long intake trumpet installed
05-19-2005, 06:12 PM
#1
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long intake trumpet installed
Hello again 
I finally got around to installing a long intake trumpet on the front cylinder (same unit as found on rear cylinder). It took all of about 15 minutes to do (no tank removal necessary either, I simply held the tank up with a bungie cord from the ceiling). I just returned from a ride and am VERY happy with the result. The bike seems to pull better in the lows and mids. I did not try it up on top to see what effect it has as virtually all of my riding occurs below 7K (no race track duties for me or bike at this point).
I am really really happy with all of the changes I have made to the VTR this year (43 teeth rear sprocket, 4.5mm rear shim, raise forks 6mm, install heavier bar ends with cruise control, Micron slip-ons). I never though my bike could be so much fun Next year, I will fine-tune the suspension ($$$$)
I am now REALLY anxious to install my Dynojet kit to put a healthy dose of icing on the cake. She runs great now (very torquey and responsive; the roll-ons from @ 4.5K in 6th are sooooooo much fun). I expect the DJ kit to make it even better.
Bye for now.
Micky
I finally got around to installing a long intake trumpet on the front cylinder (same unit as found on rear cylinder). It took all of about 15 minutes to do (no tank removal necessary either, I simply held the tank up with a bungie cord from the ceiling). I just returned from a ride and am VERY happy with the result. The bike seems to pull better in the lows and mids. I did not try it up on top to see what effect it has as virtually all of my riding occurs below 7K (no race track duties for me or bike at this point).
I am really really happy with all of the changes I have made to the VTR this year (43 teeth rear sprocket, 4.5mm rear shim, raise forks 6mm, install heavier bar ends with cruise control, Micron slip-ons). I never though my bike could be so much fun
Next year, I will fine-tune the suspension ($$$$)I am now REALLY anxious to install my Dynojet kit to put a healthy dose of icing on the cake. She runs great now (very torquey and responsive; the roll-ons from @ 4.5K in 6th are sooooooo much fun). I expect the DJ kit to make it even better.
Bye for now.
Micky
05-20-2005, 08:10 PM
#2
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Re: long intake trumpet installed / now Question
Hello again
I finally got around to installing a long intake trumpet on the front cylinder (same unit as found on rear cylinder). It took all of about 15 minutes to do (no tank removal necessary either, I simply held the tank up with a bungie cord from the ceiling). I just returned from a ride and am VERY happy with the result. The bike seems to pull better in the lows and mids. I did not try it up on top to see what effect it has as virtually all of my riding occurs below 7K (no race track duties for me or bike at this point).
I am really really happy with all of the changes I have made to the VTR this year (43 teeth rear sprocket, 4.5mm rear shim, raise forks 6mm, install heavier bar ends with cruise control, Micron slip-ons). I never though my bike could be so much fun Next year, I will fine-tune the suspension ($$$$)
I am now REALLY anxious to install my Dynojet kit to put a healthy dose of icing on the cake. She runs great now (very torquey and responsive; the roll-ons from @ 4.5K in 6th are sooooooo much fun). I expect the DJ kit to make it even better.
Bye for now.
Micky
I finally got around to installing a long intake trumpet on the front cylinder (same unit as found on rear cylinder). It took all of about 15 minutes to do (no tank removal necessary either, I simply held the tank up with a bungie cord from the ceiling). I just returned from a ride and am VERY happy with the result. The bike seems to pull better in the lows and mids. I did not try it up on top to see what effect it has as virtually all of my riding occurs below 7K (no race track duties for me or bike at this point).
I am really really happy with all of the changes I have made to the VTR this year (43 teeth rear sprocket, 4.5mm rear shim, raise forks 6mm, install heavier bar ends with cruise control, Micron slip-ons). I never though my bike could be so much fun
Next year, I will fine-tune the suspension ($$$$)I am now REALLY anxious to install my Dynojet kit to put a healthy dose of icing on the cake. She runs great now (very torquey and responsive; the roll-ons from @ 4.5K in 6th are sooooooo much fun). I expect the DJ kit to make it even better.
Bye for now.
Micky
I'm just wondering though,
If on a stock bike,
front cylinder , short trumpet, is jetted #175 main
rear cylinder, long trumpet, is jetted #178 main
should the front cylinder now be jetted #178,
Now that it has a long trumpet like the rear?
Or is the rear cylinder jetted richer because it runs hotter than the front?
Because it's air flow is preheated from the front cylinder?
Anyone know the answer to this?
Also do you remember the price of the long trumpet?
