I am very seriously considering 4.10 in my A4, and I have run a gear calculator, and the RPM's to MPH do not seem that bad, i.e. 80 MPH in OD is 3,000 RPM, if I "kick her down" at that speed (which I doubt I would ever do), I would be turning 4200 to 4300 RPM, again well below the red line. Is there something I do not understand about running such a low rearend ratio?

I do understand that the 98+ A4 shift by MPH, not RPM, I do not know what speeds the computer has the A4 shifting at (i.e. 1-2, 2-3, 3-OD), nor do I know the maximum "kick down" speed the computer gives from OD to 3rd, however maybe that enters into the mix.

At 70 MPH (my normal freeway speed) I would be turning 2600 RPM with the 4.10, again not unusually high RPM.

Would you please explain to me what exactly is the detriment (sp) with installing 4.10 in a A4 car. I really do not care about giving up the gas milage, for my 2001 Z28 is not my daily driver.

I do understand that I would have to recalibrate the speedometer, I was planning on purchasing the SLP recalibrater.

Thanks in advance.

SteveC

 

It is my understanding that the 4:10's would increase your ET at the stripe but you could possibly have traction issues----you would have to deal with this. Another consideration, these gears are harder on the stock rearend (10 bolt). Therefore over time you may have to buy a heavy duty rearend such as moser or strange. I read an article the other day a car with these gears set the backlass at 10 thousands which put more fluid between gears, etc inside rearend and this would make the rearend last longer. As you mentioned, your gas mileage would go down and your car RPM's would be higher crusing and driving. It appears that some of the faster cars in the country used 4:10's with the automatics. I have a A4 and used 3:73's with a 3200 vig convertor. Choose a convertor with your gears if you plan on drag racing. Faster cars generally run a 4400 convertor. Just general information for you to consider. If you want a fast car, review other people cars in the forum and ask questions. This is already be down by somebody. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

Kent, thanks for the information, if I understand you correctly the main issues would be the performance of the car at the drag strip? I would not take my car to the dragstrip, nor do I plan to race in anyone, I wanted something alot peppier off the line than my 3.23, and the 4.10 are very intreguing (sp).

Did you have your 3.73 installed before the converter? Did you feel a SOTP feeling over the 3.23?

Taking the "drag strip" factor out of it, do you think the 4.10 gears would be good for a street car?

Thanks in advance.

SteveC <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

If you do not want to race it at the track, and do not street race. I see absolutly no reason to get 4.10:1's!!!
Like kent basically said 4.10's are just gonna be harder on your car.
If you do any modification to the drivetrain, I would not recommend going over 3.73!
I would go with other means.Perhaps you should also consider a aluminum driveshaft. Believe it or not this does make quite the noticable difference in "peppyness".
A aftermarket Torque Arm/Trailing Rods/Panhard rod will make it hook up alot better off the bat.

<img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" />

 

Quote: At 70 MPH (my normal freeway speed) I would be turning 2600 RPM with the 4.10, again not unusually high RPM.
--------------------------------------------------
I am runnin 3.73's in my 98 A4 and I tach 2500 at 70 in OD. I think that # might be a little off. I agree with Andy..if you don't race, dont get 4.10's.

If you want peppier off the line invest in a converter...say Vig 2800-awesome tire spin and decent from a roll.
I put the 3.73's in before my converter and felt a huge difference..but I was comin from 2.73's.

Good luck, Stu

 

The main problem that I was informed of when I planned on going with a 4.10 is that at the track your rpms would be too high to stay in 3rd gear and you would have to go to O.D. which would not be very good(but I would think the gears might help.... Just My Opinion) I have also though of still going with a 4.10 and when I go to the track I could put on some 28" tires to do a little evening out. Check my post on this to see if anyone has more info.

Josh S.

 

If you don't do any racing, then why are you modding your car? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

 

Thanks for all the answers guys!

Pro Stock John, so I take it then that you are satisfied with 4.10's running an A4 transmission?
Do you think I can leave the transmission alone, without any modifications, and it will shift properly during normal driving conditions (i.e. not stomping on the gas)?

