914 with a Motorcycle motor concept?

[TeckniX]

Originally Posted by roblav

I've started studying how to do this... using my 914 tub now sitting in a rotisserie makes it easier.

I've also done this three times before in formula racecars - one with Hayabusa, one with Yamaha R1, and last one with 2013 ZX-10R.

A few issues in the 914:
- As others have stated, weight needs decreased. The new drivetrain will be at least 300 lbs lighter then the 914 and 901 box. I think 1500 lbs maximum is the target.
- A wet sump has worked very well turning > 2 G's in the formula cars. Dry sump is more complicated and adds weight.
- Chain length - If I recall my measurements, the engine sprocket to diff sprocket will be about 17 inches if the engine is placed fairly cl;ose to the firewall. I'd be happier if it were longer.
- Rear sprocket size will have to be quite large. A typical setup on formula cars using 13" wheels is 15 tooth front and 48 tooth rear to get to about 145-150 MPH. 15" wheels will require an even larger rear sprocket, and there may not be anough room to clear the trunk floor.
- The front mount to the firewall will be easy... similar to a 914/6. What is nice here is that the mount can be integrated with tube triangulation to the rear suspension legs to stiffen up the box sections of the chassis behind the engine.
- The rear mount can be integrated into the differential cage and attached to the 901 box chassis mount.
- The normal motorcycle radiators are already curved, and that curve matches the front of the trunk.
- An oil cooler will be a requirement.
- Taylor/Taggert used to make a nice Quaife LSD that had Hewland MK9 stub axle distance. These had provision for Porsche 930 type CV's (if I recall).
- The motorcycle dashboard can be placed where the normal gauges go.
- A couple options on wiring - either integrate the 914 wiring harness into the engine harness or use a complete motorcycle harness and extend the wires. Option 1 is easier.
- Shift mechanism will need built. I prefer a hand bump type over the expensive electronic versions, but those are also cool.
- The engine clutch is easy... add stiffer springs and use a cable.
- Throttle is easy too with a cable.
- A decent air intake should be fabricated.
- Exhaust is easy... stainless Sidewinder type will work.

Now to decide whether to do it or not! Anyone want a 3.0 911 core?

Simply because I've been thinking about a similar conversion and it sounds like you're already ahead...

[reflexr]

I came here looking for exactly this.
I have a 72 roller, and a 06 GSXR1000 wrecked bike with a good motor.

Originally Posted by roblav

I've started studying how to do this... using my 914 tub now sitting in a rotisserie makes it easier.

I've also done this three times before in formula racecars - one with Hayabusa, one with Yamaha R1, and last one with 2013 ZX-10R.

A few issues in the 914:
- As others have stated, weight needs decreased. The new drivetrain will be at least 300 lbs lighter then the 914 and 901 box. I think 1500 lbs maximum is the target.
- A wet sump has worked very well turning > 2 G's in the formula cars. Dry sump is more complicated and adds weight.
- Chain length - If I recall my measurements, the engine sprocket to diff sprocket will be about 17 inches if the engine is placed fairly cl;ose to the firewall. I'd be happier if it were longer.
- Rear sprocket size will have to be quite large. A typical setup on formula cars using 13" wheels is 15 tooth front and 48 tooth rear to get to about 145-150 MPH. 15" wheels will require an even larger rear sprocket, and there may not be anough room to clear the trunk floor.
- The front mount to the firewall will be easy... similar to a 914/6. What is nice here is that the mount can be integrated with tube triangulation to the rear suspension legs to stiffen up the box sections of the chassis behind the engine.
- The rear mount can be integrated into the differential cage and attached to the 901 box chassis mount.
- The normal motorcycle radiators are already curved, and that curve matches the front of the trunk.
- An oil cooler will be a requirement.
- Taylor/Taggert used to make a nice Quaife LSD that had Hewland MK9 stub axle distance. These had provision for Porsche 930 type CV's (if I recall).
- The motorcycle dashboard can be placed where the normal gauges go.
- A couple options on wiring - either integrate the 914 wiring harness into the engine harness or use a complete motorcycle harness and extend the wires. Option 1 is easier.
- Shift mechanism will need built. I prefer a hand bump type over the expensive electronic versions, but those are also cool.
- The engine clutch is easy... add stiffer springs and use a cable.
- Throttle is easy too with a cable.
- A decent air intake should be fabricated.
- Exhaust is easy... stainless Sidewinder type will work.

Now to decide whether to do it or not! Anyone want a 3.0 911 core?

[avendlerdp]

This exists. I have this.



So... This car was originally hacked in the 90s for a Buick v6, and unsurprisingly, never really got finished. I bought it out of a Santa Cruz barn.

Now, after roughly 34598751349807 hours of work, it runs a Suzuki Hayabusa motor using the "Miatabusa" kit that adapts it to the stock 901 five speed. The power comes off the primary shaft in the Hayabusa motor so it's geared down 0.6x. That way everything spins the correct speed. Uses a Kennedy clutch.

Just a 'Busa motor seemed kind boring, so it's also turbo. I'm limiting it to a 10k redline, even though the motor stock is good to over 11.5k. I also limited the boost to 10psi because I felt like the Craigslist "good core" 901 trans was going to start having big feelings past 300whp on the Church Test dyno in Long Beach. The turbo is one of the two off a Ford GT and is definitely underutilized at that low boost level. If I beefed up the Busa motor guts, a gear shearing 500hp is totally possible with the parts I have.

Other highlights are: a custom water to air intercooler/plenum, dry sump, and Link standalone ECU. All the pumps and fans are PWM controlled by the ECU. Thing is pretty docile to drive, although the sintered clutch is a bit rough.

Here, click on some stuff. Pardon the smokey Dyno run. I had chocolate in my peanut butter. Fixed now.

https://youtu.be/XSm8oAdHG28

https://youtu.be/XG_SZYkhEW0

https://youtube.com/shorts/l6TOsdgRNK8

I've been meaning to post more about this on the 914 World forum, but it's time consuming to document all my bad ideas.

[Scottymcporsche]

I say go for it ! APE race parts makes plenty of drag racing clutch and transmission parts for a Hayabusa setup. It’s my dream to put twin Yamaha R1 cross plane crank engines in my 73 2.0 liter and 360 plus horsepower.