stock injectors tested

[glenn71]

the 255lph model.Its pretty loud but just sounds like an intank gear supercharger.

[Oz Booster]

Upgraded your fuse to 15 amp yet ??

[glenn71]

Not yet.I drilled out and bypassed the internal filter today and fitted a 6L chev inline fuel filter(external).The flow went from 2.4L/Minute @49psi to 3.375L/Minute@49 psi.The pressure drop on the nose of the pump must be huge and should run alot happier now.The filter i bought cost 28 bucks,a bit cheaper than $450 from suzuki.And 15 bucks for fuel line.Hopefully with a bigger fuel rail hydraulic hammer should be kept to a  minimum and mapping it should be easier.

[glenn71]

I used the injector sizing/pressure calculators and my dyno results and worked backwards and worked out at the duty cycle i was at and the horsepower it was making the injectors were running at approx 35-37psi.With the original flow rate starving to the tune of about 1 litre per minute,based on around 246cc being used by each injector.Now with a tested 3.375L/minute tested at 49psi,I,m confident the injectors wont see a drop off from the regulators 52psi.The proof will be in the testing but I think a 300% improvement in flow should help.

[PetriK]

Very good data !

A couple of questions :

- Is the flow data from Walbro or stock pump ? (may be me reading not carefully enough)

- Have been trying to find out the Walbro 255 product code and a seller who delivers overseas. Any hints where to look at ?

ps. My problem is not peak torque or power, its sustaining the flow rate at higher rpms as the engine keeps up the power very well from 10000 - 11500.

edit - just remembered something to try out. Its cyl1 at the end of the line which starves first. How about moving the feed from between cyl3&cyl4 into middle of the tb:s - if possible should help the intank fuel delivery setup slightly ?

[sportbikeryder]

I use a GSS342   255lph hp  Not sure of a dealer who delivers overseas.

John

[glenn71]

yep its the gss 342 pump.I intend to run a bigger rail for the new motor setup.Petrik,just fit an inline pressure gauge to the fuel line,hot wire the pump and put some adjustable locking pliers on the fuel line until you get close to the cracking pressure of the regulator and measure the flow into a drum over a minute.I,m trying to see if i can keep at least a litre buffer between what the injectors need at the required pressure for the target horsepower and what the pump can deliver.This i,m hoping should help provide a more consistent pressure at the ramp up of flow when it opens.This should then give me closer to calculated horsepower from the injectors.Out of interest if everything behaves itself my current setups injector duty cycle should drop from 88% down to 73%,or put another way I,ve now freed up an extra 220cc of fuel Back at 88% or approx 40hp more fuel.

[dakinebusa]

BSFC is usually at a minimum at the torque peak at WOT.
It is mostly a function of cam timing.
A Flathead Ford gets about the same BSFC as a modern port motor.
BMEPs a different story.
You can always get a high BMEP by swamping the motor with fuel but it kills the BSFC.

[glenn71]

Duty cycle and air fuel didn,t change. :Approx 196 crank horsepower,55psi,stock injectors at 90% duty cycle.either the 100% duty cycle on the ecu isn,t really 100% locked open or the bsfc for a stock compression engine must suck..55+?I saw these injectors do 330cc per minute locked open at 50psi on a test machine.

[PetriK]

Duty cycle and air fuel didn,t change. :Approx 196 crank horsepower,55psi,stock injectors at 90% duty cycle.either the 100% duty cycle on the ecu isn,t really 100% locked open or the bsfc for a stock compression engine must suck..55+?I saw these injectors do 330cc per minute locked open at 50psi on a test machine.

How was the 100% duty cycle measured ?

I have always measured it from the fuel injector signal from an oscilloscope: The point when the signal goes flat is 100%.

On dyno when the injectors get fully locked out by the ECU usually the AFR drops a bit and then starts to climb up when the revs go up.

[Oz Booster]

PetriK how much difference is there between 100% on the oscilloscope and a/f variance.
My Innovate logs flatline on dutycycle but still have steady a/f, figure i have nothing spare 

[PetriK]

Depends on RPM. Around 10000 I recall vaguely about 1AFR point per 500-1000rpm when injectors maxed out. Would need to check that to be absolutely sure, but not much room to play. Its about year ago when I had this last time on a dyno. Luckily the VE goes down at higher RPMs so some of that is compensated by lower VE:s.

This year I experienced that on track using Innovate LC1 and DL32 and then changed the injectors. Innovate logs told me that, which the dyno could not. There may be some truth in innovates marketing which says that their fuelcell is faster than any other wide band lambda.

