Stage 7 with Velocity Stacks

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maleko89

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No stack at all pulls hard 7 K up and the mid range is soft. 4 inch stack pulls good low from 3-8 but will starve out up top. Short stack 2 inches better in top end. 3 inch stack allows me to pull down to 2000 rpm and up to 9500.
With the K&N filters and stacks I had to put the float bowl vent lines back on and get them back up under the cover due to lean out at 9000 rpm.

Here's the procedure. 1 piece of copper pipe 12" long, have it cut at your hardware store on the threading machine and tell him not to put hardly any pressure on the pipe cutter because it will put to much of a bend on the end of the pipe you want it as straight as possible he shouldn't charge you for that. After you have cut the copper pipe into 4-pieces 3-"inches long your going to smooth the ends and clean with thinner or something similar to remover any metal shavings. Next your going to Lowes or any other big store that would have the 2" heavy duty flexible couplers. You will need to buy only (4) cut rubber in half saving the part that fits the copper pipe . You can use the straps off the coupling to fasten rubber coupler to carb and copper pipe. The filters slip over the velocity stacks. Use the existing filter clamps to tighten the fitment.
 

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i have a question. i was told w/ the stage 7 you dont have the vboost anymore, is this false info. i was talking to a guy who runs trapps w/ the 7 and still has the vboost. he told me i should run the stage 1 in mine w/ the headers i have. what do ya think. thanks.
 
Some keep the vboost and some do not.Its personnal prefference.It is easier to sync the carb if you can close the butterflies to isolate 1 from 2 and 3 from4.With no vboost like mine you need a Weber synchrometer to sync them.
 
As Shawn says, depends what you want. Better performance for low end and midrange if you leave vboost stocks. The deal with open vboost for stage 7 is the same as tboost.....you get over-carburation and "good" acceleration at small throttle angles. But, you lose at WOT.

Mark
#1098
 
Mark

What is the part number of the K&Ns with the fittings for the breather hoses (with the chrome tops)?

D
 
I thought it was pre-fit so I'll probably stick with mine...What kind of fitting do you put in and how is it secured?
 
It's just a regular round grommet that I bought at Lowe's. The package says Buchanan Grommets - 1/2" inside diameter. It's a tight fit but it worked well. Part number is 74112.

Mark
#1098
 
Forgive my ignorance, but I'm totally new to the world of V-Max. I barely understand what V-Boost is. When I bought this bike it already had the Stage 7 kit on it. How can I tell if the V-Boost was left on or not? I'll be sync-ing the carbs with a home made tool and it said nothing in the service manual about a difference. Pull the vaccum hoses, hook the tool up, sync the one bank. Same for the other side, then one vaccum line per bank and use screw "C" to sync the two banks.

Thanks in advance fellas.
 
Forgive my ignorance, but I'm totally new to the world of V-Max. I barely understand what V-Boost is. When I bought this bike it already had the Stage 7 kit on it. How can I tell if the V-Boost was left on or not? I'll be sync-ing the carbs with a home made tool and it said nothing in the service manual about a difference. Pull the vaccum hoses, hook the tool up, sync the one bank. Same for the other side, then one vaccum line per bank and use screw "C" to sync the two banks.

Thanks in advance fellas.

It would be best for you to buy a Weber syncrometer to sync your carbs.It will work for you even if the vboost is removed,unplugged open or stock.
 
I understand the correct tool for the correct job believe me.

How about how to tell if the V-Boost is currently on or off the bike?
 
Easiest way is to listen for the whining when you turn the key on. If that's not there, could be just unplugged at the controller. Remove the left scoop and make sure the round plug is connected.

Mark
#1098
 
The only thing I hear when I turn the key is the fuel pump clicking or whatever it is. If it is just un-plugged, the best option is to run it correct? I read the above posts, and it almost sounded a little contradicting. The only reason NOT to run v-boost is for better low end? Without it your loosing top end?

Sorry for all the questions.
 
Correct, stock vboost is best. If you unplug it you get over carburation at smaller throttle angles and it just seems more powerful. If you look at the dyno sheets at vmax.lvlhead.com you see a pretty big torque dip in the midrange.

Mark
#1098
 
Gotcha, I've got my dyno sheet posted up in the dyno room as well. Just looking for some extra HP, and looked into ignition as well.
 
For ignition, NGK boots with good copper core automotive wire works just fine. Plugs.....irridium doesn't do much for you except they don't seem to foul as easily. Stock ignition is very hard to beat.

Mark
#1098
 
Right on. I was thinking more along the lines of the Dyna 3000 or some way to advance the ignition and give it a better rev limiter.

Habbit of drag racing cars, I can't leave anything alone. :D
 
Well I plugged in the V-Boost, it seems a little slugish, but I couldn't really get after it either today. It was just un-plugged like you suspected. I hope to get the carbs sync'd and set the idle air mixture and re-dyno.
 
What did you actually gain from the 3 inch velocity stack? sounds like some mid range and saved wot. i have the same set up minus the velocity stacks and am interested. what was the od of the copper tubing?
 
I didn't dyno test the before and after but the midrange was definitely better. Top end felt the same. I used 2 inch OD copper pipe. You could also use 2 inch exhaust pipe if you wanted. Probably cheaper.
 

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