RPM limiter Ideas?

[JamesPT]

Oi, Quick question:

Can you use the Bosch Ve4 immobilizer solenoid as a sorta Rev limiter?

I'm thinking to do the GOV mod, but I want more Fuel, till 4500 and then a DROP off real quick! I have a XUD9te (original rods) and want a Rev limiter thats NOT MY Foot, as I run a Vitara4x4 and want to Stomp on it and hold RPM without Over-revving.

[bashbarnard]

I would imagine that one it would wear that stop solinoid fast. Also it would technically turn off the engine then back on. If you keep doing that I cant see it doing the pump a lot of good at full chat. Be like revving it to 4 1/2 k then turning key off

[powerandtorque]

Will the solenoid even reliably work to cut fuel on an pump/engine already at full revs/load?

[Dave]

Does work fast enough been tried, best to use a different spring as the govnor, they are multistage so past a certain rpm can make them drop fast if you fine tune it enough but using the solenoid to cut fuel doesn't work quick enough it sort of dies too much.

[darrenjlobb]

Solenoid wont work, will stop it fast enough but due to the instant vacume drawn underneath it at high rpms and case pressure on top, the magnet in the solenoid isnt strong enough to re open it until revs have dropped down a fair bit .

[JamesPT]

Ok, Cut-Off Solenoid is out then,

Gov Mod is still on the table, but we already know this one

So, ideas line up like this...

Well tuned GOV-Mod (planned anyway... AFTER I get the 11mm head in there)

Triggered 3 way valve that vents the LDA pressure at 4500+ RPM(Shift light!!) (kinda fuel cut, but only the fuel that's controlled by the LDA)

and maybe a EBC from gizzmo that can retard boost based on RPM (of course at WOT, even a fully open wastegate has its limits)

Other IdeaS?

[Ruan]

LDA pin would jam - it's only spring loaded, soon as it's down, it won't return until your foot comes off the accelerator.

[darrenjlobb]

You need a single spring gov tbh, would do exactly what you need out the box with no mincing....

[Dave]

You need a single spring gov tbh, would do exactly what you need out the box with no mincing....

You sure about this? Surely that would be very linear as the RPM's rise. Mine is pretty full on fuelling right past 5600rpm then cuts right at the last 100rpm before 6000.

[silverzx]

Why not put a block of wood under your pedal.. File/sand down as required..

[JamesPT]

LDA pin would jam - it's only spring loaded, soon as it's down, it won't return until your foot comes off the accelerator.

Damn, was wondering about that, so basically it can only go down, and can't come back up until you let off the accelerator? Regardless of reducing the Pressure in the "Dome" to atmosphere?

This woulda been so simple to do...

[Ruan]

Yep - have a look how they work:



Notice because it's sloped, the following pin would be jammed up against it (due to your foot being on the throttle and it stretching the governor spring) so unless you removed your foot from the throttle, there'd be too much spring tension against the following pin on the LDA with it down.

I've seen it happen in the reverse, i.e. you jam your foot on the accelerator, the follower pin jams against the LDA pin, too much spring tension even with the pressure applied to the diaphragm, the LDA pin won't drop down - let alone when the pin is trying to come back up!

[Mal]

I had my 406 pump shimmed solid, yet it would only rev to 5600 rpm, I'd never put it to that though. Strangely, with a Xantia ECU it would rev to 6k rpm....