Anybody have stock rallys and suspension upgrades? would it be worth it 67-68 camaro

[Bobby05]

I have a 68 camaro with a ls2 and t56 with factory suspension besides the 3" lowering leaf springs and disc brakes all around. I wanna try and keep the factory look with the 15" rallys but wanna make it handle a little better. I was wondering if anybody kept the factory wheels and upgraded the suspension. I saw somebody on here awhile ago ran 3" drop leafs with tubular a-arms and coilover kit up front with 2" drop spindles and it looked good but cant find the post. Im going for the best ride and handling I can get but making it look like factory inside and out. I didnt know if anything would be worth it keeping the 15" wheels.

[SPG]

I am basically doing the same thing on a 2nd gen, suspension won't be the limiting factor, it will be your brakes. You can only add so much brake to a small package.

People generally have a misunderstanding of big brakes, it doesn't always mean better. But something that can fit behind a 17" wheel would be the best bang for the buck upgrade without doing anything absurd.

Basically, a bigger brake allows more heat dissipation, so you can driver harder longer without fade. If you have rotors for 15" rims you'll get the heat soaked quicker, hurting their ability to preform.

Wilwood does make a 6 piston brake for 15" rims (make sure yours fit, not all 15" fit) and that will get you the extra leverage you need. Bigger piston doesn't not mean better, think of it like pushing your fingers on a plate that is spinning, one finger doesn't stop as well as you putting down two fingers, you're getting more leverage. 6 pistons might have smaller surface area than one giant piston, but you're spreading out the load to make for a more even clamp.

This doesn't factor in brake pad material or anything which is a big part of it as well.

One thing you can do, is add air ducts that go to your rotors to help with heat, but again, there is only so much you can do.

Rob Dahm made a good video on why bigger doesn't mean better


https://www.youtube.com/watch?v=WwtUtw3tjMo

The other major factor in how well you stop, are tires.....and the reality is, the best 15" tire that isn't a drag slick is probably going to be some cooper cobras.....Not really the most performant type of tire out there.


Anyways, I am not going to tell you to get bigger rims, I get where you're coming from because I'm doing the same thing, but I will say, if you ever want to track the car, or do some performance events, I would strongly suggest you buy a 2nd set of wheels that are at least 18" so you can get tires that are good. You will also have to accept the fact in high performance scenarios, you might have to deal with brake fade sooner than you would if your rotors were larger

[mikedc]

Saying "I want the car to handle better" is sort of like saying "I want the car to be faster." It's not specific enough.


Are you trying to make the body stay flatter and lean less in the corners?

Are you trying to tighten up the rubber bushing & tire isolation, to give the car a more connected sporty 'feel' (and more NVH)?

Are you trying to remove slop in the steering?
Or make it return itself to center more strongly when you let go of the wheel?
Or quicken the steering gear ratio so it's fewer turns from lock-to-lock?

Are you trying to make the brakes "clamp harder" when you first hit them?
Or fade less after repeated stops?


Start by identifying your specific grievances with the car. Then you can make good decisions about fixing it. Otherwise you may just throw a lot of money at it and end up with a poorly-matched combo.

There are definitely things worth fixing even if you keep 15" wheels. A 3rd-gen Camaro has a very different front end from a 1st-gen even though they were still running 15" wheels in the early 1980s. The difference was they were running wider-tread radial tires instead of the 1960s bias-plys.

[Bobby05]

I would go to a 17" wheel but didnt know if i could get the look without mini tubbing. The stock 15 on it now kindve tuck into the rear fender and there isnt a a gap between the fender and tire which i like. I cant find a example of a 67-68 where its lowered with 17's and there inst a big gap between the tire without being mini tubbed. I have 17" wheel vintiques rallys on my 69 and it looks good but the fender on 69's and 2nd gens is squared off and is tucked up under the fender. The 67-68 have the round fenders and its hard to get that look. I wouldnt mind doing the ridetech 4 link coilover kit but never really saw it ran without being mini tubbed. I just want it to handle, stop,and steer better then something from the 60's and staying away from mini tubbing.

[SPG]

Mini Tubs just allow you to run a wider tire, mini tubbing isn't going to do anything about the gap between the fender and the wire, that would be tire diameter and how much the car is lowered.

[mikedc]

I wouldn't expect the wheelwells to be such an issue for enlarging the rims. You can get tires that have similar overall sizes with different rims.


Try playing around with this thing:

https://tiresize.com/comparison/

I mean, look at a 245/60/15 next to a 245/50/17. The two tires have exactly the same overall diameter & tread width.


Asterisk:

A bigger rim/shorter tire sidewall makes the tires look more wide & flat for the given dimensions. It's because the sidewall bulge is located closer to the treads. If you want to maintain an old-school appearance then you might want to pick a 17" tire that is slightly thinner (the tread width spec) than the tread with of the old 15" tire you are imitating.

So in this example, you might take the new size down to a 225/55r17. A low-profile 225 will look wider than a hi-profile 225 does.

