AFM... anyone tried boring one out?

[pupp]

Just had this off to chuck the gauze, and it has loads of spare meat on it... must be scope for increasing the diameter of the thing by boring and reprofiling. Anyone tried it? I know the Jag unit can replace with wiring mods etc, but I quite like the idea of retaining the standard unit if that can opened up...

[chassis 33]

Gary, yes it is possible, no it doesnt help that much.

Regards
Iain

[Cider Andy]

Interesting this. Someone on the TVRCC forum cut two plenum tops in half and welded two halves together to form a plenum with two air intakes, then fitted two AFMs and some simple electronics to combine the two signals and fool the ECU. I never heard how this ended up, but it did get me thinking that if breathing is an issue with the larger RV8s (ie. the ones over 3.9l using the same ancillaries as the 3.9l), why not fit a bypass hose parallel with the AFM along with some electronics to fool the ECU? Has anyone done this? Or does anyone know why it couldn't be done?

[dickkark]

you could remove the afm and fit a map sensor instead but you would need electronics, again its hardly worth doing,you ae still governed by throttle body size.
I built my own plenum using a few old ones and fitted two afms etc,
5.0litre,mucho modifications,much cleaner revving,sounds throatier too.
but is hardly worthwile if you dont include other more extensive/expensive mods.

[GreenV8S]

Cider Andy said:

why not fit a bypass hose parallel with the AFM along with some electronics to fool the ECU? Has anyone done this? Or does anyone know why it couldn't be done?

That's basically the size of it, the hotwire sensor is just a small assembly which could be put into any size pipe or hose you like, and you could use a bypass to increase the range of the sensor in the existing casting as long as the flow distribution between the bypass and the 'main' flow was constant. You'd need to rescale the fuel map to account for the fact that the sensor was only reading part of the flow. That's trivial for the Mark Adams' of the world, but not very feasible for the rest of us.

[sjpalmer1]

It may have been my thread with the two halves welded together. All the bits will be on the car shortly. Popped to see TVR power yesterday to see about getting on the rollers for a health check.