I know that the GSXR 750 throttle bodies are commonly used, but will any others do? eg: 1000 or 1300?
Regards, Ian.
What capacity is your engine??
I believe that even the GSXR600 throttle bodies are 40mm or so in diameter and would be perfect for a 1600 or 1800cc engine.
It's a similar technique to sizing carbs' for an engine - you can go too big.
[Edited on 7/2/05 by JAG]
For my 2ltr vauxhall I went for 45mm as I'd heard 48mm would give more topend but would diminish the lower and mid range slightly. Larger
diameter for larger/heavier breathing/faster revving motors imho, same as carbs i guess!!
Ned.
I saw plenty of bike carbs 4 up at the kenpton park bike jumble last time,there is another jumble on march 5th (sat) so i'll check out some
prices and take some numbers if i see any.
Not quite Ned.
Carbs such as DCOE40 and 45 usually have a venturi fitted which reduces the inlet diameter downwards to approx 32-36mm. They are not 40 and 45mm,
only when venturi removed. The venturi is needed to increase air speed thru carb body past openings so that there is sufficient 'pull' on
the various fuel jets. Unlike injection which is forced fuelling.
TBs are straight thru or tapered by a couple of mm because they don't need the extra 'pull' with the injection.
Gixer 600s are 38mm tapered bore. Each one up has minor differences in design but larger bore by a few mm per increase in capacity bike. i.e.
750's are a couple of mm bigger than 600's and so on.
Rob,
Sorry I meant the size goes up as the revs/breathing characteristics of the engines goes up, I didn't mean the carb and tb sizes are directly
comparable, as obviously they're not.
Ned.
I run Jenvey 48mm bodies on my 2.016v XE grasser engine, and did before on the same engine fitted to my Opel Manta road car, with no problems.
I will be running 45mm Jenvey SF type bodies on my 7 when It's finished (got the bodies, got to finish the car!)
I don't think there is much difference between the two but I have a suspicion that I may be missing out on a bit of torque using the 48mm ones
and you lose some of the reflected pulse strength with the airflow on std cams.
[Edited on 7/2/05 by NS Dev]
theres a difference in torque production between direct to head and manifold/bodies on an XE , after i did some testing with my air trumpets on SBD dyno , the extra curve of the manifold i believe produces better torque , the ports are 40mm on a volvo head so 38mm bodies wouldnt be any good for me , ive got a few ideas coming that will rid the individual throttle bodies for good ! .
quote:
Originally posted by Volvorsport
theres a difference in torque production between direct to head and manifold/bodies on an XE , after i did some testing with my air trumpets on SBD dyno , the extra curve of the manifold i believe produces better torque , the ports are 40mm on a volvo head so 38mm bodies wouldnt be any good for me , ive got a few ideas coming that will rid the individual throttle bodies for good ! .
sorry , i should say it was QED dyno that i was mucking about on , i had some curved airhorns that would be ideal for use in kit cars etc , i think i sold one set to a guy with a turbo gixer - such is life . It was around that time that i did the testing aswell , i remember talking to ken about it .
quote:
What capacity is your engine??
I just got some 2003 GSXR 600 T/Bs off ebay for £86+£10 p&p. Arrived quickly. Same guy now has some 2004 GSXR 600 T/Bs on there.
Ben.
GSXR 1300 are 50mm ID. Too big I suppose?
TIA Ian.
Ian
As i said earlier i'll have a look for GSXR 750's at the motorbike jumble on march 5th here at kempton park,if i find anything i'll
give you a call
Thanks Bob. Had my head firmly where the sun doesn't shine!