39 replies to this topic

[Twincam]

How do you adjust the limiter? Thinking for those who want a launch control, could they not add a switch (inline to the positive connection on the coil) so the power only goes to the system when you want and therefore limits the revs when you're pressing it, and hence once you release, its back to normal?

[iwatkins]

Indeed, what I said.

But, if you want a rev limiter *and* a launch control you would need two, or something like an Omex unit.

With a soft cut limiter, you also have the ability to full throttle gear change.

[Twincam]

From what you're saying, you'd need one to limit the revs at max RPM (say at 6K), and one to be working as your limiter when you wanted to use launch control (say at 3k - not sure what you'd want to use to limit spin etc)?

 

Am thinking if people would want to use just the one to limit the revs when they push the switch, then as soon as they've got away release the switch (and therefore they wouldn't have a top limiter)...? Or wouldn't that work?

 

I've played with the launch control on an Omex before (a friend has it on his MK4 Fiesta (running jenveys, shawspeed cams and what not) but just wanted to know for my own reference.

[iwatkins]

Am thinking if people would want to use just the one to limit the revs when they push the switch, then as soon as they've got away release the switch (and therefore they wouldn't have a top limiter)...?

That would work fine. It is exactly how old school launch control works and what we used to use for drag strip usage.

Not sure how well it would work on a Mini, but worth a try. Might be good fun for the traffic light Grand Prix.

Cheers

Ian

[Twincam]

 

Am thinking if people would want to use just the one to limit the revs when they push the switch, then as soon as they've got away release the switch (and therefore they wouldn't have a top limiter)...?

That would work fine. It is exactly how old school launch control works and what we used to use for drag strip usage.

Not sure how well it would work on a Mini, but worth a try. Might be good fun for the traffic light Grand Prix.

Cheers

Ian

 

I like your thinking! Would be quite fun, esp the other drivers faces as you're popping next to them at the lights... That combined with a shift light...hmmmmmm.

[iwatkins]

Got one of these Accuspark systems the other day and fitted yesterday.

What a lovely and tidy little unit, very impressed. If you open it up, all the internals are totally covered in potting compound so it should be fairly weatherproof too.

Just need to set ours to about 6200rpm but was a bit late last night to do that on the driveway.

Fitted mainly to stop anyone buzzing the engine.

Cheers

Ian

[JustSteve]

noobie question, but what is ''launch controll''? I assumed it was to hold your revs, but obviously you could only do this with fuel injection...    

 

 

also the accuspark kit is described as 'soft cut', has anybody actually got any McPoppin'? 

[iwatkins]

Launch control on turbos/4wd is to allow full throttle to a fixed limit and hence generation of boost at standstill. Allows you to get off the line quicker without bogging down when you lift the clutch and all that power moves the drivetrain. Wheel spin isn't usually an issue but overcoming all the inertia of a 4wd system and four wheels is important for a good launch.

For a Mini, I would use it to allow full throttle on the line giving power off the line and to restrict wheel spin.

The Accuspark is soft cut, so as a rev limiter rather than a launch control, it's very gentle which at say 6200rpm is what you want. We've just been out setting ours up and got it about right. Once the engine was hot we were getting the occasional bang and pop on the limiter. Nice but not stupid. I would expect once we get a LCB and bigger exhaust on there it'll be more noticeable.

I'm going to get another unit, make it switchable, I.e. off/on then also try it to control it from a switch on the clutch. I.e. with it switched on, clutch in, you can go full throttle. Will try around 4000rpm as a limit. As the clutch comes up, it'll switch the unit off so you can get all the revs. up to the actual rev limiter. So in theory, you can go full throttle off the line without wheel spin. Also as you change gear, you can keep your throttle buried and do full throttle gear changes.

I've used this exact system on an Alfa in the past for sprints/climbs and with a lot of fiddling especially the clutch switch, you can get great results. But it takes a lot of tweaking to balance the limit set for launch against the limit used for full throttle changes. In all cases with launch control and full throttle changes, your drivetrain and clutch *will* suffer additional strain.

Cheers

Ian

[Brad_Raybould]

How's the limiter going? I'm thinking in getting one soon and was just wondering if it lasted?

 

Cheers

[bloomers]

This is a brilliant post. Thanks for the videos. It's made me feel all warm and fuzzy inside

[Gremlin]

I've got a rev limiter and a launch control feature, it's brilliant, very effective and cheap!

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[Gremlin]

I've just been thinking about this, Lets say your in second accelerating away from junction/traffic lights, and you get to the rev limiter, it cuts out the spark, but the fuel keeps going in, so the car is not being powered and slows, the revs drop below the limit, and you get a spark again, in the meantime, quite a lot of fuel and air has gone into the cylinders, been compressed, allowed to expand, and has been blow out of the exhaust, Brilliant for fuel consumption! But bot only that, the whole exhaust will be filled with petrol filled 'un combusted' air, which when the revs drop and the spark comes again, you get pulses of red hot exhaust gas, which will ingnite the unburnt fuel and air in the exhaust, and blow your exhaust off!

[bloomers]

That sounds a little extreme to me. I think you'd have to spend a lot of time on the limiter to damage your fuel consumption, and if you're up by the limiter I don't think most people will be worrying about fuel consumption.
But I see your point. Still, saves the engine a bit.

[The Otter]

How's the limiter going? I'm thinking in getting one soon and was just wondering if it lasted?

 

Cheers

 

Well to be honest I can't be 100% helpful here as the Mini has been laid up in the garage since August 1st! It was working fine up until then though, still doing as it should and at the same RPM setting I put it on back in May, so it's lasted me at least 3 and a half months without any issues 

[Moggyton]

 

How's the limiter going? I'm thinking in getting one soon and was just wondering if it lasted?

 

Cheers

 

Well to be honest I can't be 100% helpful here as the Mini has been laid up in the garage since August 1st! It was working fine up until then though, still doing as it should and at the same RPM setting I put it on back in May, so it's lasted me at least 3 and a half months without any issues 

 

Is the limiter still working ?