I am running 630cc/min injectors at the moment and have a very low 'req fuel' and small values in the fuel map around idle and cruise.

I know the minimum repeatable opening time for my injectors is 1.391msec and my idle and low speed pulsewidths are under 1ms which leads to me having to run slightly rich at idle (according to my now broken LC-1) and slow engine speeds to compensate as otherwise I get lean misfires.

The MOT may be interesting tomorrow if I do need an emissions test as I dont think I will be able to get it under the limit - though its only a hunch.

I could get away with running smaller injectors as I am not anywhere near maxing out on the ones I have. Max pulsewidth is 7.2ms at peak torque and 1bar boost.

If I do go smaller then I guess its another remap

Anyway - what size injectors are other people with ~300bhp and forced induction running?

Thanks,
David

quote:

---

Originally posted by flak monkey
I am running 630cc/min injectors at the moment and have a very low 'req fuel' and small values in the fuel map around idle and cruise.

I know the minimum repeatable opening time for my injectors is 1.391msec and my idle and low speed pulsewidths are under 1ms which leads to me having to run slightly rich at idle (according to my now broken LC-1) and slow engine speeds to compensate as otherwise I get lean misfires.

The MOT may be interesting tomorrow if I do need an emissions test as I dont think I will be able to get it under the limit - though its only a hunch.

I could get away with running smaller injectors as I am not anywhere near maxing out on the ones I have. Max pulsewidth is 7.2ms at peak torque and 1bar boost.

If I do go smaller then I guess its another remap

Anyway - what size injectors are other people with ~300bhp and forced induction running?

Thanks,
David

---

Yes, I could do it, just need to check with Omex how to though

Again, another remap. Or if the emissions are OK I could just live with it as I am not too fussed as I get over 30mpg on a run anyway.

Its only the idle and very low speed 30mph in 5th in traffic where it causes problems as the throttle opening is under 2%

I'm running 525cc injectors at around 280 bhp. Haven't dyno'd it yet so I'm guessing bhp from duty cycle and performance. The dc gets above 85% at around 11:1afr so theres nothing left!
How many injections per cycle are you running?

As far as I know its set up to be semi-sequential...

I have asked the same question to Omex anyway.

I know people do run mahoosive injectors on cosworths etc, so its doable with some compromises. I just hate compromises!

525cc injectors shoud be good for about 350bhp subject to fuel pressure

im running 760cc injectors on the sr20 and its a bit rich on idle but the car it was removed from passed mot's with this setup, car was K reg and had no cat fitted

would lowering the fuel pressure help for the MOT? That way you could have a trick map for the MOT, and then you can raise your pressure again and go back to your normal map.

Just a thought.

What MOT requirements do you have to meet?

Matt

I got a good idle with 420cc injectors.
Homemade ecu 0.05ms resoloution.
Being 6 cylinders it means you get more power with lower flow rate injectors.

Darren

You might not need a complete remap if you fitted smaller injectors - make a global % reduction change to the injector map and just keep an eye on the AFR for a while.

My ecu has 0.01 resolution, thats not the problem - its the fact that the injectors are under their minimum repeatable opening time thats causing the issues.

Will wait and see what I get at the MOT later