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Hi,

So i have begun tuning, all going well so far. One issue i am having is that the car is going lean when full throttle up in the revs.
Wondering if this might be a fuel pressure/flow issue and maybe the filter and/or pump are blocked?

Below is the history and the map that was used.

Its a 355, H286 cam with stock intake and pacemakers on the stock HSV exhaust and a set of 28lb LS1 injectors.

Have you tried adjusting the injector rate up and dropping the whole VE by the same amount?

Try multiplying the injector rate by 1.15 and dividing the VE table by 1.15. That will give you another 15% to work with.

So thorugh the Kinjflow spreadsheet, i have a number of 0.103 (can you confirm i have that right?) should i change that UP to 0.118 and drop the whole VE table down?



Lb/hr 28
Cyl Size 0.72717
Fuel Type Petrol

Fuel Weight 0.7372
cc/min 287.1279123
g/s Value 3.527844949
KAL3 Value 0.141729585
BPC 0.103

raw Value 0.103061502
Kinjflow 0.103

Yeah, sounds about right.

I also had to add to the initial kinjflow value about about 10% on my builds too. I think the reason is the expected VE values are based on stock engines, modded engines will have a bigger VE range.

LS injectors are rated @ 58 lb's fuel pressure.
Increased pressure makes the injector flow more. If you're using 3bar, drop the 28 lb/hr to 26 (or thereabouts). There are charts that give comparable flow per pressure.
Use around 0.111 for Kinj/flow.
Get the injector data correct and then have at the VE table.
Looks like you sorted the 'enter new value' issues?
Did you upgrade the fuel pump.

'quipt4it wrote:LS injectors are rated @ 58 lb's fuel pressure.
Increased pressure makes the injector flow more. If you're using 3bar, drop the 28 lb/hr to 26 (or thereabouts). There are charts that give comparable flow per pressure.
Use around 0.111 for Kinj/flow.
Get the injector data correct and then have at the VE table.
Looks like you sorted the 'enter new value' issues?
Did you upgrade the fuel pump.

Did some Googling, at 43.5psi they flow around 25lb, so that is 0.116 on the Kinjflow, which is around 15% different as Vlad suggested.

I've use maffs to change my points down by 15% and i'll upload for my drive home and see how it goes.

Your 99% VE values look 'optimistic'.
As they say, highly tuned race engines can approach 100% VE and slightly higher if the intake and exhaust are highly efficient (and tuned).
Stock Holden manifold, I doubt it ha ha.
Work out where your peak torque figures are, then you can scale your table around those maximums.
Did you upgrade the fuel pump?
If not, you need to. Before tuning.

Mr DOHC wrote:Did some Googling, at 43.5psi they flow around 25lb, so that is 0.116 on the Kinjflow, which is around 15% different as Vlad suggested.

Yes, but with the wrong reasoning lol

They work out about 24lb and pretty easy to max out on a 304. What's the commanded fuel pulse width and duty cycle at in your logs

I don't think you have enough injector. May mates 355 with banana's and a smaller cam needed a better pump and 36lbs injectors, now with a COME intake manifold it's rich so I think we will end up around the 80-85% DC.

Here is what you might expect if you use 24lb/hr., for argument's sake, as your figure. Table courtesy of Fuel injector Clinic.