Well here a chassis for a chevelle

[R67Chevelle]

This may be the route I will go if finances get better here soon....

http://roadstershop.com

What have any of you all think about this?

Blessings,

[ProdigyCustoms]

I saw the orange car autocross pretty hard at the Run thru the hills event last week, It made it into the top 5 shootout. The car looked like it had a push in it, but that is probably more a tire stagger issue (too big on back) then anything. I could not say it is the best thing since sliced bread or not, but I have to say to perform like it did, it was not bad. Only based on what I saw, it looked like smaller rar tires may make a better balance, assuming you cannot put more front tire on it which I only ASSUME you cannot or it would seem they would have it on the test car.

[XcYZ]

If the car is tight, regardless of tire sizes, basic chassis changes like a lower front spring rate, higher rear spring rate, less sway bar and raising the panhard bar would help, if not correct the problem. These are basic principles of race car chassis setups (not counting tire pressures, shock settings, etc), but they should also be the basics when setting up a street car.

I know this post doesn't add much to what the original thread was about, but the topic of tire sizes and understeer comes up from time to time and I wanted to add my two cents.

[Steve1968LS2]

Thier test car, running the subframe, was out a the Run Through The Hills autocross event and did VERY well. I think it was in the top 3, maybe even top two, times for cars on street tires (non-R-compound)

They also tested the car out here in CA at the El Toro Marine base. I can't release the numbers but the car did very good. I think it almost got a 1g on the skidpad. Again, on non-r-compound tires.

Their chassis uses a lot of DSE parts including chuncks of thier hydoformed subframe.

Anyways, it's a cool car and beat the snot out of it. lol

http://picsorban.com/upload/coner.jpg

[Derek69SS]

In all honesty, you can get equal geometry improvements with bolt-on parts on your stock chassis for a LOT less money. The only real benefit I see over the right combination of bolt-ons is the added chassis rigidity.

The big rear tires are cool if you're not serious about road-racing/track days (which most of us aren't but if you are...), they will come up to temp much slower than the smaller fronts, effecting the balance of the car differently throughout the run... if it starts neutral, when the fronts get sticky it will go loose, then the fronts get too hot as the rears just start to get sticky and it goes tight. They also require running the springs/shocks further inboard negatively effecting the motion-ratios.

Edit: ...should add the big tires may help on a tight course such as an autocross, but likely a hinderance on a big course.

[Steve1968LS2]

I saw the orange car autocross pretty hard at the Run thru the hills event last week, It made it into the top 5 shootout. The car looked like it had a push in it, but that is probably more a tire stagger issue (too big on back) then anything..

Actually I think the push was more a function of the big block under the hood.. lol

I bet that thing weights 4,000 pounds..

[ProdigyCustoms]

One thing is for sure. As the day passed they were able to tune the push out or drive through it. I was not watching them to see if they tuned on it. But the car absolutly improved through the day. And yeah, it is probably damn heavy. As was the Air Ride Chevelle that won.

[MarkM66]

I agree with Derek 100% . Not worth the money over modified stock.

I've also see the car in person, and I thought the front crossmember was too low to the ground, especially since that car really doesn't sit that low.

I'd do an AME or keep stock.

[XcYZ]

The big rear tires are cool if you're not serious about road-racing/track days (which most of us aren't but if you are...), they will come up to temp much slower than the smaller fronts, effecting the balance of the car differently throughout the run... if it starts neutral, when the fronts get sticky it will go loose, then the fronts get too hot as the rears just
start to get sticky and it goes tight.

I will agree with that, but if you're going to look at how the tire temp changes are different with different size tires, then you might as well start looking at everything, such as fuel load. As you use fuel your balance is going to change, just like it will with tire temps. I know some guys that used to race using methanol but have switched to race gas because you don't use nearly as much over the course of the race, which means the change in balance isn't as drastic.

Of course, with street tires, this is just about pointless. lol But if you're serious about competing (in sanctioned racing), nothing is left out of the equation.

I still say that tire sizes differences from front to rear can be dialed in with the right chassis setup.

