Preliminary Exuberance

[Guest captain nemo]

If you are easily frightened or believe that your bike should remain technically legal, or that welding torches and hack saws should never approach a Guzzi, please skip this review.

 

OK, I'm back from the custom header guy. I went down with my funny idea on my crossover and he said I was half baked, but half totally correct. He has 40 years experience running one of the best exhaust outfits in the Northwest. Basically, he explained to me how crossovers work and that mine was just fine the way it was. They are all designed to simply balance the exhaust pulse. So my idea to make it larger was silly. OK, fine. I also wanted him to weld shut one exhaust port coming out of the crossover and to weld in my short Supertrap pod onto the other one. I told him I believed this would increase the low end. I realized I would do this at the expense of top end power. This was correct. He thought my pod ought to be a bit larger, but would do what I thought it would do.

 

OK, got home and bolted everything on just to see if it would start. All the innards for the Supertrap haven't arrived, so we are talking straight pipes here. I wanted to see if it would run wide open anyway since I will probably have to keep it nearly wide open. I was terrified to start it in my nice little quiet community here, but had to. It fired right up and idled on choke just like it always does. The tempo was slower and the note was actually beautiful, but a bit over the top decibel-wise. Not half as bad as I thought it would be. One of the first things I noticed (besides being thrilled that it did not blow up) was that the exhaust pulse can be felt on your pant legs 20 feet away - just like at the race track. Nice.

 

I strapped on my new seat that I haven't tried yet and I was ready for my usual 'test' run around my neighborhood that takes me down to the ocean, up a little mountain and back down a main low speed road without street lights back to my house. Just 3 miles or so. God was I pleased and surprised!

 

The riding position and comfort of my new seat was just perfect. And then - the bike was actually running and going through the gears. Swell. Right off I noticed WAY MORE low end power up to 3500 rpms where it becomes 'normal' again. This is fine with me because this is where I spend most of my time anyway - especially in corners. I didn't go very fast, so I have no idea about the top end, but don't really care about going over 100 anyway. The power is so radicalized that I almost crashed twice! I actually got in trouble rolling out of corners like I usually do, but now found myself terrified as the bike almost ran out underneath me and I was headed for the ditch on the opposite side of the road! Whoa. And all this without any change in mixture settings and no idea how far off I am with that.

 

After Christmas I will pick up my Supertrap innards including the baffles. I will experiment with the discs to see what is best. The other great thing about today was I found another 'Jethot' type place (4 blocks from the header guy) - 'Performance Coatings' which does the exact same ceramic coatings in and out that Jethot does. Up to 2000 degrees F. So, if all goes well and the bike is running great, I will have the exhaust all cleaned and coated in and out. Then over to Moto International for a new 'tune.'

 

I can only give you my impressions because there are no Dynos around here. Sorry about that. I suppose this spring I will meet a couple other guys from the forum here and they can check it out and report. A good day in Guzzi heaven.

 

[emry]

Congradulations. Glad to hear you have made the bike just a little bit more "yours". Post a pic when you get a chance

[dlaing]

This probably is not too different from a Quota exhaust system.

Just louder and more free flowing.

[Guest captain nemo]

Yes, I didn't know anything about the Quota besides it being an off-road type bike, but I see now that it also has 2 into 1 exhaust and these numbers below here 'sound very much like what I think I've done to the V11 (the 'Enter the Dragon Quota/Rosso'. I have forgotten where the stock V11 makes the most torque, but I believe it is quite a bit higher up in the revs. Same number though: about 70 foot pounds. Less hp and top speed as I would expect. I'll trade that for torque where I can use it.

