I ran a little test for myself and all you guys.

I ran on the I-Forged 19's probably 30 times with temps from 50-70 and always stayed within 14.2-14.4 at 97 or 98.XXmph trap, not once did I EVER break into the 99's. The rubber on the I-Forged 19's is SO3's 245/40 and 275/35, the total weight was 55-56 lbs.

I then bought some Track rays with Kumho Ecsta's, the weight was 44lbs so I was extremely excited about possibly doing 13's. The rubber is 225/40 and 265/35's. Out of the 4 runs so far I have posted 14.17-14.35 with traps at 99.5-100.18. I'll definitely see 13's with cooler nights, it was 80 degree's.

I guess it looks like the lighter wheels will probably help .2 seconds and around 2-3 mph. I would have though 12lbs per wheel would have supported better times, I guess once it cools down a bit, maybe I'll see stock 13's finally.

 

The most helpful weight reduction is unsprung weight, good luck getting into the 13's.

 

what iForged wheels did you get??

I got mine without RIVOTS/BOLTS because it saved 7-8 pounds on all 4 wheels, ALSO SO3s are heavy *** tires, thats why I went with Toyos, My set up is about 9 pounds lighter than stock touring wheels. Not as light as track wheels, but I get much better rubber and traction rating and treadwear rating than the stock 040s.

btw, how many more miles do you have on it now, breakin makes a difference too

 

I forgot to mention, typically 100 lbs of car wt=10lbs of rolling/rotational wt=decreasing 1/4 times by .1 of a sec. So, you roughly lost 40 lbs of rotational wt, thus decreasing yout 1/4 by .4s seems to fit.

 

I have the 3 piece Aero's 19X8.5 and 19X10. I have 6100 miles on the car.

 

Don't forget that having a larger rim with a smaller aspect ratio decreases the sidewall flex for a better launch.

 

My rears (same as yours, as you know), mounted on 275/35-19 S-03s weighed 60lbs. on my bath scale.

 

how high of a sidewall is needed for a perfect launch...i mean i know the wider the tire the more traction and the smalller the sidewall the better handeling you'll have but is there a perfect combination so u dont sacrifice launching

 

and I bet his weighed 2-3 pounds more PER wheel with the bolts and his fronts are even heavier since they are 8 1/2 and not 8". Mine were 56 lbs for rear and 48.5 for fronts with Toyos.

 

Mine quite possibly could have been a bt heavier, I too measured mine on a VERY crude bath scale. I have some very accurate scales at work, I'll do a better measurement this weekend.

 

I think we know that. The point of the post was the performance penalty for the heavier wheels. It was less than I thought it would be, actually!

 

My time below is with no brake torque and 3/4 gas spare, bone stock. I think its possible to get under 14 with an auto!

 

It's definitely possible.....it's been done.........MaxHax ran a 13.9 on all motor, in an auto

 

I don't understand why you guys have such heavy forged rims....I though forged were suppoesed to be lighter. My ADRs with heavy-*** S-03 tires weight only 55lbs in the rear, with some toyos I'd be around 50lbs in the rear. My stock Touring Rims with tires weighed 56lbs in the rear just for reference.

 

Forged= more metal= heavier.

Personally I don't think forged wheels are necessary on a street/ track duty car. I believe the Z06 Vettes started out with Forged wheels but moved to regular wheels for weight reduction and b/c forged wheels weren't necessary.

Just my 2 cents though.

 

The forged material is stronger than cast, so if the wheel is designed around this idea it can be made lighter by using less total material in the wheel. Just because a wheel is forged it is not necessarily light.

 

BINGO!!! stronger material=less material needed for same strength=lighter wt.

as far as the guy with ADRs, you have 18s, 19s are heavier because there is more material.

REmember I went from 225/245 18" to 245/275 19" and saved 9 pounds!!!! I wouldn't call that "heavy" If I had the same size wheels (18") and went with 225/245 tires, I would expect them to be lighter. Also, you happen to have a wheel (that particular ADR) that seems to be pretty light weight, it definitely isn't the norm for such an inexpensive wheel, you just got lucky. I have no idea how strong they are though.

 

are you sure they are lighter??? My guess is that they did it to save money on the overall car. FOrged wheels are MUCH more $$v to build.

don't assume that since they switched, it was for the better, perhaps it only increased profit margins.

 

The Corvette engineers said it was for lighter weight saving somthing like 3 lbs. per wheel......heck these guys went so far as slicing the windshield thinner to save weight on the car.....I'd call that pretty hardcore about trying to save weight.....not to mention other things they did.

The Z06 is the Premium Corvette.....the profit margin on the C5s is already high so they really wouldn't have a need to increase it any.

And if you think about it.....Forged components are A LOT heavier.....
Forged wheels and parts are going to be HEAVIER every time.....just think about it.....
When you forge somthing it is A LOT heavier.....even if they use less material in some areas the overall piece is going to be significantly heavier......
and as I said before Cast wheels are MORE than strong enough for light duty track and street applications.