[Z06] 28" drag radial at the track on stock C5Z?
06-30-2015, 05:24 AM
#1
Pro
Thread Starter
28" drag radial at the track on stock C5Z?
Been doing as much research as I can lately before I purchase a C5Z. I noticed at stock level you have to shift into 4th at 112 before you go through the traps.
Anyone try a 28" drag radial to give them a little extra room? Looks like it would give you a little more wiggle room (117 mph) . If so did you're ET/MPH get better?
-Scott
Anyone try a 28" drag radial to give them a little extra room? Looks like it would give you a little more wiggle room (117 mph) . If so did you're ET/MPH get better?
-Scott
07-01-2015, 04:23 PM
#2
Just curious your other specs.
By my calcs, a 3.42 gear and 305/35/18 tire (26.4" tall) has me at 104.4 mph at 6500 rpm redline.
Going to a 28" tall tire gets me to 110.7 mph @ 6500 rpm. Still not enough to eliminate the need for shifting to 4th.
6750 rpms gets you 115 mph, 7000 rpms gets you 119.2 mph.
By my calcs, a 3.42 gear and 305/35/18 tire (26.4" tall) has me at 104.4 mph at 6500 rpm redline.
Going to a 28" tall tire gets me to 110.7 mph @ 6500 rpm. Still not enough to eliminate the need for shifting to 4th.
6750 rpms gets you 115 mph, 7000 rpms gets you 119.2 mph.
07-01-2015, 10:16 PM
#4
Melting Slicks
Last edited by skyavonee; 07-01-2015 at 10:27 PM.
07-02-2015, 11:38 AM
#6
Melting Slicks
Our rearend is 3.42, and our 3rd gear is 1.43. MT's 28" DR advertises a 87" circumference. Using these numbers, I have 3rd gear topping out right around 111 mph at 6600 rpm in 3rd.
07-02-2015, 01:31 PM
#7
Pro
Thread Starter
I'm not sure how you're coming across these numbers, but my calculations align more with TX Z06 02 than yours.
Our rearend is 3.42, and our 3rd gear is 1.43. MT's 28" DR advertises a 87" circumference. Using these numbers, I have 3rd gear topping out right around 111 mph at 6600 rpm in 3rd.
Our rearend is 3.42, and our 3rd gear is 1.43. MT's 28" DR advertises a 87" circumference. Using these numbers, I have 3rd gear topping out right around 111 mph at 6600 rpm in 3rd.
The tires are from M&H 325/40/18 is 28.24. What am I missing?
07-02-2015, 06:45 PM
#10
Melting Slicks
07-02-2015, 07:13 PM
#11
Pro
Thread Starter
07-02-2015, 08:04 PM
#12
Le Mans Master
The car will be a dog on the 28"s with the MN12.. Stick to 26s. You will have to shift to 4th if you trap atleast 113-114. The Hoosier 275/40/17s are bad a$$ hooking, very light tires to run.. On a good track, you'll fly on them and the car won't bog as much after the 3-4 shift.
07-02-2015, 09:03 PM
#13
Pro
Thread Starter
The car will be a dog on the 28"s with the MN12.. Stick to 26s. You will have to shift to 4th if you trap atleast 113-114. The Hoosier 275/40/17s are bad a$$ hooking, very light tires to run.. On a good track, you'll fly on them and the car won't bog as much after the 3-4 shift.
07-03-2015, 12:34 AM
#14
Le Mans Master
Trust me... I had 28"s with 850rwhp and it ran 12 mph slower (however this was with stock speedlines all around and 28s) vs. a CCW drag pack (70lbs lighter) and 26" ET Street bias plies...
Stuff it in 4th on 28s and it just lays down.. The MN12's gear spacing from 3rd to 4th blows...
You would go faster if you ran the 26" tires....Learn to shift 4th well. That or have your rev limiter extended to 6900 or so and rev out 3rd.
My car ran 12.17-12.35 @ 116-117 on 26" BFG drag radials, bone stock other then a vararam, shifting to 4th.
07-03-2015, 11:36 AM
#15
Pro
Thread Starter
I'll most likely go with weld RTS 18's all the way around.
Man, I didn't realize it would be that much harder to launch. I would have thought it would be easier with a taller sidewall.
Man, I didn't realize it would be that much harder to launch. I would have thought it would be easier with a taller sidewall.
