This is a GREAT THREAD! Thanks for posting this stuff all in one place, very helpful.
I have a small correction for the Kawasaki GPz1100 TB's
The spacing is actually 77-97-77mm NOT 80-100-80. Only DOHC Honda CB Supersports (79-83) used the oddball 80-100-80 spacing.
I also have a question about the GSXR600 38mm TB's. I am installing a set of these on my bike. Do you have confirmation on the 240cc/45psi figures? Do you know the stock pressure? Thx
Also re another discussion of these bodies. On the Keihin corporate website, they describe the ecu controlled TB's as a way to meet tough emissions standards. There is probably little value in preserving the system if you are building a performance vehicle. Restriction of air will not give better torque, it is just a way to burn less fuel...and keep the front wheel on the ground during roll-ons!
chris900f wrote:
I have a small correction for the Kawasaki GPz1100 TB's
The spacing is actually 77-97-77mm NOT 80-100-80......
Thanks, the spec´s are updated.
I also have a question about the GSXR600 38mm TB's. I am installing a set of these on my bike. Do you have confirmation on the 240cc/45psi figures? Do you know the stock pressure? Thx
No confirmation yet, tried both Keihin and Suzuki for spec´s but with no luck.
Should be abel to measure my injectors in a few week if all goes well.
I have read 43.5 psi as stockpreassur on a GSXR750 but can´t remember where I found that info.
Also re another discussion of these bodies. On the Keihin corporate website, they describe the ecu controlled TB's as a way to meet tough emissions standards. There is probably little value in preserving the system if you are building a performance vehicle. Restriction of air will not give better torque, it is just a way to burn less fuel...and keep the front wheel on the ground during roll-ons!
Seems like Suzuki use the sec. throttle for better low rpm respons but as I binned them I´ll try not to run on low rpm so much instead.
Marcus Sundin
GPZ900R A5 Restoration & Modification www.gpz900r.se
spag wrote:Waxstat... I didn't spot that, is that the thing I think is a vac jobby, with 2 hose fittings on the end ??
Oooo, just taken it to bits, and yep it's a waxstat.
With all the other vac plumbing I got confused.
Easy for the cold/warm idle thing, but not so good for idle control - sorry
bizarre but true on the CB (Honda Hornets ie non CBR) the air bleed is operated by a cable attched to what in effect is a 'choke' cable on the handle bars..
I have some 36mm bodies from a CB919 Hornet fitted and running on my Imp engine.
Make/Model: CBR 954 Fireblade
Year: 2003
Number of Tb: 2
Inside Diameter: Tapers from 45-41mm
Center-Center (left to right from behind): 80-80-80
Overall Length: 77mm
Outside Diameter (intake): 50mm
Outside Diameter (filter):
Separate casting: No (dual Tb´s)
Injector Make/Model: Denso 12 226 4490 I suspect the 226 is cc/min, as the bike is good for 150hp... 13.3 ohms
Flow Rate (45psi/100%): ?? (Std fuel pressure on bike is 50psi)
Fuel Rail Inside Diameter:
Additional Info: Factory couplers need to be used as inside diameter is offset and not a perfect circle.
-1988 325is BMW M52B28 - > MS2 Extra n Spark (60-2 Wheel, Wasted COP, Single VANOS)
-2004 Opel Corsa C / Holden Barina Z18XE - > MS1 Extra n Spark (60-2 Wheel, Wasted COP)
-1976 Triumph Dolomite Sprint Race Car -> MS1 n 'EDIS'd
-1984 C1 2.3 Alpina -> MS2 Extra n Spark (60-2 Wheel)
Marcus wrote:Make/Model: GSXR750
Year: -98, -99
Number of Tb: 4
Inside Diameter: 46mm
Center-Center (left to right from behind): 80-80-80mm
Overall Length: 91mm
Outside Diameter (intake): 54mm
Outside Diameter (filter): 54mm
Separate casting: Yes
Injector Make/Model: Keihin,
Flow Rate (45psi/100%): 240cc
Fuel Rail Inside Diameter:
Additional Info: No sec. throttles.
I have it from a reasonably knowledgible source that this is the only setup that does not have "vacuum operated secondary throttles" behind the driver operated main throttles. Does anyone have any information about this? I'd like to find out more about how these secondary throttles work.
According to the specs posted, these also seem to be the biggest throttles around as well.
i am in need of a set of throttle bodies for a 250cc ninja. anyone have a clue as to where i would come up with around a 30-35mm throttle body apart from "make it your self"?
Marcus wrote:Make/Model: GSXR750
Year: -98, -99
Number of Tb: 4
Inside Diameter: 46mm
Center-Center (left to right from behind): 80-80-80mm
Overall Length: 91mm
Outside Diameter (intake): 54mm
Outside Diameter (filter): 54mm
Separate casting: Yes
Injector Make/Model: Keihin,
Flow Rate (45psi/100%): 240cc
Fuel Rail Inside Diameter:
Additional Info: No sec. throttles.
I have it from a reasonably knowledgible source that this is the only setup that does not have "vacuum operated secondary throttles" behind the driver operated main throttles. Does anyone have any information about this? I'd like to find out more about how these secondary throttles work.
According to the specs posted, these also seem to be the biggest throttles around as well.
Yes you are correct, those TBs from the 98-99 GSXR750 dont have secondaries.
However with regard to your main question, the secondaries are there to help control the airspeed in the inlets, just like a slide in a CV carb does. They are controlled by the main suzuki ECU and operated by a stepper motor (I believe its a stepper motor). Thus far most people seem to agree that there is more to be gained by removing the secondaries and their shafts, than leaving them in (even in their stock applications like the GSXR series of bikes that now come with them).
Devilman wrote:
Yes you are correct, those TBs from the 98-99 GSXR750 dont have secondaries.
However with regard to your main question, the secondaries are there to help control the airspeed in the inlets, just like a slide in a CV carb does. They are controlled by the main suzuki ECU and operated by a stepper motor (I believe its a stepper motor). Thus far most people seem to agree that there is more to be gained by removing the secondaries and their shafts, than leaving them in (even in their stock applications like the GSXR series of bikes that now come with them).
Hope that helps.
You are correct!
Schematic of the GSX-R1000's SDTV (Suzuki Dual Throttle Valve) fuel injection system, which functions like a digital CV carburetor to tame the lurchy off-on throttle response encountered with earlier fuel injection systems.
Hi all, i've just gotten hold of two sets of 38mm (choke plate size) cbr 600 bodies for my 3.9 rover v8. The engine is in a relatively mild state of tune, do you reckon these will be big enough for it? I'm starting to wonder. . . . . Also, does anyone know if the injectors will be any good and if not if there is any direct fit (no mods required!) bigger injectors available for them? Thankyou all!
I've got the same TB's on my Dolly Sprint. Mine were sourced from a CBR954 and have bluey/green coloured injectors. These are currently making around 40-45hp per cylinder at just over 50% duty cycle....
-1988 325is BMW M52B28 - > MS2 Extra n Spark (60-2 Wheel, Wasted COP, Single VANOS)
-2004 Opel Corsa C / Holden Barina Z18XE - > MS1 Extra n Spark (60-2 Wheel, Wasted COP)
-1976 Triumph Dolomite Sprint Race Car -> MS1 n 'EDIS'd
-1984 C1 2.3 Alpina -> MS2 Extra n Spark (60-2 Wheel)