3.42's

[c5z28]

I have a bolt on a-4 with the stock 2.73's. My car is my dd and is occasionally used at the drags and autocrossing and on the street. I want my car to be able to accelerate quicker while going from a roll so a stall is not in order since most racing won't be from a dead stop. Question is it better to buy the whole gear housing or just the ring and pinion? I have never taken apart a rearend-i'm screwed

[dpinson]

if you have no fear of blowing the ten bolt then buy gears but if you think you will have the need to launch your car on stickies just wait and get a whole rear end


im not sure if your housing will accept them but i would at least put 3.73 in if it will

[dpinson]

a higher stall would deffinitely help out the role racing in an auto though


i wouldnt even think of roll racing my auto against my manual most of the time but with a 4200 stall it actually does quite well against a manual car

[c5z28]

Unfortuantley the auto is all I got and I want the rearend to last longer so stickies and a stall aren't in order. Someone has suggested a torque arm but it looks like I will have to get rid of my dual setup first. Thanks for any help guys.

[Cayenne97]

Your stock rear will be fine with a stall converter. I wouldn't worry about it breaking because of that.

[dpinson]

as long as you arent launching on stickies the rear will be fine

i think you are under the impression that a stall only benefits a dig race and infact it makes a big difference when it comes to roll racing


a set of 3.73 and say a 3000 stall would definitely liven up your car man

[c5z28]

Yah I figured a stall would kill me in a roll race, because of the way some people talk.

[dpinson]

no sir, a stall will help tremendously

it puts your car in its powerband quicker,which is definitely a plus with an auto car from a roll

[Wesman]

Yah I figured a stall would kill me in a roll race, because of the way some people talk.

Stalls are kind of two faced for that reason.

Basically a stall just allows more slippage between the engine and trans, which means you can launch higher off the line, and the engine's RPM's stay in the powerband after each shift, as opposed to falling off due to the widely spaced gears in the 4L60E.

So the downside is that you will probably put down less power to the wheels, and your fuel economy will probably drop some, but at the same time your 1/4 mile times will greatly improve. Since you're losing more power through the slippage of the converter your trap speeds should theoretically go down, but in practice they should actually go up, because the engine is in its powerband much more of the time throughout the race, even when the power loss due to the converter is factored in.

[rel3rd]

Unfortuantley the auto is all I got and I want the rearend to last longer so stickies and a stall aren't in order. Someone has suggested a torque arm but it looks like I will have to get rid of my dual setup first. Thanks for any help guys.

Not sure what a torque arm is supposed to help with in a "roll race", but I'd save that mod for way down the road.

I have 342's in my 2000 SS because when I bought it, the stock rear was howling and at the time, it made economic sense to try and find a whole rear to swap in, rather than dish out a lot of money on a known weak part (aka the 10 bolt rear). I found a low mileage 342 geared rear out of a 95 Z28 (for $150) and swapped the whole thing in.

Since you admittedly don't have any rear rebuilding/gear swapping experience, I'd suggest searching for a complete (and hopefully low mileage) rear and simply swapping it over. It'll be much cheaper than having someone rebuild/refreshen yours and swapping new gears in.

FWIW, the A4 cars are a LOT easier on these weak rears than the M6 cars are. My car's a perfect example. I made 23 passes in it last Sunday without a worry in the world. 22 passes were in the 11.60's and one 12.0 when I spun one pass. I drove 45 miles to the track, let some air out of the drag radials, raced all day, then drove on home.

It weighs 3755# with me in it, has 342 gears, MT Drag Radials, and a 3600 stall. It has probably 100 passes on this swapped in used rear, as well as a good bit of street abused miles. I still run a stock torque arm and my car yanks the driver's wheel up a 3-8" on every launch (60 foots are high 1.5's with best of 1.57), which is why I would question why anyone would say to add one to your car already? Not to mention that I had a high dollar Spohn chassis mount torque arm in my car before and it actually 60 footed slightly slower, and clunked intermittently whenever I just drove the car...enough so that I went back to stock.