07-11-2015, 12:23 PM
#16
Melting Slicks
I also vote sticking to a 26"
i'm currently on a 26.6 and wish It was a little smaller so I can get more usable RPM in 4th. unless you dont mind sacrificing mph for E/T
i'm currently on a 26.6 and wish It was a little smaller so I can get more usable RPM in 4th. unless you dont mind sacrificing mph for E/T
07-12-2015, 09:36 AM
#18
Le Mans Master
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The car will be a dog on the 28"s with the MN12.. Stick to 26s. You will have to shift to 4th if you trap atleast 113-114. The Hoosier 275/40/17s are bad a$$ hooking, very light tires to run.. On a good track, you'll fly on them and the car won't bog as much after the 3-4 shift.
Yes, it saves you a 3-4 shift but the car will be harder to launch, will not pull as strong in 1st/2nd costing you ET.
Trust me... I had 28"s with 850rwhp and it ran 12 mph slower (however this was with stock speedlines all around and 28s) vs. a CCW drag pack (70lbs lighter) and 26" ET Street bias plies...
Stuff it in 4th on 28s and it just lays down.. The MN12's gear spacing from 3rd to 4th blows...
You would go faster if you ran the 26" tires....Learn to shift 4th well. That or have your rev limiter extended to 6900 or so and rev out 3rd.
My car ran 12.17-12.35 @ 116-117 on 26" BFG drag radials, bone stock other then a vararam, shifting to 4th.
Trust me... I had 28"s with 850rwhp and it ran 12 mph slower (however this was with stock speedlines all around and 28s) vs. a CCW drag pack (70lbs lighter) and 26" ET Street bias plies...
Stuff it in 4th on 28s and it just lays down.. The MN12's gear spacing from 3rd to 4th blows...
You would go faster if you ran the 26" tires....Learn to shift 4th well. That or have your rev limiter extended to 6900 or so and rev out 3rd.
My car ran 12.17-12.35 @ 116-117 on 26" BFG drag radials, bone stock other then a vararam, shifting to 4th.
No reason to keep it in third. Most of your ET is determined in the first 330'. The 3-4 is the quickest shift to make and will hurt ET the least.
07-12-2015, 10:56 AM
#19
But I think you are missing the point. Unless you have a SLOW car, you are going to need to shift to 4th regardless of your tire height. My car is slow and I am trapping 112 mph with horrid 2.2+ 60's (haven't been to a well prepped track yet). Once I shore that up, I should be trapping 3-5 mph faster.
Would you rather make that 3-4 shift at 1000' or at 1200'+? On the latter, by the time you make a perfect shift in less than 1/2 second and get back on the throttle, you have already crossed the finish line. You could have just bounced it off the rev limiter and your mph would be the same.
And further, it seems that increasing rev limiter doesnt do much good on stock motors. They are already losing HP fast. At least according to ECS who did my tune.
07-12-2015, 11:31 AM
#20
Pro
Thread Starter
I have only run the 26.4" (305/35/18)and 26.1" (295/35/18).
But I think you are missing the point. Unless you have a SLOW car, you are going to need to shift to 4th regardless of your tire height. My car is slow and I am trapping 112 mph with horrid 2.2+ 60's (haven't been to a well prepped track yet). Once I shore that up, I should be trapping 3-5 mph faster.
Would you rather make that 3-4 shift at 1000' or at 1200'+? On the latter, by the time you make a perfect shift in less than 1/2 second and get back on the throttle, you have already crossed the finish line. You could have just bounced it off the rev limiter and your mph would be the same.
And further, it seems that increasing rev limiter doesnt do much good on stock motors. They are already losing HP fast. At least according to ECS who did my tune.
But I think you are missing the point. Unless you have a SLOW car, you are going to need to shift to 4th regardless of your tire height. My car is slow and I am trapping 112 mph with horrid 2.2+ 60's (haven't been to a well prepped track yet). Once I shore that up, I should be trapping 3-5 mph faster.
Would you rather make that 3-4 shift at 1000' or at 1200'+? On the latter, by the time you make a perfect shift in less than 1/2 second and get back on the throttle, you have already crossed the finish line. You could have just bounced it off the rev limiter and your mph would be the same.
And further, it seems that increasing rev limiter doesnt do much good on stock motors. They are already losing HP fast. At least according to ECS who did my tune.
Have any of you tried a different ratio gear? 3.90s?