single TB blow through turbo

[Issues]

Just after some feedback and some professional oppinion, most of the turbo stuff I've done has been on 4.2l nissan deisels but just curious if there would be any reason why I could not run a blow through turbo setup using a single TB from a LS1 for example. With injectors on small inlet runners before ports, with a plenum about 1.5 times capacity of motor to a single TB from a chevy LS1/gen3 or similar. Standard LS1 TB is around 72mm dia but aftermarket are available to 100mm+.
Not quite sure what bike its goin on yet, it will be a future project but lookin at ZX12. Also lookin at some sort of Garret GTxxR ball bearing turbo, I will have to sort out size later.
As double diameter on pipe is roughly 4 times the flow I was thinking a large single TB might be easier to set up n tune. As it will be force fed I'm not sure if it will need a TB/cyl.
Any help and advice will be great, as the fuel system on the nissan deisels is stand alone mechanical, so very easy to tune and I'm not real familliar with the computer driven fuel n timing requirements on a bike.
Thanks

[Deano]

if you already have a fi bike to start with you would be mad note to just add a piggy back computor and retain all the standard throttle body assy.

for starters if you look at a single tb then try something like 55mm not 100mm+ the bigger you go the worse the throttle response. you have to find that happy medium between flow and throttle response. your theory is right but what it would be like in practice is another thing. remember throttle response on a bike is your friend

exben i believe has done single tb before and booster is a guru around here for all things turbo.

i am sure either of those 2 will shed some more light on the subject

[Issues]

thanks Deano, I was lookin more at the 72mm TB, the idea was to save room, I am a EFI nooby. Was thinkin if std TB is 40mm ish 72mm should be close enough.

[Deano]

quote:Originally posted by Issues

thanks Deano, I was lookin more at the 72mm TB, the idea was to save room, I am a EFI nooby. Was thinkin if std TB is 40mm ish 72mm should be close enough.


still think that 72mm would be to big.

there was a thread started on OSS a while ago about single tb sizing. worth a read, head to the forced induction section.

[Booster]

Ozkat may be able to shed some light here, the only single throttle bike turbo i know of ended up in his hands for a while, the original owner had issues tuning the flat spot out.it had a daihatsu throttle on a log style plenum.
ZX12 would be one of the more difficult bikes to turbo because of the frame (it is the airbox) esp in the manner you are looking at.
As Deano said if you have a FI bike all the hard work is already done,bigger fuel pump, a boost sensitive piggyback or a FMU and powercommander and you have the fueling sorted

[EXBEN]

Wot he said^^^^
My first turbo bike had a single throttle body. It was fine on boost but suffered a bit in the throttle response. Would be fine on a drag bike but like Booster said, why bother when all the hard works done for you already.

http://www.streetfighters.com.au/forum/upload/769447831114594.jpg

[Issues]

Thanks for the info guys

[ozkat]

The thing i found bout a single T/B was throttle response was terrible and when it did come on the bike wanted to loop its self even in 5th at any speed. The power was absolutely amazing but totally unusable. Maybe changes in T/B sizes or turbos would have made a difference, i dont know. I ended up blowing through standard CV carbs which really isnt that hard if you have the right info. The bike was a 1991 GSXR1100.