Nearly stock V7R and "GuzziTech" V7R comparo

[tonUPRacer]

This weekend I got a chance to hook up again with another V7 rider who lives nearby. I was really looking forward to seeing and hearing his bike since he went with the full "GuzziTech" mods. ECU remap, 2-1 exhaust, open air box etc. I was even happier when he suggested we swap bikes! It was an unusally cool June morning in our neck of the woods, maybe 55 and overcast. Anyway, I had about a 100 mile route mapped out through some alphabet soup country roads that turned out to be as rough as they were twisty. Back to the bikes. My riding buddy's bike was spotless (in case he's reading this) and the 2-1 pipes with the shorty can looked really nice. The welds were good and pipe bends looked great. The rear of the bike looked a bit "empty" with the exposed swing arm, but I guess I'm just used to seeing my long Arrow pipes. When he fired up the bike it was quite a shock, it was LOUD. But it did sound good. Just think of the old dirt track stock car races you used to attend. We set off and after about 20 miles stopped again and now it was time to switch. I was amazed at how different his bike felt just putting a leg over it. I guess that was largely due to his suspension settings and he also had the instrument lowering bracket which I thought also looked nice. The biggest difference was sound, did I say LOUD? Again, he did have the shorty can on, he also purchased the standard exhaust can from Todd too, but I did want to hear what that shorty was like, so I'm glad he kept it on.

I really didn't notice any major difference going through gears as far as the fueling goes, I know GuzziTech promises some mid range improvement, but I didn't notice it, maybe I'm just not that experienced. It was fun gassing the bike and hearing it roar along. My friend said he wanted to hear his bike over the wind, mission accomplished. There was a little decel popping on over-run but no harsh backfiring. The biggest thing I noticed was on a couple of high-speed passes trying to do the "ton" the bike started to miss and cough bad enough that I had to get off the gas. So something needs to be adjusted there. My friend said he hadn't ridden much and I guess he should have known who he was lending his bike to! The other thing was I was missing my suspension on those bumps, my upgraded front and rear springs really did make a big difference on those roads. I wouldn't be a bit surprised to find my buddy has those upgrades soon too.

[Kev m]

Fantastic report!

Thanks for sharing!

 

[bad Chad]

Interesting.  Doesn't sound like his performance mods are doing what they are advertised to do, except for the greater dbs.   

[Rough Edge racing]

Interesting.  Doesn't sound like his performance mods are doing what they are advertised to do, except for the greater dbs.

 The  description of the high speed runs seems like the engine fueling is lean...

[kevdog3019]

Pipes alone aren't going to yield much except sound. If that floats your boat so be it. There's a good bit to invest if you want to change real figures.

[tonUPRacer]

I don't think GuzziTech makes claims of HP increases but they do claim better cold start and mid-range. Since the bike was already warm, I can't tell how that is and I forgot to ask. I was curious to see about any mid-range "punch" that maybe I was missing but I couldn't detect it. I guess it does come down to sound and how much you like to tinker. I did pay a premium for my Arrows but at the same time they have been bolt on and go. I didn't have to mess with any fueling etc. So when you add it all up they weren't much more expensive if at all when you consider time invested, and my bike hits the ton and keeps going.

[bad Chad]

Kev, he said this, "since he went with the full "GuzziTech" mods. ECU remap, 2-1 exhaust, open air box etc. "   So there is a lot more invested than just a set of cans.

[tonUPRacer]

GuzziTech is planning to offer a Big Bore 4V kit which should be interesting and I'll be curious to see what HP gains they get with that. I'm sure some will go down that path, if I'm lucky my riding partner will and I'll get to test that too! 

[Vasco DG]

So he's spent a substantial sum of money making his bike anti socially and tiringly loud and run worse than stock. Damn!

[Moto Fugazzi]

That would have been money well spent on suspension upgrades instead.

Iv'e tried open air boxes, and I think they're horrible-putting the airbox back to stock should help, although I'm sure some would argue that.
Ken

[Perazzimx14]

This is why I hate FI. I had to spend $300 to mostly stop the popping on decal when I added Mistrals to my V7R. 

[Guido Valvole]

Wow! Two V7Rs in one spot, almost a NAR!  Reminds me of the ride here a few years back with three (3) Monzas. Call the Guinness people… Sounds like you had fun and yeah, suspension upgrades usually give more for your money than engine.
cr

[kevdog3019]

GuzziTech is planning to offer a Big Bore 4V kit which should be interesting and I'll be curious to see what HP gains they get with that. I'm sure some will go down that path, if I'm lucky my riding partner will and I'll get to test that too! 

