750 V12 (97) in M5 E34??? - The Unofficial BMW M5 Messageboard (m5board.com)

16th February 2002, 18:30

Hi

I got a German M5 E34 3,8.
I have got the opportunity to buy a complete V12 out of a 97 750. Can this engine be mounted into an E34 M5? What parts have to be changed?

Thanks

Christoph

IvanDias · 16th February 2002, 19:22

Loads.

Why? The resale value of the 3.8 M5 will be devastated.

You`ll get more torque, but the BHP is similar, so the overall speed increase will not be worth the aggravation.

This has been done a few times in 535i cars, but to do so on an M5 would be considered sacrilage.

Still, if you want to do it, you should buy the entire 750s wiring loom and computer components.

Remember that the M5 gearbox is unique to the M5, so any modifications or adapters that need to be obtained to mate it to the V12 are going to be custom made.

To my knowledge, no-one has ever wrecked an M5 by using it as a donor car for the V12, so you are probably the first to do so. The problem is because as you are the first, no-one has ever made the parts to link the box to the engine!!

I`m not even going to continue.

To take a M5 3.8, pay for a V12, add months of aggro making it go in, only to be left with a car of approximately the same performance but worth a whole lot less, and living ***** to insure, is a bad move.

What you need to do is sell the car, add the money you have for the 750s engine and ancillaries, then think long and hard about an Alpina B10 BiTurbo if you want the E34 shape, or have a looksee for how much the first of the E39 cars are selling for now.

Welcome to bmwm5.com. This is not an attack on you, maybe I am too strong with my words above, but I stress to you that for more power, choose another car instead of what you are proposing for the 5.

Ivan.

IvanDias · 16th February 2002, 19:31

PS.

1.
What did a 20 year old student pay in Germany for a M5 3.8 with GT2 brakes on it? How ?

2.
Your profile lists your interests as "computers" and "illegal street racing".

Your enemy is weight. The M5 is too heavy for street racing.
If the racers won`t increase the distance raced over, allowing you to get the M5s performance at greater speeds than 100mph, then sell the car. That is why all the Honda Civics and Saxos and the ricerockets are beating you.

PS. Steet racing is sad and stupidly dangerous. As opposed to "the fast and the furious" which is just sad.
"I live my life a quarter mile at a time..."
purlease !!

Try Nurburgring for a real thrill. I`ll send you a prize if you get under 9 mins BTG.

17th February 2002, 01:39

Thanks for your replies.

1. I paid 9600 € for my M5 with about 90000kms, the brakes had to be replaced anyway, so I paid another 4000€s for GT2-brakes out of an accident GT2. Where have I got this money from? I am running a computer service business...

2. Well, 911s are faster than my M5 but most other cars aren't.

3. I am not doing 1/4mile races but our race distances are about 20-30km (I live in the Alps).

4. It was just a thought that V12 thing, but when it is that difficult I will save the money

5. Nürburgring rules, my one and only lap was 11:31 which I think is not too bad for a beginner.

E39s are still too expensive, so I will keep my E34.

cu

Chris

raymondw · 17th February 2002, 18:16

Chris,

See http://www.bmwm5.com/vbulletin/showt...&referrerid=85

Rgrds,

RAymond

1990 E34 ///M5 3.6
1985 E28 ///M5 M88/3 (The granddaddy of all German Sport saloons)

jrturbo · 17th February 2002, 20:23

Hi there

I have to agree with Ivan

the resale value of the car will be recked, add to that the fact the 750i engine develops 326 bhp which is less than you have currently. I also believe that all 750 where only availabe with auto boxes,your existing gearbox will not mate with engine and the your only likely source to find a manual gearbox would be find a the gbox out of a 850 csi coupe, virtually imposible, very few numbers produced.

In addition to this fact your bigest problem in the conversion will be making the engine electronics work, the 750 i is very complex its has one engine mangement computer per bank of cylinders and another one thats overlooks both of them, fly by wire throtles, to say that that you have an uphill task ahead of you is understatement.

I dont believe you will gain any performance improvement from the conversion to be quite honest.

If you race your car the bigest improvements to be had are to improve that handling and grip, soft compund tyres will give you more grip at the expense of durability and they improvement could be measured in seconds a lap on a circuit, but to be quite honest i think that you are using the wrong car for that purpose, I doubt you could keep up with a mildly modified subaru impreza of mitsubishi lancer evolution on a mountain road, thay enjoy the benefit of lighter weight and 4 wheel drive.

Interesting idea never the less though.

Regards

Joe Rubido

Marek · 28th April 2002, 20:54

BMW M-division experimented with V12 engine from 850 CSI before they implemented 3.8 liter engine. That was supposed to be their answer to the Merc 500E. A spokesman for the M division said the E34 M5 with the V12 engine was very fast but the regular M5 was much faster on the Nurburgring.

Marek

IvanDias · 29th April 2002, 02:07

Marek,

Before the 3.8, or before the 3.6 ?

It makes quite a difference, as far as accurate history goes.

There would have been effectively a fourth generation of M5 had the engine replaced the 3.6 in 1992/3.

Would have been fun if the engine had had more power than the 326bhp mentioned above.

Ivan.

Marek · 9th May 2002, 00:27

Ivan,

If I remember, it was before they implemented the 3.8 liter engine. It was written in up in the Roundel.
Anyway, a car with a straight six had a superior weight distribution as comparing to a car with a V12.

Marek