Thanks,
~Jeffers
05-20-2005, 09:30 PM
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Re: long intake trumpet installed
Hey Jeffers,
not sure about your jetting question. I have heard on several occasions though that the rear cyl. is jetted richer due to the fact that it runs hotter (exposed to less cooling air). For this reason, they run it a bit richer thereby allowing the extra gas to cool the piston (I would imagine that a slightly richer mixture would also burn at a slightly lower temp). AS I will be getting my jet kit installed and having the bike dynoed shortly I will let the tech worry about how to jet for it.
In so far as the price was concerned, I paid @ $35 CAN at my Honda dealer.
I just returned from another ride and cannot believe how much fun my bike is now. All teeth here now
cheers
Micky
not sure about your jetting question. I have heard on several occasions though that the rear cyl. is jetted richer due to the fact that it runs hotter (exposed to less cooling air). For this reason, they run it a bit richer thereby allowing the extra gas to cool the piston (I would imagine that a slightly richer mixture would also burn at a slightly lower temp). AS I will be getting my jet kit installed and having the bike dynoed shortly I will let the tech worry about how to jet for it.
In so far as the price was concerned, I paid @ $35 CAN at my Honda dealer.
I just returned from another ride and cannot believe how much fun my bike is now. All teeth here now
cheers
Micky
05-21-2005, 03:32 PM
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Makes no difference in the jetting. This mod is harmless, but I'd be wary of it. Why wouldn't Honda have made this decision if it gave free horsepower and reduced by 1 the size of the parts catalog. They have a financial incentive to have done it themselves.
The front trumpet is shorter to give clearance for the air to turn (from the top of the airbox.) I'd bet the clearance spec is about the same for the front and back.
The front trumpet is shorter to give clearance for the air to turn (from the top of the airbox.) I'd bet the clearance spec is about the same for the front and back.
05-21-2005, 06:09 PM
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Originally Posted by jschmidt
Makes no difference in the jetting. This mod is harmless, but I'd be wary of it. Why wouldn't Honda have made this decision if it gave free horsepower and reduced by 1 the size of the parts catalog. They have a financial incentive to have done it themselves.
The front trumpet is shorter to give clearance for the air to turn (from the top of the airbox.) I'd bet the clearance spec is about the same for the front and back.
The front trumpet is shorter to give clearance for the air to turn (from the top of the airbox.) I'd bet the clearance spec is about the same for the front and back.
seems like a seat of the pants placebo effect taking place.... but oh well, if it feels faster, go ahead and keep it. but it may make your bike run more rich seeing how air may nopt be flowing as smoothly entering the front of the airbox. see if your gas mileage drops like 15 or so less miles.... telltale your runnin rich.
05-22-2005, 03:03 PM
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Re: long intake trumpet installed
Moriwaki sells aluminum velocity stacks that are supposed to add 2-3 HP. Might want to look into if they're diff for the front or back. Can't imagine those guys screwing it up.
05-23-2005, 02:19 PM
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Re: long intake trumpet installed
So how<s the bike running with the new jet kit? Did you see a big improvement in performance and/or throttle response/engine smoothness? What were your final jetting specs^ Did you choose to install the K&N or not?
In regards to the intake runners, if you go to the Dynamo Humm website and look at the VTR prepared by Brian Law, he did try some aftermarket intake runners made by H-Power nd found that they not only did not improve performance but actually cost a bit of power.
In regards to trying the long runner on my VTR, I may get the local dyno shop to do dyno runs stock vs. two long runners to see what happens.
cheers
In regards to the intake runners, if you go to the Dynamo Humm website and look at the VTR prepared by Brian Law, he did try some aftermarket intake runners made by H-Power nd found that they not only did not improve performance but actually cost a bit of power.
In regards to trying the long runner on my VTR, I may get the local dyno shop to do dyno runs stock vs. two long runners to see what happens.
cheers
05-23-2005, 03:59 PM
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Re: long intake trumpet installed
The bike is still apart. I've had a lot to do on it, fluids, plugs, SS brake lines, farting around with the '94 VFR 750 bars, APE CCT's and possible TPS mod. I'm gonna try it with the K&N and 185/190 mains and see what happens. You were right. The Microns came with a Dynojet kit @ 4th clip, 180/185. I'll let you know when/if it starts ha ha
05-23-2005, 04:58 PM
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Re: long intake trumpet installed
[quote] Makes no difference in the jetting. This mod is harmless, but I'd be wary of it. Why wouldn't Honda have made this decision if it gave free horsepower and reduced by 1 the size of the parts catalog. They have a financial incentive to have done it themselves.
The front trumpet is shorter to give clearance for the air to turn (from the top of the airbox.) I'd bet the clearance spec is about the same for the front and back.
