Does anyone know what bikes come with 45mm throttle bodies that can be easily spaced like the Gixxers. Also I guess it would be best to avoid those with electronically controlled secondary butterflies if not using the original ECU.

I really fancy TBs rather than thirsty carbs.

For an Alfa 75 motor if that helps at all.

- Jim

You need the throttle bodies from a GSXR 750 or 1000 from 2001, 2002 or 2003. These taper down from 48 to 42 mm. The secondary butterflies can be easily removed.

Do you think the taper to 42mm will make them lower flow than say webber 45s? I will be looking at c.200bhp performance are larger injectors freely available or would the standard ones cope?

I was thinking of a two pairs of carbs from a big twin (eg VTR) but dont know much about them.

- Jim

The throttle bodies have almost the same dimensions as some jenvey 48mm tapered bodies and surely flow enough for 200 bhp. The injectors are probably also enough for 200 bhp. Standard bosch injectors won't fit, but you only need to drill the hole a little bit bigger to make these fit.

i have gsxr 750 tb's the ones that dont have the second butterflys and the injectors are the same as some model subarus and are a direct upgrade


Description

also the ones with the second butterflies are no problem they are easily removed and the holes blanked

Excellent thanks guys.

Hi Jim the zx12 are best ones 48mm down to 44mm and splittable and if you would have rung me around 10 am today were in stock but sold them to a mr luben today
also the sp1 honda v twin are a massave 62mm down to 58mm with twin injectors
but you would need 2 sets i have 1 set for £77 delivered if you want these

cheers malc 07960011585

42mm TBs will flow more than 45 webers. The webers will have chokes fitted which will be less than 42mm. Standard 750 injectors with raised fuel pressure will be good for around 200bhp but I guess they will be running close to max duty cycle. Scooby ones sound like a better option for higher flow requirements.

quote:

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Originally posted by liam.mccaffrey
i have gsxr 750 tb's the ones that dont have the second butterflys and the injectors are the same as some model subarus and are a direct upgrade

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quote:

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Originally posted by TangoMan
42mm TBs will flow more than 45 webers. The webers will have chokes fitted which will be less than 42mm. Standard 750 injectors with raised fuel pressure will be good for around 200bhp but I guess they will be running close to max duty cycle. Scooby ones sound like a better option for higher flow requirements.
Personally I wouldn't go any bigger than 42mm as these will be capable of well over 200bhp and already will be too big for low end running (if this matters to you!!)

I would hope I am running around 185-190 bhp on GSXR 750 TB's and injectors and feel 600 TB's might have been better for road use.

quote:

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Originally posted by liam.mccaffrey
i have gsxr 750 tb's the ones that dont have the second butterflys and the injectors are the same as some model subarus and are a direct upgrade

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Liam you're a star. Do you know which scooby the injectors can be sourced from.

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My query was more about which direction to go with my Alfa GTV either a 2ltr ts 75 motor with race cams, overbore, pistons and 45 throttle bodies. Or just go Nissan SR20DET and smile sweetly at the Alfa officianardos

I am not a real fan of carbs and would rather go FI.

Thanks

- Jim