Update on upgrades:

[Guest black knight]

PCW 500 *

1500 (85mm bore)

street

11 to 1

includes sleeves

 

MAX-RS gears

Bub exhaust

Kuryakyn Universal ISO™-Grips

BULLET TACHOMETER, White Face, 1" Clamp

Part Number: BA-7570-00

So far this is where I am at, there will be some polishing on the heads and K&N air filters and some tweaking, but I think this will put the Venture back where it should be, Yamaha's detuning of the Venture was a major mistake, this bike is big and heavy and needs the low end snap and strong midrange to make it the complete touring bike. This will make it seem like a whole new machine, all the comfort and style along with the necessary power and torque, the complete touring machine.

[hipshot]

RIGHT ON , man!!!!

i can see where the tach, and iso grips, will add LOADS of low end and mid range torque!

 

 

 

just kidding! keep us posted on all the "other" mods that you do!

just jt

[Guest black knight]

I just thought I would post all planned changes, the grips and tach will be nice, anything that makes my 2nd gen a little better.

[KiteSquid]

Can you provide a URL for the big bore kit? I cant seem to find it when I search the Internet.

 

Are you going to have to modify the Carburetors?

 

I am toying with adding HP to my bike.... and would like to know the total cost of some upgrades.

[pegscraper]

Are you sure that the 32mm carbs can support 1500ccs well enough? The older Royal Stars have 28mm carbs on 1300ccs which was a really bad mismatch and clobbered their performance. Even Y realized that and corrected it to some extent in the later bikes. But putting 1500ccs underneath 32mm carbs is creating almost as bad of a mismatch as that was. The 32mm carbs are barely big enough to feed the stock 1300ccs. Even the 1st gen Ventures have 34mm carbs on them. A 1500cc engine will badly need bigger carbs than 32s. The V Max has 35mm carbs on 1200ccs and they say that they are still too small.

 

Then you still have cams that aren't big enough to feed 1500ccs. Really, there are a lot of easier things you can do before pulling the engine apart. Best to make the most of the displacement you have before adding more displacement that the rest of the parts won't very well support.

 

You're sure starting out with the biggest possible mod first. Is this going to be a winter project? If you're going to have the engine apart and the heads off, for that much displacement, I'd recommend putting bigger valves in while you're at it. It'll be interesting to see how it turns out.

[Squeeze]

http://www.pcwracing.net/

[Squeeze]

Lynn,

 

i was at EGLI, world famous Tuner from late '70 and '80 in Bettwil, Swiss.

btw the only official Vmax Importer for Switzerland. Yammi itself doesn't bring it in Country ... :D

 

I talked to the Tech which does the Work and he said, they do not touch the 35mm Carbs except for 2 Numbers(157,5) bigger Mainjets with 1500cc Engine.

 

He acknowledges on the Limitations regarding the small Carbs, but he said, most People want only low End ond Midrange Profits, so they let it go this Way. There where only 39mm or 41mm FCR on the Market for Years, very expensive and not so troublefree Upgrade. Stage7 i not allowed in Swiss and can not pass Inspection.

 

But overall, i agree with you. The 32mm Carbs are too small for proper feeding, regardless 1300cc or 1500cc.

 

On the other Hand, you know ...

 

 

Nothing beats cui, except ........

 

 

more cui .... :D

[Guest black knight]

Folks, my mechanic is a professional racer and knows his stuff, he told me if top speed was my goal, bigger carbs may be an option, but since I want more low end and midrange, bigger jets will work fine, there is also the option to machine the carbs. As far as valves go, it is not necessary to change them as top end is not the goal here. To complete all the work that needs to be done, I am looking at $4000, but it will be a completely different machine. There will be no need to bring the revs up high to get the power, it will be there immediately, much nicer when loaded up or climbing the mountian roads. My Venture will be what it should have been right from the factory.

[pegscraper]

Bigger valves are for higher air flows, which will increase not only with higher rpms, but also by increasing displacement even if you only stay at lower rpms.

 

By machining the carbs, do you mean boring them out? I looked at that once myself, as I have a lathe and a mill. But I didn't think these carbs had much meat to give. I'd be afraid to bore them more than 1mm bigger in diameter, and that's not enough to make a real significant difference anyway. Then you'd also have to turn out your own throttle plates.

 

If there's one thing I've learned in my playing around with engines, the biggest key is that you get the most out of the engine when all the parts are sized to match and complement each other. Increasing the displacement on an engine that's already borderline too big for the carbs and cams that set on top of it is only going to make the mismatch of parts worse. IMHO this is not the angle that needs attacked first. I hear ya, Squeeze, the only substitute for ccs is more ccs. But the package of parts need to be complementary. It may be great out of the hole, but unless I miss my guess it's going to fall on its face on the interstate. The carbs will be running at their max and won't have anything more to give. This is why so many around here notice that gas mileage goes down the tubes when they try to hold more than about 75 mph for very long (and that's on a stock size engine). The carbs are running at their maximum capacity. If they were bigger that wouldn't happen.

 

(When I run my manually operated V boost wide open on the interstate I notice that gas mileage doesn't go down. Before I put that in, I used to notice the same gas mileage drop on the interstate that every one else does. That tells me that the engine needs more airflow on the highway, and these 32mm carbs aren't big enough to give the engine what it's asking for.)

 

Like I said before, it'll be interesting to see how it turns out. I wish I could have a chance to ride it when it's done.

[Guest black knight]

Pegscraper, I am interested in your V boost, can you explain this to me, it sounds very interesting, thanks for your feedback, I appreciate it.

[Squeeze]

Bigger valves are for higher air flows, which will increase not only with higher rpms, but also by increasing displacement even if you only stay at lower rpms.

 

By machining the carbs, do you mean boring them out? I looked at that once myself, as I have a lathe and a mill. But I didn't think these carbs had much meat to give. I'd be afraid to bore them more than 1mm bigger in diameter, and that's not enough to make a real significant difference anyway. Then you'd also have to turn out your own throttle plates.

 

If there's one thing I've learned in my playing around with engines, the biggest key is that you get the most out of the engine when all the parts are sized to match and complement each other. Increasing the displacement on an engine that's already borderline too big for the carbs and cams that set on top of it is only going to make the mismatch of parts worse. IMHO this is not the angle that needs attacked first. I hear ya, Squeeze, the only substitute for ccs is more ccs. But the package of parts need to be complementary. It may be great out of the hole, but unless I miss my guess it's going to fall on its face on the interstate. The carbs will be running at their max and won't have anything more to give. This is why so many around here notice that gas mileage goes down the tubes when they try to hold more than about 75 mph for very long (and that's on a stock size engine). The carbs are running at their maximum capacity. If they were bigger that wouldn't happen.

 

(When I run my manually operated V boost wide open on the interstate I notice that gas mileage doesn't go down. Before I put that in, I used to notice the same gas mileage drop on the interstate that every one else does. That tells me that the engine needs more airflow on the highway, and these 32mm carbs aren't big enough to give the engine what it's asking for.)

 

Like I said before, it'll be interesting to see how it turns out. I wish I could have a chance to ride it when it's done.

 

I agree from my deepest Heart. Only bigger Displacement is less than the half Way.

 

 

But, there is allways a but, isn't it ?

 

 

 

Dark Knight's Mech is not wrong in his Opinion. With the bigger Bore alone, the Engine is going to have a fair Ammount of Gain in Low- and Midrange. The upper End will not suffer a Lot, me thinks. (BUT ...) It wouldn't surprise me, if there would be another Winter and some other Upgrades.

[Squeeze]

Pegscraper, I am interested in your V boost, can you explain this to me, it sounds very interesting, thanks for your feedback, I appreciate it.

 

Well, i'm not Pegscraper, but i can explain that also.

 

 

V-Boost is a System, which Yamaha invented when they took the Venture Engine and developed the Vmax Engine out of it. It is a Set of two Butterfly-Valves which connect 1st and 2nd Cylinder and 3rd and 4th Cylinder. The Valves are controlled by a Electronic Box and a small electrical Motor.

 

Starting at 5750 RpM the Valves open continuing until RpM reaches 8k and full open V-Boost. The Valves are same Size as the Throttle Plates, 35 mm. This Way, each Cylinder sucks Mixture from both Carbs the front and rear Carb. Which feeds each Cylinder with 35mm from his own and, my guess some 32 mm Amount of Mixture from the corresponding Carb.

 

On my Max, i have a (non Stock) control Switch. When i had it on a Dyno, it pulled 80 kw on the rear Wheel without V-Boost and 88 kw with V-Boost on.

 

Lynn has modified his Bike and mounted the Unit. He controls these V-Boost manually instead of the Electronics.

