GTB/ZR-1

I'm thinking abt giving one a go for next year. I haven't used a Vette for AutoX since '07 when I had a C6Z (been primarily in AWD the past 7 years).

Anyone have any feedback? Contemplating the Magnetic ride & wonder if the real-time damping has any benefits between the cones...

Also, wheel/tire choices in 18/19" (R-S3 275 & 305s?)?

Alignment & ride/height settings?

I'll also post this in the Autocross & Roadracing section.

NTMD8R

Alignment....

-1.8 Neg Camber front
1/8" Toe out front
-1.5 Neg Camber rear
Zero Toe rear

Stock Z51 wheels and Tires.

Since we are quite experienced, we set it on Track... Number 5... all "nannies" off.
The car did very well the first time we went out (late September... clear about 10 deg C).

The 2nd time (clear -5 Deg C)... oh oh.... those Tires do NOT like cold.
We really had to dial our aggression back.

Looking forward to Spring.

GTB/ZR-1

Thx for the responses so far, gents.

Looking more @ wheel/tire combo. I think the new V2 Hankook R-S3s (200 TW) in 275/35-18 & 305/30-19 on CCWs in stock-sizing (w/ custom offsets), may be a good ticket--if the sidewalls are stiff enough. I've had good luck w/ the first gen of that tire--good & sticky & they like heat. Also may be a good bit of weight-savings there possible, as well...

Exhaust? $$$pend the big bucks for an Akra system (if they make an axle-back) for the car. Again, good luck w/ those on my old GT-R & now on my M3. I got great deals on both systems & they return (most of) capital when time to sell lol.

Batt? I don't think an aftermarket is legal, but... I need to look into whether an OEM batt from another GM model is a possibility. I've been mired in SM or ST classes forever, so.... I need to get schooled on Street!

No bar, for now--I'd like to see how the car handles as-is. Some of these cars are just too high, so lowering slightly to even things out & get a slight rake.

Is there really any advantage to Mag ride in the new iteration? In my old C5 & C6 Zs, I used to turn all the nannies off & I understand that w/ the Mag option, all of them CANNOT be defeated--but... Have heard that they do work & make the car more driveable. These comments are from journalists, mind you.

NTMD8R--do you have Mag, or just Z51?

Thx again & let's keep this going.

savage

i ran a c7 base this past season(20 plus events) this is what i learned/seen. the top cars in ss,ssr,ssp. are not running mag-ride, there could be many reasons for this, im not getting into them, all i know is the fastest autocross car i have ever seen in 25 years of doing this is a(2007 z06)also without coilovers, who F.T.D.'S most events is mag-rideless. the cars he sets up are the same(all top 10 cars out of 160) i have a z51 coming and because of what i seen i will be mag-rideless. about your wheels/tires as your know your stuck with a 8.5 wide wheel up front(cant put much of a tire on that, 265?) the alignment in 1st post will work fine, that was my start point with c7. as the season went on i played with the neg. camber in the front and ended up with -2.5 camber, 0 tow. once you go past -2.0 front camber any tow in or out wears out inside of tire to soon. you might think anything over -2.0 is alot but you need contact patch to turn you dont need it to go foward, there will be cars in SS that came with 9.5 and 10 inch front rims you have to do something to have the contact patch they do== neg.camber!, i could not get myself to run the 8.5 fronts, 10 inch rears so i went with 10.5 front and back-- SSP, this years setup will be factory offsets 18x10( 295/30/18) front, 18x11(315/30/18) rear, forgelines and a7 hoosiers SSP. good luck

savage

i went to your other post in autocross threads, good luck getting any answers there for c7, those guys, posts are mostly about c5'. c6's. cars that have been tested and retested with many aftermarket parts, ect. it will be years before the c7 willl have the aftermarket parts lists those cars have. it might be years before top drivers autocrossing will get into a c7, i really dont like to toot any ones horn, but intill froggy, strano, ect get a c7, get the picture? i dont care who gets mad at me for this post, the c6 was out for 9 years, tons of tests and aftermarket parts, it will be at least 1 more year before the c7 will catch up! i love the c7, i have my 2nd on the way, the truth does not hurt my feeling.

talon95

Tires, RS3 is the way to go. Those sizes will probably work although the sidewall is pretty soft. The V2 was only a compound change so if you liked the V1 for autocross, you'll love the V2. They do overheat a little more easily but are far better in cool weather and good in the wet.

