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fallzboater

Faq: Low-budget Fixes

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I just got my '02 VTEC for a song, and was able to pay cash, but not much left for mods right now. Great bike, but definitely could use some improvements, especially in the FI and suspension. I've been searching the forum, but thought it'd be cool to have a list of little to no cost mods to improve the bike, with comments on their benefits. Should be a good FAQ once compiled, and my bike is bone stock now, so I'm willing to be a guinea pig. Mostly looking for improved driveability and suspension performance, also aesthetic (visual and/or aural). I think weight reduction would be another good catagory. By low-budget, I mean: free, using (adjusting, modifying, or removing) stock parts (or used parts from other models) if possible or worthwhile, or the most cost-effective aftermarket options. For example, a new Ohlins USD fork would be nice, but Race Tech springs, gold valves, and rebound pistons and adjuster caps from an F4, while not free, would be more cost-effective for the majority of riders.

Please add comments, links to how-to threads, and any new mods. I'll compile and edit as we go along, and add my impressions as I perform the mods. Feel free to PM me, or just reply.

Let's go!

-David

INTAKE SYSTEM

Mod: Flapper valve disable

Benefits: Smoother acceleraton through 5k rpm??? Sound enhancement at low rpms?

How to: Lift fuel tank, pull vacuum hose off of flapper control valve diaphram on top of air box, plug hose with bolt, secure with zip tie (optional).

How it works: Disconnecting the vacuum hose will keep the flapper valve from closing the second intake opening under the control valve.

Time: 5 minutes

Cost: $0

Permanance: Completely reversible.

Help: got to http://www.vfrdiscussion.com/forum/index.php?page=parts

click on "Air Cleaner" for drawing

Mod: Remove intake snorkel

Benefits: Sound enhancement at WOT, possible performance benefit due to less restriction.

How to: Lift fuel tank, pull snorkle out of right front of airbox lid.

Time: 5 minutes

Cost: $0

Permanance: Completely reversible.

Help: got to http://www.vfrdiscussion.com/forum/index.php?page=parts

click on "Air Cleaner" for drawing

EXHAUST SYSTEM

Mod: De-baffle stock exhaust

Benefits: Sound enhancement, possible performance benefit due to less restriction.

How to:

Time:

Cost: $0

Permanance: Not reversible without buying another stock exhaust.

FUEL SYSTEM

Mod: Adjustable fuel pressure regulator (FPR)

Benefits: Improve drivability by reducing lean running conditions

How to:

Time:

Cost: $130 (retail)

Permanance: Completely reversible.

Mod: Dynojet Power Commander (PCIII)

Benefits: Improve drivability by modifying fueling maps

How to:

Time:

Cost:

Permanance: Completely reversible.

FRONT SUSPENSION

Mod: Heavier fork oil

Benefits: Increased compression and rebound damping with stock internals

How to:

Time:

Cost:

Permanance: Completely reversible.

Mod: Raise forks in triple-clamps

Benefits: Improved handling due to steeper head angle, reduced trail

How to:

Time: 20 minutes

Cost: $0

Permanance: Completely reversible.

Mod: Replace fork springs with Race Tech appropriate for rider weight and use

Benefits: Improved handling, reduced brake dive. Stock springs are too soft.

How to:

Time:

Cost: $110 (retail)

Permanance: Completely reversible.

Help: got to http://www.racetech.com/evalving/SpringRat...SpringType=Fork to choose your rate, or direct (15% discount for VFRDG) or through your favorite vendor

REAR SUSPENSION:

Mod: Increase rear ride height by shimming under top shock mount

Benefits: Improved handling due to steeper head angle, reduced trail, increased cornering clearance

How to: Add approximately 4mm of shims under top shock mount to raise ride height ~12mm.

Time:

Cost: $0

Permanance: Completely reversible.

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Don't let the LSFD kill me, but don't forget fender removal or cutting off.

Also wheel striping and polishing. Cost of paint stripper and sore hands.

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Don't let the LSFD kill me, but don't forget fender removal or cutting off.

Also wheel striping and polishing. Cost of paint stripper and sore hands.

LSFD? Sorry, I'm new. My bike came with a $130 fender eliminator "kit", but I definitely would've just chopped it up, myself. Nothing like a good hack job.

Yep, I'm definitely going to strip the outer rims, maybe the next rainy day here (I'm in the PNW, it's coming!). I think it looks awesome with the contrast. Doing the whole wheel would be too hard to keep clean IMO.

There's no "edit" button on my post, maybe becuase I posted from another computer?

BTW, I got a good ride in at lunch, and I'm very pleased with the flapper valve and de-snorkle-ization mods. Nice low rumble, and definitely smoothed things out a bit below the VTEC range. Sometimes you really can get something for nothing! Would be interesting to put a vacuum gage on the hose and see when the solenoid tells it to open and close. I had drilled a ton of 1" holes in my Hawk GT airbox lid which made a big difference in that bike (after re-jetting), I bet it would sound sweet on the veefer.

