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Are those 315s or 335s
315=11" rim
335=12" rim
To me look like 315s...315s will stretch hard on 12" rim and almost impossible to inflate...found that out last week
315's on the Forgestar F14 12X18 rim.
Jake can chime in if there will be an inflation issue.
I copy and pasted this post from another thread for the fellas on here:
So I was able to actually test my theory of using a small drag radial on a c7 with the stock clutch.
I haven't been to a drag strip since 2014 and as mentioned above I have no experience with a c7. However, I felt that my experience in the c5 platform has provided me with enough knowledge to understand what it takes to launch a manual c7 successfully.
I had not planned to track my new c7 GS but after reading so many threads of people searching for the widest drag radial possible I felt I might have test out some theories so I could provide concrete evidence that a narrow drag radial might in fact be the best option for many c7 racers with a reasonable amount of HP.
Rewind to about 1 month ago, I was watching 2 new c7Z06 (M7) owners taking passes at the strip. The were both struggling on the launch. I was a little surprised to see that both had glazed their clutches with stock cup tires. This made me more convinced that a drag radial is just going to make this problem worse.
So eventually I caved in a bought a Hoosier drag radial and mounted in on my buddy's (Gary2004Z06) c6Z front rims and they cleared on the back of my GS despite all efforts not wanting to beat on this car.
I was able to sneak out today last minute to give them a try. I used the hour drive down to the track to get a feel for this car that I hadn't shifted over 5500rpms yet.
Test: Does a narrow drag radial, that most wouldn't even consider, have enough traction to provide a good enough launch and 60' with the stock clutch?
So here are the result. I say my theory is plausible based on only 2 passes.
Launch 1: (first launch in years)
~4800 rpms
22.5 psi cold
touring mode 1.74 60'
perception: Some bog and stumble. A little too long on clutch and slightly too quick on throttle. Slight glaze of the clutch. Track prep was good.
On this shakedown pass the car ran 11.51 shifting around 6200/6300 if anyone cares.
Adjustments made and flushed in some fresh fluid via the "Ranger method". Fluid didn't look bad.
Launch 2:
4500rpms
25 psi warm
Sport mode 1.53 60'
perception: car felt good with a slight stumble/hop, released clutch quicker, and quick throttle squeeze. Slight glaze of the clutch.
Aborted pass due to hitting limiter on the 1-2
So there's the real world data. It's obvious to me that the small radial works and there is still more left in the 60'.
Conclusion: A narrow 245 drag radial with 25psi can hook well enough to propel a 3500lb c7 to a respectable 60'.
A wider tire would put even more strain on the stock clutch and the car in general and slow the car down IMO.
My goal is to provide knowledge through my experience to corvette drag racers so they can utilize the same parts and techniques I have without wasting valuable time and money.
I copy and pasted this post from another thread for the fellas on here:
So I was able to actually test my theory of using a small drag radial on a c7 with the stock clutch.
I haven't been to a drag strip since 2014 and as mentioned above I have no experience with a c7. However, I felt that my experience in the c5 platform has provided me with enough knowledge to understand what it takes to launch a manual c7 successfully.
I had not planned to track my new c7 GS but after reading so many threads of people searching for the widest drag radial possible I felt I might have test out some theories so I could provide concrete evidence that a narrow drag radial might in fact be the best option for many c7 racers with a reasonable amount of HP.
Rewind to about 1 month ago, I was watching 2 new c7Z06 (M7) owners taking passes at the strip. The were both struggling on the launch. I was a little surprised to see that both had glazed their clutches with stock cup tires. This made me more convinced that a drag radial is just going to make this problem worse.
So eventually I caved in a bought a Hoosier drag radial and mounted in on my buddy's (Gary2004Z06) c6Z front rims and they cleared on the back of my GS despite all efforts not wanting to beat on this car.
