edge04

All, looking for some advice and opinions. I own a 2006 z51 that is dual purpose but plan is to do more HPDE's each year.

I have an opportunity to buy and upgrade the rear body to the wide z06 style which of course would allow me to run a wider rim and tire. I am installing Brembo GT calipers and bigger rotors. Currently I have Cray 19x9 fronts and 20x10.5 rears. Don't think the brembo calipers will work (maybe with spacers) and I don't like that big of rims so plan on getting 18's all around but before doing so I want to sort out the body.

My question is, do I bother with the rear wide only and not the front or is the only way to do it is all around? Or do I just buy the widest 18 rims that allow for the most tire contact and fit the brembo's as there won't be much difference. Thanks

edge04

so would I be better off with 19's all around?

FAUEE

I think that this is an emotional decision, not a statistical one. Yes you can run wider tires on a wide body. But you could also just run a sticker tire on the narrow body for the same effect.

Keep in mind, you're doing DEs, you're not racing people competitively. There's as much glory/shame whether you're the fastest guy or the slowest guy out there, there are no trophies. The goal is to have fun, learn, and not break anything.

So the decision comes down to if you want to wide body your car or not. I think he wide body cars look better, so I traded my '09Z51 for a '10 Grand Sport. At the end of the day though, its all personal preference.

edge04

all true and I didn't think of the stickier idea. I am not interested in looks at this point, I have plenty of older muscle cars for that ego high.

I'd be happy with the tire sizes listed above.

JerryTX

I'm at 305mm slicks square on 10.5" front wheels and 11" rear. With the low stance on coilovers and -2.6 camber it rubs the front inner fenders THROUGH. In other words, if you put coilovers on a narrow body C6 you should only run 285mm fronts unless you accept the consequences. This to me rules out a wideBOOTY C6.. My car has LG Sphericals and G2 Coilovers and handles perfectly neutral, just like I like it. If you did a Widebooty it would tend to understeer more, not my preference.

Can the car use more front grip, absolutely! I'm too vested in 3 sets of wheels for the narrow body I can't afford to go widebody at this point. If you are starting out and have money to spend then go for it and do it all. If you are kind of new to this, then get 18x10.5 square setup and just drive the crap out of the car; with basic mods like brakes and cooling upgrades you will be faster than 90% of the cars on track as it is.

edge04

what size tire with what offset would you run if you did the square 10.5 set up?

ratt_finkel

This is very similiar to the aero or not thread.

And I'll poise some of the same questions. Why do you want to make these changes? What are your goals with the car? With your driving? Ultimately, it's your money. You can buy whatever you want.

If you are on a path to upgrade to make the car faster. There are other things that you should be doing first. Sounds like you have a lot of research to do.

Jeremy Foley

edge04

the goal is to make the car faster. I have an opportunity to buy a rear kit cheap which is the only reason I am asking. But I don't want to spend any money or time on useless things or not helpful.

ratt_finkel

Well the usefulness of the widebody kit itself is fairly low. It does give you the ability to run wider tires under the fender. But that's about it.

It wouldn't be the first thing I would do.

edge04

ok so save money or use elsewhere.

sounds like best rim/tire set up would be 18 10.5's all around if I plan on running coils

edge04

Anyone know if 18 x 10.5 speedlines with 58mm offset will fit with no issues including brembo's? Thanks

edge04

Thank you. I would rather not have them stick out. Based on previous post I should be looking for 59mm offset?

B Stead

That's 79mm rear wheel offset and 56mm front wheel offset.

285 rear tire at 65mm wheel offset
305 rear tire at 75mm wheel offset but call it 74mm
315 rear tire at 79mm wheel offset
325 rear tire at 79mm wheel offset with car lowering to tuck the tops of the tires

Well, both Cray and Oz Superleggera III have 19 x 11 73mm to 75mm. There is an Oz Alleggerita in 18 x 11 75mm but that wheel has a reputation of being very light weight without being a forged wheel. The Superleggera is available for the C6 front from 9.5" to 11" width by checking the C5 rear listings
.

Bill Dearborn

I'll add one other question. Where are you starting from? You say you want to do more HPDEs so I assume you have done some already. A novice can make a car a lot faster by just learning how to drive it properly so where are you in the experience spectrum?


I believe most people would recommend the following sequence of mods:
1. Safety Equipment, harnesses, harness bars, seats, HANS, etc
2. Wheels/Tires chosen with the idea of upgrading brakes later
3. Brakes
4. Suspension Mods
5. Body Mods (if you go wide body I believe you do both front and rear)


There is a point where upgrading your current car becomes more expensive than just trading it in for a GS/Z06. Either of those cars will have features that you don't get in the Z51. On top of that certain mods that you purchase for your current car can be easily converted to a GS/Z06 etc.


Bill

GettReal

think this needs to be in there

edge04

Thanks for posting, always value your opinion.

Still a novice and I don't base that on the number of events I have but the quality of improvements that I or the drivning coaches feel I make. If all goes well I hope to do 15 driving events this year.

What I've done so far is brakes, cooling and harness components. So next on my list is suspension and tires. Too be honest I really don't care for my current rims....looks or size.

So since I am buying new rims and have an opportunity for a rear wide body I thougt about doing it.

Looks like I am looking for rims for base body as that should work better than fine for me to get to the next level and if I do enough research can even find them used for a good price. Will also upgrade suspension at the same time.

That's the plan for now at least lol

edge04

These offsets don't seem very common in the used market. Was thinking about running 18x10.5 all around with 285 front and305 rear.

Grabbed_Crow_Mobe

I have a 2005 z51 that I'm returning to stock. I have a set of T1 ccw wheels. 10x18 and 11x18. PM if interested.

Have a bunch of other parts too you may be interested in.

Kevin