[torqhead]

Originally Posted by mrrat1

How is your front end set up? 90 10 shocks up front will help getting some weight transferred to the rear.

The front end is all completely stock, only thing that is modified is the drivetrain and fuel system. It's a A/C car as well. So biggest change in front is weight since I'm using aluminum heads/intake and a Sanden compressor.

[GTO TEX]

Considering all control arms & bushings are good, you seriously need to look at the rear sway bar system from HRpartsNstuff. My '66 GTO had similar issues of hooking & spooling up the rear tires. Boxed control arms from Summit and this sway bar solved the problem.

http://www.hrpartsandstuff.com/

[Tom Vaught]

Originally Posted by GTO TEX

Considering all control arms & bushings are good, you seriously need to look at the rear sway bar system from HRpartsNstuff. My '66 GTO had similar issues of hooking & spooling up the rear tires. Boxed control arms from Summit and this sway bar solved the problem.

http://www.hrpartsandstuff.com/

Worked well on Marty P's 735 HP Street Car (Naturally Aspirated).
Prior to the rear sway bar installation the car was all over the place.
It was a 70+ vehicle so it already had the good reinforced lower control arms.
I know he also used adjustable upper arms on the vehicle.
Nice and straight and good 60 ft times after the mods.

Tom V.

[GTO TEX]

Originally Posted by Tom Vaught

Worked well on Marty P's 735 HP Street Car (Naturally Aspirated).
Prior to the rear sway bar installation the car was all over the place.
It was a 70+ vehicle so it already had the good reinforced lower control arms.
I know he also used adjustable upper arms on the vehicle.
Nice and straight and good 60 ft times after the mods.

Tom V.

Yes, adjustable upper arms too. This is the combo I'm using. On launch as the suspension begins to rise and unload, the bar pushes back equally and loads the axle side to side. Launch is straight and predictable.

[HWYSTR455]

Just to say it out loud, the 'No Hop' bars are for changing Instant Center, and not specifically to control wheel hop. So the name is misleading. Changing to a more favorable IC plants the tire under load.

There are down sides to using them though, like corner exit speeds decrease, and the dreaded effect of 'oscillation' of the rear on sweep turns under power increases. That oscillation has a term, but for the life of me I can't recall that at the moment.

Of course you need to consider anti-squat as well.

Quick primer:

http://www.how-to-build-hotrods.com/tuning-4-link.html

.

[Formulajones]

Originally Posted by HWYSTR455

Just to say it out loud, the 'No Hop' bars are for changing Instant Center, and not specifically to control wheel hop. So the name is misleading. Changing to a more favorable IC plants the tire under load.

There are down sides to using them though, like corner exit speeds decrease, and the dreaded effect of 'oscillation' of the rear on sweep turns under power increases. That oscillation has a term, but for the life of me I can't recall that at the moment.

Of course you need to consider anti-squat as well.

Quick primer:

http://www.how-to-build-hotrods.com/tuning-4-link.html

.

Yes the name is very misleading. Changing instant center is what you're after and these work perfect for that. They are also stealthy and can't be seen. Some used to do the lower bars instead with drop down brackets. Does the same thing but is very noticeable, and reduces ground clearance. Either way what you accomplish by shortening the instant center is pushing the rearend (hence the tires) into the ground.

As far as drivability, we have never experienced any oscillation or problems with corner exit speed, but these are simple street cars, we don't go flying around corners with them If normal driving and even some mild spirited driving is what you do with the car, you'll never even notice the no hop bars back there. My car as well as my fathers drives like a normal car under normal conditions, up through the mountains and all.

[torqhead]

Lots of great stuff guys, could someone give me an example or link to what you're calling no hop bars. Years ago I had a set of what was commonly referred to as traction bars on the car but frankly in my opinion they made no noticeable difference in making the car hook up and were an eye sore.

[torqhead]

Originally Posted by torqhead

Lots of great stuff guys, could someone give me an example or link to what you're calling no hop bars. Years ago I had a set of what was commonly referred to as traction bars on the car but frankly in my opinion they made no noticeable difference in making the car hook up and were an eye sore.

Nevermind, found a few articles on them.

[torqhead]

Alright, you guys gave me a lot to read... A good thing for sure! So it sounds like although I have a factory sway bar on the back that if I upgrade to a better anti-roll sway bar at minimum it should make a big difference in getting the car to plant both tires and leave straight. Going to call the HRpartsNstuff guys and talk with them. Thanks for all the input!!!

[Scott65]

They make some nice stuff. I have their anti roll bar and adjustable uppers. Good stuff

[72LuxuryLeMansLa.]

I don't know if your specific issue is addressed in detail here but it is good reading......

http://www.dapa.org/category/0300tec...with-jim-hand/

[Formulajones]

I run the parts I listed earlier, and still use the factory GM rear sway bar on both my Chevelle and my fathers GTO. I've never had an ill affects. Both cars launch nice and straight and are very predictable.

One of the reasons for the stock bar is because we prefer to keep the stock appearance on the cars everywhere we can. One thing that helps with this that I neglected to mention is that we both also run a right rear air bag. On the street I don't run any air in it but at the track we'll move it around from 5 to 15 psi depending. Really helps to keep the right rear planted and the car level under load. It's cheap and easy. Like I said the setups on ours are very basic, drives like stock on the street, none of the changes are visibly noticeable unless you're crawling under the car, and it just flat out works. I expect my father this year to better my 1.5x 60 foot time with the power he's making now.

[JLMounce]

One thing I didn't see mentioned was simply getting in some seat time.

Learning how the car reacts with differing method of launch can make just as much improvement in the short term as does changing out parts. Simply getting to the track and experimenting there might find you those extra 10ths in the first 60 feet. Our cars are wildly different, but I know if I flash the converter from idle (even as tight as mine is) all it does is blow the tires off. On the other hand if I let the engine stall against the converter on the brakes, the slower application of throttle and a modulated release of the breaks allows the suspension to work better.

Every car will be different, but just getting behind the wheel and experimenting in a scientific way can really bring that ET down.

[tpssonic]

"...but I know if I flash the converter from idle (even as tight as mine is) all it does is blow the tires off. On the other hand if I let the engine stall against the converter on the brakes, the slower application of throttle and a modulated release of the breaks allows the suspension to work better. "

Mine acts exactly the same same way.

[torqhead]

Originally Posted by JLMounce

One thing I didn't see mentioned was simply getting in some seat time.

Learning how the car reacts with differing method of launch can make just as much improvement in the short term as does changing out parts. Simply getting to the track and experimenting there might find you those extra 10ths in the first 60 feet. Our cars are wildly different, but I know if I flash the converter from idle (even as tight as mine is) all it does is blow the tires off. On the other hand if I let the engine stall against the converter on the brakes, the slower application of throttle and a modulated release of the breaks allows the suspension to work better.

Every car will be different, but just getting behind the wheel and experimenting in a scientific way can really bring that ET down.

Yeah, I've had the car to the track numerous times over the years I've owned it. The last time out if I flashed anything above idle I would just melt the tires so have been doing the same as you on launches. Hence where I'm at which is trying to figure out how I can plant the tires better.

[JLMounce]

Right right. I don't know a great deal about the converging 4 link's in those cars. The only thing similar I've ever dealt with was on my 2002 GT mustang, but I never modified it.

Physics is always at work, so anything you can do to help weight transfer will help. If you've got adjustable shocks on it, loosening up your rebound at the track would help. As would disconnecting or removing your front sway bar. That effect would likely be minimal as the old cars don't run nearly as much wheel rate through the bar as modern cars tend to do. It's free though, which is a plus.