omex rev limiter and lauch control

[r5 rich]

been looking at this to buy as I have no rev limiter and I have seen two versions, single coil and twin coil!

I take it that I need the single coil one as below!

http://cgi.ebay.co.uk/Omex-Single-Coil-Rev-Limiter-with-Launch-Control_W0QQitemZ350119527485QQcmdZViewItem?hash=i tem350119527485&_trksid=p3286.c0.m14&_trkparms=72%3A1301|66%3A2|65%3A12|39%3A1|240%3A13 18

[jantheeven]

Sweet... rev limiter and launch control on a 5! I want it too! :laugh:
But how does it work exactly? And how/where do you install it?

[car.crash]

rev limiter is great, launch control is crap, i ripped mine off, was a right pain in the arse.

[r5 rich]

so i take it that its only worth getting the rev limiter on its own then?

[Rob@Backyardracing]

Isnt the LC used as the full throttle shifter on these as well... :confused:

[markey b]

twin coil ones are for cars with 2x coils, like the old RS1600 etc

[r5 rich]

cheers mark, just wanted to check. so i take it the one with launch control is not the one to go for then!

[Ian S]

You'll never use LC after having a play with it and the rev limit is a dam nuisance. I set mine for 8000 rpm and it still got in the way at 7000 or so.

Full throttle gear change is useful though for flat shifting at a slightly slower pace than at the Pod.

Seems that some higher boosted engines have failed though when the spark cutting happened whilst at full duress.

[James George]

New poster! (less than 10 posts)

i have an omex limter and think its good, easy to setup and adjust, soft cut feels exactly that, and comes exactly as set, think mine is set at 7000 and certainly does not come in at 6000

Ian curious why would it cause engine failure?

i only fitted it as when racing with helmet on and red mist looked down and often rev counter is off the end of the clock.

[Ian S]

Not sure. It misses a combustion so there a full charge of unburnt petrol. Maybe this somehow does something it shouldn't.

There was stuff about it on the old site.

My 5 reved easily to 7500 so I took it there often. It didn't seem to matter how high I tried to set the limiter, it still started to soft cut the area I wanted to use.

Mine's the other make, Armtech?

[Scoff]

I think generally those limiters are not very good, compared with what you can set in most aftermarket ECU's anyway. the omex and armtech share the same units as far as I know. I used to find that you needed to set the limiter much higher than "half the engine speed" in order for it to work as expected. nearly always came in early.

re the engine damage, I think that would be pretty unheard of, most mapping guys use a ignition-cut limit in their maps, fewer tuners cut the injectors. I tend to think that cutting injectors but not spark is more of a risk than doing the opposite.

re the launch control, how does that work with the omex/armtech ? I assume there is a speed input else how does it know when you've begun moving ? is it on a button ? If it is, I wouldn't bother!!

[James George]

New poster! (less than 10 posts)

think omex is different to armtech, omex you dont do the half revs job, you set the exact cut point, its preset at 6000 rpm then you use up and down buttons to adjust by 100 rpm.

[Scoff]

New poster! (less than 10 posts)

think omex is different to armtech, omex you dont do the half revs job, you set the exact cut point, its preset at 6000 rpm then you use up and down buttons to adjust by 100 rpm.

interesting, well atleast some of them are the same as the armtech, but not all then :)

[markey b]

can't cutting the spark shock the collets on the valves?? i know i've had problems in the past by overrevving past the 7k limit

[Scoff]

can't cutting the spark shock the collets on the valves?? i know i've had problems in the past by overrevving past the 7k limit

yup, just like it might rattle the exhaust free, or crack a manifold, .... :D when you want uber fast gearchanges you just have to hope you've built a solid engine, and go for it.

most factory car's seem to cut both ignition and fuel, some just cut ignition but in stages - it might start with a "soft" cut that cuts alternate pots, finally all of them if the RPM continues to rise.

[James George]

theres micro dynamics that might work the same as armtech,

[Mart]

Omex/Armtech are made by the same company.

Agree with Ian about high boosting engines (well, c1j's anyway) eventually going pop if being bounced off the limiter on a regular ish basis. Maybe coincidence, but there were several reported (from a good few years back on the old site) engine failures (read either cracked liners or piston ringland failure) where a rev limiter was in situ/being 'used'.

Pie in the sky though, and for sure no concrete facts to pin-point the limiter being to blame, but it is an uncanny coincidence never-the-less.

[Ian S]

re the launch control, how does that work with the omex/armtech?

IIRC, with the type I have, the rpm one wants to hold the revs at is reached with loud pedal, then the clutch pedal is pushed down operating the Armtech switch on the pedal box. WOT can then be selected but the rpm stays about where it was, until the clutch pedal is allowed up again.

I never used it. I suppose it would get the turbo spinning a bit. Then upon launch just fully spin the wheels or clutch or break something. Maybe different with 9 inch M&H's?

[markey b]

yup, just like it might rattle the exhaust free, or crack a manifold, .... :D when you want uber fast gearchanges you just have to hope you've built a solid engine, and go for it.

most factory car's seem to cut both ignition and fuel, some just cut ignition but in stages - it might start with a "soft" cut that cuts alternate pots, finally all of them if the RPM continues to rise.

isn't cutting the spark the same as revving ya car up, flicking off the ignition, and making it bang when you turn it back on??

[Ian S]

The rev limiters don't cut all of them, ie, turn off the ignition.