Rear Differential For ESS Twin Screw.

[spartanwarrior]

Ok i know this has been discussed but need to know a few things, right now i have a 3,46 lsd that bimmerworld built for me a few years ago and have not had any problems with it, now with my TS2 and soon to be TS2+ i keep hearing how a longer gear would be better, i have talked to Rob at BimmerWorld and he told me that they actually use a lower gear for there E36 twin screw units and states that i would have better acceleration than say going to a 3,07 or 3,15, i have found a 3,07 diff here for 500.00 Euro but it is open diff (no lsd) and then i would need another 2,000,00 Euro to have them build a lsd into it, now if there really is a big difference other than having more top end then so be it i will do it, but i myself don't think that a 3,07 will accelerate faster than my 3,46 and find it will be a waste of money.

[MachRc]

if you like it the way it is keep it. The LSD will make up for it.


do you feel that the short gears are holding you back in anyway? do you find yourself in 5th alot on the highways?

[spartanwarrior]

if you like it the way it is keep it. The LSD will make up for it.


do you feel that the short gears are holding you back in anyway? do you find yourself in 5th alot on the highways?No they seem fine to me, on the highway doing like 80mph my rpm is at 3700 so i don't think thats really bad.

[kevinterkelsen]

If you are happy with what you got then don't change! As long as you dont have excessive whelspin at take off it seems to me that you should spend your money on the cams from ess. I have a TS3 with m3 gearbox and a 2.93 rear diff - and it works for me in terms of both accelleration and top speed (cruising in Germany) - but i still have to be 3000 rpm for max power/acceleration - so speedlimits also play a factor ;O)

[spartanwarrior]

If you are happy with what you got then don't change! As long as you dont have excessive whelspin at take off it seems to me that you should spend your money on the cams from ess. I have a TS3 with m3 gearbox and a 2.93 rear diff - and it works for me in terms of both accelleration and top speed (cruising in Germany) - but i still have to be 3000 rpm for max power/acceleration - so speedlimits also play a factor ;O)Do you have Lsd or is it open diff? if not how is your wheel spin? it seems that when i press the dsc button in till both yellow lights come on i have wheel spin even in 2nd gear (though i need new tires) but when i press the dsc button once till i get the 1 yellow light it seems to help out a lot, maybe that is the way to use the dsc button to only show one light instead of 2.

[TxZHP04]

Just a suggestion but... don't go making changes to your car just because someone else thinks it might be better. Make changes to address specific issues or to tune performance towards a specific goal. If you are happy with your current setup, keep it as-is.

Gearing really depends on a number of factors, including a person's tolerance for high rpm cruising. For me, 3700 rpm @ 80 mph would be too much. That's why I'm running a 3.23 instead of a 3.46 or even a 3.38. In terms of performance, the "best" final drive ratio becomes an issue of managing the engine's power band for the type of driving you do. Added mid-range punch often comes at the expense of off the line traction. Improving traction (ie, reducing transmitted torque) in lower gears comes at the expense of less mid-range punch. Then of course, there's the effect on top speed, ability to stay in the power band, time spent between gears (ie, time wasted via the act of shifting), etc, etc. Do you frequently find yourself bouncing off the rev-limiter in first because the engine hits red line so fast?

Shorter gearing might make sense for a road course race car that rarely engages first gear or starts from a stop. Super short gearing might not make so much sense on a drag strip if you have to change gears a lot more than the guy in the lane next to you. If you have too much wheel spin in the lower gears, and improving traction isn't a possibility, then you may be better off with taller gears. If you can feather the throttle and manage the wheelspin in lower gears, you'll end up with more pull in the mid range.

Like I said though, if you're happy with things as-is then leave them as-is.

[spartanwarrior]

Just a suggestion but... don't go making changes to your car just because someone else thinks it might be better. Make changes to address specific issues or to tune performance towards a specific goal. If you are happy with your current setup, keep it as-is.

Gearing really depends on a number of factors, including a person's tolerance for high rpm cruising. For me, 3700 rpm @ 80 mph would be too much. That's why I'm running a 3.23 instead of a 3.46 or even a 3.38. In terms of performance, the "best" final drive ratio becomes an issue of managing the engine's power band for the type of driving you do. Added mid-range punch often comes at the expense of off the line traction. Improving traction (ie, reducing transmitted torque) in lower gears comes at the expense of less mid-range punch. Then of course, there's the effect on top speed, ability to stay in the power band, time spent between gears (ie, time wasted via the act of shifting), etc, etc. Do you frequently find yourself bouncing off the rev-limiter in first because the engine hits red line so fast?

Shorter gearing might make sense for a road course race car that rarely engages first gear or starts from a stop. Super short gearing might not make so much sense on a drag strip if you have to change gears a lot more than the guy in the lane next to you. If you have too much wheel spin in the lower gears, and improving traction isn't a possibility, then you may be better off with taller gears. If you can feather the throttle and manage the wheelspin in lower gears, you'll end up with more pull in the mid range.

Like I said though, if you're happy with things as-is then leave them as-is.

Yes your right i do see that in first gear it is pretty much useless and it does bounce off the rev-limiter, but i do have 3.07 gears but it is open diff not lsd and the 3.46 i have on now is lsd, would it matter if i installed the 3.07 without lsd because it is to expensive to have it done;)

[MachRc]

its not expensive at all to swap..you can even DIY, if you have tools and the time..it took lees then an hour to swap the diff including putting new fluids in...


but in my opinion(ive said this before many times) like txzhp4 (he has 6-speed i have 5) i cant stand the high way in fifth at such a high rpm... plus dropping down to fourth where its perfect for the 5speed powerband......with a 3.46 its way too high strung...

I ditched the 3.46 in about one day and went back to the old 2.91, now im a 3.07

with that much power and with 5speed and so little space to spread the power..due too the short arse gearing.. Id try the new 3.07 and see if that makes drivability(spinning tires in 2nd) a non-issue.

but id miss the LSD..so difficult!


safetysafetysafety

[TxZHP04]

Yes your right i do see that in first gear it is pretty much useless and it does bounce off the rev-limiter, but i do have 3.07 gears but it is open diff not lsd and the 3.46 i have on now is lsd, would it matter if i installed the 3.07 without lsd because it is to expensive to have it done;)

The LSD isn't essential but I know I would sure miss mine.

If you can find someone local who rebuilds diffs, you should be able to have your 3.46 ring and pinion swapped with the 3.07 for a lot less than buying a new LSD. I would be careful about who I let perform that type of work though.

FWIW, I wasn't completely happy with my 3.07. I'm much, much happier with my new 3.23.

[HighBoostin330]

Do you have Lsd or is it open diff? if not how is your wheel spin? it seems that when i press the dsc button in till both yellow lights come on i have wheel spin even in 2nd gear (though i need new tires) but when i press the dsc button once till i get the 1 yellow light it seems to help out a lot, maybe that is the way to use the dsc button to only show one light instead of 2.

I don't get much wheel spin at all after 1st gear even with a 3.46. :cry:

[kevinterkelsen]

Yes I have a Quaife LSD and the wheels spin in 1st and 2nd gears when pushed :o) - don't know about DSC settings as I only have one - on. However, I no longer have ASC so it does not cut the throttle - In order to get my m52 single vanos enigne to work in a e46 we installed a fully programable ecu instead of the factory one (it allowed os to take out the ASC).

I agree with the other input - stick with what you got and if it really bothers you at some time (or you just won the lotto) then fix it (change ratio's) - should be fairly inexpensive.