Intake mods 2017: bits and the bite

Need advice on which oil to use or which tyre best suits you? Share your topic and get help here.
Post Reply
mik_str
Posts: 2149
Joined: Thu Apr 01, 2004 10:45 pm
Location: Montreal, Canada

Intake mods 2017: bits and the bite

Post by mik_str »

As many of you know, my VTR has been, and remains, somewhat of a mobile laboratory for my modding (ie. OCMD) ideas. Part of this process has led me down the road of some rather extensive mods on the intake side of the engine (including, among others, filter in lid mod, gutted and enlarged airbox, HPower-replica velocity stacks, custom X-wing intake diffusers, streamlined butterflies, HDJ needle jets, HRC needles, revised lift holes, Flo-Commanders on main and pilot circuits,....). The results were great, but alas, my curiosity pushed me yet again. So, for 2017, a few more mods aimed at improving airflow further:

- replaced screws holding carb butterflies in place with lower profile units (which were ground down as much as possible)
- built a new airbox lid (ie. "Filter-in-lid design) with a larger filter element (area is up 40% over previous version) which also increased volume slightly and increased clearance over the stacks
- raised the tank a bit to improve airflow into filter/airbox/engine
- matched carb throats/intake collars/intake ports (minor dremmeling to latter two to provide a smooth and uniform channel for the air)
- put thermal barrier on underside of airbox and carburetors (cooler airbox and carbs mean cooler air, better air density for improved power)

To improve response, I drilled a small additional lift hole in each slide (was running single hole before, just added 18% more area)

Having taken a couple rides for the purpose of tuning, I had to richen the pilot circuit (easily achieved by turning F-C screw) and go up 3 sizes on the mains (from 155/158 to 162/165) to give the bike enough fuel.

The end result? A noticeable increase in intake noise (not a bad thing) and some new-found response and power. The bike pulls better everywhere (response is sharper, the pull more authoritative) and dropping down a couple gears at cruising speed and rolling on the gas now has the bike surging ahead with more fervour (had the front come up on me!)

A true win-win (one for a successful experiment, and one for more power on the bike). Another successful day in Mikstr's OCMD-land :)
Last edited by mik_str on Fri Apr 28, 2017 11:14 pm, edited 1 time in total.
99 VTR1000F Firestorm, a.k.a. The Carbon Express
tony.mon
Posts: 16274
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: Intake mods 2017: bits and the bite

Post by tony.mon »

Get it on a dyno and let the numbers do the talking, Mik :beer:
It's not falling off, it's an upgrade opportunity.
mik_str
Posts: 2149
Joined: Thu Apr 01, 2004 10:45 pm
Location: Montreal, Canada

Re: Intake mods 2017: bits and the bite

Post by mik_str »

maybe someday, but the bike's been on the dyno many, many times already (over my 16 years of ownership) and I don't feel a particular need to get it on there again at this point to be honest.... You don't ride a dyno, and my butt has become a pretty good judge (250,000+ kms on this particular bike) over the years.
99 VTR1000F Firestorm, a.k.a. The Carbon Express
User avatar
Stephan
Posts: 983
Joined: Sun Apr 15, 2012 6:58 pm
Location: Prague, Czech

Re: Intake mods 2017: bits and the bite

Post by Stephan »

Do it for me, I need the comparison so we can measure our, uh, bikes ... :D

Was on dyno 4 times last year, and it seems I will go at least 2 times again this year, as open airbox and DJ slide springs look like the progress (all thanks to endless help from Roger) Top end ruined my clutch again so this time it is time for replace, midrange is improved. Personally I need to see afr for fine tuning.

Not to say I dont believe you, I have just feeling you are saying something is delicious, but I didnt taste it :)

Btw, zcoo pads are great. Power is the same as before, but feel on lever much much better, nice soft first touch and modulation.
Post Reply