I'm looking to replace the standard 240cc GSXR injectors with some bigger ones as these are going to be running at their max. I have found some 400cc injectors, will these be ok or are they a bit big.
The engine is a standard 2.0l silvertop at present but may get modified later on.

240cc will be ok on a 2 litre up to around 180bhp

400cc will also be ok on a tuned 2 litre up to around 280bhp NA. Should still idle ok too.

Don't forget if they're flowing too much resulting in poor idling you can (to an extent) always lower the fuel pressure..... assuming you have an adjustable fuel pressure regulator. That could easily take the 400cc down to circa 300cc which is about right Certainly you don't want your duty cycle to run at more than 85% otherwise you risk a high RPM / high load episode of lean running. Which would be bad

If you're going to modify the engine I'd look at getting the 400cc injectors and lowering the pressure if you were keeping the silvertop standard and just wanted a bit of "over-head" on the duty cycle I'd maybe increase the pressure a bit (though depends what bar you're running at present).

I had a perfect idle with 420cc injectors, v6 with an injector timimg resoloution of 0.05ms.

Darren

I am running the 240cc injectors at 3 bar. I told Troy at Northampton motorsport where it is going to go for rolling road that this was what I am using and he advised that they are going to be running at near maximum duty and may also have to turn the FPR up. This is not ideal so I want to find some bigger injectors.
I can't find any around 320cc which are the same fitting hence this thread to see if 400cc would be ok as I've found some of these.

i have 4 vectra sri injectors, but i dont know if they are any good for you??

what gsxr injectors are you using are they 600 ones? dont know if GSXR750 are interchangable as ment to flow 270 i think which should be ok @ 3-3.5 bar for a fairly powerfull zetec

I've got GSXr 1000 ones one the car if you need me to measure/compare? PM me if you do as I don't always keep track of threads on here...

[Edited on 23/3/10 by chasmon]

All Suzuki/GSXR injectors are the same capacity, right up to the standard Hayabusa injectors.

quote:

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Originally posted by flak monkey
All Suzuki/GSXR injectors are the same capacity, right up to the standard Hayabusa injectors.

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This is not a definitive answer, but these are the specifications on the KN4 Keihin injectors of the sort on the early gsxr (i.e. pintel type).

The 42.7psi quoted fuel pressure is remarkably similar to the Suzuki fuel pump regulator, so these may be the specs for our injectors.


keihin_k4_injector_specs

I have seen 240cc/min and 190cc/min quoted for the flow rates, but its only internet talk.

On a 4 cylinder N/A engine (using the factor of 4.6 from A.G.Bell), 191cc/min goes to 166bhp, and 250cc/min goes to 218bhp (in both cases ignoring the time for opening/closing).

Matt

[edited to add bhp calcs]

[Edited on 25/3/10 by matt_gsxr]

It seems that the s2000 and cbr xx injectors are the same form factor as the gsxr ones.



cbr xx forum link

the s2000 injector are 390cc/min
the injector from cbr 1100xx are 335cc/min


These numbers don't tie in with the table perfectly, but might be useful to someone.

Matt




[Edited on 27/3/10 by matt_gsxr]

According to Ron Ayers all these bikes have the same injectors:

Suzuki Part number:
15710-24F00

GSX1300R
X,Y,K1,K2,K3, 2004,2005,2006,2007

GSX-R600
2001,2002,2003

GSX-R750
Y,K1,K2,K3

GSX-R1000
K1,K2


So Dave (Flak Monkey) is right again.

I don't quite understand where the 190, 240 and 270 numbers come from, maybe different pressures.

The good news is that my engine is using more fuel (and hopefully making more power) than I previously thought, it seems to be using 154bhp (i.e. 85% of 180bhp) worth if that means anything.


Matt

I know this is becoming my own personal store of gsxr trivial but....


It turns out that Honda used these injectors in some of their cars (in addition to the s2000).

Other useful part numbers;
06164-PCA-000 Honda cr-v 97-01 2.0l
06164-PCB-000 Honda CBRXX1100 (obviously a bike not a car)
06164-PCC-000 Honda Odyssey
06164-PCX-010 Honda s2000


Honda Integra Type R seem to have had the same injectors at some point in its lifecycle, but I couldn't work out which year.

I don't know the flow-rates for these different versions.

Interesting if you are a GSXR TBI anorak!

Matt

just an addendum to this thread (somewhere to store random information).

The Hayabusa workshop manual for 99-2000 model has a fuel pump test that requires at least 468ml/30sec. This would equate to 234ml/min from each of 4 injectors.



The busa uses sequential injection so 1 pulse every 2nd cycle, opening times are 0.95ms (or thereabouts*) peak torque is at 8000rpm. Running those calculations with a flow rate of 249ml/min from the injectors yields 233.25ml/min actual flow. which would require a fuel pump of 466.5ml/min(close enough to 468 for me).

Anyway, some guesses in here, but it makes sense to me.

Matt


*from here http://injector-rehab.com/kbse/lag.htm using the s2000 for this value