, how much angle you set depends on how well your chassis
responds to the load. Also, if you run a transbrake, use about 2 degrees
less pinion angle...

If I recall anything else, I'll post. Otherwise, any questions or
comments?

where is a soure for a twin Th 400???

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Rich
Cocoa Beach, Fla
Team Chevelle #380
46 but feeling like 20 when i'm in my 70 SS 454
wa3men@aol.com
www.chevelles.com/showroom/70_SS_454.jpg (http://www.chevelles.com/showroom/70_SS_454.jpg)

Rich,

You can buy just the conversion parts or a completely assembled trans. There are many ways to configure the setup as well. I run manual, reverse ordered valve bodies in both trannies and have two ratcheting (B&M Quick Silver) shifters. I understand there is a mod to use a single shifter- now available.

Call U.S. Speed Research at (414)744-7166 and ask for Ken.

Buy the South Side Machine lower control arms. They change the instant center and improves weight transfer. Follow instructions and you'll love 'em !!!

Instructions explain in detail what problem is with factory geometry, and how the bars correct it. Pinion angle is important !!

oops wrong post dah! never mind

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ACES # 1493
NCOA # 18189
Chevelle-abration Video available E-mail me!

[This message has been edited by 66 MYSTERY CHEVELLE (edited 06-20-2000).]