[pegscraper]

The V boost system comes on the V Max. It a pair of tubes that run between the front and rear intakes with a butterfly valve in the middle of them to open or shut off the connection. On the V Max, it is designed to start opening at 6000 rpms and be fully open at 8000 rpms. At higher rpms any given cylinder can breathe through two carbs. They did this because even the 35mm carbs are too small for the 1200cc V Max engine. So rather than use bigger carbs and lose the low end, they stayed with the 35s and used this staged system to open up the high end more. Many V Max owners will modify the system to open up at lower rpms. And if they don't mind losing a little low end, they will put 39mm flatslides on their bikes and take the V boost out.

 

I personally think that Y should have designed the V boost to open up based on throttle position, starting to open at about half throttle, like the secondary barrels of an automotive carburetor, rather than basing it on rpms. But it is what it is.

 

Putting the system in my bike was a JOB. It's a custom fit as you go operation all the way. This bike wasn't designed for it and there's barely room for it. The sync screws are almost impossible to get to with this in the way. I also didn't use the electronics. I operate it manually with a choke lever from a V Star 1100. I can leave it wide open at idle if I want, where it makes the engine sound like there's a huge, lopey cam in it, but I usually don't. It does make the throttle a little cantankerous when I'm just hopping around town. On the interstate is where it shines best. I don't have to hold the throttle near so far open to hold a high speed. I have some other ideas I'd like to try for operating the V boost valves. But everything takes time, and for now this is satisfactory.

 

Holding the throttle more than about halfway open is what clobbers gas mileage, for two reasons - the carbs are operating on the main circuit which is designed for full power, which means rich, and the part throttle spark advance is taken out above about half throttle, which also makes a big difference. Having the V boost wide open and being able to close the throttle a little bit while still maintaining a high speed saves a lot of gas by giving the engine the air and fuel it needs without having to run on the richest circuit in the carburetor and by adding in the part throttle spark advance.

 

I'm not disagreeing with your mechanic. I have no doubt he knows a lot. I suspect that about this bike in particular, he may not realize that the carbs are already borderline too small for the engine and that increasing the displacement will ask too much of them. He probably, and naturally, assumes that the engine is already a perfectly matched set of parts from the factory, in which case what he says would be absolutely right. But this engine is not a perfectly matched set of parts. Carbs and cams both are borderline too small for the engine's displacement.

[Redneck]

Bigger valves are for higher air flows, which will increase not only with higher rpms, but also by increasing displacement even if you only stay at lower rpms.

 

By machining the carbs, do you mean boring them out? I looked at that once myself, as I have a lathe and a mill. But I didn't think these carbs had much meat to give. I'd be afraid to bore them more than 1mm bigger in diameter, and that's not enough to make a real significant difference anyway. Then you'd also have to turn out your own throttle plates.

 

If there's one thing I've learned in my playing around with engines, the biggest key is that you get the most out of the engine when all the parts are sized to match and complement each other. Increasing the displacement on an engine that's already borderline too big for the carbs and cams that set on top of it is only going to make the mismatch of parts worse. IMHO this is not the angle that needs attacked first. I hear ya, Squeeze, the only substitute for ccs is more ccs. But the package of parts need to be complementary. It may be great out of the hole, but unless I miss my guess it's going to fall on its face on the interstate. The carbs will be running at their max and won't have anything more to give. This is why so many around here notice that gas mileage goes down the tubes when they try to hold more than about 75 mph for very long (and that's on a stock size engine). The carbs are running at their maximum capacity. If they were bigger that wouldn't happen.

 

(When I run my manually operated V boost wide open on the interstate I notice that gas mileage doesn't go down. Before I put that in, I used to notice the same gas mileage drop on the interstate that every one else does. That tells me that the engine needs more airflow on the highway, and these 32mm carbs aren't big enough to give the engine what it's asking for.)

 

Like I said before, it'll be interesting to see how it turns out. I wish I could have a chance to ride it when it's done.

Just curious at what rpm do your carbs max out? The reason fuel mileage drops with more speed is because it takes more power to overcome the wind drag. It happens on every motorized vehicle ever made. There is no magic bullet more power requires more fuel. Your assumption that the engine needs more air flow to run at interstate speeds is wrong if the engine needs more air flow then open the throttle. I don't know how your bike runs but if I hold my throttle open for more than 20 seconds my speedometer is pegged at 120 and climbing. A gasoline powered engines speed and power are regulated by restricting air flow thats what the butterfly valve is for.

