'80 BMW 316 e21 in Alpinweiss

[l3v4rt]

No more driving with the battery behing drivers seat! I managed to install the box into trunk and rewire it there. Ground was bolted into holes for the reat seatbelt and the whole thing got a cable protection on. The small box is for joining cables (e46 cable wasn't long enough) was also bolted. The battery is in the nautic box for batteries on boats and the lower portion for fixing into trunk is from some Renault. It should work.

[Mihajlo]

photobucket issues..... charming!

[l3v4rt]

photobucket issues..... charming!

You're right, looks like photobucket is out. Hopefully now the pictures will work!

[l3v4rt]

First vacation with the car - I did about 650km with the bimmer and the drive was great, the only issue was the fuel consumption. It was me and my girlfriend and a bit of lugguage and the car burned about 10l/100km on highway and primary roads witch is too much if you ask me. I have 3.91 ratio diff so maybe thats the problem, since the m42 is connected to 5 speed gearbox with 0.80 ratio in the fifth gear. I'll check if there is any fuel leaks since I can sometimes smell a but of fuel outside of the car but I think thats from the fuel line going back to the tank from the pump and it smells from the passanger rear where the expansion tank is. But fuel consumption is definetely too high!

Overall it was great, great roads - I visited Island of Krk and I took a few backroads in Croatia and it was great!

[joe14]

By my calculations 10l/100km is about 23MPG, thats far too much fuel!

I'm getting about 35MPG (7 l/100km) on mixed driving and even 40MPG (6 l/100km) on a recent 300mile motorway trip.
Also running an M42 but from an E30.

[l3v4rt]

I'm probably going to put it on a tester because I have the OBD and we'll see, I'm thinking maybe faulting lambda (O2 sensor), There are no signss of any fuel leak..

[joe14]

Yeah it may be putting too much fuel in if it's getting the wrong reading.
Does it smell really rich or anything?

[l3v4rt]

I had it on a tester and nothing fuel related showed up. It wrote 2 errors but one was some valve that I don't have since the fuel system is from e21 and the other one was speed sensor - none of this have an effect on the fuel Joe14 what diff are you running? I still have the stock 3.91 e21 diff so maybe the rpm si too high - I need to get an rpm meter instead of the clock. Any other ideas? Maybe the exhaust system is too small from the e21?

[joe14]

I'm still using the standard 316 diff, 195/45/15 tyres on the back too.
At 70mph I'm probably doing 3200 RPM.

I can't see the e21 exhaust causing the added fuel consumption..

[l3v4rt]

huh, than I have no idea what to do... If the rpm isn't all that high and tester shows nothing. :/

[l3v4rt]

okay guys - I managed to track down an LSD diff out off an e36 and I have read on the internet that with a bit of modification it fits to our e21 shell. My question is this - if I do that and I leave in the 3.45 ratio from that diff will I need to replace the speedometer and if so - with what model? Also what kind of an effect should I expect, will there be a big difference in acceleration? Highway rpm is way to high right now even with 5 speed gearbox., hopefully this will take it down a bit.
Also, has anyone done the LSD swap, is it difficult?

[joe14]

It seems it has been done several times,
here's some likes i found
https://www.bimmerforums.com/forum/show ... o-e21-case
https://www.bmw2002faq.com/forums/topic ... ial-build/

What size E36 dif did you get? I believe you need a specific sized diff to fit (168mm i think??)

I don't think there was different speedo heads fitted to e21's?
You should be able to work out how it will change your speeds based on your tyre size, diff ratio and gear ratios.
It may be that you'll have a good idea of how far out your speedo will be.

Do post your progress, I'd be interested to see how you get on

[joe14]

here's a good calculator
http://westfield-world.com/gtc.html

[l3v4rt]

Hey Joe!
You are correct, I had to get the 168mm differential from the e36. I've seen this thread:
http://www.bmwe21.net/forum/viewtopic.php?f=61&t=1629

and by the looks of it I'll be needing the 323i speedo unit (cluster) since it has the correction factor for the differential that is the same ratio that I'll be putting in (3.45) otherwise my speedo will still think I have the 3.91 diff on and since it reads in the gearbox it has no idea what is going on with the diff. That is why I think I will be needing the 323i speedo with correction of 0.762 because of the differential difference ( both 323i and e36 168mm I'm getting are 3.45). Hopefully someone can confirm this so I'm not complicating things too much and going into the wrong direction

[joe14]

Hey Joe!
You are correct, I had to get the 168mm differential from the e36. I've seen this thread:
http://www.bmwe21.net/forum/viewtopic.php?f=61&t=1629

and by the looks of it I'll be needing the 323i speedo unit (cluster) since it has the correction factor for the differential that is the same ratio that I'll be putting in (3.45) otherwise my speedo will still think I have the 3.91 diff on and since it reads in the gearbox it has no idea what is going on with the diff. That is why I think I will be needing the 323i speedo with correction of 0.762 because of the differential difference ( both 323i and e36 168mm I'm getting are 3.45). Hopefully someone can confirm this so I'm not complicating things too much and going into the wrong direction

Sounds sensible to me.
What gearbox are you using?