C4 Frame Project

[chevynut]

Congrats on a great project and great documentation of the build. I'll be curious about your driving impressions when you push it a little more.

[Custer55]

Car looks great, and what an awesome job getting it back together, and on the road in record time!

Thanks RD
Lots of late nights the past month or so to get to this point. All well worth the effort though.
Looking forward to driving it as much as I can now.
Brian

[Custer55]

Congrats on a great project and great documentation of the build. I'll be curious about your driving impressions when you push it a little more.

Thanks Lazlo,
I did take it out on the freeway Sunday night. I didn't push it to hard but it takes the on and off ramps pretty well. 50 mph on a 30 mph ramp was no where close to the limit, very comfortable at that speed. Tonight I turned the rear shocks up the stiffest setting to see how that feels. The ride was more like our Corvette at that setting but still not harsh, so shocks obviously have a big affect on ride quality and handling. My tires for now from my 95 Trans Am are 245/50/16's so that has an effect on ride and handling also, since they are an inch narrower and have a 1/2" higher sidewall than the tires on our Corvette which are 275/40/17's.
At least the tires and wheels I am using now are a good starting point to now what will work well once I invest in set of wheels and tires for my 55.
Very happy with the results so far. If your working on one now "Git R Done"
Brian

[Custer55]

We made out to St. Paul and back for Back to the 50's weekend without any issues with the new C4 frame set up. I was a little nervous about going that far from home (200+miles) with only about 70 miles on the car after putting it all back together but the car ran just like it always did before. Just with a lot better handling and steering!! The weather was great this year. We just had a light mist early Thursday morning on the way out, which was good because my front tires don't have much tread left on them!!
The show was great as usual, over 12,000 cars registered this year. Lots of vendors selling parts! Dave Kindig and Kev Dog were there with 3 of the cars they built on "Bitchin Rides" too, so that was pretty cool.


All put together, cleaned up and ready for the trip to St. Paul

At the show Friday morning, The 57 belongs to our friends that live just down the road.

The Copper Caddy, and the Buick from Bitchin Rides. Their cars look even better in person!!

I got my picture taken with them, Super cool guys!!

A few cars from the show, Always a great variety of cars with a 1964 or older cut off. Plenty of Tri-fives too. You can't walk to far without seeing one. I remember one year hearing that there is more 55 Chevys at the show than any other car.

Iola car show and swap will be coming up the weekend after the 4th of July so that's coming pretty quick. I'll probably won't be doing to much on mine the rest of the summer, Just driving it as much as I can and having fun with it.
Last week I helped my son start working on his 60 T-Bird project so that will keep us both busy for a while.
Brian

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

Awesome Bryan great job!!!!!

[chevynut]

Congrats on making it to the show! Awesome!

Just had the owner of project #69 take his frame back to Seattle this morning. No sooner did they leave and I got a call from another Texan wanting a frame. We have a couple more projects in the schedule already so we'll have to fit his in.

[Custer55]

I have been looking at wheel and tire options for my 55 with the C4 set up. For the rear it looks like a 10" wide wheel with a 7 3/8 back space should work with a 275 to 285 tire. Up front an 8" wheel with a 6 1/2" back space with a 245 tire will work with out any clearance issues. Right now I have 95 Trans Am wheels on it which are 16 x 8 w/55mm offset (approx. 6 3/4 back space) and 245 tires with plenty of clearance.
Options I have been looking at are Budnick custom wheels which they can build with the required back space but are $1,800. plus for a set of 4.
I was looking on ebay recently for C5 & C6 wheels. They come in 9.5 and up for the rear in 18" and 19" dia. and 8.5" front wheels in 17" and 18". Price varies based on condition and wheel style from $400. and up for a set of 4. Most of these would need spacers as they have a more back space than would work on a C4 set up.
Another option I saw was for C6 Grand sport replicas made to fit a C4 in 17 x 8 1/2 and 18 x 9.5 combo with back space very close to what I would need. Just under $800. for a set of these.
So I cleaned up the 90 Corvette wheels I have to put them on ebay while I consider my options. Today just to make sure an 8 1/2" wheel and tire combo would clear ok on the front I bolted on the 90 Vette wheels to see how much clearance I have with those, 275/40/17's on 9.5" wheels with 7 7/16 bs. (56mm offset stamped on back of wheel). I was pleasantly surprised that they fit fine and didn't have any rubbing at all on the fender or frame. I just went for a short ride at 30 mph or so because the tires are old with cracking in the tread area. I backed up and turned full lock in both directions and took a turn at the end of our road at 25 mph or so at near full lock with no rubbing any where.
Here is pictures with the 90 Vette wheels on the front and the TA wheels on the back.

So I am looking for opinions on how the Corvette wheels look on here. Don't worry about hurting my feelings, I want your honest opinion.
Also any body else that has a C4 conversion Tri-5 let me know what you have used for wheels and post a picture if you can.
Thanks, Brian

[chevynut]

I had to look back to see what vintage suspensions you had, early or late, and I see you have late front and rear. That makes a pretty big difference in wheel selection.

Also, I prefer to talk offset rather than backspacing, because backspacing changes as wheel width changes.

Here's my take on fitment.....

Your stock rear wheelwell lips are probably around 71.5" wide inside width (you should measure them). The inner wheelwell in the rear is 46.5" wide. So you have 12.5" to work with in each wheelwell. Assuming you allow only 1/2" on the outside and 3/4" on the inside, that theoretically limits you to a 285 nominal width tire (11.25") and that's pushing it and everything has to be right on. I personally wouldn't go closer than 3/4" to the tub on the inside but maybe you have info to support going closer.

Assuming the above dimensions and clearances, the centers of your tires would be at 59.25". The late C4 rear is 63.25" wide with discs. That means you'd need wheels with +2" offset (~+51mm) to get that fitment in the rear. For a 9.5" wheel that would be 7.25" backspacing.

In front I usually recommend no more than 67.5" wide on the outside of the tires. A 245 (9.6") tire would put the centers at 57.9". The late C4 front is 62" wide at the wheel mounting surfaces (I haven't measured it super accurately) so you would need +2.05" offset (~+52mm) to get there. For an 8.5" wheel that would be 6.8" backspacing.

As far as the style of wheels, that's a personal preference. I don't really care for the C4 wheels myself, and I have C5 Z06 replicas on my Nomad for now. The front tires are 245s on 8.5x17 wheels and the rears are 295s on 10.5x18 wheels. I think the rear wheels need a spacer because I narrowed the IRS 3" and have over 1" clearance to the fenderwell. I will probably go custom once I get it running.

[Custer55]

Your right. The key is to get the wheel centered in the opening as that centers the tire also. The 90 Corvette wheels would probably need a 1/4 or so spacer to center them properly. I know the clearance was tighter on the inside than the outside when I was setting up my frame. I am considering using the C4 wheels now since I have a pair that are in decent shape that clear with the 275's so I would just need new tires for those (which I need anyway as the tires on the Trans Am wheel have very little tread left). They should clear a bit better with a 255 or 245 tire. For the rear the wheels I have need repair and refinishing and new tires. I may have to "borrow" the wheels and tires off my better half's Corvette to try it out.
Brian

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

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