-David

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:D

FOOTPEGS:

Mod: Buell XB9 footpegs

Benefits: Lowers footpegs by 1 inch.

How to: Grind down the excess metal on the Buell footpegs, create some spacers, and install.

Time: 30-60 mins

Cost: $15 - $30 for the Buell pegs, maybe 50? for the spacers

Permanance: Completely reversible.

Help: installing Buell footpegs thread

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:D

FOOTPEGS:

Mod: Buell XB9 footpegs

Benefits: Lowers footpegs by 1 inch.

How to: Grind down the excess metal on the Buell footpegs, create some spacers, and install.

Time: 30-60 mins

Cost: $15 - $30 for the Buell pegs, maybe 50? for the spacers

Permanance: Completely reversible.

Help: installing Buell footpegs thread

Sounds good! I've actually got a 38"+ inseam, so that would be a nice comfort increase for me (hard to believe I could ride my Hawk!). I'll add a catagory for "ERGONOMICS".

-David

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Lower forks in tripple clamps & raise rear ride hight 12mm, bloody hell how fast do you want your bike to steer. I feel this is not a good thing as it really is to much & upsets balance of bike way to much from design (with link brakes your rear will lock up way to much).

I think lowering forks in tripple clamps is bad for 1 main reason ground clearance, I scrap RHS lower link pipe with reworked standard suspenion which has rear raised 6mm & there is a trade off even there due to less loading rear I spin up the rear wheel alot more.

Due to so much front loading with your mods you would have to do springs & increase fork oil to 15 weight to cope. (fitting the right profile tyre will also speed up steering like a pilot race or diablo corsa)

The rear shock is weakest link in system even when reworked because being a emulsion unit, the problems with temperature and cavitation related dramas will always exist. (I'm just about to upgrade to a penske 3 clicker & yes I know its not a cheep mod)

Edited by zRoYz

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Lower forks in tripple clamps & raise rear ride hight 12mm, bloody hell how fast do you want your bike to steer. I feel this is not a good thing as it really is to much & upsets balance of bike way to much from design (with link brakes your rear will lock up way to much).

I think lowering forks in tripple clamps is bad for 1 main reason ground clearance, I scrap RHS lower link pipe with reworked standard suspenion which has rear raised 6mm & there is a trade off even there due to less loading rear I spin up the rear wheel alot more.

Due to so much front loading with your mods you would have to do springs & increase fork oil to 15 weight to cope. (fitting the right profile tyre will also speed up steering like a pilot race or diablo corsa)

The rear shock is weakest link in system even when reworked because being a emulsion unit, the problems with temperature and cavitation related dramas will always exist. (I'm just about to upgrade to a penske 3 clicker & yes I know its not a cheep mod)

Thanks for the tips. Right now I have the forks raised 6mm, and have not changed the shock length. I didn't notice a real significant difference, but I'm new to the bike, so I'm still adapting to it every ride (probably best not to fiddle too much, but that's a lot of the fun for me). I plan to get some spacers for the shock, and will probably drop the forks back down at that point, to maintain about the same balance with increased clearance.

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I just had a buddy help me measure static sag, I'm OK in the rear with preload on "4", but I have 2" (50mm) of front sag with the preload cranked all the way in, and I'm only 190 lb! So, I think I will go with 0.95 or 1.0 kg fork springs. The front end will be quite a bit higher, so I expect I'll want to raise the rear end and leave the forks at 6-10mm up. If the springs aren't going to be available for a while, I might throw some more preload spacers in.

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other people maybe diff but i've found 10 weight & 30-35mm static sag is spot on, but my fork springs had to be upgraded.

its ok to add spacers to standard springs but you need to make sure your still using 2/3rds of travel or front will be to stiff & ride every bump.

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10w fork oil is standard for the 5th and 6th gen vfr, I actually use 5w oil now with stiffer springs, the springs dont need as much damping action so a lighter wieght oil is better.

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Fallzboater

I had the same condition, preload cranked all the way to get desired sag setting. Disassembled forks, check spring free length (within spec) reassembled with 10 wt synthetic amsoil now have 3 lines showing with 35mm sag :goofy:

I would suggest doing the measurement from top of cap to oil level rather than the oil measurement method as some oil will remain in cartridge unless you do a total disassemble which i didnt.

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INTAKE SYSTEM

Mod: Flapper valve disable

Benefits: Smoother acceleraton through 5k rpm??? Sound enhancement at low rpms?

How to: Lift fuel tank, pull vacuum hose off of flapper control valve diaphram on top of air box, plug hose with bolt, secure with zip tie (optional).

How it works: Disconnecting the vacuum hose will keep the flapper valve from closing the second intake opening under the control valve.

