AFM

[jojackson4]

Is there an upgrade wich will run with the std 14 ecu running a 5AM now but cannot get the right voltag on set up
Thanks Peter

[phazed]

The 5AM is adjustable, have you tried?

[QBee]

I have a P38 GEMS AFM, bigger voltage range, but the 14CUX needs a Tornado chip change so that it understands the voltages. I was told that the 5AM can max out above 280 bhp

[phazed]

QBee said:

I was told that the 5AM can max out above 280 bhp

Funny, I had 346 out of my old 5.0. On a standard 5AM which went like stink!

[QBee]

phazed said:

QBee said:

I was told that the 5AM can max out above 280 bhp

Funny, I had 346 out of my old 5.0. On a standard 5AM which went like stink!

I cannot be definite about it. My engine was changed by V8 Developments for a 5 litre, and the power suddenly switched off under heavy boot at 4800 rpm, with the AFR saying that it was switching to excessively lean in an instant. Discussions followed with my TVR guy and V8D, and the injectors and AFM were both changed. So not one component at a time. After remapping by Mark Adams it now works fine, but I cannot be definite about what fixed it. What I can say is that I was told that the P38 AFM voltages are higher than the Lucas 5AM ones

[blitzracing]

The P38 one has a lower voltage output. Ive managed to remap its output to match the 5AM with a "UAFC" digital unit that Triggerwheels where doing, but now they have stopped importing them after bad feedback on the product. Joolz of Kits and Classics is currently doing more investigation on this, as my 3.9 does not draw enough air to make use of a bigger AFM, so I cant do any more testing. There is no point in fitting a bigger AFM to anything less than around 280 BHP as the stock one is fine up to this point. Above this it does start to restrict, but as already said you can still run over 300 bhp with it fitted.

[QBee]

phazed said:

QBee said:

I was told that the 5AM can max out above 280 bhp

Funny, I had 346 out of my old 5.0. On a standard 5AM which went like stink!

I cannot be definite about it. My engine was changed by V8 Developments for a 5 litre, and the power suddenly switched off under heavy boot at 4800 rpm, with the AFR saying that it was switching to excessively lean in an instant. Discussions followed with my TVR guy and V8D, and the injectors and AFM were both changed. So not one component at a time. After remapping by Mark Adams it now works fine, but I cannot be definite about what fixed it. What I can say is that I was told that the P38 AFM voltages are higher than different to the Lucas 5AM ones, so need a different voltage table in the ECU

[phazed]

I wasn't doubting what you were told Anthony, just that that figure which I have heard from other sources can't be true just a reasonable guess when you are squeezing the last once!

[Chilliman]

Regarding the standard AFM, it seemed to be a common understanding that if you were looking at bhp above the 280 figure, then the AFM was a 'bottleneck' for gas flow, which is to say that whilst you can still get the bigger numbers well in excess of 300, the more gas flowing/bigger valves/etc etc you do/have, the bigger the requirement for air you will have, and the standard AFM will become restrictive.

Well that's my understanding, and it does make sense, after all a modified 500 will need significantly more air than the Range Rover the AFM came off of. It's why we fit bigger plenums/multiple throttle bodies and the like. However, I've never seen any figures to substantiate this, ya know, heads flow this much, you need x amount of cubic feet a minute etc etc... The 280 figure may just be the stuff of myth and legend... or smoke and mirrors... or just plain boox

Chilli

[rigga]

SILICONEKID343HP said:

QBee said:

I have a P38 GEMS AFM, bigger voltage range, but the 14CUX needs a Tornado chip change so that it understands the voltages. I was told that the 5AM can max out above 280 bhp

Think you will find it starts coming restrictive after 280hp ..

Did you not read Peters post way up the page ?

[SILICONEKID343HP]

rigga said:

Did you not read Peters post way up the page ?

Yes it starts being restrictive after 280hp.

[Chilliman]

SILICONEKID343HP said:

rigga said:

Did you not read Peters post way up the page ?

Yes it starts being restrictive after 280hp.

You two kill me

[carsy]

phazed said:

Funny, I had 346 out of my old 5.0. On a standard 5AM which went like stink!

Peter, if you had only known. I recon you could have hit 380 wit that engine.

[rigga]

SILICONEKID343HP said:

Yes it starts being restrictive after 280hp.

Did you do maths at school, ? coz pretty certain 346 is above 280

[SILICONEKID343HP]

rigga said:

Did you do maths at school, ? coz pretty certain 346 is above 280

It does not stop dead and give no more power ,it just becomes restrictive .

346 may of be 10 or 15hp without the afm .

There is a graph somewhere showing the retriction.

Won`t the more modern larger afm work on the 14cux ?

Like the one`s fitted to Ford cobra V8`s.

I was advised to fit one with the after market ECU for ultimate fueling .

http://www.ebay.com/itm/87-93-5-0-MUSTANG-70MM-MAF...

[QBee]

I nearly understood three words of that last post......

[phazed]

carsy said:

Peter, if you had only known. I recon you could have hit 380 wit that engine.

Thanks for reminding me!

The day the engine died we, (7TVR and me) were doing a TD at Snetterton.
That RV8 5.0 running the full Lucas jobby could keep up with Christians 4.0 Red Rose T350, just

[Sardonicus]

QBee said:

I nearly understood three words of that last post......

Sorry Anthony, I was referring to the Megasquirter's if you like a read http://www.carcraft.com/techarticles/electronic_fu...

Edited by Sardonicus on Friday 5th July 13:02

[SILICONEKID343HP]

Sardonicus said:

orry Anthony, I was referring to the Megasquirter's if you like a read http://www.carcraft.com/techarticles/electronic_fu...

Edited by Sardonicus on Friday 5th July 13:02

Is it possible to mix and match ?

Got this message some time back from Baily motor sport

"The maf(AFM) is not a restriction, the benefit is better slow speed driveablity and mpg.
.

We use the maf (not map) with the tps for acceleration enrich. So not alpha n or map"

Explain that one !

Control Algorithm” lets you choose between Speed Density and Alpha-N. In all cases, you should choose speed density unless you have a good reason to do otherwise, and understand how this will change your tuning efforts. All tuning advice in this manual is based on the speed-density algorithm. Alpha-N uses the throttle position (alpha) and RPM (N) to calculate the amount of fuel to inject as opposed to using the manifold absolute pressure (MAP) and RPM to calculate the amount of fuel to inject. Alpha-N is useful for long duration cams where the resolution of manifold air pressure (map) would be small. It is also useful to get smoother idle on engines that have erratic map values. MegaSquirt® be converted from its default speed-density calculations to Alpha-N which uses RPM, temperature and TPS only. You must have version 2.0 (or higher) of the embedded software installed. Start up the tuning software, go to the Constants dialog and change speed density to Alpha-N. Re-map your VE table. You will no longer use the MAP sensor for estimating the load on the engine -- the throttle position and rpm are used instead. This can help with cams with long duration and/or a lot of overlap, as they have low and variable vacuum at idle, making tuning very difficult.

Edited by SILICONEKID343HP on Friday 5th July 14:01

Edited by SILICONEKID343HP on Friday 5th July 14:24

[chris1972]

I think Blitz has managed to map the Bosch AFM to work with 14cux? I was intending to head over to see him but I'm suffering from drip-fed payments at the moment, so as soon as my money comes in... it goes out the other way!!!