I dont measure duty cycle with Innovate. As I use a flashed ECU I can check each map on my workbench before goint to dyno for an exact out fuel amount per map cell with an (automotive) oscilloscope. May be a bit exaggeration, but its just to be on the safe side with my own engine.

[glenn71]

Injectors shut down when  they get to 100% on my 04 ecu.

[gazza414]

When you say shut down??..does that mean the F1 light pops a code or the motor shuts down ?

I 've had mine maxed on the dyno and same as Maj says...adding trims did SFA to a/f in order to fatten it up....you know ya going backwards then

[Busa Quick]

Very good data !

A couple of questions :

- Is the flow data from Walbro or stock pump ? (may be me reading not carefully enough)

- Have been trying to find out the Walbro 255 product code and a seller who delivers overseas. Any hints where to look at ?

ps. My problem is not peak torque or power, its sustaining the flow rate at higher rpms as the engine keeps up the power very well from 10000 - 11500.

edit - just remembered something to try out. Its cyl1 at the end of the line which starves first. How about moving the feed from between cyl3&cyl4 into middle of the tb:s - if possible should help the intank fuel delivery setup slightly ?

 I had good result in the US from these people.   http://www.fiveomotorsport.com/FuelPumps.asp



Mark

[glenn71]

the motor acts like a soft limiter where you don,t drop revs but you know your on some kind of rev limiter.Its happened around 8500 and around 9500 in the past.I saw it on the dyno again the other day around 9500.It just goes into a flutter a bit like valve bounce on a holden red motor.When i pull fuel out in that area it doesn,t do it.My bike always would show an fi  red flashing light whenever i hit the rev limiter as well.

[PetriK]

That FI light is interesting - when tuning by flashing the ECU I dont see FI light at all. I vaguely recall from testing that first every second pulse disappears and then the signal just becomes flat. When tuning ECU by reflashing it really locks the injectors fully open. With bigger injectors you just update the fuel pressure/injector parameter and it shortens the basic pulsewidth.

Anyway the maps between stock injectors and S2000 are different like day and night. At lower RPMs not much differences, but at higher RPMs S2000 can really deliver much more fuel. You can see the difference when you compare the stock injector and S2000 injector maps with ECUeditor.

Youre running a powercommander ? I guess that after a certain point PC can not anymore detect the pulses as there is none when injectors are locked open ? Does the PC then lock the injectors open - or what happens ?

EDIT, hope you dont mind adding this info how to see the differences between stock injector and s2000 maps in a 1397, 13.2:1 compression, brocks cams, akra exhaust. In both cases stock fuel pressure.

ECUeditor download: http://busaecu.redirectme.net

EU 1397 Stock injectors map: http://macmadigan.no-ip.com/Public/Hayabusa%20EU%201397%20with%20Brock%20cams%20and%20Akra%20Exhaust%2013-1%20comp.bin

EU 1397 S2000 injector map: http://macmadigan.no-ip.com/Public/Hayabusa%20EU%201397%20with%20S2000%20injectors%20Brock%20cams%20and%20Akra%20Exhaust%2013-1%20comp.bin

File open other map and set the other map as a compare map and you can see the differences on the fuelmap. Differences are coloured and difference as an actual figure is shown up right as +/- figure.

[Gnarbunkle]

My question to te the enlightened, do the injectors remain flowing for the full 720 deg of crankshaft revolution at all times?

[Gnarbunkle]

Page 4-15 of the workshop manual suggests otherwise, sequential injection at the exhaust stroke prior to inlet opening, from what I see in the illustration.

[PetriK]

Got the Walbro GSS342 - that is a bit long (5mm) for Busa - can fit it though. But GSS342 fits perfectly to ZX-14, so we swapped pumps with my friend, he had Bosch 0 580 454 032 which was a bit short for ZX-14 but fits perfectly into Busa. Both won ! That Bosch is for a 450HP Audi, so I guess its ok for an all motor Busa

The Bosch flows at Busa std pressure about 180LPH (measured) which is exactly the same as Walbro, even both manufacturers claim 250LPH. No filter, just plain tubing with adjustable regulator and 13.7V. Walbro takes about 14A to run, Bosch takes about 8A to run. The Walbro has a flowby valve which activates around 4.5-5bar so you can not run it higher than that.  Walbros flow at around 4Bar is significantly better than Bosch - anyhow Bosch blowby valve activates way higher up in pressure so it gives more adjustability for pressure.

Due to the installation easiness (only electric connector change and one white pastic piece cut) I would choose Bosch over Walbro again.

