webdzynes

I'm really inclined to put S/C on a Z51 manual, but don't want to get involved with all the ancilary upgrades (except intake and exhaust). BUT, I don't want to break anything either... Any guesses as to what HP is safe?

docrings1

From some of the C6 threads in the "C6 tech/performance" forum, I'd say to be confident during racing/modding, to upgrade the output shaft, torque tube bushing, and differential if you are going above 450-500 HP.(50 to 100HP above stock). Transmission should also be addressed, too, for both auto and manual above 500HP.

You might be able to get away without upgrades up to 500HP -- but over a large sampling of cars, a higher percentage will break without upgrades than do break with upgrades. Just remember, stock cars with no mods still break, too, at the track, just in lower numbers than modded cars.

It's all "risk/benefit/cost" ratios... if you mod for a "benefit" of 10 - 25% HP upgrades, but don't really do any drag/road racing, you will probably not be running a significantly higher "risk" of breaking parts if you don't upgrade at a significantly higher "cost" (*probably* used in the statistical definition).

Insert big BUT here:
Remember HP upgrades should be part of a whole "package": brakes, suspension, driveline, safety equipment for car and driver, etc. Upgrading "just" a lot of horsepower is not a good thing, and no professional racer worth his/her salt does only HP mods...

M2CW,

Doc

Happy motoring!

SSkindog

The A4 Auto has been upgraded for 05 to handle 670 ft/lbs of torque.
Not sure what the rating is on the 6 speeds. I think the weak link wont be the trannies.
It will be the rear gear, and the clutch.

JWD01

It's not a question of how much horsepower but of how much traction. If you're going to run stock tires you should be okay. If you're going to run slicks, you'll break lots of parts unless you upgrade some parts.

C5 CU

[QUOTE=SSkindog]The A4 Auto has been upgraded for 05 to handle 670 ft/lbs of torque.
QUOTE]
I recall seeing a discussion awhile back about the TQ upgrade and as i recall the 670 ft/lbs is not exactly the measurement we think about but some "other" tranny TQ measurement...as i recall the actual increase over the C5 is like 50ft/lbs...albiet an increase but not the several hundred the 670ft/lbs could lead one to believe....i.e. tranny still weak link.

Scissors

Someone once told me that you should start at the rear wheels and work your way forward.

That someone has never broken down at the track.

In reality, the transmission can take a lot, but the differential and shafts need to be upgraded. And the clutch may need some help as well.

Scissors

[QUOTE=C5 CU]Correct. The 670 lb.-ft. rating was misleading. In reality it can only handly about 400 lb.ft. of input torque.

lager99

Is there even anything available for tuning, programming or kits yet in the s/c market? That will take some time. As far as h.p goes, why is it any different than the C5 ZO6? Stock tires will light up in 3rd gear...no damage to anything else at that point. The damage occurs when you actually get that power to the ground. Some people stayed with their stock clutches even w/o recourse. I changed out my clutch, never had any rear end problems, but with compound & a track I'm sure it would be inevitable. If you aren't interested in potential belt problems, clutch, rear end, fuel pressure, tuning, tire problems etc...it's not a good mod. I never had any problems, but the potential is there. A blower adds a ton of power, in fact I'd be scared to see some people try & handle that power...especially with stock tires. You can be facing the other direction faster than you'd ever believe. Do some research. I'm not trying to talk anyone out of it, I'll probably do it again, but it turns a car into the devil.

If you wanna play you gotta pay.