[pegscraper]

Everything I've already said should pretty well explain it. If what I've said is misunderstood, well... I really don't know how to make it any more clear. You didn't even contradict anything I said anyway. I don't know what your point is.

[Redneck]

Everything I've already said should pretty well explain it. If what I've said is misunderstood, well... I really don't know how to make it any more clear. You didn't even contradict anything I said anyway. I don't know what your point is.

Your contention is that the carburetors are too small.My question is at what rpm do they start restricting the engine? ( become too small)

You stated that the carbs are maxed out at freeway speeds that could only be true if the throttle is wide open and the slides are wide open and the engine can not get enough air to make more power. You also stated that fuel mileage suffers at 75 mph because the carbs are too small and they are open too far causing a rich condition that is not true. as the slide opens it opens the air flow and the fuel flow at the same time air fuel ratio stay the same only the volume of the mixture changes. If you want to know when your carbs start to restrict your engine hook up a vacuum gauge to the manifold and run it full throttle from low rpm to top end and when the manifold vacuum make a significant increase your carbs are restricting the engine. I would be willing to bet you will not see a significant restriction until you get to the very top of your rpm range if at all.

[Squeeze]

.... I would be willing to bet you will not see a significant restriction until you get to the very top of your rpm range if at all.

 

The Vacuum in the Manifold will not change much from 2.5 k RpM on to red Line, because the restricted Intake takes it already down. The Airbox and their Design restricts the Engine from a early Point on.

 

What do you think on a 2Gen limits the Power vs 1Gens and Maxxes? It's all on the Intake, Airbox, too small Carbs and Cams.

 

Why are there some People who report that additional Boring's in the Airbox lower the Consumption with virtually no Loss in Power or Throttle response. Well, i doubt that in Throttle Response and would not do that for other Reasons also, but its there and i believe the lower Consumption.

 

btw, just to remember, Lynn has mounted Vmax Cams and they lift the Valves higher and at a more aggressive Cam Timing.

 

On a Vmax, you can expect a Gain of 15-20 SAE hp if you only mount a Set of 39mm FCR Carbs(35mm stcok Carbs). It's all about getting more Mixture in. These Engines can handle it. All of them. See, a 1000cc Engine from a Thundercat has 38mm Carbs, the earlier YZF-R1 have also 38mm Carbs. Even the earlier 600cc R6 has the same Carbs. Thereby these Engines have a inherent Lack of Torque on lower End, therefore the Designers invented EXUP-System to gain more Torque on the low and mid Range. But they do not have any Restrictions on Top End. You remember the first RAM-Air Inducts?? Why is it that everbody wants more Air in the System ? These Bike gain 10 to 15 hp when RAM-Air is active.

[Redneck]

The Vacuum in the Manifold will not change much from 2.5 k RpM on to red Line, because the restricted Intake takes it already down. The Airbox and their Design restricts the Engine from a early Point on.

 

What do you think on a 2Gen limits the Power vs 1Gens and Maxxes? It's all on the Intake, Airbox, too small Carbs and Cams.

 

Why are there some People who report that additional Boring's in the Airbox lower the Consumption with virtually no Loss in Power or Throttle response. Well, i doubt that in Throttle Response and would not do that for other Reasons also, but its there and i believe the lower Consumption.

 

btw, just to remember, Lynn has mounted Vmax Cams and they lift the Valves higher and at a more aggressive Cam Timing.

 

On a Vmax, you can expect a Gain of 15-20 SAE hp if you only mount a Set of 39mm FCR Carbs(35mm stcok Carbs). It's all about getting more Mixture in. These Engines can handle it. All of them. See, a 1000cc Engine from a Thundercat has 38mm Carbs, the earlier YZF-R1 have also 38mm Carbs. Even the earlier 600cc R6 has the same Carbs. Thereby these Engines have a inherent Lack of Torque on lower End, therefore the Designers invented EXUP-System to gain more Torque on the low and mid Range. But they do not have any Restrictions on Top End. You remember the first RAM-Air Inducts?? Why is it that everbody wants more Air in the System ? These Bike gain 10 to 15 hp when RAM-Air is active.

I understand what you are saying my point is the possible gain from bigger carbs is at the very top rpm range. we are not talking about a 4 or 5 hundred lb race bike we are talking about an 800 plus pound touring bike that very seldom goes to the rpm range where bigger carbs have the potential to boost power. What the venture needs is good low and mid range power and bigger carbs will do absolutely nothing to help low and mid range power.

