Tell me if I'm right ?

[*Glenn* 854]

As most of you know, I'm doing a manual conversion on my car. I assumed (bad word) that the Getrag 250G that I'm using was an overdrive gearbox... it's not.Ive checked it.. 5th gear is 1:1. Now that means I have to look at diff ratios. At the moment I'm running a 364:1 which means in top gear at a 100kph the engine will be reving at 3,030. I dont want to go too tall... my choices are : 325:1 @ 2,718 rpm or a 315:1 @ 2,634rpm

With the M52B28 and light flywheel I think the right choice is the 315:1 with the LSD. This ratio should give me a calculated top speed of 245 kph

Am I right ??

Edited March 6, 2009 by *Glenn*

[*Glenn* 854]

Thanks for that Ron. You have confirmed what I was needing to know. You must have been typing when I was editing. I wrote the wrong engine speeds in there. 245 kph @ 6,500 rpm is enough and will give me what I'm looking for and I'll get there quite alot quicker with what I'm doing. I'm not too worried about fuel consumption.

After reading this :http://www.metricmechanic.com/pdfs/metric-mechanic-differential-booklet.pdf

I pretty sure the 3.15:1 is the way to go

Edited March 6, 2009 by *Glenn*

[*Glenn* 854]

3:15 will do the business

Just a follow up - My understanding is the Getrag 250G was fitted to some 318s and 320 and 323 only and the ZF to the 328 and M3

Are you sure the 250 G will tame the M52 2.8 its pretty torquey

I'm fairly confident that if the gearbox isnt abused it will stand up to it. Others have done this conversion before.

The gearbox was used in E36 318's, 320's, 323's and Z3's

[BM WORLD 1283]

3:15 will do the business

Just a follow up - My understanding is the Getrag 250G was fitted to some 318s and 320 and 323 only and the ZF to the 328 and M3

Are you sure the 250 G will tame the M52 2.8 its pretty torquey

i have a ZF box in my 92 e36 325i coupe that came from a 92 320i coupe.

[Boost Junky 1]

I am also using the ZF box in my e30 turbo setup and have been told by a few people that it should hold up, how reliable the recomendations of those few are, I am unsure of. I guess it will come to the driver and clutch setup etc...

Edited March 7, 2009 by Boost Junky

[CamB 48]

I think 3.15 will be ok - good for getting to the track, but a bit tall for using there. It's a tradeoff.

I doubt it'll do 245kph down the back straight at Puke - it's not long enough. Don't be fooled by the speedo - its at least 5% out.

[Silver Fox 43]

I think 3.15 will be ok - good for getting to the track, but a bit tall for using there. It's a tradeoff.

I doubt it'll do 245kph down the back straight at Puke - it's not long enough. Don't be fooled by the speedo - its at least 5% out.

Agree Cam, I'll be running a 3.46 in mine with a 1 to 1 top as a dedicated race car. Although I think the 3.15 will suit Glenn just fine.

[CamB 48]

Yeah I should really have made it clearer - I think it's the right decision!

[*Glenn* 854]

I think 3.15 will be ok - good for getting to the track, but a bit tall for using there. It's a tradeoff.

I doubt it'll do 245kph down the back straight at Puke - it's not long enough. Don't be fooled by the speedo - its at least 5% out.

I used this:

http://www.unixnerd.demon.co.uk/revs.html

I know its a compromise... I dont want the thing screaming its head off on the motorway. As for the back straight... you can start braking just before the kitty litter.... I know it can be done...... Dave showed me last time

[Ian 535 0]

As most of you know, I'm doing a manual conversion on my car. I assumed (bad word) that the Getrag 250G that I'm using was an overdrive gearbox... it's not.Ive checked it.. 5th gear is 1:1. Now that means I have to look at diff ratios. At the moment I'm running a 364:1 which means in top gear at a 100kph the engine will be reving at 3,030. I dont want to go too tall... my choices are : 325:1 @ 2,718 rpm or a 315:1 @ 2,634rpm

With the M52B28 and light flywheel I think the right choice is the 315:1 with the LSD. This ratio should give me a calculated top speed of 245 kph

Am I right ??

Hi there Glenn, it's Ian here. I was passing you multiple times a month or so ago when you had your car out there with that slush bucket auto and the suspension you must have nicked out of a Nissan Primera . Yeah, swap the dif over fast and go for mid gearing. And with only a 'small block' 2.8 motor and your average driving ability (lol), I shouldn't imagine calculating a top speed of 245 kmh actually achieveable nor relavent. What you want is acceleration so that you can stand a chance of keeping up with proper BMW's which have 3.5 litre engines and boots.

