MG Ti & Quat-D comparison

[v50man]

Now you've got me thinking. Problem is, I'm not an engineer -- not even close.

 

Flogged the V11 hard today. Surreal. Wonderful.

 

and, uh -- more engine braking than any of my 2-strokes

[dlaing]

If the Quat is a freer flowing exhaust the engine braking may be less because of less pressure?

86268[/snapback]

I think the engine braking comes from the lack of power when the throttle is closed.

Freer flowing exhaust should make no perceptible difference, although it MAY change how open the throttle is at idle???which would effect the engine braking.

But I don't recall switching mufflers changing the idle...nor noticing a change in engine braking.

BFG, do you have a PCIII?

[belfastguzzi]

I think the engine braking comes from the lack of power when the throttle is closed.

Freer flowing exhaust should make no perceptible difference, although it MAY change how open the throttle is at idle???which would effect the engine braking.

But I don't recall switching mufflers changing the idle...nor noticing a change in engine braking.

BFG, do you have a PCIII?

86299[/snapback]

Engine braking comes from compression, rather than lack of power as such. It is turning the power off that allows the engine compression to brake the motor. It's the power of compression taking over from the power of combustion. So the the thing that really changes the amount of engine braking is having lower (if the spark plug blows out ) or higher (like a diesel ) engine compression.

I'm wondering if there is some additional effect from exhaust pressure characteristics, with changes in exhaust systems? It feels like it, but it could be down to the ears and the vibes and the infamous seat-of-the-pants-dyno rather than actuality.

 

P.S. I don't have a PClll. I do have the MG Race ECU. So things are smooth enough. Maybe someday I'll get into dyno world and see what's really happening.

[dlaing]

P.S. I don't have a PClll. I do have the MG Race ECU. So things are smooth enough. Maybe someday I'll get into dyno world and see what's really happening.

86303[/snapback]

Note that when I had a custom map done, it corrected air to fuel ratios as high as 17 to 1.

The Ti mufflers demand a totally different map than the Quat-D.

I suspect that there is no other muffler on the market, other than Enzo's Cobra or similar, that will have as different of fueling demands from the stock or Ti setups as a QuatD does, especially with catalyst removed.

[belfastguzzi]

I've added the weight of the MG standard exhaust to the figures in the first post. It's a stone heavier than than the Quat-D.

 

So DL, you reckon that a PClll is a necessity with the Quat?

Looks like I may get an analysis done.

[v50man]

I just had my dealer tweak the on-board computer to accomodate the Quat-D. So far -- so good.

 

I think you NEED a PCIII for the Quat-D in the same way that I NEED an MV Agusta F4.

[OldButNotDead]

I've added the weight of the MG standard exhaust to the figures in the first post. It's a stone heavier than than the Quat-D.

 

So DL, you reckon that a PClll is a necessity with the Quat?

Looks like I may get an analysis done.

86374[/snapback]

 

 

I'm guessing a PCIII + proper map would be good for an even wider grin

 

My Quat-D just lost its cat and the bike is feeling pretty lean below 5k. Not bad elsewhere, but I don't trust my butt to feel anything other than dips and bumps in the power delivery. I've just scheduled some dyno time for early May and will post the maps when done.

[dlaing]

So DL, you reckon that a PClll is a necessity with the Quat?

Looks like I may get an analysis done.

86374[/snapback]

Considering I got an A:F ratio of 17:1, I would consider it a necessity.

http://www.guzzitech.com/Quat-D_David-L.html

http://www.scripps.edu/~dlaing/v11s/DLV11-vs-TEJack.jpg

Here is my PCIII map

0 2 5 10 20 40 60 80 100

500 0 0 0 0 0 0 0 0 0

1000 0 0 0 0 0 0 0 0 0

1500 0 26 23 14 27 11 17 20 20

2000 0 0 17 0 5 -3 -2 -12 2

2500 0 0 15 17 -2 2 9 3 17

3000 0 0 0 20 1 17 15 21 29

3500 0 0 0 11 5 3 15 11 15

4000 0 0 0 17 7 1 14 22 24

4500 0 0 0 18 13 4 9 15 4

5000 0 0 0 18 20 4 -3 -6 -1

5500 0 0 0 0 24 1 -6 -7 -4

6000 0 0 0 0 0 1 -8 -6 -7

7000 0 0 0 0 0 -2 -2 -13 -10

8000 0 0 0 0 0 0 -3 -14 -17

Consider that the 29 at 3000 RPMs represents a correction of the 17:1 Air to Fuel ratio, you can just imagine how rich and how lean it can be.

But keep in mind I did not get perfect success.

I had pinging at 5000-6000RPM and WOT, where they actually leaned it out!!!

The more ideal way to tune it would be with WBO2 bungs welded into the headers so that the cylinders could be individually mapped.

Or better yet spend bigger bucks for a more accurate multi gas analysis dyno tuning.

Or have fun and get your own WBO2 meter and directly tune the ECU with TuneBoy.

BFG, I think Tuneboy has your name on it! This could be a good excuse for you to buy a MacBookPro and load Windows

If one makes the partially correct assumption that higher numbers on the map likely correspond to more power, you can see the Quat D will gain power at lower RPMs and lose it at higher RPMs.

But you have the later Quat'D with catalyst removed, so your numbers will be different....