The rub in regards to tires is there is a good chance BFG will release a new Rival that's faster than the RS3 next spring.

The other issue is the last Fastrack suggests the C7Z will be in SS next year. So the base C7 may not be very competitive depending on your goals.

I would not want to give up adjustable shocks for the mag shocks unless this latest iteration is absolute magic.

Dave G.

savage

thank you talon95 for one more reason to run my 15, z51 in SSP, its not just the HP( HP IS NOT EVERYTHING IN AUTOCROSSING) of the new out of the box race car(c7z06) its the rim sizes, im all about contact patch, the z06 cars can run a 305 easy up front, some will run a 315. and forget about the rear-345's all day long. even with a great alignment( you can do the same on z06) the contact patch will never be close to a car, any car with a wider wheel. that was one of the reasons for the c6 grand sport, wide body-wide wheels, great SS car. also i like how you put the shock issue, as im sure most that have been around a while know, someone( maybe GM) will come out with a setup-springs, sways, and a non-mag ride shock that works better tracking/autocrossing than anything thats on the cars today. you read it here first! sooner or later even the mighty z06 will be better on non-mag ride shock. lol

talon95

The problem with the C7Z is tire sizing. I guess you could run the 305/19 RS3 square on it. Probably not what you really want with 650 ft-lbs of TQ though. One upside is I think the offset for the rear is the same as the C6Z, so maybe that would provide a lightweight cheap 19" wheel.

As I recall, BFG doesn't make anything that would work. They have a 335/18 that the C6 can run, but that won't work with a car starting with 20's on the rear obviously. BFG makes some 20's but IIRC they're crazy tall.

Que Sam Strano for a street tire rant...

I doubt the mag shocks will ever be as good for autox as some of the $$$$ doubles we run. They'll always be tuned for the street/track which isn't necessarily ideal for autox. OTOH I doubt there would be a huge difference. Various people have been very competitive on the stock C5/C6 shocks. Depends on your level of effort and clubs you run (regional, national, NCCC, etc...). I wouldn't get the mag shocks thinking I was going to get an advantage, but if I were less serious and wanted the improved ride, etc... they might be tempting.

savage

i could live with the tire/size of the new z06 for SS untill more tires/sizes are released. i could not get pass the dodge neon size tires that fit on the c7 base/z51 wheels. so i went SSP. for me its not how well i do in ssp, its how i do at the event. i think the man's name was Burns who came up to me at a 160 car event at hershey park, pa. and asked what was the biggest tire i could fit on the base c7 i had at the time, i told him the 315/35/17( yes i said 17, base cars can run 17's up front) was rubbing to much inside and outside, 295/35/17 or 295/30/18 works better, even the 315/30/18 worked up front, that 315/35/17 rubbed? and in the rear i had 315/30/18. i tried the 335/30/18 out back and had to cut what was left of my rear inner fender lips off with a saw!! not kidding, anyway he said that he had a c6 grand sport and he will wait for a wide body car to run a real tire sizes on, real as in WIDE. for me the 295/30/18 front and 315/30/18 rear will have a balance i can live with for autocrossing. if i was a track rat, i would want more tire than that on a 3400 lb car. thanks

NTMD8R

To add to my info,
yes we have Mag Ride on the C7.
And... that Toe out in front is TOTAL (not on each wheel).

So far I have not made any changes... we want to see how things go in the spring.
I would consider wider wheels and tires .
Probably 10" front and 11" rear.
Not sure what tires yet... but definitely WIDER.

But I think the Mag Ride shocks are quite good in Track/5 mode.
I will lower it on the stock bolts.
I also am going to remove the mufflers, and replace them with straight pipes.

On my C6, we had GT2 Coilovers, and PFADT Sway bars,
and 18x10 front wheels and 19x11 rear wheels,
with Toyo R888 285x30x18 front, 305x30x19 rear.
That car was awesome.

