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I've Got Gas: New Projects w/ Pictures! :-) - Misc including parts cross references - The Lotus Forums - Official Lotus Community Partner Jump to content


I've Got Gas: New Projects w/ Pictures! :-)

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So my Fuel Project finally finished up last week after beginning it in

January with the purchase of new RC injectors.

The long wait was exclusively my fault, not any of the vendors, but

the results were certainly worth it!!

The entire fueling system was redone (sans tanks and fuel pump) and

some ancillaries were lumped on the "to-do" as well, including a

Michael's Motorsports Cam Gear and a bespoke Wind Splitter.

HUGE thanks go to **Kirt @ Hyper Sport Engineering** (who performed

all the work here in Atlanta) for going way out of his way to make

sure everything was done to an uber high standard.

Also, thanks go to **John @ WC Engineering** for answering dozen of

emails and for supplying a beautiful Ported and Anodized Fuel Rail.

Please click here for pictures and more details on the fuel project,

et al:

...and click here to see my new Wind Splitter (also installed by Kirt)

The car is still running the stock S4 code and is holding up great.

Idle is a little rougher but I definitely feel a tad more low end


Luke Colorado, Super Spy.   -  Lotus Owner No Longer

1987 Zender Widebody 560SEC | 1994 Lotus Esprit S4 | 2013 Honda Fit EV (#269)

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  • 2 weeks later...

I got my car dyno'd today to see the results of my recently completed fuel project.

On my previous run this January the A:F curve looked pretty consistent but it was 1-2 psi higher than desired.

I was hoping to have corrected this problem with an adjustable FPR, bigger secondaries, bigger fuel filter, bigger lines, etc.

Static pressure was set at 43 PSI.

The ONLY other engine mod I've done, really, is a turbo-back exhaust.

Here are the results:

(it's a big image)

As you can see the result was a LEANER MIXTURE and LESS POWER!!! WTF??

You can also see on the second run we increased static pressure 10 psi to 53. This helped on the low end but the results were similar above 3000.

Unfortunately, we couldn't log fuel pressure so we hooked up a mechanical gauge and one of the techs watched it. Apparently fuel pressure would rise to 55 PSI and then drop off. Increasing the static pressure did not change this behavior.

The turner was pretty sure that the fuel pump was busted or under sized but I thought it may be the FPR as I remember reading the OEM fuel pump was MORE THAN ADEQUATE.

Well, imagine my surprise when I read back though the service manual and saw that the OEM PUMP is only designed to supply 55 PSI max.

How is this possible??? How can that be enough???

If static pressure is supposed to be 3 bar, and if boost can hit 1-1.25 bar, that would mean fuel pressure would need to reach 58-62PSI to compensate!!

Why am I having so much trouble??? Most people run bigger turbos with the stock fuel system and I can't even run the OEM turbo with out going way lean.



Luke Colorado, Super Spy.   -  Lotus Owner No Longer

1987 Zender Widebody 560SEC | 1994 Lotus Esprit S4 | 2013 Honda Fit EV (#269)

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