I'd have to agree with reply above that more gear and a stall would do the most good for you. You just have to be careful that you don't over gear, or over stall the car. My stall is actually a little bit too low of a stall for my baby cammed combo, and I have tried 410's only to remove them when ET/MPH stayed the same as with the 342's.

This link has links to 3 different vids of my poor little 10 bolt getting shown no mercy, along with lots of details about some things I proved to myself regarding some mods:

http://www.ls1.com/forums/showthread.php?t=101927

[dpinson]

people buy torque arms because when they do break it is bad just like a drive shaft
search for blown up driveshafts or torque arms and you will see that either one can literally rip your car in half if broken at speed

wesman i was waiting for you to chime in thanx for mentioning the fuel economy and powerloss i forgot to mention,but still a small price for the improvement in time ,i think

[dpinson]

nice run rel3rd i do see some daylight under the driver front

as for the ten bolt it is an iffy
some people run 10's problem with them and some break them in the 12's
true that auto's are much easier on them but the op really doesnt seem to be in the market for a rear and as long as no sticky,high rpm launches are in the future i dont see why he would be

[rel3rd]

people buy torque arms because when they do break it is bad just like a drive shaft
search for blown up driveshafts or torque arms and you will see that either one can literally rip your car in half if broken at speed

I know why people buy aftermarket torque arms, but couldn't help but wonder why someone would be recommending one as a mod to help acceleration in a "roll race" like the OP was asking about...since it'll not make any difference whatsoever.

[Cayenne97]

I know why people buy aftermarket torque arms, but couldn't help but wonder why someone would be recommending one as a mod to help acceleration in a "roll race" like the OP was asking about...since it'll not make any difference whatsoever.

...

Unfortuantley the auto is all I got and I want the rearend to last longer so stickies and a stall aren't in order. Someone has suggested a torque arm but it looks like I will have to get rid of my dual setup first. Thanks for any help guys.

I believe the OP (comment above) was saying someone recommended him to buy an aftermarket torque arm for insurance reasons, not for roll racing. Atleast that's what I got out of it.

[rel3rd]

nice run rel3rd i do see some daylight under the driver front

Thanks. After being into the 5.0 Mustangs for about 12 years, I'll never go back.

as for the ten bolt it is an iffy

I agree 100%, I just wanted to hopefully take a little fear out of the guy and help him see that not everyone needs a $2500 9 inch or 12 bolt.

On the street, on regular tires, with an A4...gears and a converter and he's good to go, IMHO...

[dpinson]

...



I believe the OP (comment above) was saying someone recommended him to buy an aftermarket torque arm for insurance reasons, not for roll racing. Atleast that's what I got out of it.

same here could be wrong though,although it might help traction a bit from a roll i dont see any other advantage really

[dpinson]

Thanks. After being into the 5.0 Mustangs for about 12 years, I'll never go back.

yeah i owned a few,know exactly what you mean

I agree 100%, I just wanted to hopefully take a little fear out of the guy and help him see that not everyone needs a $2500 9 inch or 12 bolt.
we are on the same page here he has no need for it
On the street, on regular tires, with an A4...gears and a converter and he's good to go, IMHO...

100% truth

[rel3rd]

insurance reasons

do you mean insurance reasons as in preventative maintenance?

I know I really should have one on my car, but couldn't stand all the noise it made in regular old day to day driving. Maybe mine was just a worn out POS since I did buy it used?

[dpinson]

do you mean insurance reasons as in preventative maintenance?

I know I really should have one on my car, but couldn't stand all the noise it made in regular old day to day driving. Maybe mine was just a worn out POS since I did buy it used?

yes he means preventive


you shouldnt have noise i have installed a few on my cars and no problems

[dpinson]

now the tooth i broke off the ring gear made a hell of a racket