Then about the the stock pump. We measured 115-120LPH with std pressure, 13.7V. That is a very good flow figure. Anyhow it has one very interesting feature: At around 4.3bar the flowby valve is activated so you can not adjust pressure above 4.2bar without loosing pressure completely. The Busa stock pump in question is from K5 and manufactured by Mitsubishi.

When modifying the stock busa regulator with stock pump, around 4-4.2bar is absolute maximum. After that you start to loose the pressure because of flow by valve getting activated.

I am just wondering if the flow numbers are in line with others ? 180LPH vs 255LPH is a big difference. Have not checked that at which pressure the 255LPH was promised...

EDIT - When thinking now afterwards, I am pretty confident that we used 2.8bar instead of 3.0bar and did not check the voltage. We assumed 13.7V which is the spec for the power supply we used. Need to redo some of the tests just to confirm these points. Also the appr 14A for Walbro but only 180LPH indicates that there may be some serious restriction in the testing system ?

EDIT2 - Disregard the above flow figures, we just remeasured the testing system and confirmed that test system was accidentially set around 16V. Anyway the Bosch figure measured earlier and according to the manufacturer are  120LPH@5bar, 150LPH@4.3bar, so based on that Bosch is good for around 400hp@crank depending on voltage and injectors. I guess that Walbro flows around 160LPH@5bar. More importantly we need to measure the running voltage at pump in bike to be able to have more exact testing numbers.

[glenn71]

my walbro fits fine.yes the advertised flow rates are at 43psi pump pressure.The intank filter is massively restrictive,so if you measure the flow rate at 43psi in the fuel line you will get a much lower flow rate as the pump is seeing(depending on how dirty the filter is probably 100+ psi once you add the 43psi to run the injectors to the filters own flow restriction.I drilled out my filter and fitted an inline filter and got 3.4L/min at 55psi in the fuel line after the inline filter with the walbro pump.It must work as i just did a 9.24@148 with regular 150mph passes with a stock gen1 engine only with adjustable cam gears.

[PetriK]

EDIT - forgot to write the most important thing. Yes Walbro is about 5mm longer than the stock K5 Mitsubishi pump. It can most likely be shortened by taking some plastics off from the top end of the fuelpump and leaving the rubber out - but still very tight fit - where as the Bosch is exactly the same size and only requires only the bottom plastic retainer being modified just from one corner. Maybe Suzuki changed the fuelpump at some point if Walbro is a direct fit to some other models ?

Have you guys measured what is the voltage @ pump.  255L (67 US gallons) becomes soon 58 Gallons if voltage is dropped to 12.5 ?



To calculate the RWHP from 148..150, what is the weight of bike and driver ?

[glenn71]

I did my testing off a diesel truck battery.so 12 volts.My bike and rider weighed 305kg when i did those times and a simple horsepower calculator showed i went from approx 170 on a night meeting to 178hp at the tyre in cold dry morning air.

[PetriK]

Yes - sounds like the bike is around 170rwhp.

To have the fuelpump / injectors discussion on practical level I created a small table showing how stock and S2000 injectors have varying flow need from various pressure settings. I think that the key finding here is that S2000 require a fuelpump upgrade almost from start if you can get the duty cycles over 80% (which happens with my 1397 anyway). With nitrous and 1397 an fuel pump upgrade is mandatory.

With my 1397 i was able to get around 215true rwhp (* 1.125-1.2 = appr 250 dynojet rwhp) when the fuel pump was starting to give up. A clear indication was that the bike was not anymore reacting to the map changes. So I ended up running S2000 injectors  running 100% duty which should have given me close to 300rwhp with stock pressure. Checked the math that did not add up and figured out that I needed to upgrade the pump.

Luckily I did not decided to try out a higher fuel pressure, as the pressure is lost if regulator is set much over 4bar. Now I am running stock pressure again and a Bosch pump that should give me around 160LPH at stock pressure and still 120LPH at 5bar (if I ever need to get to the 400hp mark )

If I would have seen this table earlier, the pump would have been orded at same time with S2000 injectors. These figures are rounded numbers, not exact - but should give a good indication of the need for a fuelpump upgrade particularly with nitrous usage already.

[glenn71]

good info,i just took another tack by reducing the head pressure the pump sees versus what the injector rail sees by reducing the filter  restriction i can run higher rail pressure before bypass on the pump itself.I,m not sure what pressure the bypass is activated on a walbro,but in my case i will run blackbird injectors at 65 psi if the pump allows it.Hopefully i can still get a decent idle out of it.