robz

Fyi: c6z front wheels fit the back of the c7.

robz

A lot depends on how serious they are about racing.

robz

See post # 18.

JerryU

Surprised you can launch at those rpm's without a lot of wheel spin! Yep you will be needing a better clutch! But then that puts more strain on the rest of the drivetrain! From what I have read on the forum, the spider gears are next to go! No fun! Not like the old days where we just changed rears with different gears and welded spiders when we went to the track!

Recall a friends '57 Chevy we would put 5 something gears in and tow it to the strip! It was a solid lifter cam and we shifted at 6500-7000 rpm's! As I recall our rev limiter in the late '50's was sound and valve float!

Do remember we were eating up trans gears and bearings until the fellow who's lift we used at the local gas station watched us rebuilding the trans for probably the third time. He had apparently worked for Ferrari and brought over a drill trying to tell us we needed to drill a hole in the top of the case and install a breather! He said we were just creating foam. It was my buddies car and he said no but I convinced him to try! Solved our trans problems!

Woodson

Not as much challenge as introducing turns in your racing.

JerryU

^^^

Hmm, both are challenging! I'm a big fan of professional drag racing and F1; both are difficult and cost cubic money!

This year John Force Racing with only one AA/Fuel car, his 26 year old daughters, won the National Championship! Her record speeds are in the 330 mph in 3.7 second range in 1000 feet! She was up against the Don Schumacher dynasty with 3 top fuel cars!

The Force Team also won the Funny Car title this year. These folks have to be in top shape and are now breathing oxygen to get an edge when launching off the line! Force runs 3 funny cars, including his other daughters against Schumacher with 4!

Even ProStock is challenging. The completion is very tight and those engines are more sophisticated than the top fuel classes. They are producing >1300 hp from a NA 500 cid engine limited by rule to 10,500 rpm!

Lewis Hamilton and Sebastian Vettel are great drivers, on the edge for the whole race (at least Vette trying to catch Lewis!) However I get the impression they are partly that good from spending a lot of time in simulators matched to each track, optimizing every turn!

robz

I'm thinking the spider gears may not be an issue with proper launch technique and preventing wheel hop at my power range and a bit higher.
The smaller tire helps with that as does a drag radial over a street tire.

The c6Z crowd got away with tons of launches and the clutch recovered for those who weren't racing all the time. This clutch is more stout but does have it's limits but 10 passes a year wont be an issue.

The fact that the clutch strained at 25 psi and there wasn't excessive wheel spin is a tribute to the tire which was the whole point of my experiment and this thread. A quality 245 drag radial is all most people need.
It will take practice though.

woodsguy

I've thought about trying mine at a track for grins, all this "breaking" talk making me chicken out. LOL. Interesting reading.

Also wondering what gear are you in by the end of a 1/4?

robz

Had to shift to 4th.

Don't do dry burnouts try practicing possibly at a rental with someone who has experience with a manual vette.

Often the carnage comes from inexperience and people doing things they shouldn't like high rpm launches on street tires or dumping an aftermarket clutch.
Wheelhop is the cause of a large majority of failures with these cars.

woodsguy

Wasn't sure if you would make to 4th or not. I do not want any carnage, probably why I haven't tried it yet. Luckily I race offroad bikes and have a sport bike to feed the itch. Thanks

okaythen

What does this do/benefit?

When practicing launches on the street, do 2 in a row then let it rest for 5, 10 min is that good? Or how do you do it to minimize wear and tears.

robz

Circulates fluid.
I don't practice launches on the street but getting to know your car and it's subtleties is imperative to a good 1/4 mile pass. It's important to get a good feel where that clutch pedal engages for the launch.

robz

Was able to take some passes in my c7Z today with the 245 drag radial. And again it was more than enough traction for my car which is near stock in power.
I didn't cut a great 60' but it was not from spinning but rather bogging. I was basically in the 1.6's bogging each pass with 24psi cold and the stock clutch. I even tried launching aggressively close to 5000rpms and it wouldn't blow off the tires. The track good but nothing special and the air was great. I eventually ran in track mode to stiffen up the launch. I definitely need more seat time in this car. It was the first time I shifted over 5K rpms. lol
Next time out I'll launch around 5000K or just under and keep airing the tires up until it spins in track mode and report back. We know there's a 1.5x coming, but want to sneak into the 1.4's on the baby radial.
Again, for all the newer racers who want to make some passes at the strip and have some fun I'd strongly encourage you to try a drag radial like this and avoid the super wide meats that will only slow you down and wreak havoc on your clutch.

65fastback

So....its been 2-3 years since you made a couple hits netting a 1.53 60' WOW! thats amazing in my book . what kind of times have you gotten and how have things held up? new clutch yet? you obviously have a bunch of drag racing experience and i appreciate this thread & your advise and knowledge.
just for kicks awhile back I made 3 passes with my base stingray C7 M7 with run flats ... ( have another car i bracket race ) it was fun but pure hell trying to 60' the thing, it went mid 12's @114 all three times but still would be a huge fail in a bracket race with out good ties.
amazing how much a good tire and skilled driver can make a car look impressive.

65fastback

Ops i was typing the same time you were i guess.

robz

I'm here to help anyone who wants it.
Only took 2 passes in the Grandsport, and like I mentioned back then I glazed the clutch but it recovered fine with no issue.
With the C7Z I just took 4 passes so far and although the clutch wasn't happy it's fine as well.
The Grandsport seems to be a little easier to launch due to much better gearing even though it lacks a lot of power and torque. But in my experience with these late model manual vettes, you can use rpm to get you out of the hole and sometimes it's better not to have too much torque especially for the limited tire options we have for these cars. With that said this C7Z will see 1.5x's on that tire.

65fastback

So... you dont have the C7 GS? you now have a C7 Z06?

I suspect if you got a 1.53 60' in a stock GS on your second try ( if iam reading your post right ).... a 1.4X should be very possible in a Z06 assuming your on a good DR

Dr.Ron

Hey Rob,
Can I make a couple of passes on those wheels/tires with you at Atco one day?
I don't want to buy a set only to use them 1x at the track. Lol
I am curious what I can run in the Z.

Ron