I wish someone would map their PCIII or ECU for the quatd, so we could see the dramatic changes.

Perhaps OBND may post his results????????

[belfastguzzi]

Consider that the 29 at 3000 RPMs represents a correction of the 17:1 Air to Fuel ratio, you can just imagine how rich and how lean it can be.

I had pinging at 5000-6000RPM and WOT, where they actually leaned it out!!!

The more ideal way to tune it would be with WBO2 bungs welded into the headers so that the cylinders could be individually mapped.

BFG, I think Tuneboy has your name on it!  This could be a good excuse for you to buy a MacBookPro    and load Windows 

But you have the later Quat'D with catalyst  removed, so your numbers will be different....

86416[/snapback]

On the one decent ride so far, I didn't have any pinging.

Although The MG 'race' ECU isn't set-up for this purpose, I'm assuming that it is still better than the stock (which I guess you had?) and that it will definitely be better at 3,000.

 

There are plugged points on each header. I don't know what size the WBO2 inserts are?

There is also a big screw plug in the top of the box..?

If I go down the PClll route some time in the future, I'll have to install Virtual PC or get an old actual PC for this purpose. That's just one of the reasons that I haven't seriously considered it so far (in addition to cost, another technical gizmo in system and already having the MG Ti ECU).

 

I'll enquire about a DynoJet session...£$€groan£$€

[OldButNotDead]

Considering I got an A:F ratio of 17:1, I would consider it a necessity.

http://www.guzzitech.com/Quat-D_David-L.html

http://www.scripps.edu/~dlaing/v11s/DLV11-vs-TEJack.jpg

Here is my PCIII map

0 2 5 10 20 40 60 80 100

500 0 0 0 0 0 0 0 0 0

1000 0 0 0 0 0 0 0 0 0

1500 0 26 23 14 27 11 17 20 20

2000 0 0 17 0 5 -3 -2 -12 2

2500 0 0 15 17 -2 2 9 3 17

3000 0 0 0 20 1 17 15 21 29

3500 0 0 0 11 5 3 15 11 15

4000 0 0 0 17 7 1 14 22 24

4500 0 0 0 18 13 4 9 15 4

5000 0 0 0 18 20 4 -3 -6 -1

5500 0 0 0 0 24 1 -6 -7 -4

6000 0 0 0 0 0 1 -8 -6 -7

7000 0 0 0 0 0 -2 -2 -13 -10

8000 0 0 0 0 0 0 -3 -14 -17

Consider that the 29 at 3000 RPMs represents a correction of the 17:1 Air to Fuel ratio, you can just imagine how rich and how lean it can be.

But keep in mind I did not get perfect success.

I had pinging at 5000-6000RPM and WOT, where they actually leaned it out!!!

The more ideal way to tune it would be with WBO2 bungs welded into the headers so that the cylinders could be individually mapped.

Or better yet spend bigger bucks for a more accurate multi gas analysis dyno tuning.

Or have fun and get your own WBO2 meter and directly tune the ECU with TuneBoy.

BFG, I think Tuneboy has your name on it!  This could be a good excuse for you to buy a MacBookPro    and load Windows 

If one makes the partially correct assumption that higher numbers on the map likely correspond to more power, you can see the Quat D will gain power at lower RPMs and lose it at higher RPMs.

But you have the later Quat'D with catalyst  removed, so your numbers will be different....

I wish someone would map their PCIII or ECU for the quatd, so we could see the dramatic changes.

Perhaps OBND may post his results????????

86416[/snapback]

 

I will post the curves, and am willing to PM my maps. My experience is that my previous PCIII custom map (no airbox lid/Stucci/Ferracci cans) was money well spent. Not perfection, but significantly better. The bike would still ping if I whacked it open too quickly - even with the "accelerator pump" feature turned on. I haven't heard a price yet for individual cylinder mapping, but will ask when I bring it in. Also considering putting the airbox lid back on, the volume is a bit over the top as is.

 

Removing and replacing the QuatD (to pull the cat) has encouraged me to fiddle with it's positioning, and I've gradually removed some of the washers I originally installed to maintain clearance. Not all gone, but it sits a bit higher now. Hats off to BFG - taking a big hammer to a pricy brand new I-talian gee-whiz bit is beyond my courage Also, for anyone else that wants to pull the cat, aluminum rivets won't cut it; use stainless steel.

[belfastguzzi]

 

Some pictures of the bracket are here LINK

and a sound file of the Quat-D here.

 

[v50man]

 

Some pictures of the bracket are here LINK

and a sound file of the Quat-D here.

 

86494[/snapback]

 

Put the washer on the TOP and life will turn good again. Great looking bike, BTW...

 

v50..........................

[belfastguzzi]

Put the washer on the TOP

86497[/snapback]

But to get space for that, I'd have to hit it with the hammer again!

 

Yep, the whole thing is still ever-so-slightly low. There's a fibre washer in there as well.

I suppose the answer is to grind a bit off the bike bracket.

[v50man]

But to get space for that, I'd have to hit it with the hammer again!   

 

Yep, the whole thing is still ever-so-slightly low. There's a fibre washer in there as well.

I suppose the answer is to grind a bit off the bike bracket.

86498[/snapback]

 

Put the hammer down. Have a drink. Re-evaluate. Try again.

 

It's all good...

[jrt]

I smell a bodge point coming on.