Raising fuel pressure.

[pingpong]

Next on the list - would like to raise fuel pressure to circa 5 bar. Fuel rail is Jenvey item with braided lines / mocal fittings etc. Stock injectors.

Vehicle has a fuel tank without a return it seems so my belief is that an additional pump can be installed in series post OEM pump to generate the pressure required.

The secondary pump will have its own relay / fused circuit and will be run off the same ECU output for on/off. Is there anything else to consider or that I have missed? There has never seemed to be a requirement for a swirl pot on the car in question; so although this would be a good opportunity for its addition it may be over complication...

Your thoughts please...

Many thanks.

 

[Laine_16v]

Save yourself a whole load of hassle for the small amount of flow you will gain and buy bigger injectors??

 

[scotty2hotty81]

Why when your running stock injectors? If you want a uprated pump Bosch 044

 

[Dan519]

as above, just buy bigger injectors. Megane 225 items are ideal

 

[pingpong]

Thanks you for your input. Stock type/volume injectors are being retained for resolution during mapping at the suggestion of the company involved.

Many thanks.

 

[Chip-mk1]

Thanks you for your input. Stock type/volume injectors are being retained for resolution during mapping at the suggestion of the company involved.

Many thanks.

They will lose resolution anyway when you wind the fuel pressure sky high.

I cant think of any valid reason for wanting to run that much fuel pressure on a 172 injector if that is what you are referring to? If so just go megane injectors instead, they are still capable of passing emissions tests as they are a high resolution injector anyway and designed for a 2 litre engine in the first place.

Who is the company? They sound like they dont have a clue TBH, but maybe I am making some unfair assumptions so I would be keen to hear more of the story.

 

[BIGASH]

Thanks you for your input. Stock type/volume injectors are being retained for resolution during mapping at the suggestion of the company involved.

Many thanks.

I would recommend to change them after lots of advice I have had recently! Although I was advised a year ago not to by one company. I would presume they are the same company

 

[pingpong]

Sorry I won't be mentioning company names - forum politics are of no interest.

Thank you for the detailed reply, very helpful.

 

[Fred@BTM]

what engine spec is it? no point doing anything really unless the engine requires it

 

[Chip-mk1]

Sorry I won't be mentioning company names - forum politics are of no interest.

Thank you for the detailed reply, very helpful.

Ive no interest in politics either, just trying to help you out and the more we know about what you are doing the more we can help you.

With regards to a swirl pot, be careful about the fact that if you are adding this to a phase2 172 using the standard setup as a lift pump (again I am guessing as you arent telling us anything about your car so we can be more accurate with the nature of our replies!) then the entire swirl pot will end up at 3 bar off pressure, and thats a lot of fuel to have at that sort of pressure in the event of an accident etc.

 

[pingpong]

Ok fundamental information that will help you guys advise.

Originally a Clio 182 road car.
Jenvey ITBs, fuel rail & ITG filter element.
High compression pistons.
Forged conrods.
Balanced throughout.
Valve springs
422 CatCams with VVT.
Headwork of some description; TBC.
Alternator & waterpump are only Aux Losses.

Advised based on expected output that stock injectors will be at their limit; even with the compression ratio increased. I can't tell you exactly what the compression ratio will be at the moment.

Any advice appreciated.

 

[Dan@SJM]

Deffo go megane injectors, Mine was max'ing out OEM injectors on stock compression and 421's.

 

[Fred@BTM]

yep you have no chance with stock injectors, megane or 043's

 

[pingpong]

Ok thanks. So based on the above: stock fuel pressure & replacement injectors.

Fred; 043's - Can you provide more information? Picco?

 

[Chip-mk1]

Raised fuel pressure on the standard injectors will probably work, but its messy, it gives the pump a harder life, and its just generally considered bad practice.

For your spec a set of megane injectors would be ideally suited IMHO

 

[Dan@SJM]

yeh Pico 043's are 380cc/min(IIRC???)

Edit, a quick google suggests they are 330's

 

[pingpong]

Thank you everyone. Very helpful.

 

[Fred@BTM]

Yep Pico 043's which are now 162's i think (white band)

 

[Dan519]

Megane injectors are ideal because of their spray pattern and fantastic atomisation. Injectors of the same flow rate such as pico yellows have a pencil jet spray which makes they very hard to control at lower rpm so resolution becomes an issue. With the megane ones it's not a problem

 

[pingpong]

Thank you all; I can't believe how knowledgeable this community is!

 

[Chip-mk1]

Lots of us have used the megane injectors and had good results thats all mate.

Bottom line is they are designed from the factory for a power output similar to what you want, and with the ability to pass stringent emissions tests, aftermarket injectors tend not to be, and increasing the fuel pressure although it increases flow can cause excessive puddling by firing the injector so hard it pushes the fuel onto the manifold walls more which leads to decreased atomisation as a result.

So megane turbo injectors get my vote over winding the fuel pressure up for that reason, but also in terms of reliability and the fact that you wont have to change the rest of your fuel system pointlessly which is just going to add more weight, add more potentialy points of failure, add costs, and take time.

 

[pingpong]

... in terms of reliability and the fact that you wont have to change the rest of your fuel system pointlessly which is just going to add more weight, add more potentialy points of failure, add costs, and take time.

Now you are talking my language!

 

[Chip-mk1]

Motorsport application then I take it?

 

[pingpong]

Yes chip, something along those lines!

If you could all take a moment to look at this thread and provide me with some advice that would be much appreciated:

http://www.cliosport.net/forum/showthread.php?663239-Race-engine-parts-configuration

Thanks again.

 

[pingpong]

Can I get a Renault part number for a suitable Megane injector please?

 

[Chip-mk1]

8200511099

 

[pingpong]

:star: