sounds interesting...
would the throttle bodys be too small for the flow of a 3.6l?
675cc X2= 1350.

 

Don't forget that the 675 does quite a few more revs than the Porsche engine, so throttle bodies are over-sized compared to most cars.
The standard inlet port size on the Porsche 964 engine is 42mm. It is common practice to use 40, 44 or 46mm ITBs on these engines even for racing.
This is where I am at for now ...

 

One throttle body per cyclinder is great...whats the measured CFM for a throttle body tube?

 

On the TPS, pin 3 is the sensor ground, pin 2 is the +5 volt supply that goes to most of the sensors on the bike and Pin 1 is the "output" to the ECM. So, Pin 1 is the one that will have the varying output based on the throttle position.

I could not make out the purposes of the various wires on the stepper motor.

It looks like the injectors get 12 volts directly from the main EMS relay and are "grounded" by the ecm when it's time for them to squirt.

 

PM "hordboy". He runs an aftermarket ECU and built his own wire harness. He's very technically literate. :laugh:

 

Meh, I'm not so literate on the wiring. If I get a chance I'll sift thru the wiring diagram tomorrow to see if I can decipher the stepper connections. I don't use the stepper on mine, I use the " race kit" manual adjuster in conjunction with a spark advance vs. coolant temp strategy to control the idle until the engine is fully up to temp. The steppers on these things can be a bit of a PITA. Trying to keep 2 of them in synch sounds like a nightmare to me.

 

Hi Guys,

I'm planning on the same path with an Alfa Romeo GTV6 2.5 engine- it's basically a Group A spec engine, with Luigi Racing cams from the 1985 Australian GpA cars, 11.3:1 comp, oversize stainless valves, revs to 8000, haltech ecu etc etc.

My plan is to have a mate fabricate some inlet runners and an adaptor plate so I can use some bike throttles- Triumph ones would be great, because I can use two sets of triple throttles and they already have injector pockets and a TPS I can try and get the ECU to talk to (vacuum signal is a bit lacking with individual throttlebodies, so tuning will be via TPS/RPM).

I'm after some info on the Trumpy throttles-

I'm aware that you can split GSXr throttles and space them out (they are built like this), and there are plenty of linkage kits available that will allow me to sync the six throttles correctly.

Do any of the triumph throttles come apart?
Does anyone have any info on what throttle diameter different models/years of these bikes were released with?

If not, can anyone identify these Daytona throttles?

http://www.alfabb.com/bb/forums/picture-room/10299-post-pic-your-alfa-172.html#post728904

Thanks, all
J

 

"My plan is to have a mate fabricate some inlet runners and an adaptor plate so I can use some bike throttles- Triumph ones would be great, because I can use two sets of triple throttles and they already have injector pockets and a TPS I can try and get the ECU to talk to (vacuum signal is a bit lacking with individual throttlebodies, so tuning will be via TPS/RPM)."

I chickened out of trying to setup two TPS to run with Megasquirt. Couldn't source a suitable connector anyhow. The Daytona 675 TBs have two vacuum ports on each TB, so I am using a remote idle air control valve (ex Jeep) which is connected to one port on each TB. I use the other port (x6) for brake vacuum.
One of the TBs on each set has three vacuum ports so I use the third port for fuel pressure regulator and vacuum to MS3X.

"Do any of the triumph throttles come apart?
Does anyone have any info on what throttle diameter different models/years of these bikes were released with?"

The 675 TBs can be spaced apart, see pics.
The throttle diameter is 44mm, but the lower section of the body is tapered and oval so I opened them up to about 44mm right through.
I plugged the injector ports in the TBs and installed injecors at the bottom of my intake runners.
The pics might give you some ideas. BTW, the engine is still on the stand, so I can't comment on performance just yet.

 

The pics might give you some ideas. BTW, the engine is still on the stand, so I can't comment on performance just yet.

Not that I follow Porsches that closesly, but this is the coolest Porsche engine I've seen to date. Very clean. Looks like a fun project! :thumbup:

 

Looks very tidy!

I'm enjoying the updates, please keep them coming.

Cheers,
Erik

 

Just curious but who came up with the idea to use motorcycle TB's? Seems like quite the out of the box idea but maybe its just me...

 

Just curious but who came up with the idea to use motorcycle TB's? Seems like quite the out of the box idea but maybe its just me...

Its all to do with the $$$$$
Motorcycle triple TBs can be picked up for around $100 a set. Purpose-built TBs from various after-market suppliers or OE start at $1000!
Besides, I am an old school do-it-yourself type, so I love a bit of a challenge.

Thanks for the comments. Here's a few more pics for your viewing pleasure!

 

Definitely subscribed!


Sent from my Motorcycle iPhone app

 

I can't say i know exactly what im looking but i like it.