How to test suspension travel to modify wheel wells?

[k72nova]

I'm in the process of modifying my front fenderwells on my '72 Nova and I just want to make sure I'm doing everything correctly.

What I've done so far is remove the drivers coilover, and set the passenger wheel on the ground and jack up the control arms on the driver side with the drivers side frame on a jack stand.

Now I'm marking everywhere the driver wheel touches and going to modify from there.


Is there a better way to do this? I'm worried that I'll go a bit too far with the modifying because the suspension is traveling further than it ever really will on a track, by that really I mean I don't want to roll my fenders (since I painted the car last year) if I don't have to based off of inaccurate suspension travel.

[65 drop top]

Find out how much travel your coilovers have. For example, they might have 4” of overall travel. So depending where you have them set at ride height, you might have 2” compression and 2” of droop. Another way to check this would be to install the bump stops and compress the suspension until it bottoms out.

[Lonnies Performance]

It's not a bad idea to put the shock back on without the spring to see if it limits travel in any way.


Depending on spring rate, you may not see much more than 3" in either direction & most likely 2" under normal driving.
Also steering is typically limited to 15-20 degrees on typical roads, besides parking & intersections.

Trying to run a huge tire in the front often restricts your turning radius. A little compromise is sometimes necessary.

Ideally the bump stops be adjusted to should protect you from body contact, but be aware during cornering, getting into the bump stops can have an adverse effect on handling causing that corner to lose traction. The urethane stops typically used are to too harsh & a more progressive one will start making contact to slow the travel & stop it before contact is made. Factory styles are usually curved & pointed & made from a softer rubber to start working around 1" before the physical contact has to be prevented.

I just had a similar problem where I had 2" travel in the rear of my vehicle & it would touch the outer rear stop in a hard corner & cause it to slide. I drilled holes in the urethane around the perimeter to soften it.

How bad is the contact with 3" compression & about 1/4-1/2 turn of the steering wheel?
Give us a rough idea of where the contact starts.

Also what are your spring rates?

[k72nova]

Lots of great info here thanks! What I did was remove my spring from the shock and removed the sway bar from the driver side then jacked the control arm up as far as it would go. These are Ridetech single adjustable coilovers. I from Ridetech is Compressed: 10.48" Extended 14.08" which should put me at 3.6" of travel other than what I'd lose with spring compression? My spring rate is 650 lbs./in.

Below is where I makes with a silver sharpie at the rough point that I start to rub, which is right at 3/4 turn, I'll have to start with massaging the fenderwell since I can see where it's pressed out from the fenderlip a bit.189582

[Lonnies Performance]

Shock travel is not 1:1 with the wheel movement.
it is approx 1.6:1 wheel to shock. Just a SWAG.... I do not have the dimensions on your control arms.

How much compression from ride height are you seeing?
How is it at 2" compression?

Are you ok with full steering at ride height?

What ratio steering box?

[k72nova]

I hadn't even thought of the control arm pivot extending the wheels travel, maybe not enough coffee, anyway I took some measurements.

The steering at ride height is OK and doesn't rub until roughly 4 1/4" of total travel or 1" more than ride height.

Fully Extended to ride height: 3.25" (3 1/4")
Ride Height to full compression: 1.44" (1 7/16)
Total Travel: 4.69" (4 11/16)

Steering Ration: 12.7:1

[Lonnies Performance]

I looked at your build thread & the car looks very good with the current stance.

Unfortunately, you left very little travel to let the suspension work while driving.
This may be ok for riding around, but during spirited driving you will be on the bump stops quite a bit.

My S10 which had a 650# spring would move close to 1.5" while traveling at high speeds on bumpy roads, touching the inner fender in 1 spot, even with the shocks set pretty stiff.
I was forced to raise it 1/2" so I could drive it how it was meant to be driven. My wheel opening is now flush with the top of tire... I liked it visually lower, but didn't want be afraid to scrape things.

I also ended up with a 850# spring which aided handling & reduced front end travel, but also made the ride less pleasant.

As for steering clearance, I rarely turn over 1/4 turn during normal driving. You just have to be more careful in parking lots & through intersections.

For reference I am .7" from outer tire edge to fender lip but it has never touched while driving.
In this case negative camber & a lot of caster are your friend here, pulling the tire away from the fender while cornering.

[k72nova]

I've raised the car since the build thread since I was smashing my headers on ever pot hole, I've raised it a little more while working on this rubbing problem but I don't think I can go much higher than I am now without maxing out the coilovers, I'll have to drive it and see if I'm already there now. This might lead me to stiffer springs but we'll see.

This is the current front stance, I'm not as happy as when it was lower but I'd rather it not be the exact look I want then be stressed out every time I drive it.

189692

[67-LS1]

I’ve always thought the area of the fender above the wheel opening was to tall on Novas, and 66 Chevelles like mine for that matter. Your car looks painted so this probably isn’t an option for you now but I’m thinking of cutting a 1” section out of my fenders. I would slice up from the bottom and then take a 1” tall piece of fender out between those two vertical slices.
I would have to do som other small sections to get the body lines back to where they need to be and reshape the inner fender to match the new outer but I think the result would be better clearance or the ability to go lower with the front suspension.
If you kept the cut to just an inch or so most people may not notice.
I’ve (crappily) marked your photo to show where I would cut.
190132

[408maro]

Are these bc forged ?