I ordered the "Performance Axle" (GU5) with my car, and also, when the car has been on the hoist, I know I have an aluminum drive shaft.

I have had installed BMR boxed LCA's, Torque arm, Tunnel brace, STB, Panhard rod, and SLP bolt on SFC, in preperation for the gear swap.

My ultimate goal is to have a quicker off the line car, not necessarally (sp) to race, but just to have more fun with the car. I DO NOT RACE ANYONE, as far as i'm concerened every car out on the road is faster than mine, and I do not need to prove anything to anyone.

Any more information will be greatly appreciated.

SteveC <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Based on reading all of these threads, your best bet is to go with the 3:73 gears and a convertor. I am not going to recommend which type or stall, because I am not knowledgeable at this time. I am running gears above with 3200 vig and is pretty quick for street driving. If you have the funds, I recommend you buy a carbon fiber driveshaft ($800) and lighter wheels which will reduce your rotational mass for a quicker car. Get better suspension stuff such as lower control arms, Random Technology Torque Arm set at 2 or 3 negative degrees, and a little bigger front and rear sway bar. Also, you will need a sticky tire for a quick takeoff----if you ever do this---such as Nittos or MT Streets. Review forum and perform all free mods such as free ram air, port and polish mass air flow and throttle body. Anyway, just a few more ideas for a fast street car that is not be raced................. <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

 

Get a torque converter and keep your current gears if you want to launch hard. A 3000 - 3500 stall would be fine. If that is not enough, then get 3.73s. I think the combination of the SuperYank 3500 converter and 3.73s is an awesome street combo.

Besides gas mileage, running at 3000 rpm gets loud if you have an aftermarket exhaust and may cause you to use oil (an issue in earlier LS1s, not sure if it was cured for the 01's.)

 

I have 4.10's in my A4.

I do turn about 3000 rpms at 80mph.

Pro's:
-Car will have more ballz in 2nd and 3rd gear and at cruising speed, might be able to beat some M6 cars from a roll. I'd hate to be an M6 guy trying to race you at 55mph.

Con's:
-Not as good of a gain (for racing) as a good converter. Converter is worth like 5 tenths and the gear might be at the most 2 tenths.
-You are going to run thru (for racing) the first two gears really fast. It would be nice to wind out 1st and 2nd a bit more. I am shifting my setup at 6600 rpms.
-the teeth on the ring and the pinion will be dramatically smaller than the stock 3.23, so you are more likely to shear them off. But usually the M6 guys shear off 2-4 teeth off the ring with a harsh launch.

John
ARE 422ci
Yank 4100
FLP level IV
Moser 9"/4.10

 

Thanks for all the information guys, this forum is a great source.

I am 2 to 3 months down the road from getting my gears changed, and I want to get all my ducks in a row.

To me taking a stock car and modding it correctly only makes it better, and more fun to drive. It's like completing what the factory failed to do.

SteveC <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Well, don't discount how much a good converter will give you from a roll too, my friend's TA keeps up with Z06's from a roll and he has a PI3200 converter.

Personally I think that 4.10's might be too much for a car with stock shift points. From an acceleration standpoint keep in mind that a stock converter is like a 2000 stall. Now you make peak tq (stock) at 4500 rpms I would guess. More stall gets you into that 4500-6000rpm powerband QUICKER. 4.10's will keep your rpms and accomplish the same thing but not as well as a converter.

Lastly the problem with a lot of old skool cars is that they run too much gear and not enuff converter.

 

Again, a big thanks to all, you have given me alot of information, and a lot of food for thought.

SteveC <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Just like everyone has said I think you'd be much better just going with a good solid 2800-3200 torque converter and keeping your stock 3.23's. However, if you don't want to deal with the looseness issue and like the stock torque converter feeling, I'd say step up to the 3.73's or 4.10's. Keep in mind you'd probably have to play with your stock shift points if you end up running those gears(especially in the 1/4 mile). Not to mention you might have to deal with some gear whine and higher revs during normal cruise(mainly highway).

Its your car so you can obviously do whatever you want to it. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> And I do know of some people that have had success in mostly stockish LS1's with the 4.10's.

Mike