How tall is your Chevelle?

[Tiger]

Hi all,
I'm having a hard time deciding ride height on my 1968 Chevelle.
Before changing to the vette IFS and IRS I had 24" from the front fenderwell to the ground and 25" from the rear fenderwell to the ground.
With the new setup and the tires I want I'll have about the same but I'm unsure if it is to high.
I therefore wonder how tall your 68-72 Chevelle is, and if you eventually can post a side pic to see the stance.
thanks!

[bochnak]

I just lowered mine:

http://www.chevelles.com/forums/showthread.php?t=203024&highlight=spacer

If I remember correctly, ground to fender distance is 24.5" in front? I have not had it on the road yet, and hopefully my 2-3" collector clearance is not an issue.

[Tiger]

thanks for answering.

IMO 2-3" collector clearance = problems, at least I would try with a set of old headers before putting the new ones on.

[bochnak]

thanks for answering.

IMO 2-3" collector clearance = problems, at least I would try with a set of old headers before putting the new ones on.

Don't worry, they are old and the clearance is measured to the SMASHED tubes!

[Tiger]

:o) Been there, done that :o)
When I took my long tubes out the lower tubes were flat, after that I changed to shorties and a nicely tucked exhaust and become happy.

[andrewb70]

You should read this:

http://www.chevelles.com/forums/showthread.php?t=213271&page=2

Andrew

[Tiger]

Andrew,

The tunnel part is already figured out, its not final welded yet, I'll do after the driveshaft is in.
I will use two full 5" rings around the driveshaft (other than body/frame flex the driveshaft wont move with an IRS). To compensate for the cut off reinforcements I have bent a piece out of 1/4" x 2" flat iron

I have indeed figured out that I wont have a problem anyway, I just looked at the rear end angles and got hysterical as a crazy mom, when I started measuring it looked all fine.

thanks for replying

[Blown353]

As far as height goes... with my 69 (same fender lip heights as a 68) on 26" diameter tires my front fenders are 24" off the ground and my rear fenders are 23.2" off the ground. The rear of the car is very slightly higher than the front going by frame to ground measurements, it's just the rear wheelwells on the 68-69 cars are lower than the front fenders.

I may drop it down another 1/2-1" now that my tunnel mods are done (Andrew linked my thread for me... LOL!)

[Tiger]

thanks man!

do you have a side shot of your car so I can get an idea how it will look?

[Blown353]

thanks man!

do you have a side shot of your car so I can get an idea how it will look?

http://home.comcast.net/%7Eprocharged69/pictures/exterior/exterior_6.jpg

Rear wheelwell lip is right at 1" over the top of the 17" wheel. Still have plenty of ground clearance at this ride height, about 4.2" from under the front crossmember to the ground.

[andrewb70]

http://home.comcast.net/%7Eprocharged69/pictures/exterior/exterior_6.jpg

Rear wheelwell lip is right at 1" over the top of the 17" wheel. Still have plenty of ground clearance at this ride height, about 4.2" from under the front crossmember to the ground.

That looks pretty low! I really don't want to cut my transmission tunnel. Do you have an idea as to how low I can go in the back without having issues? Perhaps a measurement from the top of the frame arch to the top of the axle tube?

I also have a feeling that the back of my transmission is higher than yours Troy. I think this makes it better, right?

Andrew

[Blown353]

Andrew, I know it sounds like a cop-out but the answer is this: It all depends on your current clearances.

As you drop the car more the u-joint working angles increase, driveshaft to floor clearance decreases, and so on.

To see if you have a problem now, easiest way is to support the car via the frame on jackstands or a lift, remove the rear springs, and then jack the rear end up until you hit the bumpstops. Hopefully the driveshaft won't hit the floor, if it does you'll need to limit compression travel (or hack the floor-- which in my experience is inevitable if you want a very low rear ride height and still maintain low u-joint working angles.)

Then support the rear and at your new desired ride height and measure the u-joint working angles. For the smoothest operation especially at higher speeds you want as little angle as possible but no less than 1 degree (otherwise the u-joints will fail as the needles don't get a full rotation and they'll flat spot.) The lower rear ride height, the greater the u-joint working angle. Only way to reduce it is to raise the transmission, which may cause floor issues. Get the trans as high as you possibly can, reset your pinion angle, and go take it for a ride at the new lower ride height to see if you have any rubbing or vibrations.

