GSXR ITB's

[grelland]

I have run my Ghia with GSXR TBs all summer now, and very few problems so far. I used Devestators pulley, and a cable setup that was really easy to install and maintain. I have had to re-sync once.

The most involving issue in my build was the shortening and welding of the intakes. It cost me about $100 with a local hotrod fabricator guy to to the welding. The rest was pure fun, and I am more than happy with the setup, compared with last year's single tb / plenum setup.

Only thing I will be fixing over the winter is a positive idle stop for the butterflies, as the current setp relies on the cable tension for idle, and it is not perfect.

I am building a new 2110cc oxyboxer for next season, and these ITBs will be used for that project also (that is until I turbo it )

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[andy198712]

but you cheated

[andy198712]

The pulleys center area can be made pretty thin, it looks like no issue on the `08 GSXR units I have.
The flanged 42mm ITBs I have off a R1-motored Jetski each has its own stops and idle air screw.

Fabbing throttle stops should be the easier part of the project, they can go on the other end if required.
You shouldn't be hitting WOT stops in any case, great way to bend things.

I added a short spring inside my splitter as a soft stop, like an automatic might have..

OTOH i have the luxury of being able to weld on a tab if needed.
Welding aluminum is never quite as trivial as that sounds, but much like paint, it's 99% prep.

yeah could easily aly weld a little tab on and thread that ala idle screw on the solex carbs

[supaninja]

Roy- I'm glad your setup has been working good for you

Andy- here is my current setup:

06-07 40mm TB's with GSXR 1000 inj mounted in the TB's
Devastator's sexy pulley
3/8" aluminum bolt plates
spigot boots
shortened 45 DCOE stacks
DIY cable linkage

This combo is working a lot better then the modified type 4 endcasting setup. You can use 38mm 04-05 GSXR TB's for your smaller displacement motor if you want to, but you will need two of Devastator's sexy pulley's (one will need another hole drilled into it for the throttle cable). I have yet to have any sealing issues with the spigot boots, I think the one guy had issues because he was stretching the boots to make those TB's fit IDF mani's. I like Dale's idea because it does keep the whole setup a little shorter, but I like the simplicity of the bolt plates/spigot flanges.

I recently adopted a '68 type 2 and I now have a extra MS1 kicking around, I'm still on the fence if I'm going to squirt it and if I do will it be a Supa GSXR setup (I got a set of 38mm ITB's all ready to go too) or a mexican plenum setup.

[andy198712]

Roy- I'm glad your setup has been working good for you

Andy- here is my current setup:

06-07 40mm TB's with GSXR 1000 inj mounted in the TB's
Devastator's sexy pulley
3/8" aluminum bolt plates
spigot boots
shortened 45 DCOE stacks
DIY cable linkage

This combo is working a lot better then the modified type 4 endcasting setup. You can use 38mm 04-05 GSXR TB's for your smaller displacement motor if you want to, but you will need two of Devastator's sexy pulley's (one will need another hole drilled into it for the throttle cable). I have yet to have any sealing issues with the spigot boots, I think the one guy had issues because he was stretching the boots to make those TB's fit IDF mani's. I like Dale's idea because it does keep the whole setup a little shorter, but I like the simplicity of the bolt plates/spigot flanges.

I recently adopted a '68 type 2 and I now have a extra MS1 kicking around, I'm still on the fence if I'm going to squirt it and if I do will it be a Supa GSXR setup (I got a set of 38mm ITB's all ready to go too) or a mexican plenum setup.

Cheers bud,

so your using the later TBI's that are splitable into 2 halves.... i was thinking the ones that split into 4....? or am i best off with 2 for a type one setup?

i guess if i get the earlier ones i can still keep them in pairs anyway?

is the bolt spacing the same for type one twin carb mani's then? i guess you could easily elongate the bolt holes....

Dales does look pretty good and i will look into both options, just getting the parts made/brought locally here in the UK.

are TBI's best off as close the to the head as then can be?

what would you do for the manifolds on the T2 if you went gixxer?

Cheers
PS enjoyed the blog alot!

[supaninja]

The 04 and later gsxr 600 TB's are 80mm center to center, while the 1000's are 85mm IIRC. The bolt plates have a mild porting job to help transition the air to the wider 90mm center to center of IDF mani's. My original modified type 4 endcastings were ultra short and I didn't like them, intake length tuning is real and makes a difference. I tuned the length with the velocity stacks now my resonance frequency is around 3500 rpms which is perfect for a street car.

[andy198712]

ahhh i didnt think about tuned intakes.....

[Steve Arndt]

Can the original subject be changed to ITB insead of TBI?
The typo makes it hard to search.

[Dale M.]

Why.... I've always referred to it as Throttle Body Injection (TBI).... That's what I've always known it as..
I really think its more descriptive... Injection Throttle Body (ITB) sort of sound like the basic part not the process....

Dale

[roobar678]

ITB is Individual Throttle Body an individual runner/throttle plate per cylinder
TBI is Throrttle Body Injection an injector located at the throttle body and not at the intake valve.

Although the GSXR throttle bodies are both ITB and TBI, I believe most people are referring to them in the ITB sense and are interested in replacing a centrally located single throttle body with them.

[Steve Arndt]

Sure it is called throttle body injection because of the geometry of the parts, but the "parts" themselves" are known as ITBs.

Individual Throttle Bodies ITBs. Most of use move the injectors down into the manifolds, but they are still ITBs, one individual throttle body per cylinder.

Semantics. And new ones.... :p

[andy198712]

Can the original subject be changed to ITB insead of TBI?
The typo makes it hard to search.

wasn't a typo but changed it

[Dale M.]

Well when you guys finish trying to "pick the fly poop out of the pepper" can we get back to making these things work....

Dale

[supaninja]

Well when you guys finish trying to "pick the fly poop out of the pepper" can we get back to making these things work....

Dale

Mine's been working

[grelland]

mine too

But I think I measured the center distance to be 70 mm; that's why I had to cut down and make new flanges on the intakes.