MOT Assistance

[Steve_D]

tjlees said:

Cheers

I actually have a AFR fitted to the ultima just to make sure it's not starting to burn lean and potentially causing detonation problems. Under hard acceleration it's around 11.7 so over fuelling but his is probably how Gail intended it to be.

I'd be happy with that for hard acceleration.

Steve

[gt5594]

Yes, perfect, you are spot on with that 11.7 under max load.

I'm actually race-mapping an Ultima race car on a MOTEC M800 today and that's exactly where I am going with it under max load. MOT emissions are only taken at part-load at around 2500 rpm steady state, so depending exactly what you have driving the load measurement for the ECU, and the ECU itself, it's not a major deal to tweak part-throttle sections of the MAP to run clean.

What you've done with the high speed lambda is a brilliant, especially if you get to run the car very hard.

Gotta go. Loud noises and big flames await me.

[Mr Pid]

This is something i looked at last year...... For me I felt this particularly important as I have a supercharged SBC.

I have gone for a combined vacuum\boost and AFR gauge in mine. All in one 52mm gauge. Its like having your very own mobile rolling road.

You can set it up with a few different display arrangements, set alarms that will alert to out of range AFR with respect to boost\vacuum and it records data for download via a USB interface.

While I was at it I also swapped the std msd ignition for their digital programmable version so I now have full flexibility to programme ignition timing to both rpm and vacuum\boost.... And added an analogue fuel pressure gauge to the carb fuel inlet.

So although I still have a carb I have full control over the ignition and can keep tweeking the tune in the real world.

..... I have learnt out a lot and have a much better behaved engine, particularly at low revs.

[gt5594]

That looks certainly belt and braces. Remember that you will get variable AFR's across different runners on the carb's intake manifold, as the length and shape of the runners varies considerably across the cylinders. You'll have your carb set up on the rich side to compensate for the lower (leaner) AFR's on the outer 4 runners, no doubt..

[MKnight702]

Well, I have fitted the new exhausts with cats just need to get retested.

One thing bothers me however, the exhausts are very close to the bodywork. There is heat protection on the underside of the body, but it's still very close.

[deadscoob]

How have other owners with tuned/cammed LS engines got on at mot time?

First mot in July, not sure in its current tune with a mildish cam, 110lsa, whether it'll pass. It certainly smells nice when idling

[Abbosevolution]

deadscoob said:

How have other owners with tuned/cammed LS engines got on at mot time?

First mot in July, not sure in its current tune with a mildish cam, 110lsa, whether it'll pass. It certainly smells nice when idling

The dreaded MOT time - not any more - after years of being shafted by garages only interested in profit I've found a proper garage - have had Caterhams, Skylines and AMGs all proving to be an issue when it came to MOT time but not any more. All I can say is find a decent garage, I'm sure the MOT guys on here are decent and dont treat punters with expensive toys as cash cows but there are a few out there who do. Maybe pm some Ultima owners on here local to you and find out where they get theirs tested.

[gt5594]

If you had 5% CO readings first time around, that's a clear indication of an over-rich mixture. Just fitting catalytic converters/lambdas on its own I'm afraid is not going to be enough. You need to take fuel out on part-load throttle.

Zircotec for the heat - expensive but works. Cheaper than the scorchy marks on the body

Very best of luck with the re-test!

[MKnight702]

I have found out that the ECU is a GM E67 unit.

Can anyone recommend a good tuner to set the engine up?

I did try Troy at Northampton Motorsport, but they don't do the E67.

If there is anyone within 100 miles of Cambridge that would be even better!

[Storer]

I used Mark at LS Power Ltd near Bedford

07876498120

I am sure there are others not too far away.


Paul

[MKnight702]

Is LS Power still going? I can't find it on the web, plus I think that may be who mapped it before and the jury is still out on that.

[deadscoob]

Try Richard Ingram, the European efilive distributer. Efilive.eu

[MKnight702]

YAHOO, passed!!!!!

[Storer]

Well done.

Might pay to take the car to the same place next year.


Paul

[deadscoob]

Congrats. Just with cats or other tweaks?

[MKnight702]

Just cats. It did take 3 goes, but he got it through in the end. Now to put it all back how it was!

[gt5594]

Well done! Sounds like you found a sympathetic and understanding tester.

Best go back next year!

[MKnight702]

FYI the tester was the same one both times, but without the cats there was no way it was going through. Pity they didn't come with the car when I bought it.