Project: Lets confuse the hell out of everybody.

[2l2ltq]

Yes, less weight than an M20, 2x the power output, and likely an absolute symphony of induction sound when coupled with a carbon fiber plenum.

In a perfect world I would be using S1000rr engine to keep it BMW (and also because those are amazing engines) but the pricing and availability is much more favorable for the Yamaha and Suzuki engines. Example: a few months ago when the idea popped in my head I browsed Craigslist for used bike engines. a 12000 mile R1 engine with harness, and ECU was $1000, and a 16000 mile engine with no ECU/harness was $800.


Assuming this project is completed with a pair of R1 engines, I would eventually want to step up to a pair of S1000rr engines.

As i am a motorcycle mechanic as well as a bmw tech I would strongly suggest going with a suzuki motor rather then a r1. They put out much more power and have a much more broad power range. If you are looking for a good engine to do this with as well i would go with the k5 gsxr 1000 due to the large amount of parts available for them and them being cheap as well. Not to mention the literature for them is all over the place if you needed to find anything.

[Sagaris]

What are you planning transmission wise?

There are certainly a few ways to go about this.

I hate the thought of having 3 transmissions in the car but at the moment but the initial approach is to keep the G260 and E30 driveshaft just how they are and lock the bike gearboxes in 3rd, 4th, or whatever ratio makes the most sense (would even be interesting to design a linkage system that would allow it to be shifted on the fly.... 30 possible forward gears, 6 reverse :rofl:)

Depending on calculations, the bike clutches will likely be upgraded to something suited for drag racing duty to prevent slippage from the extra weight of the car vs bike+rider, but the E30 clutch and transmission will be the only ones being operated while driving the car.

[Sagaris]

As i am a motorcycle mechanic as well as a bmw tech I would strongly suggest going with a suzuki motor rather then a r1. They put out much more power and have a much more broad power range. If you are looking for a good engine to do this with as well i would go with the k5 gsxr 1000 due to the large amount of parts available for them and them being cheap as well. Not to mention the literature for them is all over the place if you needed to find anything.

I appreciate the input, I will definitely consider it. I am not set on any particular set of engines at this point but have used an R1 engine for modeling, pricing, and some calculations to gauge the feasibility of the project.

As the feasibility of the project continues to look better and better, more thought and decisions will be made, including a serious comparison and research of which engine(s) would be best suited and what is available.

If I was Scandinavian, and single, I assure you that this project would be finished over the winter, would have some type of gigantic turbo, and I would be playing it off as if it was a beige Camry.

I certainly welcome the ideas of the E30 community and knowledge of those more experienced with motorcycles. I have a good idea of how it all could go together but my ideas are not the final word and there are likely many other better ideas and options that I have not considered. :up:

[unevolved]

How are you planning on dealing with the opposite rotation of those engines oriented like that?

[Hey_You]

I agree with using the Suzuki engines as well. But I'm a huge fan of cars with bike engines after watching this video.
Busa MK1 Golf

[Sagaris]

There are a few possibilities for transmitting the torque to the G260 from both engines but as it is shown in the solid model, the thought would be to use a gear drive to connect the engines or an intermediate gear incorporated with the sprockets + chain drive. I would have to sketch it out to explain it clearly but I do have solid ideas for all possibilities, it is more a matter of narrowing down which will be most reliable and cost effective.

[SirWolfian]

I am fucking subbed,

[unevolved]

Yeah, I think linking the power from two engines rotating in opposite directions to a G260 in a reliable fashion will be your single biggest design challenge. There's precedent for just about every other process except that one.

It's definitely possible, though. If you've got the right combination of money and skill (and more of one can offset the other).

[Keith M]

I watched a YouTube video a couple of years ago that had a spec racer, maybe a Stohr or Radical, at The Ring clocking a sub 7 minute lap with a dual motor setup like you are planning. I'm sure there is a write up on it somewhere.

[2l2ltq]

As far as the clutch set up you would need it would have to just be very heavy basket springs as all the other clutch set ups for drag are centrifugal and only
Get stronger as they spin. Soo yeah.

[Massimo]

Seems silly, you could easily mirror a R1 block design to create a V8 have it CNC'ed, get a custom crank made up and done. While my option will proably be more expensive you know you will have a reliable system that has a good weight distribution and non of the harmoics issues.

While what you are trying for is achivable I think you are going the wrong way about it. But who cares what I have to say if you want to do it good luck. keen to see the end results

[Sagaris]

As far as the clutch set up you would need it would have to just be very heavy basket springs as all the other clutch set ups for drag are centrifugal and only
Get stronger as they spin. Soo yeah.

Good to know, thanks!

[Sagaris]

Seems silly, you could easily mirror a R1 block design to create a V8 have it CNC'ed, get a custom crank made up and done. While my option will proably be more expensive you know you will have a reliable system that has a good weight distribution and non of the harmoics issues.

While what you are trying for is achivable I think you are going the wrong way about it. But who cares what I have to say if you want to do it good luck. keen to see the end results

http://www.h1v8.com/page/page/1564764.htm

I completely agree, I believe I read somewhere on this site that the V8 busa block was about $25k.

[LJ851]

Why would you not use sequential, dog engagement, 6 speed transmissions when you will be carrying them around anyway? Most people would give their left nut for a gearbox setup like that. Plenty of people have made 2 motorcycle 'boxes work in harmony in minis and super sevens.

Since you are going to have to make an intermediate gearbox to get both powerplants meshing anyways, an output flange exiting that 'box should be a relatively simple addition.

[petrolhead]

Why not use a V8 made from bike engines, one that already exists. They aren't cheap in think, but neither will this project of yours, be.