Disable the power?

Toby · Post by **Toby** » Mon Mar 24, 2008 10:44 am

There are times when you have to leave your car at a workshop or even at a relative's place where there's a boy racer dude. What is the best way to disable the power of the car, while still allowing it to be driven? I thought of:

1. Rev limit. This requires chipping your ecu, or having an aftermarket one. Easy to undo when you get your car back. I am thinking of building a circuit for this, though I don't want to splice wires. Power transistor comes to mind.
2. Disable the turbo somehow. Maybe force the wastegate open without damaging it The boy racer might figure this one out though. I've read that the ecu disables the turbo when in reverse gear - how?
3. If you got a dump valve, I guess you could just get it to dump all the time. I don't though and that might badly affect fuelling.

Thoughts? Ideas?

Riekert · Post by **Riekert** » Mon Mar 24, 2008 10:58 am

I think the first one might be the safest...

veecee · Post by **veecee** » Mon Mar 24, 2008 12:39 pm

number two sounds like the easiest of all you options!

take off the circlip, take the wastegate arm off the wastegate. the car will permanently be dumping all of the zorst gasses!

or... take the keys with you!

Doctor G · Post by **Doctor G** » Mon Mar 24, 2008 12:41 pm

Fist of all - you're crazy for letting a 'boy racer' use your car while you're off somewhere. But if you absoultely HAVE to then:

a)
I would just turn the car into NA. Connect the TB straight to the MAF at the airbox. Let the turbo spin all it want but let it blow into open air.

b)
Another option would be to mark the CAS and then turn the timing way down. Adjust the TPS so it never sees WOT or adjust the throttle cable so even when the pedal is flat the TB only opens about 75%.

HancoB · Post by **HancoB** » Mon Mar 24, 2008 2:29 pm

Get a Apexi FC control system. It got a built in service mapping where it can only do 60k/h and nothing above 3000rpm.

That should work...I guess????

veecee · Post by **veecee** » Mon Mar 24, 2008 2:31 pm

ya that'll work.

toby, in the meantime, start making applications to remortgage your house!!!

HancoB · Post by **HancoB** » Mon Mar 24, 2008 2:37 pm

ok really now its not that hard.

Get your slim sparky mate who has a electrical engineering degree and ask him to build you a rev limmiter. It connects to the coil and the negative of you battery and let it limmit to 3000rpm.

basically what will happen is that everytime the revs get up to 3000 or above it will missfire and get the revs back to 3000.

Its really not that hard, ask any electricalengineer and he will do it for you in a flash!

and the cool thing is if you want to switch it off you can just remove the negative from the battery or even better install a switch somewhere in the car that you can control it!

veecee · Post by **veecee** » Mon Mar 24, 2008 2:40 pm

toby is sharp enough to do that himself. in fact - i think he is an electrical engineer!

HancoB · Post by **HancoB** » Mon Mar 24, 2008 2:44 pm

Toby my friend....Dont you mind doing something like that for a fellow SX owner???

Toby · Post by **Toby** » Mon Mar 24, 2008 5:34 pm

Electronic engineer, actually. Big difference

That was my idea when I mentioned the power transistor - I can cut it out after certain rpm. Only thing that worries me is that there's gonna be unburnt fuel in the cylinders that might cause the manifold to overheat or create backfiring?

veecee · Post by **veecee** » Mon Mar 24, 2008 6:53 pm

unburnt fuel wont cause the manifold to overheat AFAIK, but it will spontaneously combust with the heat in the exhaust, causing backfiring.

thats how they do anti-lag systems. they fiddle with the RPM limit, as well as timing and fuel, to create a situation which causes the turbo to spin. the downside is an excessive amount of backfiring, and misfiring, and other stuff, that causes really heavy strange sounds to come from the car, and it causes the turbo to only last a few stages of a rally!!!

i'm not sure if a little bit of backfiring would be all that bad though. the example above is really the extreme of such a situation!

veecee · Post by **veecee** » Mon Mar 24, 2008 6:54 pm

Toby wrote:Electronic engineer, actually.

SKIES!

but thats what i meant!

Sokar · Post by **Sokar** » Mon Mar 24, 2008 7:11 pm

I've seen some cars have a valet key, when you start the car with this key you get a speed and rev limit.

I think the best cure for something like this is prevention, dont leave a set of keys that boy racer can get to....

veecee · Post by **veecee** » Mon Mar 24, 2008 7:20 pm

just quickly unbolt that turbo on the ca18det.

it'll probably only take about 25 minutes.

let the exhaust hang.

even if he lets it idle for more than a few minutes, he'll stop driving when he hears its open zorst ports!

Toby · Post by **Toby** » Mon Mar 24, 2008 8:10 pm

Let's not get too hung up on the boy racer, that was purely hypothetical. The real situation is that I might have to leave my car for a few days at a panel beater. The last few times I left my car anywhere, it got the shit driven out of it