In regards to above comment, I realize that the seat of the pants can be easily fooled. However, I did discuss this very topic (two long runners) with a very reputable tuner who is well-versed in all things VTR and he stated that I could reasonably expect a mid-range power increase with the mod. In so far as Honda not choosing to go with the two long trumpets as the stock set-up, you surely are aware of the pressure on mfrs to generate impressive top-end numbers. A prime example is the 2004-2005 R1. In their quest to produce high hp numbers, Yamaha left this bike with a huge dip in the torque curve in the mid-range. One of the US mags (forget which) tried an aftermarket kit which consisted of longer intake runners to see how it would affect the power of Yamaha's flagship. The net result was a decrease of about 1.5 hp on top but the torque dip was filled in making the bike much easier to drive fast and resulting in stronger and more controlled drive out of corners.
At the end of the day, only the dyno can tell for sure but as some individuals have tried using two short runners and yielded 1-2 additional hp on top, it stands to reason that using two long ones would likely result in some loss of top-end but an increase elsewhere, in this case the mids. As for me, I don't really care about hp at 9K, but I do care about the roll-on when going 120 km/h. It is all about trade-off but I know what I want out of it.
cheers
The front trumpet is shorter to give clearance for the air to turn (from the top of the airbox.) I'd bet the clearance spec is about the same for the front and back.
In regards to above comment, I realize that the seat of the pants can be easily fooled. However, I did discuss this very topic (two long runners) with a very reputable tuner who is well-versed in all things VTR and he stated that I could reasonably expect a mid-range power increase with the mod. In so far as Honda not choosing to go with the two long trumpets as the stock set-up, you surely are aware of the pressure on mfrs to generate impressive top-end numbers. A prime example is the 2004-2005 R1. In their quest to produce high hp numbers, Yamaha left this bike with a huge dip in the torque curve in the mid-range. One of the US mags (forget which) tried an aftermarket kit which consisted of longer intake runners to see how it would affect the power of Yamaha's flagship. The net result was a decrease of about 1.5 hp on top but the torque dip was filled in making the bike much easier to drive fast and resulting in stronger and more controlled drive out of corners.
At the end of the day, only the dyno can tell for sure but as some individuals have tried using two short runners and yielded 1-2 additional hp on top, it stands to reason that using two long ones would likely result in some loss of top-end but an increase elsewhere, in this case the mids. As for me, I don't really care about hp at 9K, but I do care about the roll-on when going 120 km/h. It is all about trade-off but I know what I want out of it.
cheers
05-23-2005, 05:55 PM
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Tuning for midrange can be improved by lengthening the intake runners (quite a bit.) But the stacks are to increase intake velocity. They are generally combined with a direct intake path to develop max horsepower. While you have effectively lengthened the intake tract slightly, I don't think this pre-extension will affect your midrange.
The stock velocity stack is probably too short for max velocity. I'm sure its a compromise to get the best velocity in the given room.
But who can say for sure. You may have found hidden power.
The stock velocity stack is probably too short for max velocity. I'm sure its a compromise to get the best velocity in the given room.
But who can say for sure. You may have found hidden power.
05-24-2005, 06:21 AM
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Re: long intake trumpet installed
Norrth: The Microns came with a Dynojet kit @ 4th clip, 180/185.
Do you remember what your air screw setting (ie. how many turns out) was?
cheers
Micky
Do you remember what your air screw setting (ie. how many turns out) was?
cheers
Micky
05-24-2005, 01:32 PM
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Re: long intake trumpet installed
2.5 out, it didn't need changing according to the instructions. However, we shall soon see when we fire it up.
I note that G. Nemish indicates 185/188, 4th clip, 2.25 af @ sea level for this (my) set up.
I note that G. Nemish indicates 185/188, 4th clip, 2.25 af @ sea level for this (my) set up.
12-30-2005, 09:55 PM
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Re: long intake trumpet installed
I finally got my special ordered long stack to try out on my own shawk.
Long velocity stack:
Part Number: 17239-MBB-D40
Description: FUNNEL, AIR
Price: $17.73
Put it on just before an overnighter trip to the Sierras and it did seem to enhance the low to midrange.
But like Micky's experience, it also seemed to make the bike run a bit rougher as well. I did a carb balance before and after installing it, but balance didn't really change after installing it.
I later decided to make a intermediate stack like mikstr.
I still have to do 'back to back' tests when I get the time, but so far it seems to work.
~Jeffers
Long velocity stack:
Part Number: 17239-MBB-D40
Description: FUNNEL, AIR
Price: $17.73
Put it on just before an overnighter trip to the Sierras and it did seem to enhance the low to midrange.
But like Micky's experience, it also seemed to make the bike run a bit rougher as well. I did a carb balance before and after installing it, but balance didn't really change after installing it.
I later decided to make a intermediate stack like mikstr.
I still have to do 'back to back' tests when I get the time, but so far it seems to work.
~Jeffers
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