Hey, what is the fuel injector rated at for flow?

What pressure if anyone knows that?

I have searched, but so far nothing.
thanks

Hi everyone!

The ORIGINAL OEM injector is the BOSCH 0-280-158-325. It features 4 holes for better spray pattern.

I've been unable to obtain the data sheet. If anyone can obtain reliable flow data I can do the math... For the stock 44hp engine, let's suppose a 290cc/min injector flow should be enough. For a 50hp target power (after "customization") engine,l injector should flow 328cc/min (31 lb / hr).

But injector flow depends on fuel pressure. For example: let's supose KTM OEM single injector flow to feed a naturally aspirated stock 44hp engine, considering 80% duty cycle you will need njector flow of 290cc/min @ 3.0 BAR (27.5 lb/hr @ 43.5 PSI).

At 3.2 BAR (46.41PSI) the same injector will flow 300 cc/min (28 lb/hr). 3.5% flow increase.

At 3.5 BAR (56.76 PSI) the same injector will flow 313 cc/min (30 lb/hr). 8% flow increase.

At 4.0 BAR (58 PSI) the same injector will flow 335 cc/min (32 lb/hr). 15.5% flow increase.

As I said, for a 50hp target power (after "customization") engine, injector should flow 328cc/min (31 lb/hr).

With better fuel atomisation, better idling and better driveability at low revs.

All of you considering bigger flow injector, piggyback boxes, autotune, map swapping or ecu repro just to avoid eventual lean conditions after decat pipe, exhaust tube wrap, airbox lid, slip on "akrapovic" etc. may consider instead, replacing the original 3.0BAR fuel pressure regulator by another one rated 3.2 or 3.5 or 4.0 BAR (depending on how aggressive is your bike's "customization").

This will let the stock ECU do the closed loop adjustment via stock lambda O2 sensor readings. Open loop (idle, accel transient and wide open throttle) only needs to be slightly on the rich side of lambda to make power and grant engine integrity.

It's a cheaper option for a street bike and "only" requires to disassemble the fuel tank, extract the fuel pump assembly, and do the fuel pressure regulator swap... Can this reduce the lifespan of the fuel pump? Maybe. How many aftermarket hi flow fuel pumps can be purchased with the cost of a piggyback ECU plus Dyno runs, more than six, more than ten???

Having the right amount of fuel granted will be only half the work done. The ponies always hide behind ignition advance map. Avoiding lean moisture conditions will allow to use slightly aggressive ignition advance Map. A cheaper approach option would be improve faster flame propagation inside the chamber using an Iridium sparkplug. With the fuel tank removed it is easy to change the OEM spark plugs by the NGK LKAR9BI9 (Iridium, substitutes stock Bosch VR6NEU).

This is why without changing anything else in the bike, after piggyback fuel management boxes upgrade, most of the times without ability to control closed loop, driveability remains crappy. And the open loop side only improves the mid range RPM, but piggyback ECU are unable to improve WOT due to phisical lack of fuel when exahust and air intake are improved without increased injector size or increased fuel line pressure.

Regards!

 

Hi everyone!

The ORIGINAL OEM injector is the BOSCH 0-280-158-325. It features 4 holes for better fuel atomisation.

I've been unable to obtain the data sheet. If anyone can obtain reliable flow data I can do the math... For the stock 44hp engine, let's suppose a 290cc/min injector flow should be enough. For a 50hp target power (after "customization") engine,l injector should flow 328cc/min (31 lb / hr).

But injector flow depends on fuel pressure. For example: let's supose KTM OEM single injector flow to feed a naturally aspirated stock 44hp engine, considering 80% duty cycle you will need njector flow of 290cc/min @ 3.0 BAR (27.5 lb/hr @ 43.5 PSI).

At 3.2 BAR (46.41PSI) the same injector will flow 300 cc/min (28 lb/hr). 3.5% flow increase.

At 3.5 BAR (56.76 PSI) the same injector will flow 313 cc/min (30 lb/hr). 8% flow increase.

At 4.0 BAR (58 PSI) the same injector will flow 335 cc/min (32 lb/hr). 15.5% flow increase.

For a 50hp target power (after "customization") engine, injector should flow 328cc/min (31 lb/hr).

With better fuel atomisation and better idling.

All of you considering bigger flow injector, piggyback boxes, autotune, map swapping or ecu repro just to avoid eventual lean conditions after decat pipe, exhaust tube wrap, airbox lid, slip on "akrapovic" etc. may consider instead, replacing the original 3.0BAR fuel pressure regulator by another one rated 3.2 or 3.5 or 4.0 BAR (depending on how aggressive is your bike's "customization").

This will let the stock ECU do the closed loop adjustment via stock lambda O2 sensor readings. Open loop (idle, accel transient and wide open throttle) only needs to be slightly on the rich side of lambda to make power and grant engine integrity.

It's a cheaper option for a street bike and "only" requires to disassemble the fuel tank, extract the fuel pump assembly, and do the fuel pressure regulator swap... Can this reduce the lifespan of the fuel pump? Maybe. How many aftermarket hi flow fuel pumps can be purchased with the cost of a piggyback ECU plus Dyno runs, more than six, more than ten???

Having the right amount of fuel granted will be only half the work done. The ponies always hide behind ignition advance map. Avoiding lean moisture conditions will allow to use slightly aggressive ignition advance Map. A cheaper approach option would be improve faster flame propagation inside the chamber using an Iridium sparkplug. With the fuel tank removed it is easy to change the OEM spark plugs by the NGK LKAR9BI9 (Iridium, substitutes stock Bosch VR6NEU).

