m50b20 help

[zewolfen]

heey all

I am new here to this form.. and i have a question please bare with me.. i am also kind of new to the bmw swaps .... i have e30 1989 it was stock 318 and i swapped to the m42 from an E36 1995 and after 6 months i had some problems with the m42 so i swapped to M50B20 but with the m42 Gearbox getrag 240.. and with differential non lock 3.64.... the problem is i cant go over 200 km/h , 122 mph ..... also the 5th gear almost useless.......

Can any one help me please..... Thnx :)

[zewolfen]

is there is any one going to help me ? ?

[Wh33lhop]

200kmh is 126mph which sounds about right for a 2 liter.

What does "useless" mean? Your 5th gear is about the same as a stock 325i's 5th.

[Gruelius]

sell the car buy a e46 m3

[jrdeamicis]

Get a different diff. Done. 3.25 or 2.93. Voila

[nando]

i don't get how a stock M42 with a 4.10 and G240 can do ~130mph but an M50B20 with a 3.64 can't do over 122?

[trackjunkie21]

i don't get how a stock M42 with a 4.10 and G240 can do ~130mph but an M50B20 with a 3.64 can't do over 122?

obviously something is wrong with the m50.

[zewolfen]

200kmh is 126mph which sounds about right for a 2 liter.

What does "useless" mean? Your 5th gear is about the same as a stock 325i's 5th.

okay i will tell you why its useless ... for example when i am on 180kmh with the 5th the car sticks to 180kmh and it doesn't have the power to go over that ... but when i switch to the 4th gear i reach 200kmh fast...thats why i feel the 5th gear is useless...... and i cant go more than 200kmh .. some one told me thats because i have 17 inches rims

do you have any idea about that ? ?


and what if i switched to G250 ?

[zewolfen]

i don't get how a stock M42 with a 4.10 and G240 can do ~130mph but an M50B20 with a 3.64 can't do over 122?

and something else i wanna tell .. i have free flow 2.5 inches exhaust ... does it sound good for M50B20 ? ? ?

[Mr.SWISS]

and something else i wanna tell .. i have free flow 2.5 inches exhaust ... does it sound good for M50B20 ? ? ?

Dude that motor sucks, I couldn't justify a swap for a 10hp bump over what you had.

[nando]

yeah, I'm thinking the M50B20 is just weak. Perhaps the gearing is even too tall.

[zewolfen]

Dude that motor sucks, I couldn't justify a swap for a 10hp bump over what you had.

its weaker than the m50b25 but that doesn't make it stay on 200 kmh i dont know where is the problem.... is it the differential too short ? but i dont think so its 3.64.... maybe the exhaust but its 2.5 inches but all i know its so fast it goes to 200 very fast

[MattM]

lowering the ratio will just make the rpm lower that its doing at 200, and will take you longer to reach those speeds. IF they engine doesn't have the power then it doesn't have the power. I am not really surprised that a stock M50b20 can only hit 200.

You can try to boost the power with chips and bigger injectors and stuff, or put a bigger engine in. No replacement for displacement

[zewolfen]

lowering the ratio will just make the rpm lower that its doing at 200, and will take you longer to reach those speeds. IF they engine doesn't have the power then it doesn't have the power. I am not really surprised that a stock M50b20 can only hit 200.

You can try to boost the power with chips and bigger injectors and stuff, or put a bigger engine in. No replacement for displacement

do you know any recommended chips for that engine ? ? ?

[The Humjet]

Maybe you can put shorter a 3.91 or 4.10 diff in it so the the b20 can have enough power to push it beyond 200km/h. My SLOW m40 with only 80whp can make make it to 190km/h with a 4.10 diff and that was in 5th gear running out of revs to allow it to go faster.
Also may I ask your not running a big F1 wing on the back are you?