[68protouring454]

they were out of the top 5 until they got to hot lap it 4-5 extra laps to knock the last 2-3 10ths off, at the end before the top 5, the car is cool and did well for a boat..
cool chassis, and they were nice guys too.

[mazspeed]

Thier test car, running the subframe, was out a the Run Through The Hills autocross event and did VERY well. I think it was in the top 3, maybe even top two, times for cars on street tires (non-R-compound)

They also tested the car out here in CA at the El Toro Marine base. I can't release the numbers but the car did very good. I think it almost got a 1g on the skidpad. Again, on non-r-compound tires.

Their chassis uses a lot of DSE parts including chuncks of thier hydoformed subframe.

Anyways, it's a cool car and beat the snot out of it. lol

http://picsorban.com/upload/coner.jpg

I saw that car at the last goodguys event here in Aug. They had a display of chassis and the quality looked killer. Yeah, that has a big block merlin right? It was nice, and had bugs on it, which means they drive it. :D

[R67Chevelle]

Reason for my interest is that the rear tires on a stock chassis is max 10" on the rear. On my chevelle the chassis is not rigid at all and want a firmer handling and more stable ride. The weight difference would be a interesting issue. Also the time is consuming in redoing the stock frame. It would be nice to roll a new chassis and be ready to finish the paint and body. The price after all the options are definately going to be over 20k and not too pleased about this, but you camaro guys have some awesome chassis options out there.

With the orange 66 chevelle the RS concerts has is a neat car. I do not like any wheel over 18" on a chevelle.. It does not to me look any good. I would like a 18X12 wheel in the rear and a 18X9 in the front. Cornering is not the biggest factor but I want something with 700-850hp and need a stable chassis and rear tire to handle the power on the street.

Thanks for all the input. This decission helps. My project is now a complete redo. Not going to cut coners this time, Had the velle for 22 years now and I want to do the build like I have always wanted.

Blessings,

[MarkM66]

Reason for my interest is that the rear tires on a stock chassis is max 10" on the rear. On my chevelle the chassis is not rigid at all and want a firmer handling and more stable ride. The weight difference would be a interesting issue. Also the time is consuming in redoing the stock frame. It would be nice to roll a new chassis and be ready to finish the paint and body. The price after all the options are definately going to be over 20k and not too pleased about this, but you camaro guys have some awesome chassis options out there.

With the orange 66 chevelle the RS concerts has is a neat car. I do not like any wheel over 18" on a chevelle.. It does not to me look any good. I would like a 18X12 wheel in the rear and a 18X9 in the front. Cornering is not the biggest factor but I want something with 700-850hp and need a stable chassis and rear tire to handle the power on the street.

Thanks for all the input. This decission helps. My project is now a complete redo. Not going to cut coners this time, Had the velle for 22 years now and I want to do the build like I have always wanted.

Blessings,

It takes more then a chassis to fit a 12" wheel, you'll also have to mini tub it.

[Roadster Shop]

Hi everyone. Quick intro. My name is Phil and I am one of the owners of the Roadster Shop (RS Performance) and was the one driving the orange Chevelle at Run to The Hillls. I am new to the message boards so bear with me a little.

There are definitely more advantages to our chassis than just strength. Bolt on componets are just that...bolt on. Not to be putting anyone down, but when using an original frame as a starting point there are a good number of limitations that come into play. We are a chassis manufacturer for over 20 years and have always found that if you are looking for a change from stock, the best thing to do is start from scratch and design around the desired outcome rather than work around what is there, and settle for the outcome.

That in mind, we saw that the Chevelle frame and suspension left many things to be desired... performance handling, sloppy steering, body roll, strength, rigidity, accomodating a decent size wheel and tire, lowered ride height and many more.
To check out all of the specifics of the chassis please click on the link below.

http://www.roadstershop.com/rsperformance.htm

If anyone out there is interested in the chassis, I invite you to come talk with us at one of the shows. I would be more than happy to take you for a ride in the car, or around the autocross track (if available). A ride in that car is hands down better than any sales pitch or bench racing over specs!