This is why without changing anything else in the bike, after piggyback fuel management boxes upgrade, most of the times the top speed remains the same, although the mid range RPM (factory leaned to reduce emissions) behavior gets improved.

Regards!

Hi Everyone,

BOSCH : 0 280 158 325 Static flow rate at 3 bar, medium N-Heptane: 172.2 g/min; Resistance: 12 Ohm;
density of gas I think will be around 0.7g/cm3 => 246ml/min (a little bit small? )
For your reference

 

If I'm not wrong the pressure is 2.6bar until 2016 and 2.9 from 2017 and ahead.
The values are in the test procedure of fuel pump at service manual.
The flow of injector at 100% duty cycle I already got but I forgot and I can't remember where is the information.
I'm getting older.
Try to look at rc390 forum that has someone that made a performance kit with a bigger injector and they know the value for the oem.
https://www.rc390-forum.com/forum/ktm-performance/266-engine-kit-progress-9.html
Are you trying to improve the performance, who knows a little turbo?
Luis

 

KTMasean, no, I couldn't find it there as I don't know the exact model of injector. So many they make

LNICK, thanks, yea, I looked thru there but couldn't find the size. I messaged Chad about it.

THought of turbo, yes, but with 12.6:1 compression, a full rebuild would have to happen first. Then I suspect, even after one got all the plumbing sorted out and it was working well, the clutch wouldn't be a happy camper. Probably other things would go boom too. Going from 30lbs/ft to 75 or so would require more strength.

No, I'm just after the size so I can have an edjucated starting point for a map with the next size larger injector if I go that way. If you do a full exhaust system and one of the intake pipes, with open air filter and a properly mapped ECU, the stock injector runs out of juice around 7000rpm. Apparently, its a huge change in power and torque, and if you use the bigger injector and map it correctly, that huge change goes all the way up past 11,000 rpm! Somewhere in the 8hp range!

I don't run the Power Commander, but do run the Rapidbike Evo. I can map myself as I am fairly familiar with different ECU mapping systems, but they help out people who use PCV. No info for Rapidbike yet.

 

LNICK, yes that's the upgraded one that I plan on using, but I still don't know the original size to compare.

 

I´m using only my memory so take care since I´m getting older.

For the 44HP at the crankshaft using natural aspiration the calculated flow using 2.6 bar and 90% of duty cycle gave me around 275 cc/min.

For 65HP Turbo charged with a pump of 2.9 bar and keeping 90% of duty cycle I got around 462 cc/min.
I will look for an injector around 500 to 550 cc/min since the gas here in Brazil is E27.

Here is a online calc for injectors that could help you.
https://fuelinjectorclinic.com/flow-calculator

Luis

 

Great question, I have yet to find anything either.

 

Have you checked on the Bosch website for injectors of this model?

 

Turbo has been done already,
https://www.ktmduke390forum.com/for...m.com/forum/engine-technical-discussion/23714-turbocharged-60hp-duke-390-a.html

 

looks interesting. Not quite done yet, at the time of that posting at least.

Chad had some cautionary words, as did another poster. Echoing mine.

If they had a fully tested long term bike, and the kit was reasonably priced, I'd give it a go. $2000 Euro is NOT reasonably priced...

 

Can find it now but apparently, there is an Italian guy/firm that does/did them.
Will post here if I find it again.

 

https://www.facebook.com/BragagnoloNicola/

Company, who we are and our products - Performance Technology
I´m thinking in a small turbo in the future. Why?
1 - I´m an engineer and love this kind of mod. All mods in my bike were made by myself.
2 - It can create a performance equivalent of 600cc with the size and fuel mileage of a smaller engine. The efficiency will be much better in technical vision.
Luis

 

https://www.motorbeam.com/ktm-rc-390-and-yamaha-r3-turbocharged-by-italian-tuning-firm/

 

I'm running into the same issue as you, I was working on the MAP for a while on my PCV and hit a wall. From the 80-100% range of throttle it won't drop under 13.8 AFR. I'm guessing the limitation is due to the PCV's range and injector sizing, I imagine a slightly larger injector and some Mapping would resolve all of this and get it down to a nice 12.0-12.3 AFR at WOT range.

 

1jzsupra, if you run a full exhaust system, and a really good intake setup including a very open pipe from the throttle body out, such as the one at Grey Area, you will run out of injector, even with a full dyno tune on a PCV. But you have to have all the flow. Even the good intake piping, and filter, but if the airbox has the lid on, it will be ok. There is a thread on it.

I don't have a dyno guy close, nor do I want to pay for it, so I want a starting point, so I need a stock size to do the math with.

KTMasean, yea, same stuff as before. that post is from 2016. no where that's got anything nailed down, no fleet of them with it running, no place to buy the kit or parts of the kit.

 

Just to help.
RC 390 Injector

 

This is my complete recipe to budget performance:

My KTM 390 Duke, Adventure & Husqvarna 401...

Hi everyone! This is my full recipe for real engine performance with contained costs and an eye on minimize knocking issues... You will need all this material and do the installation following this order: 1.- Fuel Pressure Regulator: 3.5 Bar or 4.0 Bar 42€ 3,5 BAR KTM 390 Duke Bajaj 17-...

www.ktmduke390forum.com

 

He Alf,

Posting it 1x is enough and as Ede mentioned on the other thread where you posted the same, please post before and after dyno graphs.