Jump to content
Click here to contact our helpful office staff ×

Injector Size Questions


I.Mupferit

Recommended Posts

Am I right in thinking injector flow rates are identifiable by the colour of the injector and is this an industry standard or is the flow rate/colour peculiar to each manufacturer?

I have seen injectors referred to by colour ie:- Green Cosworth for up to 'X' amount of power so was just wondering if that is how you identify the flow rate of that particular injector as they don't seem to have any other identifying marks on them.

 

 

Brent

 

Link to comment
Share on other sites

I believe the colour refers to the Bosch injectors that are prevalent across the industry. Weber Pecos are popular for race engines where packaging is tight and don't conform to such colour markings. I have seen a very long list of injectors published before now but I don't have a link.

 

In case you need to benchmark a flow rate for your target power, I was running my pecos (330 cc/min @3 bar) at 4 bar and 91% duty cycle to achieve 250ish horsepower. The effect of the pressure change would have made them equivalent to 380 cc/min. I uprated the fuel pump to the JPE item to keep them properly supplied at this pressure.

 

If you do the calculation of:

4 injectors

380cc/min

1.34l/kg

91% duty

250hp

 

You get close to the rule of thumb figure of 0.5lb/hour/hp although I have exceeded the recommended max of 80% duty cycle.

 

 

 

Edited by - Peter Carmichael on 19 May 2003 17:03:11

Link to comment
Share on other sites

Brent. I have a spare set of buff ones with a known flow rate at 50psi. These were on a 230'ish VX.

It ran different fuel gain to mine. Mine is set to 74. That was set to 120. Same injectors.

If you test yours and mine are 'flowier' then you can borrow them...

 

My racing pics, 7 DIY, race prep. Updated often here

Photo's of the year here

Hants (North) and Berkshire Area club site here

 

 

Edited by - stevefoster on 20 May 2003 08:36:15

Link to comment
Share on other sites

There are many other factors other than simply flow rate to consider when choosing an injector. Impedance, Spray pattern and fequency that they can be switched on and off. If your considering Bosch injectors then try their technical Help line . In general if you want high capacity injectors then look for injectors off a turbo car. The reason being that the injector is being fired into say 1 bar pressure within the manifold and therefore requires a greater capacity over its NA counterpart to flow the same amount of fuel.
Link to comment
Share on other sites

I hadn't realised that injector selection was so involved!

 

Steve, depending on how it works out over the next couple of days testing, maybe I could borrow your injectors please to compare alongside my present ones. What exactly do you mean by the fuel gain on the injectors?

It seems I have a lot to learn about this injection lark.

 

BTW, I have the NBPS back so I can drop that around to you this week together with the pressure gauge

 

Brent

 

Link to comment
Share on other sites

The fuel gain is a setting in the MBE FI management system. Not sure exactly how it works.

But by deduction an engine in a higher state of tune using the same injectors had a higher setting. So increasing it should fuel more or for longer since injectors are binary.

 

If there is a similar one in the Emerald system (someone here must know).

 

You are welcome to the injectors anytime until the next race meeting (7th June) as I take them as spares...

 

My racing pics, 7 DIY, race prep. Updated often here

Photo's of the year here

Hants (North) and Berkshire Area club site here

 

 

Edited by - stevefoster on 20 May 2003 10:50:22

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...