gsx1300 throttle bodys

i've head alot of people talking about these gsx bike throttle bodies but why? why is it only these that are any good. are they a straight fit for bosch injectors.... do they fit the 16v manifold?

Cheers

Vduber

 

No, and no. My injectors wouldn't seat in the bodies quite right, the inner opening isn't quite wide enough. That said, I haven't tried them with the pintle cover removed from the injector. I'm not sure if the original fuel rail will fit over them either, i'll have to look.

You'd also need to make up a custom manifold to mate the odd shaped ports in the head to ~50mm round openings for the bodies. The bodies also need spacing out a bit further than they come.

The GSXR bodies are popular because they're common, and because they are actually four totally separate bodies, so they are much more flexible for different fitments.

 

so wots the diffrence between the gsx1300 and the gsxr????

might be easyer to just buy some throttle body housings than mess around with these.

Vduber

 

'busa bodies are bigger (45mm at throtttle plate compared to 42mm for the gsxr750/1000)

 

There's also a size difference between GSXR750/1000 bodies themselves depending on year, can't remember off hand but I did all the research before, around 99/00 maybe. Something like 52 taper to 44.

 

If 'proper' 45mm Jenvey bodies only gain a bit of extra torque/driveability to a mechanically similar 2 litre 16v 9A with Schrick 268/276 cams and no extra power it makes me wonder whether it's worth bothering with these bike TBs.. Two cars @ Stealth yesterday..

plots
Edited by: GVK

 

They're a whole lot cheaper. Actually, prices seem higher than a few months ago where you could pick them up for ~100 now they seem to go from 125. That's bodeis and rail.

 

I know they're cheap Ed, and it might be a challenge fitting them making them work, but at the end of it, what will you achieve?

 

I'll have learnt a lot about engines/engine management, and i'll have a 'bit more torque' to boot, all for a not unreasonable sum. There may be slightly more gains to be had by buying 'proper' kit and paying someone else to do it, but that's just dull and not what i've set out to do. If I end up with decent figures it'll be a bonus.

And they sound so cool

 

It's not really clear from the link what cars are on TB's, to me anyway . What sounds best tho?

 

but at what cost

 

my bodies cost me less than a dump vvalve for a 1.8T - go figure

 

The 1st plots on the page

B6 MKD is on Badger5 45mm DTH bodies and H909 is a very similar engine, same head, 268/276cams and also 9A but on k-jet...

I love the sound don't get me wrong
Edited by: GVK

 

Thank's GVK, that does make interesting reading!

 

Gary, have you not been out in my old car yet?
Ian drove it at the last rolling road day at TSR and commented that he would like a similar set up on his car if it wasn't for the cost involved. Remember it's how it drives that counts and the car felt much better after doing the conversion than the figures show.
A k-jet engine feels lazy in comparison due to the much improved throttle response with the itb's which i find also improved the handling of the car.
How many times have these 200bhp k-jet cars been tuned in the last year to keep them there?

 

There aren't many n/a engine mod's that give 8% more torque between 1800 and 2400 rpm.

The post 6400 rpm parts of both curves is spookey, especially considering some of the comments about throttle body sizes on here v. recently!

EDIT: i can hear the knives sharpening! Lets settle on >7% more torque.


Edited by: mark25

 

Fair comment Matt, Graham said the same about comparing plots, it's what the car feels like on the road / track , No I haven't driven a throttle bodied car.

 

If you look at some of the Hondas like ITRs that run bike bodies most of them report noticeable gains on the butt dyno at least. The effect is not too dissimilar to what's been shown here before ie improvements in torque throughout the rev range and a much stronger punch at the top. As has been shown before it needs a decent level of tune and the right cam specs to make full use.

 

this worries me too GVK, i think that the tuned length on the bodies can't be helping, maybe different trumpet lengths, reflection plate, could sort it out

also it looks like chrismc has sock filters on, SBdevelopments showed a 25bhp loss when using them on an XE over a proper big filter

 

you will also need some sort of airbox if you don't want to go deaf bwwwaaaaarrrrrrrrrrrrpppppppppp