Mistral X-over == crappy mid-range?

[Guest IanJ]

So, I got a Mistral/Agostini exhaust crossover installed on my '02 Le Mans yesterday, and immediately noticed that the midrange power sucked, when compared with the stock crossover. By midrange, I mean between 2500 and 4000 RPM. I ride a lot in this range, particularly between 3500 and 4000, since I spend a lot of time accelerating away from stop lights and cruising in slow traffic. (I also spend a fair amount of time between 4000 and 5000 RPM, but it doesn't seem to be an issue there.)

 

I called the dealership, and their head tech said that yes, that was what would happen -- low-end and midrange would suffer, but top-end power would be improved. Does this square with what most of you would expect? Was I crazy to think that a crossover would somehow improve midrange power?

[al_roethlisberger]

Hrmm, while I have never seen any empiracle data to prove the following assumption, I had always "heard" that the Mistral was tuned to give the results you've experienced, where the Stucci boosted the production cross-over's midrange "dip" without sacrificing too much of the top end.

 

So most people I've chatted with chose the appropriate crossover based on this information:

 

Mistral = Improved top end, sacrifices some low/mid range

Stucci = Improved mid-range, potentially small top-end loss

 

But like all things, YMMV based upon your bike's state-of-tune, other exhaust, head, intake mods, etc...

 

al

[Guest IanJ]

Huh, I could have sworn I read that the other way around in another thread. So, based on that info, it might make sense to try out the Stucci as well, and see if it did a better job with the midrange. Right now, the bike feels crappy. I'm going to see it through for a week or two to provide the dealer with some experimental results, but I definitely don't want to live with this thing long-term.

[al_roethlisberger]

Huh, I could have sworn I read that the other way around in another thread.

 

....oh sure, who really knows, that's just what I heard

 

But I based my purchase of the Stucci on that assumption, so I hope I'm right

 

Maybe they can map the bike to the new x-over to minimize the impact?

 

al

[mikie]

When I've experienced problems like this on other bikes, after messing around with the exhaust or airbox, I've usually found that corrections could be done by either rejetting or, in this case, installing a power commander with a proper program. If you haven't done the power commander thing yet, you should probably give it a try.

Mike

[al_roethlisberger]

I think that's true to a point, however there are generally certain performance constaints inherent to some designs. I'm not certain this is true when comparing the Mistral versus Stucci x-overs, but it's possible.

 

If so, then if by nature/design, one is more prone to favoring certain performance ranges, changing the map will only let one tune it within that range to some degree.

 

So, IMHO, it's best to get the right tool for the job. If it turns out that the Mistral is indeed better designed to favor high-rpm HP, versus low/mid rpm power... but one's goal is inverse to that, the best remedy would be to get the other x-over.

 

There may be other advantages to either x-over that I am unaware of though, and that could also influence one's choice.

 

Again... standard disclaimer... YMMV ... especially with these bikes

 

al

[jrt]

Check out the tech articles on Manley Cycles (no, I'm not making the name up)

A comparison of MG exhaust systems:

http://www.manleycycle.com/Tech/mgv11ex.htm

http://www.manleycycle.com/Tech/more_mg.htm

 

Or the main tech page:

http://www.manleycycle.com/Tech.htm

 

 

Cheers,

Jason

[Mike Stewart]

I agree with Mikie, with every change in exhaust or even air filters, you need to think about the effects on the fuel system. Will it run richer or leaner from the mods just preformed. If you already had aftermarket mufflers and then added the crossover, you may have gone waaayy lean which made the loss of midrange more noticeable. I know when I put on the Mistral mufflers, I had a huge loss of midrange and to get any power, I had to be near redline. The Power Commander corrected the midrange loss as well as added more top end.

 

As far as the Stucchi crossover goes, it really makes a difference in the midrange and by the feel of the pants, it feels like the bike reaches top speed faster (120 mph, kids don't try this at home). I have not noticed any loss of top end. I have only positive things to say about the Stucchi.

 

Mike, no the other Mike

 

Mike

[mikie]

It's too bad Manley Cycle isn't a bit closer to Pasadena, or they'd certainly get some business from me - they sound like they know what it's about. Yes, the other Mike and I are in agreement, as whenever this type of modification is done it generally needs some compensation in fuel delivery, one way or another. (I don't suppose you're the same Mike Stewart who used to sing with We Five?)

Mike

[Guest scott]

Jason:

 

Thanks for the great web site from Manley Cycle. It provided some good comparative information regarding x-overs.

 

I personally am not willing to sacrifice low rpm torque; I spend most of my time at about 4000 rpm and seldom make it to red line (I know, I know, I need to be more aggressive on the throttle). I'll probable stay with the stock x-over.

[al_roethlisberger]

....with every change in exhaust or even air filters, you need to think about the effects on the fuel system.

 

Agree completely

 

My point was simply that if either x-over had specific areas of benefit, even tweaking the map of the ECU and/or PCIII will have a limited range of benefit as opposed to first starting out with the x-over appropriate for one's goal.

 

Let us know how it goes Ian

 

al

[jrt]

Personally, I'm glad Manley Cycles is in Minneapolis instead of Pasadena . Pasadena is a much longer drive. I haven't done any business with Manley, but they have a good rep. The bottom line is that a competent tuning facility should be able to map out your bike's injection.

Are you guy's running power commanders? If so, Todd Eagan is in your neck of the SoCal woods (eh, concrete). He's supposed to be pretty good.

 

Cheers,

Jason

[Guest mcloutier]

Hi, Ian. With all the city driving you do you definately want the Stucchi. I have been testing mine for the past couple of weeks and it's fantastic. Big improvement in the middle and no noticeable drop in the top end. I will try and get a full review posted tonight. Best money I ever spent.

[wildbill]

so a couple of questions - has anyone run the stucchi x-over on their lemans without a power commander and with the stock map? if so, how did the bike run, better? did you lose that flat spot at about 3500 - 4k rpm? also, if i go with the stucchi is the installation straight forward or is there any hitches? do you disconnect the charcoal cannister? thanks all...

[Mike Stewart]

A friend of mine put a Stucchi crossover on his 2002 Lemans with stock pipes and no Power Commander, he claims that he does not feel any difference. So I guess he needs to add aftermarket cans and add a Powercommander to gain what he is missing.

 

Mike