Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 Sigma KandN Air filter for standard air-box

Loved the work we have managed on the sigma so far

https://www.youtube.com/watch?v=iCtrEFmTAJs

Looks cool, Lawrie, so the main tuning was changing the oil filler cap?

if only it could of been that cheap

To be serious, I guess you have changed pistons, cams, probably rods, alternator etc. But have you kept the variable cams if you reach 8K plus revs?

head work, yep we kept the variable timing for driveability. Alot of tuners throw it away as its costly to keep it and map it properly. The valve timing to took us about 3 weeks to sort with M-sport helping etc. The engine still makes power as the revs climb but we have to cap it at 8200 for regs

Lawrie, thanks for info, another one, just out of interest, which final ratio did you dial in, 4.1 or 4.3, in combination with 8.2K revs?

Lawrie,

When you are at work, can you check on my new TB's from Omex, I have been waiting nearly 3 months and starting to get a little feisty.

They are for my 2011 +4, not sure whether the delay is with Omex or with the remapping.

It is under the name Graeme Cockram.

I am having a knee replaced on Monday, so I guess any driving is out for 4 -6 weeks anyway, but I will be raring to go after that.

I have the K&N fitted since last sunday. As the K&N was no improvement on my former Roadster, it is well matched with the Sigma engine. Allows it to rev much easier and stronger. A note, after such a change as the air filter was, this Sigma engine needs at least 30 miles to drive before you can fully value the swap of the filter. The ECU has to adapt the new K&N filter.

Heinz - good point about the ECU needing to adapt - i wrote my impressions after just 5 miles or so. Good excuse to give it another run...Thanks for pointing it out

I see you had a roadster - how does the 4/4 Sigma compare to it?

The Roadster is an effortless well powered cruiser. I can understand everyone who likes them. I had three of them during the years from 2005 on, all were equipped with 3.0 engines.
Two years ago my Cousin rent a 4/4 for a weekend to become familiar with the Morgan world. I drove her also and I was immediately impressed. Less power but so good balanced. Before this experience I was nose up against "small" Mogs but I soon realized that a Roadster is in comparison a tad nose heavy. The Roadster in my personal view has to fight a bit against her own engine weight. The 4/4 would be an ideal Mog if the power was 170 HP on the base of the same engine/ car weight as now.
But you get used on the power of every car after a daytrip, regardles if it is high or low, and 135 HP which could relatively easily achieved on a 4/4 is not too bad at all.