I had reached the point where the angles were excessive (4.3 degrees or so) causing vibrations and also was having problems with the driveshaft hitting the floor. To reduce the working angle meant raising the tranny way up (already out of room) and to prevent the driveshaft from hitting the floor meant raising the tunnel way up, so I had to raise everything. It was a combination of problems with my setup-- the TKO's shape, my large 4" driveshaft & 1350 u-joints were already a tight fit, and the rather low rear ride height.

The other issue you'll have with a very low ride height is more frequent contact with the bumpstops, especially the fairly tall stock ones. Hitting the bumpstops can be a bit scary in a corner as it unsettles the rear end and makes the handling very unpredictable. Crashing against the bumpstops (especially hard ones) in a corner results in a nearly immediate loss of traction and a slide. When I fixed my floor I also cut over 1.5" off the factory pinion snubber and installed shorter progressive GM ZQ8 bumpstops to give about 1.5" more compressive travel than the factory pieces and the ZQ8 bumpstops give a more "progressive" hit in the event they contact, which shouldn't happen anymore now with the added compression travel.

The easy fix for my situation would have been to raise the rear ride height about 2.5"-- but that looked ugly. LOL!

[andrewb70]

Thanks for the detailed information. I guess there is no way for me to tell until I really dig into it. I am sure you remember the lengthy exchange we had a while back regarding vibrations. I too am experiencing the high speed driveline vibration that you were having. I don't hate the way my car sits now. Its actually rather high. So if I can cure the current vibration by messing around with the rear pinion angle, I will just leave the ride height where it is. As you can see, its pretty high:

https://static1.pt-content.com/images/pt/2008/02/0304PHR_GTO02zoom-1.jpg

I bet I have 3 inches from the stock bump stops to the frame.

Andrew

[andrewb70]

I found an old picture to show how high the rear of my transmision is sitting. I really hope that since I am using a Rishmond, that my tranny is much higher than the TKO. Does the picture show anything, Troy?


Andrew

[MrQuick]

I have about 5 1/2" of ground clearence.

The bottom is just fine but I gotta redo the upper control arms so they don't pop the rear window out.

https://www.pro-touring.com/forum/attachment.php?attachmentid=22103&d=1204089799

[Tiger]

thanks for the pics blown353, Im lookingfor a stance much like that except that I'd like it a bit lower in the front.
when I set it up the first time around I planned on keeping everything "inside" the frame (thinking about a belly pan), the lowest point right now are the headers but once I get them finally welded it will be thethe vette crossmember at around 4.5/5"

vince, that 67 looks cool, have you ridden in it that low?

[MrQuick]

Hi Andre'

thanks. but no, we had the rear suspension torn down for modifications. I drove it around the parking lot for fun but that is way too low,although it didn't rub....you think it looks good like that? :ssst:

[zbugger]

Hi Andre'

thanks. but no, we had the rear suspension torn down for modifications. I drove it around the parking lot for fun but that is way too low,although it didn't rub....you think it looks good like that? :ssst:

Don't even think it. If you keep thinking it, I'll be eating Taco Bell for lunch tomorrow. Just for you.

[MrQuick]

...your one SICK individual. Parts came in.

[Tiger]

HeHe,
A little bit lower in the front and a bit taller in the rear and the look would be perfect.
It would probably ride like crap tho.

Taco Bell?? the mexican phone company for lunch ??? ... ok I'm stupid

[Tiger]

Andrew,
If you put on adjustable upper arms you should be able to get much lower than that without having problems.

[andrewb70]

Andrew,
If you put on adjustable upper arms you should be able to get much lower than that without having problems.

I have adjustable control arms in the rear. I honestly don't want to go much lower. Maybe another 1-2 inches. Like in the pic below. You can compare the two stances.

Andrew

[PleaseNoSteve]

Stance #2 is perfect - make it happen

[Tiger]

Yep,
number 2 is the one :o)