I was able to sneak out today last minute to give them a try. I used the hour drive down to the track to get a feel for this car that I hadn't shifted over 5500rpms yet.
Test: Does a narrow drag radial, that most wouldn't even consider, have enough traction to provide a good enough launch and 60' with the stock clutch?
So here are the result. I say my theory is plausible based on only 2 passes.
Launch 1: (first launch in years)
~4800 rpms
22.5 psi cold
touring mode 1.74 60'
perception: Some bog and stumble. A little too long on clutch and slightly too quick on throttle. Slight glaze of the clutch. Track prep was good.
On this shakedown pass the car ran 11.51 shifting around 6200/6300 if anyone cares.
Adjustments made and flushed in some fresh fluid via the "Ranger method". Fluid didn't look bad.
Launch 2:
4500rpms
25 psi warm
Sport mode 1.53 60'
perception: car felt good with a slight stumble/hop, released clutch quicker, and quick throttle squeeze. Slight glaze of the clutch.
Aborted pass due to hitting limiter on the 1-2
So there's the real world data. It's obvious to me that the small radial works and there is still more left in the 60'.
Conclusion: A narrow 245 drag radial with 25psi can hook well enough to propel a 3500lb c7 to a respectable 60'.
A wider tire would put even more strain on the stock clutch and the car in general and slow the car down IMO.
My goal is to provide knowledge through my experience to corvette drag racers so they can utilize the same parts and techniques I have without wasting valuable time and money.
Great 60 ft time's especially for a manual. When you say glaze the clutch do you mean ride or slip the clutch to reduce tire shock/ spin on your launch from a dead stop? So you said just a little glaze of the clutch, stumble and hop which means your spinning a little. If you ride the clutch a little more creating some torque multiplication, and a little less tire spin and into the throttle a little sooner, what do you think ?
I am trying to create a decent high 1.7's 60 foot on the OE 285 30 20 pilot super sport with 25 psi warm and cannot get there. BTW, your tire size is 25.7 inches tall, that's 1 inch shorter than my OE size of 26.7 inches , providing a little gear ratio advantage. 1 Inch short is about 100 rpm higher in any gear. Also 11.50 pass in a base, Z51, or GS fantastic, with skinnies and some small bolt on mods.
Great 60 ft time's especially for a manual. When you say glaze the clutch do you mean ride or slip the clutch to reduce tire shock/ spin on your launch from a dead stop? So you said just a little glaze of the clutch, stumble and hop which means your spinning a little. If you ride the clutch a little more creating some torque multiplication, and a little less tire spin and into the throttle a little sooner, what do you think ?
I am trying to create a decent high 1.7's 60 foot on the OE 285 30 20 pilot super sport with 25 psi warm and cannot get there. BTW, your tire size is 25.7 inches tall, that's 1 inch shorter than my OE size of 26.7 inches , providing a little gear ratio advantage. 1 Inch short is about 100 rpm higher in any gear. Also 11.50 pass in a base, Z51, or GS fantastic, with skinnies and some small bolt on mods.
The clutch doesn't want to be slipped too much. So you need to get off it rather quickly. I pushed it close to it's limits and smoked it a bit, meaning hurt it slightly, by riding it a tad too much.
This can often hurt your et downtrack or sometimes end your pass.
The clutch doesn't want to be slipped too much. So you need to get off it rather quickly. I pushed it close to it's limits and smoked it a bit, meaning hurt it slightly, by riding it a tad too much.
This can often hurt your et downtrack or sometimes end your pass.
Ok, all well and good, any advise on a good launch with OE MPSS, on a decent prepped track, no launch control, no nannies et?. It seems you are getting off the clutch pretty quick to get some stumble, yet you say your slipping it enough to get a little burn, please advise. I also had a 2008 Z06, those cars had a borderline clutch imop. I thought the C7 clutch (on a base car) was quite stout and can handle more abuse than the C6 Z06.
11-07-2017, 03:12 PM