[Squeeze]

.... bigger carbs will do absolutely nothing to help low and mid range power.

 

Well, as already described in the other Thread....

 

You won't believe that there would be a good Gain in all RpM Ranges and repeating this like a Prayer Wheel doesn't add any Thruth to it .... :rotf:

 

 

 

Redneck, i sincerly understand that we talk here about Venture's. Which Year and which Displacement doesn't change anything basic.

 

I discuss my Knowledge and Experience about mostly Vmax Motors, because this is the most powerfull Motor of those V4's. The most tuned and heavily tuned Engine i know in my Playgrounds. And i know what it takes to find some, or a Lot of Horses in these Motors.

 

Of Course, we talk heavy Touring Bikes here and not Crotch Rockets, but that doesn't change anything. Most of the Vmax Guys also seek Low- and Midrange Power, because even here in Germany it is very expensive to gather a Speeding Ticket and you know what, it ain't no Fun crusing the Autobahn at Speeds around 150 mph on a naked!!! Bike. And stock Frame and Suspension is just not made for twisty Backroads at 110 mph or more ...

Not to mention that most of the Riders do not have the Abilities for such Conditions nor the Guts to do so. Or enough self-Contempt. Me myself included.

 

What is needed, is a LOT of Torque at Redlight and full Power up to 90 or 110 mph. Everthing beyond this mostly for ducked Meter-Lickers behind full Fairings.

 

And this is exactly what i'm talking about ... V4 Power ... any Frame, any Year.

 

 

I'm finished at this Point

[Denden]

I understand what you are saying my point is the possible gain from bigger carbs is at the very top rpm range. we are not talking about a 4 or 5 hundred lb race bike we are talking about an 800 plus pound touring bike that very seldom goes to the rpm range where bigger carbs have the potential to boost power. What the venture needs is good low and mid range power and bigger carbs will do absolutely nothing to help low and mid range power.

:stirthepot: I agree with Redneck. Bigger carbs will increase power at the high end of the rpm range. And actually bigger carbs MIGHT hurt the low and mid-range power by lowering the velocity of the air flowing thru the venturi, although not as much with our variable venturi carbs (the carb slides change the size of the venturi according to air velocity). Air velocity thru the carb is important for proper atomization of the gas into the air.

Here's a quote from Rider magazine Oct. 2007. On their road test of the Kawasaki Concours...."Kawasaki used several innovations to better suit the ZX-14's 1352cc inline four to touring...the bores in the four throttle bodies have been narrowed from 44mm to 40mm for increased intake velocity and better low and midrange throttle response"

So the sport bike that needs power at high rpm uses the 44mm throttle bodies and the Concours is a sport/tourer uses 40mm for more low and midrange.

[Squeeze]

:stirthepot: I agree with Redneck. Bigger carbs will increase power at the high end of the rpm range. And actually bigger carbs MIGHT hurt the low and mid-range power by lowering the velocity of the air flowing thru the venturi, although not as much with our variable venturi carbs (the carb slides change the size of the venturi according to air velocity). Air velocity thru the carb is important for proper atomization of the gas into the air.

Here's a quote from Rider magazine Oct. 2007. On their road test of the Kawasaki Concours...."Kawasaki used several innovations to better suit the ZX-14's 1352cc inline four to touring...the bores in the four throttle bodies have been narrowed from 44mm to 40mm for increased intake velocity and better low and midrange throttle response"

So the sport bike that needs power at high rpm uses the 44mm throttle bodies and the Concours is a sport/tourer uses 40mm for more low and midrange.

 

So you say, if Dark Knight bores his 2Gen Engine to 1500 cc and want's to gain Low- and Midrange Power, he'd better degrade the Carbs from 32mm to 28mm ?? :stirthepot: :whistling:

 

 

 

 

 

:rotf::rotf::rotf:

[Squeeze]

what just comes to my Mind, disregarding smaller or bigger Carbs ....

 

 

What about the Clutch ?

 

The stock Clutch can't keep up with those Horses ...

 

I would recommend a Lock-Up Conversion with stock Discs and the half Disc replaced with another full sized. Might cost a bit more in first Place, but you can stay with the way cheaper Standard Friction Discs and have no Hassle with Spinache Consumption. Ok, Spinache is very healthy, but nevertheless ...