Upcoming Shows:
Good Guys Ft. Worth, TX 10/5 - 10/7 Autocross event
Good Guys Pleasanton, CA 11/10 - 11/11
Good Guys Scottsdale, AZ 11/16 - 11/18

[andrewmp6]

i like it im with the rest of them stick with the stock frame and build it up. been me id go for art morrison or schwartzperformance.com

[TravisB]

Welcome Phil,
Glad you found the site and joined in to the conversation. I have seen the yellow car several times it is a bad ass ride for sure. We have 2 roadster shop frames in the shop right now one for a 57 nomad, one for a 55 pickup. I can tell everyone first hand these frames are hands down the nicest frames out there for tri fives short of having something custom built maybe. I have seen the Chevelle frame and looked over pretty close it has several advantages over a stock frame. You can build up a stock chassis all you want but you still arent going to be able turn worth a dam with a 275 front or stick anything over a 10" wide tire under the rear without major surgery. Trust me I know I would be happy to take pics for anyone because I have a chevelle frame that I cut the hell out of and decided to stop and go with a aftermarket chassis. The one thing the RS frame offers that Art Morrison can not.........is the RS frame bolts in. Buy it bolt it in finsh body work and go on.

I hope you guys sell the **** out of them Phil:thumbsup:

[PTAddict]

The big rear tires are cool if you're not serious about road-racing/track days (which most of us aren't but if you are...), they will come up to temp much slower than the smaller fronts, effecting the balance of the car differently throughout the run... if it starts neutral, when the fronts get sticky it will go loose, then the fronts get too hot as the rears just start to get sticky and it goes tight. They also require running the springs/shocks further inboard negatively effecting the motion-ratios.



FWIW, my '71 Camaro with a modified LS1 uses 265 front and 295 rear Pilot Sport Cup tires on the track (Portland Raceway). After a 20 min session, the pyrometer shows the rear tires 5-10 degrees hotter than the fronts, even with 4 PSI greater hot pressure.

I notice that high-powered RWD cars with near 50/50 weight balance (Viper, Z06) are often running 50mm or more rear stagger, even in full-race setups. You want that kind of car to keep the rear end stuck down when hard on the throttle exiting turns. Something like, say, a spec Miata is a somewhat different story ...

Finally, keep in mind that a solid axle car provides no provision for negative camber in the rear. Personally, I will run the biggest tires that will fit on both ends, then tune with camber, shocks, and tire pressures.

[sinned]

I have seen the Chevelle frame and looked over pretty close it has several advantages over a stock frame. You can build up a stock chassis all you want but you still arent going to be able turn worth a dam with a 275 front or stick anything over a 10" wide tire under the rear without major surgery.

My 68 "A" body ran 275/17's up front and 11.5" rears. I had one of the tightest turning radius' of any "A" body ever built (thanks to custom uprights and speedway steering arms).

[TravisB]

My 68 "A" body ran 275/17's up front and 11.5" rears. I had one of the tightest turning radius' of any "A" body ever built (thanks to custom uprights and speedway steering arms).


there are exceptions to every rule....:yes: . I havent seen you on here in awhile dennis how are ya?

[sinned]

Still hanging in there.

[MarkM66]

Anyone know what size tires and wheels are on the RS '66?

[Roadster Shop]

Mark, our '66 Chevelle is set up with the following:
Front 18x9 255/35R18 Michelin Pilot Sport PS2
Rear 20x12 335/30R20 Michelin Pilot Sport PS2

We are currently building three other Chevelles (2 '67's and a '70) that will have 18x9.5 with a 265 or 275 series tire in the front. You can go bigger if you wanted.

[MarkM66]

Mark, our '66 Chevelle is set up with the following:
Front 18x9 255/35R18 Michelin Pilot Sport PS2
Rear 20x12 335/30R20 Michelin Pilot Sport PS2

We are currently building three other Chevelles (2 '67's and a '70) that will have 18x9.5 with a 265 or 275 series tire in the front. You can go bigger if you wanted.

Thanks. :thumbsup: