thehulk

08' C6 A6 3400 stall, forged 390, stand alone fuel cell, 464rwhp + dual stage (165 shot of nitrous) 2.73 gears

I picked up a set of 17"x9.5 ZR1 rims and a new set of 28x10x17 hoosier drag slicks. This is to hopefully cure my traction blues. (Nitrous off the line traction problems)

-I've been reading about some rubbing issues with the inner fenders.

-Will I 100% need to trim the inner fenders? Or is the rubbing minimal?

-Optimal tire pressure, ive read anywhere from 12psi to 28psi to keep it from walking down the track. (I run 1/8th mile btw)

-I was running the 305/35/18 MT ET, getting a 1.54 60ft but they wouldn't hold a 100 shot off the line, I assume my gearing will be negatively affected by the 28" tires, but should hold a larger nitrous shot off the line, so it would be a decent trade-off?

Thanks

thehulk

Current shot:

Stage 1: 65rwhp
Stage 2: 100rwhp

If the tires hold im considering doing (Max Effort)

Stage 1: 125rwhp
Stage 2: 175rwhp


Anything in between is fair game. Im also adding another bottle that I'll "Y" into the nitrous line for more consistent pressure, due to the potential nitrous shot.

thehulk

The track was closed so i gotta wait till next week. However, if anyone has any input on the discussion that would be great.

dieselracer

Yes. They will rub on the liner where the storage bins are at. I fixed the issue by putting a rubber spacer to make sure the Liner is all the way to the back. Then I raised the rear of the car. That fixed the rubbing issues for me.

thehulk

Thank you for the feedback. A few questions for you if you dont mind.

1. Are your hoosiers hooking really good?
2. Is the rubbing too dangerous to run as is a few times?
3. Does raising the rear negatively effect traction?

dieselracer

My setup is a low horse power set up, but I race in a parking lot with very little prep.Basically the only way to get traction is a full slick. A drag radial are as useful as a street tire there. I tried different drag radials with no luck. The best I found was the Hoosier slicks for traction. I pull 1.54 60ft on a regular basis with them. I raised the rear and didn't not realign the car. So it actually flatten out the rear tires a little bit. So I would say it was to our benefit. If I run at a good track, I run the pressure at 16 cold.
At a bad track I run 14 cold.

thehulk

I trimmed the inner fenders near the storage bins. Heres a picture of how much space there is. My thumb is 1.1" wide with what appears to be maybe close to 1/4" left between my thumb and the storage bin.

Will that be enough space to prevent rubbing?

dieselracer

I Think that will rub. When I first put them on, I took the car for a drive. On the high way, got it to 120. Stopped and checked and saw they rubbed. took it home and raised it until it didn't rub.

irok

the spacing in your picture on my car driver side is about half the width of my thumb.with MSR and 27.8" tall tire it never rubs and goes 1.45 60ft.YRMV

dieselracer

Bias ply Slicks will grow as they spin.

thehulk

I'm running 1/8th and probably wont see 120mph anytime soon lol.

hopefully 105-107mph

thehulk

I just read that slicks can grow anywhere from 1-1.5" at 150mph.

I bet I'll be okay at the 1/8th mile track. I cant even touch 140 at the 1/4mile track. Lol.

dieselracer

When I first drove my grand sport. Stock height. They rubbed at 100 mph. As I raised the car I went faster to make sure it didn't rub. Put them up and take the up too 100 and slow down right away. You don't have to sustain the speed.

thehulk

i removed the entire backhalf plastic fender that covered the storage bins. Did yous rub with that removed too?

dieselracer

the way it rubbed on mine yes. I made sure to wedge the liner so it was sitting up against the storage bin. So the differnce would just be the thickness of the liner.

thehulk

yea its not a big difference but hopefully it is THE difference. We'll see tonight.

thehulk

1.43 60ft
6.70
104.24 mph

200 shot N20

NA
1.54 60ft
7.24
96.48 mph

dieselracer

nice no rubbing?

thehulk

Nope, checked after the first NA run (96mph) and after the 104mph n20 pass. No rub marks on the slicks