Stucci Crossover

[Guest rosso mandello]

well, my problems started at the German Autoban last summer, where we did 160 km/hour. I wanted to pull up to my maid on hees BMW 1200RS to explain to him that I needed to take a leak. Guess what, i did not catch him, every time I was neer, he just thought that I would play with him.

I will not go back on the highway with him again unless i got all the power at hand

[Guest ratchethack]

I agree that the standard crossover is not the worst solution.

A have a Dyno graph of my 2000 V11 with the std and the Stucchi crossover. The mufflers were my modified stock cans (see the "unpacking the cans" thread) which caused a 3 HP gain.

Interesting, MGNX. I'd be disappointed in this too. On your chart, the Stucchi with doctored-up stock mufflers made the midrange torque curve "WORSE" than stock - except that it shifted the "hole" and the curve coming out of the hole downward by ~200 RPM!

 

I reckon it's a brand-new ball game with freer-flowing mufflers, as you noted. With my FBF oval carbons, it's significant enough so I can really feel a positive difference in the mid-range without the pronounced "dip".

[motoguzznix]

ratchet

 

Since i've noticed the moto one link of Dlaing I could find out that their dyno runs show very similar results to mine: the biggest gains of the stucchis occur from 4500 to 5500 rpm. This is slightly above the stock torque dip. But I am happy to see that our measurements seem to be serious too.

In the meantime I further modified my cans for better flow characteristics and hope to get better results on the Dyno. They still are not too noisy. This will be accompanied by Lambda measurements and remapping the ECU.

The final step with the stock cans could be to increase the diameter of the exit pipe from 30 to 40 mm, as this has not been done by myself till now. But this would supposedly increase the noise at a more noticible amount.

[Guest ratchethack]

MGNX, by all means, be sure to post your dyno results. I've got a Pal with a LeMans, who's done some modifications to his stock cans and he'd be interested. I think many have cut 'em up, but none to my knowledge here have then put 'em on a dyno...

[dlaing]

I will try a more freeflowing exhaust in the future.

81610[/snapback]

Your dyno graphs are very interesting.

You got very nice gains from the compression and valve timing changes

As for going with more open mufflers, the general theory is that more open increases high RPM power at the expense of low RPM power.

But if you compare dynos, the more free flowing mufflers APPEAR to benefit at all RPMs when switching to the Stucchi.

But perhaps that is related to the timing and compression

I am confused once more.

The other great confusion is Jaap getting Excellent high rpm HP from the Mistral crossover.

I think there were others with the front balance pipe and higher compressioned V11, who benefitted less from the Stucchi, than the earlier models did that had no front balance pipe....I suppose that makes more sense.

[mdude]

Interesting, MGNX.  I'd be disappointed in this too.  On your chart, the Stucchi with doctored-up stock mufflers made the midrange torque curve "WORSE" than stock - except that it shifted the "hole" and the curve coming out of the hole downward by ~200 RPM! 

 

I reckon it's a brand-new ball game with freer-flowing mufflers, as you noted.  With my FBF oval carbons, it's significant enough so I can really feel a positive difference in the mid-range without the pronounced "dip".

81612[/snapback]

 

Well, this is pretty much what Ive been told that HTM found out.

The Titan ECU fixes the midrange hole (so does the PClll), so one doesnt necessarily need to change the x-box to free things up. The MG Tis is pretty much straight through pipes (bloody great hole!).

Free flowing crossovers will then help boost power from midrange up. Plus adding a lot of PHP (Perceived Horse Power) because of the noise :-)

Isnt that something like lesson one in tuning? Im no expert, but I've read the stories.

 

I am doing the "Stucchi-thing" to my Audi in a while: race catalysts and two inch exhaust, and expect a lot more whallop from 3500 rpm upwards, and a bit less oomph low down. Now it is standard and pretty restricted and explodes from 2000 rpms but dies above 4500... Same story, but on my bike I am comfortable with midrange muscle cause I drive like a little girl. Not so with my car...

[motoguzznix]

As for going with more open mufflers, the general theory is that more open increases high RPM power at the expense of low RPM power.

David

This theory is simply wrong. More open is better for high and low rpms. Every exhaust restriction is bad for a 4 stroke engine. This is supported by moto ones and my measurements.

Apart from that is the tuning for resonances and shock wave tuning. This is an other story. In this direction should we be looking to cure the torque dip.

 

My next dyno session will be soon. I'm looking forward.

[Guest rosso mandello]

Jaap, maybe it is time for you to tell all of us, what you did to get 95 HP out of your bike with the stock x-over, if the story is true.

 

I Am now holding the Agostini x-over in one hand and the stock in the other, wich one should I dump.

 

I´m going on a dyno, and I want to do it right the first time.

 

ciao

[Ballacraine]

Well I would be tempted go with Agostini....

 

but that said, it really depends what you are doing with other bits in the equation.

 

What other mods do you have?

 

( Sorry if it was posted earlier, haven't read the entire thread....in a bit of a rush at the moment )

 

Nige.