THIS WILL GET SUBSTANTIAL GAINS, YES!  Pricey but not fluff. I've known about this for awhile. We'll see when it happens, but it will be a game-changer.

[Vasco DG]

THIS WILL GET SUBSTANTIAL GAINS, YES!  Pricey but not fluff. I've known about this for awhile. We'll see when it happens, but it will be a game-changer.

I doubt it. A bit more torque and more vibration without rebalancing. The limiting factor with the Smallblocks is the heron heads. Punching them out to a bigger capacity will achieve little.

[kevdog3019]

I doubt it. A bit more torque and more vibration without rebalancing. The limiting factor with the Smallblocks is the heron heads. Punching them out to a bigger capacity will achieve little.

My experience and mwrenn's experience would say otherwise. Moving from 2 to 4 valves per head is pretty significant. Boundaries can be moved with the heron heads. Are you going on theory or actual experience Pete?  How many sb herons with major conversions have you ridden?  I personally can only go by my experience, but I've talked to Mike about his pretty extensively and I don't think he's pulling my leg.

[Aaron D.]

MWrenn's bike is a 4 valve but not a Heron head-same with any Lario.

[Moto Fugazzi]

This is why I hate FI. I had to spend $300 to mostly stop the popping on decal when I added Mistrals to my V7R.

Guzzidiag is free, but you need the proper cables. Much easier than changing jets in a carb.
Ken

[Vasco DG]

Larios use a pent roof combustion chamber with a fairly wide, by contemporary standards, included valve angle. Utterly different to the Heron head design of the 2V smallblocks. People like Ed Milich have spent years doing ongoing development work on the smallblocks and while porting may give some benefits it will be re-camming and valvetrain changes that will be paying the highest dividends.

Look, there's nothing new to see here. The Smallblock engine has remained basically unchanged for forty years apart from changes to bore and stroke. People have been trying to, claiming and failing to get radical increases in performance for all forty of those years and their efforts to get cheap horsepower out of the engine has always borne the same disappointing results. Why? Because you cannot radically increase volumetric efficiency when you are turning gasses through 90 degrees into and out of the combustion chamber and valve area is limited by the surface area of the flat head. Quite simply pi-r2 is smaller than Pi-r3/2. It's the laws of physics, they are immutable and inarguable. Sorry.

And yes, I know this from personal experience and observation.

Pete

[kevdog3019]

Pete,
     I think we are talking about two different things. The changes I'm talking about are valves (numbers and/or size) as well as things like compression and cams. If all someone wants to do is re-tune/open the exhaiust/screw with the airbox, I'd agree with you; it's fruitless.

[Aaron D.]

PEte, a crucial word got dropped-are you saying the included angle on the Lario is large or small?

I'm guessing you meant small-and that would make it a pretty good candidate for some power if the carbs (or throttle body) were in the right place.

[Vasco DG]

It's wider than the current 8V I believe but not as wide as a 2V big block from memory. I don't have a book handy. I'll modify the post.

Pete

[Aaron D.]

I only figured narrow because I've seen 'em. Good ol'' Duckworth. Among the biggest leaps in 4 stroke technology.

[canuck750]

Speaking of cool small blocks, this strange hybrid sits in the museum in Mandelo. It looks like a small block motor in a conventional tonti frame, 850T tool boxes, V7 Sport tank, front end etc.







Anyone know the history of this bike?

[Yukonica]

Backing up the thread to the OP V7R stock vs Todd'd... I am also experiencing the poor fuelling of short Mistrals.
Would love to cure it. Guzzidiag does not offer the solution yet.
Don't know what does other than giving-in to the stock map until the gurus find a model and time to work out proper options. I can ask about the effect of valve adjustment, or 'fancy' iridium plugs, and/or any other suggestion that comes my way. But for the moment; a light throttle hand is all that seems to work. And, no, Pete it isn't about the noise.
That noise is a byproduct of trying to reach an aesthetic balance on a visually light machine. The long shark gilled traditional V7 pipes matched the fashion of the day the same way American cars used rear fender fins in the 1950's. That style, still in use on Victory cycles etc. looks (to my eye) ridiculous, over weight and impractical. I like to see the seat line, the wheels, and the motor. Everything needs to balance against those proportions. Long, (quiet), pipes hide the rear wheel; again my view. I don't give a rats ass about performance. If I wanted performance I'd own a whole different marque. I enjoy the lines and visceral pleasure of 'motoring'. Here's hoping GuzziDiag finds the route to support the marque's most successful model in the present.