 

 

 

 

QUOTA 1100 ES TECHNICAL SPECIFICATIONS:

 

ENGINE:

 

type:

90 degree V-twin, 4-stroke, Otto cycle

 

displacement:

1064 cc light-alloy surface-hardened cylinders

 

bore and stroke:

92 x 80 mm

 

compression ratio:

9.5:1

 

valves and operation:

2 overhead valves with light alloy push-rods and rockers

 

fuel system:

Electronic Fuel Injection

 

ignition:

Electronic Digital Ignition with inductive spark

 

starting:

electric

 

cooling system:

air cooled

 

lubrication:

forced lube with geared pump and pressure regulator

 

spark plugs:

NGK BPR 6 ES

 

maximum H.P:

71 at 6400 rpm

 

maximum torque:

68 ft/lbs at 3800 rpm

 

valve timing:

intake 0.20 - exhaust 0.25; inlet: open 20° before TDC, close 50° after BDC; exhaust: 44° before BDC, close 10° after TDC

[gthyni]

I look at the quota exhaust,

this is a 2into1 part:

 

I don't think this is optimal,

the tubes should be of as equal length as possible AFAIK.

Comments?

[Guest captain nemo]

Yes, the expert guy told me that the whole idea of crossover headers is to make up for the fact that a multi cylinder engine often has to have exhaust tubes of different lengths. He would look at this photo and note that it needs a crossover exactly because the tubes are not the same. Even when they are the same a crossover assures a nice balanced flow. I was looking at pictures of the Quota and trying to see if it had a crossover. I thought it did from the pictures, but I guess I'm wrong about that. My set up would put out more power I think. The additional backpressure brings the torque range down in the rev curve.

 

A real race bike and a crack racing team would almost have to make a decision before every race by looking at the track and seeing what type of power they were going to need most and then make some alterations - perhaps exchanging different pipes etc.

[Guest Fonzarelli]

I look at the quota exhaust,

this is a 2into1 part:

 

I don't think this is optimal,

the tubes should be of as equal length as possible AFAIK.

Comments?

The individual primary exhaust tubes should be as close to equal length as possible. Again, this has everthing to do with the reflective exhaust wave timing back into the combustion chamber. In a nutshell, this aids greatly in the the cylinder filling during the intake cycle. To tune for a specific torque peak, it is imperative to equalize tubing lengths as well as diameters.

 

The addition of a crossover pipe does two things:

 

1. It lowers the exhaust note of the engine.

 

2. It can have a measurable increase in torque.

 

This is accomplished because the crossover itself effectively increases the exhaust outlet of each individual cyclinder. Each cylinder can use the whole exhaust system on it's own. Since each of the cyclinders fire on a seperate stroke, the exhaust strokes are seperated, thus enabling the use of the entire exhaust system.

 

If you think about it, the exhaust becomes much more free flowing for each individual cylinder.

 

An exhaust crossover is not intended to band-aid an ineffective exhaust system.

[Guest captain nemo]

Right, you've got it. The guy pretty much said what you just said, and the crossover also helps equalize differnt lengths of tube - exactly becouse the whole system becomes integrated.

 

Looks like I will need a map for a Quota now - with K & Ns and a Supertrap. Ha. ha. Funny. I'm sure that map is out there. Looks like I will be adding a whole new map to the Guzzi world when I get it figured out.

[gthyni]

I was thinking something like this quick mock-up

behind the oil-sump.

[emry]

A real race bike and a crack racing team would almost have to make a decision before every race by looking at the track and seeing what type of power they were going to need most and then make some alterations - perhaps exchanging different pipes etc.

 

We used to bring about 6 different exhaust configuartions to each track 4-1, Tri-Y, 4-1-2, etc., which could be used to help tailor the power band to better suit the riders need at a particualr track. This helped on the four cyln. machines greatly but was not even noticable on the twins, due to the flatter torque curves.

 

For example at Daytona we used a 4-1 large diameter short length pipe to maximize peak hp and thus top speed.

[roberto]

This is the sort of result you want to get from an exhaust replacement...

[dlaing]

This is the sort of result you want to get from an exhaust replacement...

That is more than just mufflers, right?

K&Ns and tuning link, stock crossover?

Nice results!