67-68 Camaro Front Inner Fender Mods

All,

I am fitting 275/35R18 Rival's or RE-71R's on my 68 Camaro this winter. I know some of you have modified your inner fenders to fit 275's square with a stock subframe. The goal is to maintain my current front spacing (which doesn't rub) while dialing out some camber from -2.8° to -1.5° and increasing dynamic camber gain to compensate. To do so, I am almost certain I will need to mod the inner wheel well. We all know the factory design is poor in regard to wheel clearance.

Since I'm about to be in the thick of this, I figured I would reach out to the experts. Pictures and a short description of your wheel well mods would be greatly appreciated.

Here is a pic of the current setup:

Attachment 168255

Thank you all for your help.

Ryan

I'll see if I can dig up the pics. Effectively you want to either trim or reshape the inner fender lip where it meets the outer fender from about 10:00 to 2:00. This gives more tire clearance and allows you to roll the outer fender lip. It also eliminates the outer fender to inner fender bolts in that area.

The easiest / cheapest way is to cut the inner fender edge off and hammer the fender followed by rolling the outer fender lip. I previously paid BOS to do it the xpensive way which was to English wheel / hammer and dolly reshape the inner fenders. In hind sight I'm not sure it was worth it.

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Originally Posted by Chad-1stGen

I'll see if I can dig up the pics. Effectively you want to either trim or reshape the inner fender lip where it meets the outer fender from about 10:00 to 2:00. This gives more tire clearance and allows you to roll the outer fender lip. It also eliminates the outer fender to inner fender bolts in that area.

The easiest / cheapest way is to cut the inner fender edge off and hammer the fender followed by rolling the outer fender lip. I previously paid BOS to do it the xpensive way which was to English wheel / hammer and dolly reshape the inner fenders. In hind sight I'm not sure it was worth it.

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Thanks Chad.

I remember you talking about the trimming awhile back when you went to the carbon inner fenders. If you happen to dig up some pictures of the progression please do post them here.

Thanks again.

Bump

It’s not apples to apples with your setup since I’m running the DSE subframe, but I’m running 275-35/18’s up front. During regular street driving, I had no rubbing issues until I was on the autocross track under hard cornering. I ended up going to the Anvil carbon inners and that eliminated any rubbing whatsoever. To give you an idea of the difference in shape, below are a couple of photos of the Anvil inners and you can see how they turn straight up from the fender bolt flange. You’ll need to do something similar to yours...Attachment 168778Attachment 168777Attachment 168776

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Originally Posted by Gmachine1911

It’s not apples to apples with your setup since I’m running the DSE subframe, but I’m running 275-35/18’s up front. During regular street driving, I had no rubbing issues until I was on the autocross track under hard cornering. I ended up going to the Anvil carbon inners and that eliminated any rubbing whatsoever. To give you an idea of the difference in shape, below are a couple of photos of the Anvil inners and you can see how they turn straight up from the fender bolt flange. You’ll need to do something similar to yours...

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Those are great Shane, thank you. Didn't realize those were even options in carbon! I knew about the speedtech fiberglass inners, which look very similar.

Given the opportunity, I would definitely go with a composite inner fender, whether carbon or fiberglass, with an adequate molded outer area to clear the wheel/tire in jounce. Unfortunately, this type of modification is out of the budget for now. When I go 315/30R18 it will be essential.

At the present time, I am focusing on modifying the factory inners to accommodate a 275/35R18. Current wheels are 17"x8", front spacing 4.5", back spacing 4.5". New wheels are 18"x9.5", front spacing of 4.38", backspacing 6.12". New wheels should help some with this clearance issue but I plan to reduce camber to about 1.5° from 2.8° which will reduce tire clearance. I will post pictures of the current location of interference asap.

I will figure it out, but any guidance/tips/pictures are immensely helpful.

Thanks again Shane.

I'm running the same 275/35-18 tire on a 10" wide wheel up front with unmodified inner fenders and have no issues with rubbing. The tires are close but not a problem close. The only thing I changed was to install button head bolts that attach the inner fender to the outer fender.

Attachment 169208

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Originally Posted by TheJDMan

I'm running the same 275/35-18 tire on a 10" wide wheel up front with unmodified inner fenders and have no issues with rubbing. The tires are close but not a problem close. The only thing I changed was to install button head bolts that attach the inner fender to the outer fender.

Attachment 169208

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Thanks Steve.

What suspension are you running? Good turning radius? What track width? What is the width between the outside of ride side tire to outside of left side tire?

Ryan

I'm running a DSE subframe with -.5 deg of camber but I don't have the other dimensions handy and the car is currently apart for winter maintenance. I seem to remember a front width of around 69" but I would have to verify that when my coilovers come back from the rebuilder and get reinstalled. To be honest the suspension is somewhat irrelevant since fender clearance is mostly determined by what offset wheels you use.

Quote:

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Originally Posted by TheJDMan

DSE subframe but I don't have the other dimensions handy and the car is apart for winter maintenance. I seem to remember a front width of around 69" but I would have to verify that when my coilovers come back and get reinstalled. To be honest the suspension is somewhat irrelevant since fender clearance is mostly dependent on what offset wheels you use.

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Well, it is related to hub to hub width and front spacing. Our hub to hub widths are almost certainly not the same, that's why I asked about suspension and tire edge to tire edge width.

The DSE frame rails are much narrower which allows you the fit the entirety of the tire inboard more than a factory frame. I do not have that luxury unfortunately. You are also running a 800 lb/in spring which reduces travel and reduces likelihood of rubbing.

Even so, I'd love to know what you outside to outside wheel measurement is once you are able to measure it.

Thanks again.

Ryan

You're right about the 800# springs, they certainly reduce nose dive under heavy braking/cornering and they fixed a number of handling issues I was experiencing. However, wheel offset is still critical to fender fitment regardless of the suspension. If I remember correctly, Ride Tech was running 275s on 18x10 wheels on the original 48 Hour 67 Camaro with a stock subframe and it obvioulsy worked very well. I should have my shocks back by the end of the month and then I can put the car back together enough to get a width measurement.

Steve,

I agree wheel offset is very important, but it cannot be used alone to compare between vehicles unless the hub face to hub face distance is known.

(Front spacing X 2) + (Hub to Hub Dist) = Wheel outer edge to wheel outer edge.

Seems a little easier to measure Wheel outer edge to wheel outer edge for most people.

Even between stock set ups: brake package, spindle, LCA, UCA, hub, and alignment all affect the distance between wheel mating faces greatly. Since your setup is from DSE, your particular wheel's offset would be unusable to me or others unless they had the exact same suspension package, or a quite accurate hub to hub measurement.

Not to derail the thread but, since I have you here, why go with the 800lb/in springs on the street? Did you increase rear spring rate as well?

I am not privy to the DSE package's motion ratios but I imagine 800lb/in would put you in the 1.9Hz front ride frequency range, assuming your car weighs something similar to mine. That's pretty stiff, almost as stiff as an SM or XP hoosier-only autocross setup.

My current ride frequencies are about 1.55 front and rear. I need to move it to about 1.7Hz Front / 1.9Hz Rear.