[FMile Pontiacs]

Hey guys,
I have a tube chassis 64 GTO. It is set up with a strut front end. I am considering adjusting the ride height up about a 1/2 inch to 1 inch on the coil overs. I want to do this because I have a Moroso 8 qt pan on the engine and it is closer to the ground than I am comfortable with. My real question is will raising the front of the car this much affect the launch or handling characteristics of the car going down the track. The chassis works extremely well as is and I do not want to screw that up. Thanks in advance for any help.

[cosgrove]

If your chassis works well now, the short answer is 1/2 inch rise won't change much. But your question brings up many variables that need to be addressed.
How much upward travel do you have? Do you use limiters? What shocks do you have and how tight are they adjusted? Does the front have much bump steer and if so, where does it occur? What ET are you running? You should plan on re-aligning the front after the changes.
One inch could make a much greater difference than 1/2", depending on many of these factors. Give more information if you would like definite answers.

[BruceWilkie]

If room, perhaps raising the motor might also be an alternative. (not a free lunch as it affects things too!)

[Elarson]

One factor....if you adjust the front, be sure to do absolute identical adjustments both sides. Even a small difference will change your corner weights a surprising amount.

Small tweaks in the front side-to-side bias are handy for getting a chassis car to do a straight burnout.

Eric

[johnta1]

How tall are your front tires?
How much ground clearance is there now from pan to ground?

Probably have to re-scale the chassis and probably rear suspension will need redone.
(4 link bars adjusted)

[J.C.you]

probably be cheaper after all is said and done, rescale, track time to adjust launch, handling, fuel, etc....just replace the pan with a shorter one.

[ErikW]

This ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Went with the Canton GTO pan after smashing too many Morosos. Nicer pan and better ground clearance.

[FMile Pontiacs]

I only have a couple of more races this season. I will probably change engines this winter and will probably put a shorter pan on it. I was hoping that it would be a quick fix but I guess not. I will also probably put a little taller front tire on it. It only has a 24.5 inch MT Front Runner on it now. Thanks to all of your input...I do appreciate it.

[FMile Pontiacs]

Originally Posted by cosgrove

If your chassis works well now, the short answer is 1/2 inch rise won't change much. But your question brings up many variables that need to be addressed.
How much upward travel do you have? Do you use limiters? What shocks do you have and how tight are they adjusted? Does the front have much bump steer and if so, where does it occur? What ET are you running? You should plan on re-aligning the front after the changes.
One inch could make a much greater difference than 1/2", depending on many of these factors. Give more information if you would like definite answers.

I am not sure of upward travel. I do not use any limiters. It is actually a stock replacement Mazda RX-7 Strut. No detectable bumpsteer. Runs 6.05 ET in 1/8 mile at around 113 mph.

[FMile Pontiacs]

Originally Posted by BruceWilkie

If room, perhaps raising the motor might also be an alternative. (not a free lunch as it affects things too!)

Not a whole lotta room for that either.

[FMile Pontiacs]

Originally Posted by Elarson

One factor....if you adjust the front, be sure to do absolute identical adjustments both sides. Even a small difference will change your corner weights a surprising amount.

Small tweaks in the front side-to-side bias are handy for getting a chassis car to do a straight burnout.

Eric

Thanks for the advice. I did not realize that about the burnout.

[FMile Pontiacs]

Originally Posted by J.C.you

probably be cheaper after all is said and done, rescale, track time to adjust launch, handling, fuel, etc....just replace the pan with a shorter one.

Probably the route I will go. I like the low slung appearance the car has now.

[FMile Pontiacs]

Originally Posted by ErikW

This ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Went with the Canton GTO pan after smashing too many Morosos. Nicer pan and better ground clearance.

Is that the kick-out style pan? I would really like to have one like that.

[J.C.you]

contact www.Kevkoracing.com ...you may be able to send your pan and pickup to them and they can fab it anyway you want it since it is a tube car, (assume it is open underneath the pan). They made me a killer circle track pan, with kickout and the price was great.

[RA462]

Take a look at the Canton 15-444. It is only 8" deep.

http://www.jbp-pontiac.com/products/...ns_access.html

[cosgrove]

Originally Posted by FMile Pontiacs

I am not sure of upward travel. I do not use any limiters. It is actually a stock replacement Mazda RX-7 Strut. No detectable bumpsteer. Runs 6.05 ET in 1/8 mile at around 113 mph.

Sounds like you are not going to raise your ride height but I'll go into your original question a little bit anyway.
You would lose upward travel if you raise ride height, so it would be important to know how much travel you have. If it is say 5", losing 1" might be just fine. This is where removing limiters would come into play as well.
Tightening the front shock extension can let you get by with less travel, assuming you can still keep it hooked.
I asked about E.T. because faster cars will react to subtle changes more than slower cars. I would say your car falls in the faster category, so small changes/ testing and recording are essential.
Back to your plan to leave ride height alone-double adjustable shocks on the front can slow down a hard landing by tightening the compression setting. A stiff compression setting will help protect your pan. When the chassis is working right, the front compression function isn't important for much else.

[FMile Pontiacs]

Originally Posted by J.C.you

contact www.Kevkoracing.com ...you may be able to send your pan and pickup to them and they can fab it anyway you want it since it is a tube car, (assume it is open underneath the pan). They made me a killer circle track pan, with kickout and the price was great.

Thanks for the link. I will have to check that out.

[FMile Pontiacs]

Originally Posted by RA462

Take a look at the Canton 15-444. It is only 8" deep.

http://www.jbp-pontiac.com/products/...ns_access.html

Thanks for the part number. Something like that is what I would like to use. I like the extra capacity with extra ground clearance.

[FMile Pontiacs]

Originally Posted by cosgrove

Sounds like you are not going to raise your ride height but I'll go into your original question a little bit anyway.
You would lose upward travel if you raise ride height, so it would be important to know how much travel you have. If it is say 5", losing 1" might be just fine. This is where removing limiters would come into play as well.
Tightening the front shock extension can let you get by with less travel, assuming you can still keep it hooked.
I asked about E.T. because faster cars will react to subtle changes more than slower cars. I would say your car falls in the faster category, so small changes/ testing and recording are essential.
Back to your plan to leave ride height alone-double adjustable shocks on the front can slow down a hard landing by tightening the compression setting. A stiff compression setting will help protect your pan. When the chassis is working right, the front compression function isn't important for much else.

Thanks for all the information. I can see there is a lot going on there that never really crossed my mind. It is quite eye opening.