Turbo help..

[Blackhauk90]

So i was thinking of installing a turbo on my bike. It is NOT a Hayabusa though.. I just figured since some of you guys can get 3-400 hp out of a bike i figure its worth listening to. I will be buying all of the parts for it separatly and not in a kit. My bike is a FZR600. Its got carb's instead of fuel injection too. I was wondering if anyone could really give me any really good tips. Most people would say go and buy another bike and all but i kinda wanted something different..

I'm kind of aiming for the 160 range for hp.. I only pretty much know how to make the exhaust and the rest i'll have to try and figure out some how. I was thinking about using a m-10 turbo because they're small in size.. Anyways if ANYONE if anyone could help me out with anything i'd be extremely thankful.


Jake-

 

[fstbusa]

Just a suggestion. I don't know much about turboing carb bikes.

Go talk to motorhead at suzukihayabusa.org. He just got done building a kaw zrx1200 carb'd bike and it has over 400hp.

he can tell you what he did to add fuel and how everything was setup and regulated.



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[Uncle Bob]

if your goal is 160HP, then you need a turbo that can at the very least achieve that. I'm not familiar with the M-10, but a good turbo would be a T25 or a GT-15 (210ish HP capability)....you always need a little room to grow or you'll have too much back pressure at peak output and you'll fall short of your goal. This will cause the boost to build late though.

Turbo'ing carbed bikes is very doable, but can take some experimenting. I haven't worked with the FZR carbs before, so I can't say how easy they will be, but have done a lot of work with Kehien CVK carbs and they are quite easy to make work with a turbo.

The FZR has a very leaned-forward engine setup, which will compromise the turbo placement. Optimally you want the turbo above the oil level so that you can use gravity to drain it back into the crank case, but you might be forced to do a external oil scavenge setup using an electric pump, which isn't fun, but does work.

You will also need a high-pressure fuel pump and a fuel pressure regulator to deal with the pressure differential on boost (this is always necessary on a blow-thru setup). The FZR already has a fuel pump, but its not a high-pressure pump, so it won't work.

 

[bajabug]

that clutch wont hold 160hp very long. and i wouldnt trust the swing arm with that power. anythings possible it just matters how much ya want to spend...

 

[2wicked]

You do not need a high pressure fuel pump for carbs.

Richard

 

[fstbusa]

You do not need a high pressure fuel pump for carbs.

Richard

how can you increase the flow of fuel then?

is the stock pump sufficient?

 

[Uncle Bob]

You do not need a high pressure fuel pump for carbs.

Richard

for a blow thru, you most definitely do. (as I stated)

Draw thru you don't. Draw thru's also suck IMO, so its a non-issue



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[2wicked]

You do not need a high pressure pump for carbs period, you only need a low pressure pump and low pressure 1:1 boost referenced regulator for blow through, low pressure pump only for draw through. Set fuel pressure to 1.5 -2 psi, this is hardly high pressure. Then no matter what the boost level you will be 1.5-2 psi above boost pressure, anymore then that and tell me how you are going to keep the fuel from overflowing the float bowls, the float and needle and seat can only handle a couple of psi. If you plan on running 10 psi you only need a pump capable of about 15 psi of fuel pressure, this is not considered high pressure.

Low pressure pump and regulator for carbs, high pressure for fuel injection.

Richard

 

[Blackhauk90]

Well i don't really think i need a 25psi boost or anything crazy high.. maybe 8 or so would work pretty good.. I was thinking about the 160hp and that might be a bit much like said above so maybe i should aim for the 140's or a tad lower instead? Just a thought..

Jake


Also.. as for the compression.. I'm rebuilding the engine right now so im wondering would the compression have to be lowered, and how much?

 

[Uncle Bob]

You do not need a high pressure pump for carbs period, you only need a low pressure pump and low pressure 1:1 boost referenced regulator for blow through, low pressure pump only for draw through. Set fuel pressure to 1.5 -2 psi, this is hardly high pressure. Then no matter what the boost level you will be 1.5-2 psi above boost pressure, anymore then that and tell me how you are going to keep the fuel from overflowing the float bowls, the float and needle and seat can only handle a couple of psi. If you plan on running 10 psi you only need a pump capable of about 15 psi of fuel pressure, this is not considered high pressure.

Low pressure pump and regulator for carbs, high pressure for fuel injection.

Richard

you are correct, but the realities are, finding an aftermarket fuel pump that is good to 20psi and only 20 psi is darn near impossible. Aeromotive makes one for example, that is good to 18 psi, but its designed for a return system on a carb'd car, so its huge physically, and it forces you to never get over ~16psi of boost (at best) which is limiting. There's something to be said about always building a buffer into your design....ESPECIALLY when its lack of fuel that you're talking!

Most carb pumps, bikes and cars, are at most 7psi, these are self regulated pumps. This is, by my definition, a low pressure pump. MOST pumps offered over that pressure are for EFI, which are capable of much higher pressure (unregulated), so they are all (mostly) high pressure pumps...this is what I use on my turbo'd carb'd bike. They are small, cheap and have a lot of flow capability. They are perfect for the application, and give you basically unlimited boost capabillity (assuming you don't run out of flow capability)

For example, if you so wish to copy what I use, I use a MSD inline EFI fuel pump (part #2225) and a 3 port fuel pressure regulator, Mallory 4309. Total cost is under $200. Beyond scavenging stuff out of a junk yard, you won't get much cheaper for the physical size and capability. Its good to at least 300HP.

 

[Uncle Bob]

Well i don't really think i need a 25psi boost or anything crazy high.. maybe 8 or so would work pretty good.. I was thinking about the 160hp and that might be a bit much like said above so maybe i should aim for the 140's or a tad lower instead? Just a thought..

Jake


Also.. as for the compression.. I'm rebuilding the engine right now so im wondering would the compression have to be lowered, and how much?

the lower the compression ratio, the more boost you can run safely on pump gas. What is the compression ratio on the stock motor?

Running 8psi with a 11:1 engine is "on the edge" (asking for some BOOM action), where as running 8psi on a 9:1 engine leaves you a lot of safety margin. There is a lot of factors involved, but if you want to make this a reliable daily driver, I'd definitely recommend lowering the compression ratio.

On race gas, its a whole different story, of course.