[Vasco DG]

The noise is secondary. It's the tuned length and volume of the pipe that governs how it will work. Generally speaking a short pipe will work better at the bottom end but will create problems at higher engine speeds. This is a crude explanation but exhaust design isn't a simple subject.

The speed of sound is the only constant in the system. Length and volume along with header diameter, valve and port size and a host of other factors will all have an impact on how the pipe performs but the length of time it takes for the pressure wave to move from the exhaust valve to the end of the pipe and return will remain a constant. It's force and impact will be more governed by pipe shape and volume.

Short, stubby pipes may look trendy but they aren't worth a pinch of shit unless all you want to do is rush noisily from traffic light to traffic light. Regardless of mapping changes you aren't going to get increased volumetric efficiency, especially at the top end, with a stubby pipe. It'll run like a mad woman's shit and no amount of pissfarting about will change that because at elevated engine speeds the harmonics will be actively inhibiting the egress of spent charge or, if you're really lucky, producing increased charge transition leading the ECU to overfuel so you get the full trifecta of hideous din, less performance and lousy fuel economy! Winner! Winner! Chicken dinner! (Not!)

Pete

[Muzz]

GuzziTech is planning to offer a Big Bore 4V kit which should be interesting and I'll be curious to see what HP gains they get with that.

Does anyone actually know whether it will be a Heron head?  If it is a kit it may well be a late pentroof or hemi design; in fact, if they were going to all the trouble to come up with a kit with barrels, pistons and heads, surely they would go the whole hog and do what Guzzi should be doing but aren't and that is do what Chuck and Kev have done.

[Yukonica]

The noise is secondary. It's the tuned length and volume of the pipe that governs how it will work. Generally speaking a short pipe will work better at the bottom end but will create problems at higher engine speeds. This is a crude explanation but exhaust design isn't a simple subject.

The speed of sound is the only constant in the system. Length and volume along with header diameter, valve and port size and a host of other factors will all have an impact on how the pipe performs but the length of time it takes for the pressure wave to move from the exhaust valve to the end of the pipe and return will remain a constant. It's force and impact will be more governed by pipe shape and volume.

Short, stubby pipes may look trendy but they aren't worth a pinch of shit unless all you want to do is rush noisily from traffic light to traffic light. Regardless of mapping changes you aren't going to get increased volumetric efficiency, especially at the top end, with a stubby pipe. It'll run like a mad woman's shit and no amount of pissfarting about will change that because at elevated engine speeds the harmonics will be actively inhibiting the egress of spent charge or, if you're really lucky, producing increased charge transition leading the ECU to overfuel so you get the full trifecta of hideous din, less performance and lousy fuel economy! Winner! Winner! Chicken dinner! (Not!)

Pete

Why defend the putrid performance of a mini bike built in Italy? Come on! We are talking about a machine that will fall off a cliff at 180 and only brake to a full stop at ground level. It is a spineless piece of shit. Get it? No Point in discussing 'performance'. There is none.
Aesthetics is the strong point of the V7. And that's where your perspective and mine part. Short pipes aren't about trendy bullshit kid's rides. They are about visual balance. Long pipes create leading lines that take the eye past the end of the machine. They are the lower part of the rule of thirds. Good visual technique brings the attention to the subject; it doesn't draw it away without very good reason. To me long pipes are as ugly as ape hangers. And, even ape hangers bring focus to the centre. I would find it very depressing if there truly is no engineering solution beyond the status quo.

[Vasco DG]

Sorry. But what part of the laws of physics is it you don't understand? I can fully appreciate the aesthetic attraction but form should compliment function, not fight with it!

[fossil]

Funny! One main reason I bought my V7 Stone were the wonderful, good sounding, not too loud, long original LaFranconi pipes...

[voncrump]

Giddy Canuck 750

The mario Colombo book describes a very similar bike.

The first experiments with a medium capacity V engine, which was later to spawn the V50, V35 and all their descendants, dates from 1972. For the road tests the new propulsion units were mounted in a V7 sport, a large flange having been fitted to adapt them to the gearbox. As can be seen, these engines had a vertically split crankcase. The carburettors fitted were 22mm units while the definitive version recieived 24mm instruments.

I saw this bike on my visit to the museum in 2012

Cheers, voncrump