Topic: Old Skool Turbo CB750

[Superbiker_uk]

  Sorry - should have checked your previous posts first - very cool bikes


Good luck with the turbo project - like many others looking forward to reading more as you post on this topic

[voxonda]

Today contacted: http://www.coneeng.com/, hoping they can help me with some parts to finish off my exhaust system of the Turbo.

[usedtoluvavdub]

When I was at Vintage Days at Mid Ohio, there was a super clean CB550 turbo there..looked great. Got my gears turning for sure.

A couple of points/questions...

I'm new school when it comes to turbos. (I have a VW GTI running 21lbs of boost currently) With a Carb, how do you control the amount of fuel to higher levels of boost? We don't need to run 21lbs, but even at 7-9lbs we don't want to lean out, right?

Having an obsession with boost, I was speaking with an old school honda tech about just doing a motor swap from one of the early 80's Turbo Hondas. CX500TC? Just an idea I had..

I suppose you can tell I'm a little new school with my attitude to just swap in the motor you want rather than build it..My past auto projects include a G60 golf II (never offered in the States) as well as a VR6 swapped Golf II and a 2.0 16v swapped Golf I.

Thanks for listening to me ramble!

[voxonda]

Never mind the rambling!! Love when people are interested! Don't know how to cope with the possible lean out when on boost. Think that, with the old tech carb's, you just make sure that there is enough fuel, do not mind economy with a Turbo. Don't forget this is a old skool projekt. Will be happy to use a Dyna2000 ignition to control detonation, and that is as far as modern technology is concerned.
If you have an idea, I would love to hear.

Cheers, Rob

[scartail]

Can you go fuel injected (i know it wouldn't be too old skool, though). But then again nor is the dyna.

How do you make sure the a/f is the same between each cylinder?

[voxonda]

Can you go fuel injected (i know it wouldn't be too old skool, though). But then again nor is the dyna.

How do you make sure the a/f is the same between each cylinder?

If one would go EFI then you can't opt for "draw-through". Nowadays with all the EFI it's "push-through".
Since I am Dutch, don't know exactly what you mean by a/f  Think you mean air/fuel ratio?? You cannot make sure!!! By using a 'divider' on the inlet side of the manifold, you split the incoming mixture to cyl. 1&2 and cyl. 3&4, the rest is up to the shape of the manifold. Problems occur at low speed, rough idle, but hey it is a somewhat old technology.

Cheers, rob

[comp]

cool build

[dp2275]

If one would go EFI then you can't opt for "draw-through". Nowadays with all the EFI it's "push-through".

i think its important to mention that any EFI system would require a fuel pump.  standalone ecu's have the benefit of controlling better coils too.  when you factor in all that needs power (injectors, ecu, fuel pump, coils, etc), you really have to think about taxing the factory charging system at lower rpms in my opinion.  it would be neat to have efi on one of these old bikes though!

[voxonda]

Here is one:  http://forums.sohc4.net/index.php?topic=30624.0

Cheers, rob

[DarkRider]

Actually you can opt for Draw through with EFI. the original Turbo I Daytonas used a draw through set up.

[fuzzybutt]

that mikuni hsr42 is marketed for use with larger displacement harley motors, think 1340cc's and up, shouldnt be a fuel or air problem there

[voxonda]

Actually you can opt for Draw through with EFI. the original Turbo I Daytonas used a draw through set up.

Thanks, I am not familiair with that setup. Any pic's?

Cheers, rob

[Ecosse]

Actually you can opt for Draw through with EFI. the original Turbo I Daytonas used a draw through set up.

Had an Omni GLH. Fun, crude, little beast that could spank the odd Camaro.

GLH: Goes Like Hell.

[usedtoluvavdub]

Actually you can opt for Draw through with EFI. the original Turbo I Daytonas used a draw through set up.

Had an Omni GLH. Fun, crude, little beast that could spank the odd Camaro.

GLH: Goes Like Hell.

Oh man, I forgot I had an Omni GLH S...the Shelby version of of the GLH. My understanding was 0-100 it was the fastest production 4 door in 1986. What a blast that thing was..complete POS...but I think back and I have to believe that it was that car that started my love of anything fast!

[scartail]

Here is one:  http://forums.sohc4.net/index.php?topic=30624.0

Cheers, rob

http://www.orleanscycle.com/Fuel%20injection.htm

It looks pretty daunting with all that wiring. But it can be done.
And you can control your a/f (air/fuel) ratio better. If you go with four injectors, you can keep a better consistency of fuel to each cylinder. Anyway, it's just an idea.

And your project looks great. I wouldn't mind putting a turbo in my 550. :-)

[voxonda]

Well, my pretty little beast has got, some, of her clothes on.

[rachet]

Your bike is tight!  I wish i could build a turbo... that would be SWEEEEET!*  Could I trouble you for some close up pics of the turbo, intake and brackets please?  It really looks good Vox.


Rachet~

*Family guy reference

[voxonda]

Your bike is tight!  I wish i could build a turbo... that would be SWEEEEET!*  Could I trouble you for some close up pics of the turbo, intake and brackets please?  It really looks good Vox.


Rachet~

*Family guy reference

Hey Rachet,

Thanks. Can make some close up pics, if you point out what you need. On page 1 are some pic's of several parts. Which brackets do you mean?
I never build a Turbo before, just start and keep asking questions to people who have done it before. You will grow into it.

Cheers, Rob

[troppo]

OK i know little about turbo`s or EFI, but i can remember there was a simple system of injection called throttle body injection long before petrol engines had individual injectors for each cylinder, LPG cars use the same system, that would be a draw through system and relatively easy to set up for someone in the know the way i see it,
One injector not four, got to make it easier

[voxonda]

Hey troppo,

Would certainly know a bid more about that system, for a future projekt. You have any info available?

Cheers, Rob

[rachet]

Hey Rachet,

Thanks. Can make some close up pics, if you point out what you need. On page 1 are some pic's of several parts. Which brackets do you mean?
I never build a Turbo before, just start and keep asking questions to people who have done it before. You will grow into it.

Cheers, Rob

I guess I'm a little confused by the tube coming out from the left side (sitting on the bike) of the turbo... is it an exhaust port of some type?  As far as pics of the "brackets", is the carburetor just hanging on the turbo or does it have it's own support?

thanks!

[voxonda]

Don't be confused, this is the exhaust from the Turbo. Or at least it will be! Am waiting for some ordered stainless pipe to create the definitive pipe, that will run downwards and then backwards. For now the Mikuni is attached only to the Turbo, but that has a mountiing to the frame, to be made in Aluminium. Will eventually make a support for the carb in case of back-fire of some sort.

You are more then welcome!

Cheers.

[voxonda]

Well today started with the definitive engine for the Turbo. Will be the F2 engine with pistons from a F1, in order to drop the CR from 9.0:1 to a healthier 7.8:1, at least when you have a Turbo and want to keep it in one peace. Engine gets new primary and camchains, a good hone and new rings. Camshaft from a F1, no need for the F2 timing. Both cylinder and main bearing HD studs. And a nice touch up with VHT spray. That should do the bizz.

Cheers.

[cben750f0]

THIS IS AAAAAWWWEEEESSSOOOMMMEEEE!!!


woooooooooooooooot



well done M8...


peace

[750essess]

Very nice Voxonda. If you ever did want to try EFI it would be fairly simple, use a harley efi throttle body and use its injectors or mount injectors on the individual runners. The harley tb would have everything you need except for a 3 bar map sensor and fuel pump.