Post Swap Question...

[SnickleFrittz]

So guys, I finished up my 24v (s52) engine swap... I gotta say i love it... it make the e30 a whole new driving experience!!!! :-) getting side ways has never been so easy in my car. Lol.. Anyways, I have a question... my donor engine and tranny was from a 2000 z3m roadster, from my research, those cars where electronically limited to 155 mph, with a 3.23/1 rear diff, meaning the the DMS would fuel cut the engine or something, before you actually ran out of gear, correct???? Also, if that is correct, why is it with my 2.93/1 rear diff, I run outta gear at like 130ish???? And that is at WOT. I have the zf tranny that came with the s52... im not real upset about it, was just kinda wondering, I just think it's strange my 91 318is, had a higher top speed than it does now. :-/ Anyways thank in advance people!

[Cephas]

inb4lock

Post count ++

[SnickleFrittz]

Not sure exactly what you by that.... anyway your could elaborate on that please...

[NC325iC]

hes just posting bs...

could be wind resistance is greater on an e30. The taller gear ratio of 2.93 requires more torque from the engine to turn it than a 3.23 the wind resistance at that speed could be enough to give the engine trouble.

just out of curiosity what RPM do you hit when you top out?

[Northern]

VSS limiter?

[ba114]

what revs are you topping out at?

[328ijunkie]

Sure you have a 2.93? Should be gear limited to ~170.

[SnickleFrittz]

I'm definitely not posting a bunch of bs... anyways, VSS, I'm not sure exactly what that acronym stands for... as my rpms go, that would be at red line, but I've always stopped before I got there.. I've reached 121 mph at almost wide the fuck open, I haven't got a coding plug yet, so my tachometer is off still, but by my ear it's almost wide open... the rear diff i bought use off a guy,it's tag say S 293.. he said he had never opened its up.... when I first completed the swap, I had a 4.10, and 90 mph was wide open..

[ba114]

you know you have a 5th gear right?

Otherwise you have a 3.73 final drive..

[SnickleFrittz]

Yeah I know... maybe the diff I bought has been opened, even before the guy I got it from... that kinda far the only thing I can think of.. how fast are your cars and with what final drive ratio???

[SnickleFrittz]

Sure you have a 2.93? Should be gear limited to ~170.

Yeah, that's what I kinda figured.. and was kinda my goal... I wanted to bury my speedo...

Was there a "close ratio" transmission option from BMW??? Or were all zf trannys pretty much the same in a 2000 z3m???

[AndrewBird]

If that transmission is a ZF 310, then you have a 1:1 5th gear.

With a 2.93 diff and 195/60-14 tires (stock size), your top speed at 6K RPM should be ~146 MPH. Undersized tires will make this slower. I'm guessing your tires are a bit undersized from stock and this is the case.

[NC325iC]

http://www.allfordmustangs.com/Detailed/608.shtml

you could get 170mph if you were at 7k. as andrewbird said above 146 has you closer to 6k rpm.

you say your tach isnt working right, so maybe youre only turning 5k rpm and 121 is correct.

That being in mind you are still asking the engine/trans to spit out more torque to turn those gears than it had to do in the m3. And the boxy nature of the e30 is not very aerodynamic. Lots of wind resistance.

[328ijunkie]

Tach/speedo is off or you dont have the gearing you think you do is my bet

[f4tj0n]

with my 3.46, I'm around 6000ish RPMs at 130-135?