ArcticWhite

Was curious on what the weight difference was between the new and old rims. I was quite surprised at the weight difference! Going to larger aftermarket rims really made my move to aluminum hat brake rotors pointless!

An increase of 55.6Lb of rotational mass!!! That is ALOT!

So, now the question: Did the new tires really improve traction, or did I add so much rotational mass, I'm getting better traction because I'm putting less power to the ground?

Rear:

Stock: 9.5x18 GM Rim - 275/40R18 F1 Supercar tire (non runflat) - 43.4lbs
CCW 505a: 13x19 505a rim – 345/30R19 Pilot Sport tire – 61.2lbs

Front:
Stock: 8.5x17GM rim – 245/45R17 F1 Supercar tire (non runflat)– 40.2LBS
CCW 505a: 10x19 505a rim – 275/30R19 Pilot Sport Tire - 50.2LBS

You definitely only want to do a mini-tub and large rear tires if you truly are making a lot of power and want better traction. That's a lot of rotational mass to add just for looks....

vette.mix

Those 345 have to look nice-Pics

Turbopower87

I'm glad you pointed that out. I want aftermarket rims but there are no wheels as light as my thinspokes that are any where near my budget.

I think a lot of people don't think about the added weight from the larger tires when they buy larger rims. Everyone asks how much the wheels weigh but don't take in to account the weight of the wheels.

BTW, pics of these 13x19s are a MUST! Post them up

ArcticWhite

13x19's stick out a bit. The LPE solid bump stops keep them from hitting the fenders, but I'm just not sure I like the look. I'm tempted to go to wide body fenders, run a wheel spacer to push the rims out a bit allowing an even wider tire and the ability to run the normal rubber bump stop again. With the poly bump stops right now, when you bottom the car out, you really feel it. Plus, that's GOT to put a lot of force on the shock mount that it wouldn't see with the regular bump stop.

Here are a few pics:

peter pan

I agree on the added weight, I like your setup and could use all that traction in my boosted Vette

ArcticWhite

It was a stupid amount of work, a crazy amount of money, and with the rotational mass increase, a decrease in power to the ground, but I did it because I saw it as added safety.

With 590rwhp and the stock rims and tires, I was able to loose traction at 70mph. Basically, spin the tires ANY time in 2nd and through 3rd with a hard shift. That can definitely get me into trouble.

Now with the wider tires, I only loose traction in 2nd gear if I deliberately try (stab the throttle quickly). Rolling into it there is no loss in traction, just a great hard pull.

vette.mix

[/quote]

That a great looking stance

Vetteman Jack

Surprised that there is that much difference in the weight. But, the CCWs looks so much better IMO.

Indy

Don't forget. You're comparing the stock wheels with non-runflats. If you were to use the original runflats, the measurements would be a little closer.

Red3644

I think you seeing a combination of extra traction and added rotational mass in your reduced tire spin. That is alot of extra weight. I don't know how you use your car but that could also show up as increased
stopping distances and less wheel control over bad surfaces. In most cases the big billet wheels people like are actually performance downgrades. I've had super light modular "racing" wheels on my Pantera and could tell the difference when I swapped to the billet aluminum Campy reproductions. The light weight wheels are delicate and I hated cleaning the bolts around the rims. A total PIA if you have to have them and ridiculous if they're just a styling feature. Just my 2 cents.

MSG C5

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Is that offset correct? I have a friend who is running a set of CCW
505s at 19" all around and his rear wheels don't stick out that far.

ArcticWhite

That is because he will be running 12" or 12.5" rims. This is the best that can be done with a 13" wide rim.