Thread: Alternatives to 14CUX for a D1

800 CFM Performer Series Carburetor Manual Choke

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Seriously though the 14cux is quite simple and the problem you are having could be a simple fix, too. There are some good used systems about like an earlier Motec and Wolf 2d which iirc doesn't have spark control. The lack of airflow meter on the Motec and Haltech is a great advantage.

Jc

I threw mine and went a nice Haltech...
I went further and locked the distributor timing static and used the ECU to control spark timing (was good for some decent improvement).
I also went closed loop during the install...

I think it was well worth it.

Justin,
I have very seriously given thought to going down the carburettor route! I'm currently starting on the build of a 4.6 that will go into a Disco ute, and it may well end up wearing a carbie.
Tombie,
I'll PM you.
Alan

I think the 14CUX gets a bad rap, and often undeservedly so. It's actually not that bad a bit of kit within some limitations. The important thing to understand is what parameters the existing box can work within and to remain within those, often by a bit of fooling if you have something much different to what it expects.

For background - I've got a healthy 300ci (4.9ltr) stroked RV8 running off the standard 14CUX with only a couple of relatively minor mods.
1. I swapped to a Visteon/Ford ?72mm MAF. This is still a 850kg/hr rated unit (same as the 5AM), but much less restrictive and largely bomb-proof. A simple laser-cut adaptor means it looks stock. I'm close to maxxing it out on a hard pull, but I don't... so that's perfect.
2. I use an UAFC MAF intercept box to remap the MAF signal back to a scaled airflow the computer recognises. And also to tweak the signal a bit to fine-tune the fuelling. The MAF I run has a different transfer function to the Lucas/Hitachi stockie.
3. I have bumped up the fuel rail pressure to 3.0bar using a Volvo pressure reg (plug and play).
As an aside I am also running EL Falcon Gen1 Bosch injectors, but these are essentially the same flow as the stock Lucas green bands and were fitted for improved spray pattern and atomisation.

My fuelling throughout is actually pretty good. I have a AEM wideband lambda gauge hooked up to a Bosch LSU sensor to monitor this in real time. It consistently idles around 0.95, cruises happily at 1.10-1.15 and richens to 0.85-0.90 under heavy throttle. And I can fine-tune any of those.

The reason for the fuel rail pressure increase was to push the fuelling up a bit to get the computer back in the box. Before that it was seeing airflow, throttle and rpm values that contradicted each other (for a stock engine cal) and then it got confused. I was surprised it ran at all off all the stock gear, and was reasonably driveable. It also meant the transient (accel pump) was a bit weak. Ideally a 3.5bar reg would work well as this would rescale the injector pulsing to very close to what the computer expects and then I just tidy it up a bit with the UAFC calibration.

A mate of mine is running a 307ci (5.0) stroker with the same basic set-up as me, but using he's using a stock 2.5bar rail pressure and GM Gen3 injectors instead. The standard rail pressure + Gen 3 injectors is very close to standard injectors at 3.5bar rail pressure. However the standard (moving disc) injectors lock up just over 3.0 bar so you have to change to a moving pintle type (like the Bosch) if you want to go there. The factory fuel pump is rated to about 5bar, so there's some headroom there.

I've got a 3.5bar pressure reg out of a Porsche (Bosch) which will be the next stage, with a retune. Still running standard sized injectors, but at the higher rail pressure. So I get good control and atomisation (no dribble). My current duty cycle breaches 90% flat-out, so I'd like to bring this back closer to 80% with the higher pressure, plus the computer should then be near the middle of the block for each parameter again rather than being off towards the edge.

Having said all that. A decent 4BBL on an Edelbrock Performer will work very, very well. You won't get the economy or driveability on an EFI system, but the power will be there and it'll work pretty well. Mine was run-in on a dyno with the Holley/Edelbrock combo. And then dropped into the vehicle with the EFI per above. There's no shame in running a carb

Hope that helps someone

Excellent write up Clax!

Only shame in running a Carby - I think the EPA/Transport Inspection teams may consider it to be not such a good idea..

Thanks Mike. Yes, well there is that. But that is a given and up to the sensible, right-minded individuals on here to make their own informed decisions. * cough *

For me, if it was a rarely used toy where range and driveability concerns weren't big issues then a well-tuned quality carby on a good dual-plane manifold with a well-sorted dizzy would get the nod. If it's a daily, or you want to cover distance between servos remotely, then it's injection all the way. And an upgrade to EDIS or similar (that's next).

BTW, a big part of me stepping up to the 3.5bar reg is that puts the 'limp-home' condition into will-still-start and can drive reasonably well (ie the overall system gets close to matching stock parameters). Right now if the UAFC carks it I am in a bit of trouble as the fuelling is miles out for start and low-end running.

Clax,
Out of interest, what sort of fuel economy are you getting with your set up?
Alan

and can I order one on line?