In the first event we did in the C7 (I mentioned it earlier),
I was almost at the same overall standing (among 88 drivers), as I was
in the C6. Note these are all varieties of cars and tires... many running modded Miatas
on A6 tires. I was about 12th overall.

GTB/ZR-1

Good stuff guys--pls keep it coming.

As mentioned by Talon, the Z06 might show up in that class--but it'll be tire-challenged (as of now) & the gearing is too tall in 2nd, IMO--although the TQ is massive.

I'll probably fore-go the Mag ride & run the stock dampers for now. Less weight & complexity, overall & dampers are an easy upgrade later. It's too bad the rim width is ****-poor, as I think the car has great potential & would have been better w/ more contact patch.

Good to hear NTMD8TR approximately matching his standings of the more-modded C6 on quasi R-comps.

If I get the car, I'll make a stop @ Dixie, then Moultrie to see how it'd stack up in SE Nat-level competition. If it does well, maybe I'll head ~1400 mi NW in late Aug w/ it... ;-)

savage

is 1400 miles north the NCCC convention at ponoco? i dont want to wish my short summer away but that will be a good week in pa. the 25th will be low and high speed at ponoco, my new vert might not see a roll bar by then so low speed event for now. then later that week its corvettes at carlisle, what a week!!

GTB/ZR-1

The SCCA Nationals in Lincoln, NE.

Although that event sounds fun.

savage

take a look, www.corvettesnccc.org.(2015 convention) im a member at large($35.00 a year), how nice would it be to go to a race event with 100 corvettes? and then corvettes at carlisle with thousands!! even the low speed at ponoco with be fast, and the next day drag racing at Numidia raceway. im not one for drag racing, im going to find out for sure, do i launch better with or without useing the launch control on c7?

dencos

I took my '15 z51 M7 w/mag suspension auto crossing this weekend. My son and I drove the car, and we haven't autocrossed since 2010, so we were a little rusty. The car is completely stock, not lowered or even had an alignment. We did put on BFG Rivals.
Right out of the box this car was flat amazing. To give a comparison, our times were in the :56 to :57 second range per lap. The Super Stock Champ running on new Hoosiers in an "07 Z06 was running mid :53 second laps. And his car is dialed in.

Since you are an experienced racer and have been tracking your C7 I have a question about your car.

I have all the nannies turned off In Track/Race mode. On the exit of most turns there is a slight hesitation when getting back on the throttle. When I was watching my son, I could hear a burble (for lack of a better word) as he was back on the gas. I think added up thru all the turns it would probably add 1 second to our time.

Have you noticed this in your car?

At Idle I notice a slight miss, it is not perfectly smooth. How is your car?

Thanks for any input, Denis

NTMD8R

I didn't notice any hesitation.
But, I get on the gas pretty early throughout a turn, so if there was, I didn't notice it at all.

GTB/ZR-1

Wasn't able to make Dixie--got the car the weekend of...

First event will be in 2 Sundays. Already have the base C7 rims (18 &19") & debating tires right now. Will be dropping it slightly on the bolts & dialing in the alignment, as well.

Also want to weigh it--seeing it's a 1LT w/ Comp seats/no MRC, I'm really hoping for 32xx on fumes w/ no washer fluid in the car. I'm not going to mess w/ the exhaust, or bars (at this point). I want to see what she'll do, first.

Hopeful...

savage

myself and a few others have been looking for a c7 z51 owner with the base c7 wheels in hand, did you do your own fitment yet? i have been going back and forth with a few others = does the c7 base wheels fit the z51, as you know hoosier a6,a7 dont come in 20 inch, so z51 owners want to run the base wheels to stay in SS, SSR ,please do me a favor, let me know if they fit without spacers or how small a spacer is needed front or back or both. thank you

dencos

I bought the GT-2 wheels from LG Racing or Corvette Mods.
They are very close to stock offsets and are 18/19. They are a 1/2" wider than stock, but I run the stock tire size. They fit just like stock and actually have more clearance on the calipers than stock.

savage

dont kill the messenger, those wheels just put you in SSP(scca) and 2m (NCCC)