Reinventing the OneLapCamaro...

[James OLC]

As many already know, the OneLapCamaro has been at Best of Show for the last couple of months getting some “tweaks” prior to testing for next year’s Tire Rack One Lap of America. I had originally planned to keep this quiet until it was “done” but as the project has moved forward I’ve had a couple of people asking for details so I figured that since some pics are already out there anyways so… here it goes…

Long story short – our performance at this year’s One Lap of America was really encouraging (in the big scheme of things). We were competitive in our class and, with the exception of a couple of “melt downs” (not always in our control), we were not far off of a really promising finish in most individual events, as well as overall. I’m well aware of the limitations of the car (mostly related to the front end) and as Mary and I were driving away from South Bend we started to discuss how we could improve the car for 2013…

I knew that we needed more front tire and better overall geometry. We have been talking for 3 years about changing the sub-frame but for me that was too complex (read expensive and risky) a change on its own – it would have required new headers, steering, inners, mounts, and cutting off the old one – so that was “off limits” for now. I also didn’t want to risk “messing up” the car by doing anything that could not be undone or put back. So we formulated a plan…

The front tires and “geometry” could be achieved in one of two ways – subframe or sheetmetal – and since subframe was off the table the decision was to try sheetmetal and so my first call was to the guys who I would trust with any project incorporating tin and paint – Dick and Jon and the crew at Best of Show.
Another piece of the puzzle was weight and we identified some of the heavier pieces that could be replaced or switched out – like the rad support and AC components – to take some physical weight off the nose. Carbon was off the table for me (I haven’t had a lot of luck with it) so everything that we were doing would be mindful of excess weight.

The third leg was Aero… David, Carl and I did a fair bit of background work, testing, and experimentation and determined that there were some (predictable) aero shortcomings with the car (in general) that we hoped we could improve on. I made the decision to change the front end (a fair bit), alter the hood for better air flow and cooling, and add some downforce front and rear. There is more room for experimentation but that will be in the future and on the track.

Piece by piece the process has seemed fairly “minor” but taken overall I think they are fairly dramatic. And… to be completely honest… some of these changes won’t be for everybody. Function is trumping form in most cases and that leads to some… different… styling in places.

The process started, predictably, with disassembly (well to be honest the process started with aero testing, wool string, and video) at Best of Show. I made the decision to replace all of the front sheetmetal – packing and boxing all of the original pieces so that they can go back on to bring the car back to “original” some day.

Disassembly:

[glassman]

Good luck with this James, I've been reading Car and Driver for 32 years now and being a Camaro junkie, I am routin for you guys big time!!! Mike

[James OLC]

The first part of the project was the front end. The goal was to move the front tires out to balance the front and the rear track width and improve the inner clearance to the subframe – all while increasing the tire width to better balance the rear. As it sat the front track width as 2.5 inches narrower than the rear – most of that was related to the offset (about 1.5”) and the balance came from the difference in rim widths. We estimated that we needed to move outside of the tire out by 1.5 to 2.0 inches to match or slightly exceed the rear. This meant building new front fenders that would accommodate the space.

That’s not a revolutionary change with what’s been happening in our community for the past couple of years but we had a couple of specific constraints. I wasn’t going to do any bodywork behind the fenders so no reworking of the doors or quarters was in the card so the stretch on the fenders was going to have to be subtle and entirely done within the confines of the fender. Dick at BoS came up with a simple and efficient technique…

They started by separating the inner and outer structure of the fender:




Then they went to work with the English Wheel

[James OLC]

I think that everyone was surprised at how effective this was – we were able to get all of the room that we had hoped for and a bit more.

Just the inner structure in place:


And mocked up for the first time:




pictures are a bit deceptive and it's hard to really see all of the change.
At this point the front end is approximately 0.5" wider than the rear (or 0.25" wider per side).

[James OLC]

With the English Wheel we were able to get 2” more width without changing the height or shape of the wheelwell itself.

Measurements Before:





Measurements After:

[Flash68]

James - that is bad ass. Bout time you posted this stuff up.

[Ron in SoCal]

That's a whole new approach to a fender stretch.

I always wondered about front a rear track width/offset. Any further insight on what is ideal? What size tire are you aiming for?

Glad you started this thread James. Hope I wasn't too much of a PITA..

[James OLC]

How much room is that? As a test fit we tried putting the current rear wheel/tire (19x11 with a 325/30-19) on the front just to see. The backspacing wasn’t ideal but we had to start somewhere…

"Lot’s" of room:







Not ideal but as I said – just a test. I wasn’t planning on the 325 tire up front and the backspacing is off by about 0.5” so our target tire should fit fine. HRE is just down the street and around the corner so they were going to stop by when we were ready to get specific.

And just for comparison - with a current 275/30-18 front

[James OLC]

Originally Posted by glassman

Good luck with this James, I've been reading Car and Driver for 32 years now and being a Camaro junkie, I am routin for you guys big time!!! Mike

Thanks Mike - I'm hopeful that we can take a serious shot at a good overall finish next year although I think that competition in Vintage is going to be pretty stiff next year on it's own.

Originally Posted by Flash68

James - that is bad ass. Bout time you posted this stuff up.

Thanks - it's coming and it was time.

Originally Posted by Ron in SoCal

That's a whole new approach to a fender stretch.

I always wondered about front a rear track width/offset. Any further insight on what is ideal? What size tire are you aiming for?

Glad you started this thread James. Hope I wasn't too much of a PITA..

Ron, I was surprised how well it worked - I really have to give the guys credit.

That's a difficult question to find an answer to. The best that I found was that it should be equal or even a hair wider on the front. Anecdotally look around at any modern car and I think that you'll see that they are pretty evenly balanced. My goal - which at this point is a done deal - is a 305/30-19 Michelin Super Sport - it's as wide as a 315/30-18 with a 12.3" sidewall and 12" tread width. These are the same size as I ran on the back for OUSCI last year and may be our choice for rears as well.

[James OLC]

With the fenders well on their way we moved to the lower valence. I wanted something similar to the OLC2 concept to blunt the overall front end and improve the aero. Testing found a couple of dead spots in the old setup that I thought could be improved upon.

Our first shot started with modifications to the stock valence and fender extensions.

We started simple:





Test fitting required use of the Track Rat's grill... well it didn't specifically require it but what the heck, it was there...



Subtle and maybe appropriate for a different setup but not quite what we were looking for...