Thanks to Al, (The Saint.)

Having discovered that there are differences between the flat and roller cams and how they make the engine pump I this morning uploaded Al's map to my freshly rollerised shitheap.

Fantastic! Transformation is outstanding. The issue with Mark's flat tappet Hi-Pipe map was that, especially in the lower gears, it went flat at about 80% throttle. Al's map, developed for his Ago pipe but high-mounted is brilliant right the way through to perhaps the last 5 degrees. That can I'm sure be addressed but it's only noticeable if you really wring it's neck and then back off a tiny bit when you can feel it get a tiny bit stronger. Probably the difference between the Ago and the Mistral. Midrange is phenomenal!

Thanks Al!

Pete

It had thought beetle's Mistral map was from a 1200. Not so?

It is. But Mark's map is built for the flat tappet engine.

Given the fact that the factory uses the same map for both flat and roller tappet bikes I'd assumed that the roller cam mimicked the profile of the flat tappet one. Up until I rollerised my bike it was a reasonable assumption. Now I've done the conversion though it is obvious that it changes the breathing considerably. Al built his map for his Hi-Piped, roller tappet engine so it looked like the most obvious choice as a starting joint for my very similar set-up.

I was right. Apart from those last few degrees of throttle it's damn near perfect.

Pete

Yes it is. It was built on a flat tappet 1200. Initially we thought the roller cams had the same lift and duration as the flat cams, but it seems not. Al built his map on a roller GRiSO.

What exhaust are you running with on your newly rollerised GRiSO Pete?

Would it be a Mistral?

Same old Mistral Hi-Pipe that's been on there for a couple of years

Just caught that thanks.

Just a thought Pete what are your tappet settings and what were Al's when he made the map?

Six and eight but I think he built the map for four and six.

I think Mark is going to try and extrapolate the roller values over to a Lo-pipe map as a starting point and then we'll have to start the logging again to fine tune it. If you have a Hi Pipe it's preset damn close right now.

Just on behalf of Al, he's been living in a tent in his back yard since Easter due to house reno and discovering asbestos materials everywhere. Just moved back in last night.

I can confirm Pete he runs .006" for both inlet and exhaust.

Pete Roper wrote:

I think Mark is going to try and extrapolate the roller values over to a Lo-pipe map as a starting point

Nup. It'd be all guesswork. Al's approach was a bit different from mine. If it were one of mine, I could guesstimate how any changes would affect it.

Cool. We start logging. First my bike, (Simply because it has the gear on.) and then other iterations.

Unlike some other folks I'm not willing to be involved in easy, 'Tick a box and spout some bullshit' solutions. Hard data. Clever people. I'm happy and humbled to be part of it.

Let's make those 8V's sing!

Pete

Excited to see how that goes. I think I'm gonna search threads to find what I need to log data then send it along.

Pete Roper wrote:

Having discovered that there are differences between the flat and roller cams and how they make the engine pump I this morning uploaded Al's map to my freshly rollerised shitheap.

Fantastic! Transformation is outstanding. The issue with Mark's flat tappet Hi-Pipe map was that, especially in the lower gears, it went flat at about 80% throttle. Al's map, developed for his Ago pipe but high-mounted is brilliant right the way through to perhaps the last 5 degrees. That can I'm sure be addressed but it's only noticeable if you really wring it's neck and then back off a tiny bit when you can feel it get a tiny bit stronger. Probably the difference between the Ago and the Mistral. Midrange is phenomenal!

Thanks Al!

Pete

You are most welcome Pete.

As Wayne mentioned, valves are 6 thou both inlet and exhaust. The final tweaks to the map were done by analysing the left cylinder independently. Then the right cylinder was checked and found to be very close and acceptable, and I only made a minor adjustment. Notwithstanding, as soon as time permits, I will match the fuelling of the right cylinder to the left perfectly, so when the afr is sampled at the collector it should be the same. Then, if I can be bothered, I will steal Marks' idea and run the wide band sensor. Another thing, all the tuning was done with the snorkel in, then I removed it to see how much difference there was. The results are posted in the Ago thread, if you remember. So the map is 95% finished thus far.

Mark, is your logging gear capable of analysing with a dual O2 setup?

Al

No, it's single channel only.

Interesting. I thought the Stelvio felt differently since being rollerized too. The fueling just isn't as good with the 52 map as it was with the flat tappet.

Pete, do you know if the factory had a map update with the rollerization?

Jacquie's GRiSO is still in for its rollerization too, so I'm assuming the mapping isn't going to be as good on hers when it comes out either.

No, no new factory mapping. The thing with the factory maps is they are a soggy mass of compromises, a sort of 'One Size Fits All' that will trim around changes to a certain degree giving the same level of universal mediocrity.

Once you go open loop all that changes and as we know the 8V is a very hard taskmaster when it comes to tuning. Go open loop and everything has to be spot on or you end up with all sorts of odd, niggling, problems of flat spots and stutters in performance.

The thing is there is no way to know this until we experience it! I had assumed, wrongly it turns out, that since the factory map was the same the profile of the roller cam must of mimicked the flat tappet cam very closely. Obviously now I'm working with a rollerised guinea pig I can see that the truth is quite radically different.

Essentially though it just proves that second guessing is just that, guessing. It looks as if Mark will be embarking on a whole new series of experiments based around the roller motor. I'll be rollerising his very soon and then the fun begins all over again.....

Pete

I've got the popcorn ready. Very interesting stuff.

So here's a question....

Can I use a custom map for set up for a newer rollered NTX in open loop mode, or is it a completely different animal?

I've got a 'new' 1 lambda Stelvio map if you want to try it Doug. I don't have access to a roller Stelvio, so there's no guarantee it will work. It's only three minutes and a test ride....

Just when Mark and Pete thought they could sit back and enjoy.
Just another classic, we don't stop learning!

beetle wrote:

I've got a 'new' 1 lambda Stelvio map if you want to try it Doug. I don't have access to a roller Stelvio, so there's no guarantee it will work. It's only three minutes and a test ride....

Sure! I'll definitely give it a try. Thanks Mark!