C4 Frame Project

[55 Rescue Dog]

I'm hoping to come up with around 295's or so front and rear, with some fender radius of course. And, forget about zero scrub radius! If it takes tires outside the body to make it work, I'll try it. Although not always the best set-up, deep dish wheels always look good.

[Custer55]

I'm a fan of 5 spoke wheels on trifives but I have seen a couple with 10 spoke that look pretty good IMHO. Might be an option for you with C4 setup

Thanks for the input Rocky. It always helps to see wheels on a car similar to your own. What looks good in a catalog or another car doesn't always look as good on your own car.
The 10 spoke style looks pretty good on that 56. I lean more towards a 5 spoke design for which Budnick has some nice options. I just don't have the budget for those right now. I will probably just try the C4 wheels from our 90 Corvette right now. I think they look a little better than the painted Trans Am wheels (I prefer polished wheels over painted or chrome wheels) and will fill the wheel openings much better. It will only cost me my time to try it out!!
Brian

[rockytopper R.I.P 5-13-2017]

They look pretty good on 55's too lol. I took this pic at a GG show a few years back.

[Custer55]

This weekend I borrowed the wheels and tires from our 90 Corvette (after a good cleaning) for my 55.
After taking some measurements on the rear for inside and outside clearance I figured the wheels needed to move outward a little bit to get them centered in the wheel wells. I made some spacers out of 3/16" aluminum for the rear which makes the original 56mm offset wheel into a 51.2 mm offset wheel, (7 1/4" backspace) so Lazlo is right on the money as to the offset wheel needed.



I'm not crazy about the style of the wheels, but I think they look better than the painted Trans Am wheels. I definitely prefer polished aluminum over painted or chrome. And they fill the wheel openings much better with 275 vs the 245 width. I went for a ride tonight and had no rubbing at all on the front even with the 275's on the front also. I took a few corners at a pretty good speed but haven't tried any curb and gutter type driveways yet, That will be the best test. If I decide to have my other 90 wheels refinished to use them (Can't keep the Corvette wheels and tires on here for to long and keep peace at home) I would probably get a 245 or 255 tire for the front which would give a bit better clearance and lower the car in the front a bit also. 245's are the narrowest tire recommended for a 9 1/2" wheel.
Brian

[chevynut]

Do you know the overall tire width in front? I'm surprised a 275 works. I could go further inside towad the frame but not outside. So with more offset i could go bigger than 245. The taller 55 fenderwell opening helps.

[Custer55]

Do you know the overall tire width in front? I'm surprised a 275 works. I could go further inside towad the frame but not outside. So with more offset i could go bigger than 245. The taller 55 fenderwell opening helps.

I was surprised that everything clears too. I just put my old wheels and tires on thinking it would just give me a better idea how wide a wheel would work. At the bottom of the tires it measures 68 3/4" wide. I would guess it should be less at the top of the tire with the camber in the front end. Should gain about a 1/4" or so per degree of camber.
FYI my frame rails measured 4 3/8" off the ground just behind the kick up. The fender openings are 23 3/4" from the ground. Slightly smaller tires would be better, even though I have not had any rubs so far, to gain a bit better margin for error.
Brian

[chevynut]

Usually around 68" and you start getting rubbing problems when you turn sharply and the suspension is compressed. However, with the large SAI of the late C4 the tire moves fore and aft a lot when you steer, and the rack limits turning radius a little. I don't think you'd get anywhere near a 275 up front with a stock suspension and steering, even at the same outside tire width.

[Custer55]

Just a quick update. I made a new tilt lever for my modified van column to match the turn signal lever. It is just a 55 turn signal lever and knob trimmed shorter and 1/4" x 28 fine threads cut on the end to replace the van tilt lever with the rubber knob.



This looks much better than the van lever and knob (below)



Brian

[markm]

I did the same thing my aftermarket column in 55 came with ugly billet crap.

[WagonWonder]

Just a quick update. I made a new tilt lever for my modified van column to match the turn signal lever. It is just a 55 turn signal lever and knob trimmed shorter and 1/4" x 28 fine threads cut on the end to replace the van tilt lever with the rubber knob.


Brian

Pretty cool