[Ian 535 0]

Agree Cam, I'll be running a 3.46 in mine with a 1 to 1 top as a dedicated race car. Although I think the 3.15 will suit Glenn just fine.

Yeah, how is it David, heard you were getting on with some great lap times the other week. I am keen to mix it up with you again soon when you get out to another Friday open day at Puke. I have a few more tricks to employ now to keep up with ya.

[Silver Fox 43]

No chance now Ian, down to 1.11's regularly, and going for the 1.10's now.

[BM WORLD 1283]

Hi there Glenn, it's Ian here. I was passing you multiple times a month or so ago when you had your car out there with that slush bucket auto and the suspension you must have nicked out of a Nissan Primera . Yeah, swap the dif over fast and go for mid gearing. And with only a 'small block' 2.8 motor and your average driving ability (lol), I shouldn't imagine calculating a top speed of 245 kmh actually achieveable nor relavent. What you want is acceleration so that you can stand a chance of keeping up with proper BMW's which have 3.5 litre engines and boots.

are you trying to stir a hornets nest here

but i have been in glenn's car this week , and its pretty good now (pretty quick going up clevedon rd) quicker than my e36 325i 5spd coupe but maybe not quite there with a silver surfer , with a few more laps under his belt , he will be knocking on your door of your red rat rod..

Edited April 2, 2009 by Brent HARTGE535i

[*Glenn* 854]

Its OK Brent... I can handle a wind up as for the suspension... Bisteins & H&R's 328 sway bar... how does that compare to a Nissan Primera ?? The car's not a dedicated race car, its a fun car and surprises many with the performance factor it has now. As for a boot... I dont need a place to store nappies & prams now... so I dont need it. Ian might need a boot though....for storing spare parts and his tool kit... these I dont need either.

I'm more than happy with what I have now.....and thats what it's all about....the enjoyment factor.

As for my track driving ability.... I've said it before... that was the first time ever I've been on a track... and the unpredictability of the "slush box" was making me very cautious & nervous... however, I had some fun & enjoyed it... didnt break anything (appart from the "slush box) which I knew had limited life, nor did I hit anyone.. so that cant be all that bad

[Ian 535 0]

Its OK Brent... I can handle a wind up as for the suspension... Bisteins & H&R's 328 sway bar... how does that compare to a Nissan Primera ?? The car's not a dedicated race car, its a fun car and surprises many with the performance factor it has now. As for a boot... I dont need a place to store nappies & prams now... so I dont need it. Ian might need a boot though....for storing spare parts and his tool kit... these I dont need either.

I'm more than happy with what I have now.....and thats what it's all about....the enjoyment factor.

As for my track driving ability.... I've said it before... that was the first time ever I've been on a track... and the unpredictability of the "slush box" was making me very cautious & nervous... however, I had some fun & enjoyed it... didnt break anything (appart from the "slush box) which I knew had limited life, nor did I hit anyone.. so that cant be all that bad

Yeah, fair comments by the both of you. I do enjoy the chance to sling off with the greatest of respect to the both of you as we are all still learning many things about our cars and individual driving abilities. As for the losely used term of Silver Surfer Mr Brent, your quaint grey shaded E28, intermixed with the odd orange and brown dots (and dents), needs a severe make over before I ever link the term silver with your car.

It would have been great to have your car already for a drive last Sunday Glenn, this would have worked out a few bugs the car may have had and honed your driving ability and quickness still further. At any rate, Brents slipery sublime smoker was interesting to watch as it pitched itself around a few corners (if only visible for brief moments due to the smoke it was producing).

I hope there is another Friday open day we all can get out to together along with this David L character with his lightweight E28.

[Ian 535 0]

are you trying to stir a hornets nest here

but i have been in glenn's car this week , and its pretty good now (pretty quick going up clevedon rd) quicker than my e36 325i 5spd coupe but maybe not quite there with a silver surfer , with a few more laps under his belt , he will be knocking on your door of your red rat rod..

I wonder if a small block 2.8 car can ever keep up with a tight E28. Still, alot boils down to driver ability and if you have had your brave pill that morning also. It was a good day on Sunday and you should check out the pics Helen posted for us all to look at. Its under news section.