Long intake runner installed :)

[mik_str]

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 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

I am really anxious to install my Dynojet kit now 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

[trebs]

Sorry for being a bit of a divvy, but can some explain this long intake lark.
I've seen it mentioned on a few sites, just wonder what parts you use, how easy it is, what are the downsides?

Cheers.
Rob.

[Max]

Its interesting what you say having installed the long tube. I replaced my long tube with a short one last week. I also removed the bar across the airbox( K+n and dynojet already on board). I took it out for a 200 mile ride on wednesday and found the change very noticeable. The bike now runs very smoothly and the induction noise is reduced noticeably. It seems to use slightly less fuel I am now getting about 40 mpg. It also will pull from 2000 rpm in top gear on the flat and from 4000 on it flies round to about 10500. All this is on std gearing and I'm also a right fat so and so (18 stoneish).
I am arrangeing to go upto see roger soon to change the shock etc and if I have time I'll ask him to put it on the dyno and see whats what. The bike does feel as though the mid range is less but its increadibly smooth now, this would square with what ben was saying in another thread about mid range and improved fuel economy.

Max

[DD]

I finally got around to installing a long intake trumpet on the front cylinder (same unit as found on rear cylinder). Micky

Ok, so can you answer this..... if the bike std has a long in the back and a short in the frount then you would expect thats for a reason.... whats the reason cos if it runs better with a long in the frount then ya'd think that thats how they would come aye

[Max]

You are probably right, but when you have a toy you just have to play with it

[mik_str]

Sorry DD. Alright folks, you heard the man, put all your bikes back to stock. That's right, no more pipes, jet kits, fork mods, shocks, .... Stock is best remember!!!!!

Seriously though, manufacturers have certain constraints (ie. emissions and sound) that we as individual owners do not have. Also, as some have noted there are top-end benefits (verified on dyno by the way) to be had from replacing the long trumpet on the rear cylinder with a short one (in the order of 1-2 hp). Does it not stand to reason, then, that a similar improvement could be realized in the mids by going to two long ones? In the end, all is know is what I felt in the seat of my pants. Maybe you should try it and draw your own conclusions

to trebs: the mod involves replacing the intake runner that links the carb to the airbox. In the stock set-up, the front carb has a short one and the rear unit is slightly longer. Depending on where you would like to see an improvement, you can easily change either one. The cost is relatively minimal (@$35 CAN at my Honda dealer, overpriced for a small piece of plastic but alas...). Either one can be easily replaced in minutes by simply removing the airbox cover and air filter.

cheers

[DD]

Sorry DD. Alright folks, you heard the man, put all your bikes back to stock. That's right, no more pipes, jet kits, fork mods, shocks, .... Stock is best remember!!!!!

sarcasm..... is the lowest form of wit mate.

Now if you use ya brain for a minute that is not what I was asking, I WAS asking why do ya reckon they use a differant size for each cyl???
Now my thoughts are maybe something to do with air flow in the air box? fuel mix's being differant in each cyl... helll maybe even a temp thing as the rear cyl would run hotter you would think.

Now what I do know is that the longer the trumpet or manafold the more top end power you get, as a general rule (not refering to the VTR here) but the same rule could apply.

[mik_str]

Sorry DD, just trying to have a bit of fun

To answer your question, I truly do not know why they chose to use tow different length trumpets on the VTR. Also, I cannot take credit for coming up with the idea of trying the tow long ones. I got it from an article on another site which explains how to set the TPS on the VTR (http://www.superhawkforum.com/kb.php?mode=article&k=4). IN it, the author states "I did try the bike with 2 long trumpets, and it did noticeably increase the bottom end, no loss of top end by my seat of the pants dyno. 2 short ones didn't seem to make any difference from stock."

Also, to my knowledge, short trumpets increase top end and long ones work at lower rpms. One example is an aftermarket trumpet kit sold for the 2004-2005 R1. AS you may know, this bike has impressive top end but is plagued by a huge dip in the torque curve in the mid-range. One US publication (I forget which one) tried this kit out and found that although they sacrificed @ 1.5 hp on top, the kit essentially filled in the torque dip and made the power much more usable. I also know of some snowmobile mods (two-stroke engines) where increased power is obtained from using shorter carb boots (intake runners).

Finally, I discussed this idea with a well-known VTR tuner and he supported the theory that using two long trumpets would yield increased torque and hp in the mid-range.

AS I said before, if in doubt try it for yourself. You may just like it.

[DD]

Sorry DD, just trying to have a bit of fun

Dont you roll ya eyes at me mounty...... or tho I was woundering that you may be a yank living in Canada
I did figer you were playing but a few wouldent go a miss....... right were did that forking sheep go, come here Barrrrrrbra