[streetk14]

To me a 17” wheel looks old school; at least by modern standards. It gives you room for a good sized brake setup and you can actually buy quality tires in 17” sizes. Like you, I was trying to keep the original look of the car, so I got a set of 17” wheels that look a lot like the Pontiac Rally wheels that could have come on the car. I was able to get a set of Michelin pilot sport 4S tires in my sizes and fit a 13”/12” 4 piston Baer brake setup under them, and it still looks like a 1968 Firebird.

The Ridetech 4 link gives you ride height adjustability, but doesn’t require mini tubs nor will it effect the wheel/tire fitment. I have it on my car with stock tubs.

[Zachalanche]

15" rally wheels look awesome. and while there will be compromises to consider, it has to be possible to build your car to perform very well on a 15" wheel. Consider that the vintage trans am series has a bunch of cars running 15" wheels. they must have some tricks up their sleeve.

Also what will you use the car for. Are you trying to win anything? or would you be happy with a car that's fun to drive even if it's not the best possible PT car. And lastly, are you a good enough driver that even if you had all the best equipment, you won't get passed on the track by some maniac in an average car.

all things to consider.

Big brakes and wheels are easy upgrades later on if you find that to be limiting your driving experience.

[pitts64]

Definatly stay at 15". Those big wheel look goofy period. You will have access to a massive amount for wheels and wheel covers if you stay at 15. You have excellent tires to choose from unless you choose to believe all the internet BS.


You do not need to update the stock Chevrolet Disc / Drum brakes. I use Porterfield brake pads with matching rear brake shoes. Make sure you have an adjusting rear proportion valve on the rear brake line and a metering valve on the front. Good brake rotors drilled and slotted. Everytime I change front brake pads I also change calipers and rotors. Believe it or not I perfer reground D-52 front brake calipers from N.A.P.A. The local store does all there own maching work and do an axcellent job!

My 69 el camino handles as well as most of the performance sedans we have today. But the brute torque of the 454 makes it even better.

I have SPC / Howe ball joints +9 upper and +5 lower on the front, +7 right side +6.3 left side. Zero camber. Zero toe erroring to toe out.

14:1 Lee steering box set at 30 pounds and its amazing!! The wheel bounces back to center in a snap better then manual but when parking its as easy as power..

Spohn rear control arms with there big Del Sphere bushings.

Stock 15 x 7 with 4.25 back space wheels.

225/70r15 Mastercraft Avenger GT tires (same tire the Mickey Thompson uses with different side wall markings).

[ridesdirt]

I did. 67 Camaro, ridetech upper and lower a-arms, the type that use a coil spring, not coilover. Fat sway bar, Koni shocks, quick ratio steering, Wilwood 12.19" discs all the way around. Leafs in the rear (may install rear sway bar) - no four link. Poly and delrin bushings everywhere. Car rides tight, handles well, no rattles or squeaks. Fun to drive with the SBC427, TKX and Moser rear with 3:73 and truetrac. 255/60/15 rear and 215/65/15 front, 15x8 and 15x7 rallys, considering a front wheel and tire change to something a little wider.

[68Formula]

Consider that the vintage trans am series has a bunch of cars running 15" wheels. they must have some tricks up their sleeve.
.

They run expensive non-DOT approved Goodyear Blue Streak Special bias plys with as much as 4* static negative camber (yes, camber). I'm sure they're running 700+lb/in spring rates too. Would not recommend any of that on a street car.

[68Formula]

If you plan to stay with stock 15" rallys (7.5, 0 offset), then you'll be limited to a 215/65R15 front and 255/60R15 rear. There's about 4 performance tires (for cornering) in those sizes (Cooper Cobra GT, B.F. Goodrich Radial T/A, Mastercraft Avenger GTs, and Mickey Thompson Sportsman S/T). These are older technology (compounds, tread design, etc). While good back when they came out, would probably rank in the bottom 50% compared to the modern tires.

If you were to go up to 17s you'll literally have 4x the choices. For the front, do a 17x8 +6 to +8mm offset and 245/45R17s on 17x9 or 17x9.5 again with +6 to +8mm offset. The added width rims will improve turning response, and the wider tires means much larger contact patch. Plus they'll be laterally stiffer.

Below is a before after from another site. The lower profile setup the owner chose is a 225/50R17 front and 255/50R17. So the front sidewalls would be same height as the 245/45s but the rears will be a little taller @ 27", but it'll give you an idea what going up in diameter would look like.

215155
https://static1.pt-content.com/images/pt/2024/10/img_8283jpg325075-1.jpg

If you do decide to stay with 15s, I'd still get custom rims. This way you can get the ideal offset and go wider rim, to optimize as much as you can out the available tires. 235/60R15s on 15x8 front and 255/60R15 on 15x9 rear with +6 to +8mm offset. You'll still be limited to the same 15" tires mentioned earlier, but it'll be an improvement.

Edit: Quick look for rally wheels, doesn't appear to be +6 to +8mm offset version in a 15x8 or 15x9. However ,as long as you stay within the 235/60 front 255/60 rear combo with 15x8, an offset up to +13mm will work with disc brakes without rubbing. Looks like Vision wheel has them in this size.