Hi,

i'm thinking about improving my car for 1/8 mile with a different ratio. Mine is stock.

My questions are :

* what is the stock pinion ratio ? (i've an A4)
* what can i expect from a different ratio on the 1/8 mile, and what is best to compromise to choose for the car which will still be a daily driver ?
* do i need a new tune for my car with a different ratio ?

I'm also planning buying Mickey Thompson ET street radial 250/50-16 on stock rims at rear. What do you think of theses tires ?

Thanks for your answers

Pierre

 

no help from anyone ???

 

Check your glovebox.

GU2 Axle, Rear 2.73 Ratio
GU4 Axle, Rear 3.08 Ratio
GU5 Axle, Rear 3.23 Ratio
GU6 Axle, Rear 3.42 Ratio
G80 Axle, Rear Posi-traction (Limited Slip)

 

most people with autos go with the 3.73 gears

 

If you go with a different gear ratio, you will need a tune to re-correct the speedo. As mentioned, most people with A4s step up to 3.73s. As for the MTs, they are a very good tire in terms of traction.

 

I would go with a 4.10 or larger if it was an 1/8th mile only car.

 

I agree, but 4.10 may be a bit steep for the hw, he mentioned he still wants it for a dd

 

oky. Thanks for your answers.

I will order these tires. Ratio might be good with a 3.73 as i will still use my car daily.

Does anyone knows what time can i hope in 1/8 miles with my set up :

* engine = 315 rwhp with hotcam kit + tune + bolt-ons
* cars has bilstein HD shocks + about 200 lbs of weight reduction,
* tires will be MT street radial 255/50-16

just to figure in which pool i might compete.

It will be the very first race (ET) in my country. No one really know what they can do.

 

you might want a stall for the best times but i would say mid 8's

 

Alright, most likely you have 3.23s. Automatic guys go 3.73, 4.10s are really aggresive and wont get any highway on them. For T56 cars you can go mild with 3.73 or wild with 4.10 and still have highway and driveability with the 6th gear. Id go 3.73 in ur case and then put some drag radials on it and dont snap the rear with heating some slicks. You must also note you will need a tune to correct speedo and most likely, when you install aftermarket gears you get less reliability because the stock gears are stronger.

 

with your current setup I say with 3.73's and a nice 3000 plus stall converter with those tires I wouldnt be suprised if you dipped into the 7 sec 1/8 mile

 

If you go with lower than 3.73's it will hard to make it harder to hookup therefore you may lose ET but if you have enough traction it will help.

 

How many high speed highways are there on the islands that make up New Caledonia? 4.10's may not be a big issue.

 

thanks for the replies.

To go on : i might go 3.73. The top speed with a 4.10 might be about 190 km/h and quite low (and for sure a big pain for fuel economy).

We don't have real highways here but we don't have so much cops too ... and it is not unusual to see someone driving 250 km/h. On my side, i occasionaly go 240 (at 220 the wind make an horrible sound suddenly, coming from the top of windows).

To go on :
* I discover i have to get a safety loop for the drive shaft
* i'm thinking going to EWP if it can make me a gain of 10 hp
* what about milling heads about 0.5 mm ? i've seen in a post it can make a gain of 20 hp ? If yes, i will also port matched heads and manifold
* i've an airfoil i never used because it doesn't fit my trickflow elbow ? Is there something to gain with that airfoil ? Will i see benefits with a 52 mm TB instead ?
* about stall : i'm afraid of fuel economy with a high stall and drivability also.
* about launching the car : i beleive best is to stay with the D engaged and go. just to be sure : what best D position to use ? the one closer to the 2 ?
* i have order my MT tires ET street radial 255/50-16 some people telling me they won't fit on stock rims ??? telle me they are wrong : i have already use 255/50-16 on these rims (i have now 255/40-18 for daily drive)

Sorry many questions but i wonder a lot ... I don't want to be the "man with an US car that will be passed by all these japanese and european cars" )

thanks for help.

Pierre

(and someday : visit my country : it's great)

 

ho help from anyone ???