Outer Limits 4x4 Board

G'day fellas,
I was wondering if anyone has ever put a rev limiter on a 1.3 carby motor before and if its a cheap and easy mod? I've noticed that when i'm going through bog holes i sometimes get a little bit over excited and give the motor to much right boot and get the rev's up too close to redline.
I dunno if its a viable mod just wanted to hear other peoples experiences (i know i probably should just tame the right boot cos it'd be cheaper but i love mods)

my belief is that a car has a redline for engine protection.
ie if you start to go over it then cars with a limiter will stop you, and its within the manufactures limits!

you have not hit the special red numbers yet, so what are you worried about!

I'll put a little disclaimer, before I get a tech god up my a$$. your motor may not last as long if you drive it near the red line all the time. although I have never had a motor blow up on me, so as yet the whole reving issue is not a drama for me!

but it would be cool hearing a 1.3L going bah bah bah bah at full noise instead of just full revs which sounds like baaaaaaaaaaaaaaah.

I love the way things can get explained so comprehensively with noises and all

a carb 1.3s limiter is the valves bouncing.
u may be able to adapt a sensor onto the coil tach and then work from there.

Jaycar has a kit i think.,

another way is a shift light and put a output on the light bit to trip the coil out

close to the redline? don't worry about it. Just drive it.

I've seen sierra 1.3's run out of tach numbers (I think that's past 8?) and whilst there is/was no point to rev one that hard, 6500-7000rpm once in a while won't kill it. Once it stops making useful power (around 7000 rpm, I think) either back off or pull the next gear.

I like the idea of a rev limiter though, bear in mind, however, that in an EFI car the rev limiter is a fuel cut but in your case it will be in ignition cut. This will lead to LOTS of bangs and pops as there will still be heaps of fuel going in but no spark to ignite it, so it will only ignite in the exhaust - very hard on the exhaust etc and I reckon would blow out mufflers just like the old school "key bangers" used to.

I don't know how "soft" the jaycar limiters are, but you really want something that pulses very quickly - effectively dropping individual cylinders quickly and randomly- so high revs are maintained rather than just cuts everything, sees a drop in revs then turns it all back on - this could lead to some nasty "stuttering" and a massive loss of torque that could see you stuck.

PS if you want to see the effect of an ignition cut, check out some of the more powerful Japanese drag cars. Here is an example- at around 11 seconds, you'll hear the car bogging and throwing flame - that's an ignition cut limiter at work.

http://www.youtube.com/watch?v=NPyY-cqbuc0

It wasn't exactly what I was looking for - I've got some old DVD's of supra's etc in Japan launching and the effect of the ignition cut is pretty extreme.

Theoretically, they should work very well and avoid the bwarp...bwarp...bwrap surging of a fuel cut, but nonetheless, there would bee some experimentation in setting one up.

Steve.

So the advice is not to bother unless i want to spend a few $$ on the project if i don't want possible exhaust explosions etc? I've had the little 1.3 spinning to about 8000rpm before but don't really want that to happen again as i've got a fresh motor in the zook now. A shift light that really catches my attention might be a better cheaper alternative than a rev limiter.

I'd agree.

Steve.

If your after a 'cheap' shift light, then Jaycar had a kit for this too. It was a shift light and rev limiter in one. (I believe it is a "Silicon Chip" kit - I bought it a couple of years ago now so I am not sure if it is still available). I run one in my race car. It has three green LEDs to indicate shift points (or approaching 'Red line') and a fourth LED for the Rev Limiter (or actual 'Red line'). Each LED's 'switch on' RPM can be adjusted separately. How you set the individual LED RPM values is up to you.

I am not using the rev limiter function of this kit at all (for the reasons already mentioned). Mine is setup purely as a shift light. Mine is set to go GREEN, GREEN, GREEN RED! all within the top usable 500RPM.

or is that GREEN, GREEN, GREEN BANG!???


It works great!

Cheers,

Pez

i know a way you can put an adjustable rev limiter on a carby car we set it up on a mates ford escort rally car works really well to!!!.... all you need is a desent tachometer with an adjustable shift light and a relay cant remember the name of it but ill call it a signal relay,

So if you had a power feed(Say power to the coil in this case) running through the relay and then another current or "signal" is supplied to the relay the power feed circut will be open then stopping the power feed to the coil but when there is no current or "signal to the relay the power feed to the coil will be complete, now for the signal all you need is carefully open up the tachometer and solder a wire to the shift light feed on the tachometer and use that as the signal, so when the shift light is off the power feed to the coil is live and when the shift light is on it opens the relay and kills the power to the coil and then you just adjust the shift light to what ever you want the car to "limit" at from 0 rev to what ever you want depending on the tachometer hopefully the quick paint shop picture i provided is a big help if anyone is confused...

Just let it valve bounce .. the 1.3 can run of the clock and stay there for quite some time without issue.

Rev limiter would be a good idea I've had the Vitara upto 8,000rpm briefly