k04-023 hybrid and high flow manifold fuelling ?

[DaveV6]

Ive been wondering for some time if us hybrid k04 chaps will need bigger injectors than the bam 225 o.e ones when we fit the new high flow manifold from ina or jbs and though ive asked on the jbs thread they havent answered, so we can only assume no one knows for deffinite yet.
Mines currently making 301 bhp at 1.5 bar on bam injectors with standard 3 bar fpr but they are pretty much at their safe limits according to my tuner.
So questions.....

If i was to just fit the manifold without upping boost, would i require new bigger injectors or would a 4 bar fpr be sufficient.

will we deffinitely need 550cc injectors when fitting the new manifold and upping boost a few psi to 1.6-1.7 bar or will a 4 bar fpr be sufficient ?

It looks like the manifold will give 20 bhp on a hybrid so that would put me at an honest 320 bhp which i would be happy with, so is it worth the extra cost of injectors and re mapping and more psi being pushed through the turbo to make 330 + bhp ?
Imo at 1.5 bar the hybrids have proven relaibility, will pushing them up to 1.6-1.7 bar compromise them in the long term??

Cheers

Dave

 

[wild willy]

Ive been wondering for some time if us hybrid k04 chaps will need bigger injectors than the bam 225 o.e ones when we fit the new high flow manifold from ina or jbs and though ive asked on the jbs thread they havent answered, so we can only assume no one knows for deffinite yet.
Mines currently making 301 bhp at 1.5 bar on bam injectors with standard 3 bar fpr but they are pretty much at their safe limits according to my tuner.
So questions.....

If i was to just fit the manifold without upping boost, would i require new bigger injectors or would a 4 bar fpr be sufficient.

will we deffinitely need 550cc injectors when fitting the new manifold and upping boost a few psi to 1.6-1.7 bar or will a 4 bar fpr be sufficient ?

It looks like the manifold will give 20 bhp on a hybrid so that would put me at an honest 320 bhp which i would be happy with, so is it worth the extra cost of injectors and re mapping and more psi being pushed through the turbo to make 330 + bhp ?
Imo at 1.5 bar the hybrids have proven relaibility, will pushing them up to 1.6-1.7 bar compromise them in the long term??

Cheers

Dave

Assuming that these manifolds actually arrive in 2010 - 2015 and actually show a performance gain fueling will need to be checked. I'm running my hybrid 1.55 bar peak - 1.35 bar at the line. I'm running 4 bar reg simply because at 3 bar the injectors are in excess of 95% Duty cycle which ain't good. The 4 bar reg isn't ideal though as its putting extra strain on the pump. Ideally i'd like to go 550's @ 3 bar not only for the extra headway they give the fueling but their spray pattern is very good as well. A custom map will be desireable but i may homebrew it and proportionally reduce fueling with lemmiwinks. I wouldn't push the hybrids any harder as i want long term reliability.

 

[Mook]

Dave, there's two reasons for going to Genesis 550s - the first is that you can just leave the fuel flowing at 3 bar and the second is because of waaaay better spray pattern over the stock injectors.

It's £300 for a set of four. Just do it

I realistically don't think you're going to get an extra 20 bhp with the JBS manifold. I know you've run yours past 300bhp (307 IIRC), so the engine's got it, so you may make 320 total, but not 327, if you see what I mean.

Or are you worried I might catch you on track...?

 

[DaveV6]

im chuffin brickin it mook,lol.

my car has an uprated fuel pump does that hold any sway for just fitting a 4 bar fpr and re mapping on the same boost.?

Dave

 

[Mook]

All the fuel pump is doing is delivering enough flow of fuel - the FPR is the key in maintaining constant pressure.

When it's remapped, you'll soon find out whether it can flow enough fuel from the AFR (air fuel ratio) and EGTs generated. If the injectors can't flow enough at the top end of the rev range, it'll start running lean when the map's first set up, so the map will be adjusted for that.

Actually, thinking about it, just leave the standard TT225 injectors on it. Genesis 550s are a really bad idea - you don't want those. In fact, what you need is some Polo 1.4 TDI diesel injectors - the ones off the 75bhp version. Those'll work

I need some kind of advantage over you - other than beating you in the handsomeness stakes

 

[ibizacupra]

just remember when upping FPR that pumps delivery volume can drop if not rated to those pressures... and without knowing what fuel pressure you actually run, its guesswork on if the fuel pressure is dropping as the revs and boost/hence fuel requirement goes up..
Rising rate regulators... to start them at 4bar, and run 1.6bar boost the pump is being asked to pump its delivery volume at 5.6bar pressure.. check its specs to be sure it can, else it can sag and then its ends badly.

(been there, done that when 1st IHI'd - Bruntingthorpe, 2 mile straight on Vmax run. Pump sagged from its 4bar and melted #3 piston and damaged the valves) a "learning experience" for everyone involved at the time..

 

[Mook]

Thanks for that Bill.

If Dave was running a 3 bar FPR and 550 injectors, what after-market fuel pump would you recommend?

 

[wild willy]

Sound advise as always, thanks Bill.