Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Rev limiter

So have had my sigma remapped a while ago.
Now I thought it had removed the limiter, & seem to remember it happy up to 7000rpm.
Due unforeseen circumstances car has not been driven as much as it used too. So as it hadn't been run for 6 weeks, decided to give it a "blat" oh 6500 rpm & the power dies. No popping or any other odd noise just a sudden loss of power. Not nil but like the power curve has "cliffed". So question what does the Rev limiter feel like on the sigma ?
(Had an s2000 that popped & crackled at limit)
Apart from that the engine comes "on cam" at 4500 and pulls all the way up to 6500rpm
With the rear axle change it goes quite well but hey we well me are always looking for a bit more.
Ps can I get a v6 cyclone in a 4/4

You are in the red area after 6500rpm . I assumed that the red is a no go area . Is one not risking engine damage by using the 6500-7000 rpm area ?
I am maybe being to careful .
MY 4/4 has K@N filter, Librands Manifold ,Williams remap ,Brake reaction Bars and panhard Rod and find the best range is 3000 to 5000rpm .

My Sigma engine 2009 Sport just died when it hit the limiter very disconcerting the first time, I can't remember what the revs were at the time now but sufficient best describes it.
The engine was un modified.

The history of rev limiters according to my faulty memory.

Lotus had a spring loaded rotor arms in the Lucas distributors of the twincam, this was not good and the cause of misfires. Owners replaced them with the standard item, and the gave rise to broken engines.

Later came electronic hard cut LT rev limiters, these came in like hitting a brick wall. This gave rise to broken drive trains as the cut in and out under hard acceleration.

Later came soft cut limiters, these would cut out every forth spark, then every second spark, the every spark.

My Roadster with a Ford V6 basically stops accelerating.

The Roadster S1 has the ST220 engine in it. It is basically the wider chassis like the old +8 & the +4.

I think 4/4 are still narrower. Also Morgan made some mods.

GoMog has details
http://www.gomog.com/allmorgan/ROADSTER1stInformation2.html

I think the cyclone is the later engine.

I would have thought it would be easier to buy a Roadster.

It would certainly be easier to buy a Roadster but all the current trads are the same width so a V6 will fit the current 4/4.

The only difference is that the 4/4 has a narrower front suspension frame by 3 inches or so.

My 2014 Sigma exactly behaves like this, if this is the method (spark reducing) I don't know. But it seems to be gently working and is not brutal to any part. The Sigma engine could rev higher if some quotes of other forums could be true, but why at all as long as you have road use.

I just had a look at the setup on my car with Omex throttle bodies but an otherwise standard Duratec 2.0l.

The strategy used is an ignition cutoff at 7,200 rpm. I have never arrived at that as, if I am giving it the berries, I always try to change at the peak power point which is 6,000 to 6,500 rpm, from about 6.5K the power drops ever so slightly until it hits the rev limiter. If my automatic rev limiter is in the passenger seat she usually sounds off before I hit that point anyway.

On the standard engine without throttle bodies the power starts dropping off at about 6K and I immagine it is not all that much different on the 1.6 engine.

If you like reving out the engine I would definitely recomend fitting a set of throttle bodies. You will love the sound and the extra urge as it comes on cam.

The standard Sigma revs out at 6.500 rpm. Less capacity but a bit more revs in comparison with the 2.0 Duratec. The best of the Sigma band is between 2.500 and 6.000 rpm anyway.

Thanks for the replies. So interesting in that is how the limiter works. The re-map should have removed the limiter, but yes above 6500 not a lot of point excepting you can hang onto a gear longer. The re-map tech has asked me to clean the MAF sensor as I am using a K&N filter.
The sigma should be happy up to 9000 rpm but wouldn't go that high as really you need light weight Pistons, so would be risking engine damage.
Interestingly in general I don't "ring its neck" but seems to be the only way to get the power out of it. IMHO the engine needs more low down torque, which the re map has helped with. ( peak torque is 500 rpm lower) it has significantly reduced the " gear rattle" as the factory put it. Below 2000rpm.