New drivetrain setup: VR6

[rossnzwpi]

fantastic work Kai! I'd be interested in the detailed measurements you have of the Alfa V6. When considering the use of 108 x 5 hubs think also about the centre bore if you are getting Cromodoras with original sizing. They are way smaller than modern 108 (e.g. Ford/Jag) hubs. I think the repro Cromodora-look wheels may have a different offset to the originals too - but don't quote me on that. Alfa 166 hubs are similar size to original Dino.

[thecarbuilder246]

Hi All

My two pennies worth. The trouble with taking a front wheel drive engine and box and placing it in a mid engine configuration is the weight transfer on high acceleration. When the box is in the front (front wheel drive) on acceleration the weight transfers to the rear of the car and often results in wheel spin and loss of grip. When you place the box in the rear or the car (mid engine) on hard acceleration the weight transfer means you have more weight at the back leading to more grip. More grip means the wheels will have less of a tendency to spin- this is what smashes the front wheel drive boxes. It's also why a lot of hot hatches with front wheel drive and 300+ horsepower now have electronic diff's. If I was starting again I'd go for a v6 from a lexus rx300 or rx350 which will bolt straight on to the toyota mr2 turbo box. This box is almost bullet proof and comes with limited slip diff as standard. I've seen mr2's and celica gt4's with upwards of 800 bhp. The lexus engine is also used in the lotus europa.
I will be sticking with my ford cosworth v6 and using a mr2 box via an adaptor plate. Ok not the lightest engine in the world but with 24valves and alloy heads and when turbo'd good for 400 bhp on stock internals. Plus I already have a brand new crate one/ a spare one and evrything that's needed to run it .

ian

ian

[thecarbuilder246]

Hi again

The toyota mr2 box will fit an alfa v6 engine too via an adaptor plate. I've seen them in the stratos, one turbo charged and pushing out over 400 bhp. Don't know if the intenet will bring up but try -turbonutters stratos mr2 box.

ian

Originally Posted by thecarbuilder246

toyota mr2 turbo box. This box is almost bullet proof and comes with limited slip diff as standard. I've seen mr2's and celica gt4's with upwards of 800 bhp.

The mr2 turbo E153 seems to be a very strong gear box indeed, accepting some 480 Nm. Problem is, they are getting quite thin on the ground (especially on the continent) and therefore quite expensive. Furthermore they are only 5 speed.

Ciao, Kai

[thecarbuilder246]

Originally Posted by hondekop

The mr2 turbo E153 seems to be a very strong gear box indeed, accepting some 480 Nm. Problem is, they are getting quite thin on the ground (especially on the continent) and therefore quite expensive. Furthermore they are only 5 speed.

Ciao, Kai

True they are only 5 speed-but woodsport do a 6 speed update/rebuild version if that's what you want. Expensive though. Personally 5 speed would do me ok. It was good enough for ferrari after all. I'm not worried about fuel economy a 6 speed would give me on a car only used when the sun's out. But each to there own I say. good luck

ian

Originally Posted by thecarbuilder246

True they are only 5 speed-but woodsport do a 6 speed update/rebuild version if that's what you want. Expensive though. Personally 5 speed would do me ok. It was good enough for ferrari after all. I'm not worried about fuel economy a 6 speed would give me on a car only used when the sun's out. But each to there own I say. good luck
ian

Not a show stopper for me either, just something other boxes have as a (non essential) pro. Standard LSD is not a bad thing however.

Thanks Ross. To be honest, I have no measurements of the Alfa V6 & box. I just based the drawings on various photos, while using the bore size and oil filter diameter as references. Apart from that, some incomplete CAD drawings from sources you have found yourself already. Sadly, most of the photos are taken from an angle. As such, it is certainly not completely accurate, but a good indicator nevertheless. I have updated the drawing with the additional info I found.
PLUS, apparently the gearbox places the engine in a tilted position. The new drawing represents both:

This gives a better position, although the driveshafts are still at an angle.

The Duratec/Jaguar V6 drawing is pretty reliable (based on Ford drawings). As it is considerable bigger than the Busso V6, it is out of the selection.

I also updated the VR6 drawing to be more accurate:

Still the best position, although the driveshafts make a very small angle.
CG wise, it could be on par with the Busso: it can be placed further forward, but the VR6 is some 40 kg heavier.

Tough decision:
- Brilliant engine sound: both
- Weight: VR6 is substantially heavier
- Liveliness: definitively Busso
- Turbocharging: definitively VR6
- Required space: VR6 is easier

Don't know yet. To complicate matters further, there is also the Nissan VQ35DE: High revving, strong internals (turbo) and light. On the other hand, slightly bigger than the Busso. Available from the likes of Renault Espace, Vel Satis, or Nissan Murano.

Decisions, decisions; sigh.