Time: 5 minutes

Cost: $0

Permanance: Completely reversible.

Help: got to http://www.vfrdiscussion.com/forum/index.php?page=parts

click on "Air Cleaner" for drawing

Mod: Remove intake snorkel

Benefits: Sound enhancement at WOT, possible performance benefit due to less restriction.

How to: Lift fuel tank, pull snorkle out of right front of airbox lid.

Time: 5 minutes

Cost: $0

Permanance: Completely reversible.

Help: got to http://www.vfrdiscussion.com/forum/index.php?page=parts

click on "Air Cleaner" for drawing

Which two hose on the diagram are you refering to? Would like to do this, but want to make sure that I get the right hoses. I am thinking #24 for the first and #4 for the second. Is that right?

Thanks!

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I actually use 5w oil now with stiffer springs, the springs dont need as much damping action so a lighter wieght oil is better.

Actually the stiffer the spring action the more dampening it will take to control it... I'd

recommend trying a 10 weight over the 5 weight HS... you may favor the more control

feel the extra dampening will afford...

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Raise the rear to increase the ground clearance you just lost by raising the forks in the clamps. The VFR is way stable stock, and is still very stable by raising the rear/raising the forks. I did this to my 94 and had zero handling problems. It turned in much quicker, nice, but did make it squirly at under 10 mph. Not a good mod for those vertically challenged.

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Actually the stiffer the spring action the more dampening it will take to control it... I'd

recommend trying a 10 weight over the 5 weight HS... you may favor the more control

feel the extra dampening will afford...

When I put in the stiffer springs I used the standard 10w oil withthe standard oil measurement. Ride was harsh and bumpy, with the front wheel hopping out of bumps much too stiff. I figure the extra stiffness of the springs take more energy to move so less damping is needed, the rider was the same and the bike was the same so the stiff springs made it too stiff. I found 5 wight gave it a much more compliant ride than the 10w for a guy of my wieght (230lbs). Not too much difference from the racetech valves and oil combo I am using now. Its slightly more compliant now, but with suspension a little goes a long way its perfect now.

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Which two hose on the diagram are you refering to?  Would like to do this, but want to make sure that I get the right hoses.  I am thinking #24 for the first and #4 for the second.  Is that right?

Thanks!

Almost. Unplug hose #24 from diaphragm #8 and plug the hose with a bolt or something. That will keep the flapper valve open.

The snorkle is #8. It comes out with a bit of squeezing.

Nice (yet subtle) noises!

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Fallzboater

I had the same condition, preload cranked all the way to get desired sag setting. Disassembled forks, check spring free length (within spec) reassembled with 10 wt synthetic amsoil now have 3 lines showing with 35mm sag :beer:

I would suggest doing the measurement from top of cap to oil level rather than the oil measurement method as some oil will remain in cartridge unless you do a total disassemble which i didnt.

I don't see how this could've had such an effect. If your oil level is now much higher than before it would tend to make your spring rate more progressive since the air volume is less. However, the air volume (unless very small) should have a near-negligeable effect on your sag.

I'm ordering some 0.95 or 1.0 kg/mm Race Tech springs tomorrow. No matter how far off my oil level may (or may not) be, it can't bring me from 50+ mm of sag with full preload, to 35 mm of sag with very little preload (preferable).

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Fallsboater,

I am not sure how or why you have so much sag at just 190lbs. I am 260, fully cranked on the front and mine are only at 40mm of sag. Too much I agree but total suspension re do is in the spring.

In the rear I am fully cranked and have 32mm sag.

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  I figure the extra stiffness of the springs take more energy to move so less damping is needed, the rider was the same and the bike was the same so the stiff springs made it too stiff. 

 

Extra stiff springs due take more energy to compress and they also rebound with a lot

more energy as well... consequently compression dampening needs to be greater to

slow the compression of the extra stiff spring and then rebound dampening also needs

to greater to slow the rebound of the spring...

I would check the forks for abnormal stiction... do you know how that's done???

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Stiction is measured by doing multiple sag measurements and then comparing them, if there is a lot of difference then you probably need to replace your seals, and check the tubes.

From what I learned rebound control is strictly a function of the spring stiffness while compression is related to the wieght of the rider, spring stiffness, and flow properties of the valves in the oil. So yea you need more rebound control with a stiffer spring but at the same time less compression cause your not compressing the springs as fast. bottom line to get back on track here - I think adding 20 wieght oil to a stock fork is a big mistake and it will ruin your ride. If you add stiffer springs and 20 w fork oil its gonna be like welding the fork tubes together.

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Stiction is measured by doing multiple sag measurements and then comparing them, if there is a lot of difference then you probably need to replace your seals, and check the tubes. 

That's one way but I think stiction is best felt with the hand...

First raise the bike enough to free the front suspension...

Then turn both fork caps until they're free from the fork tubes...

Finally grasp front wheel and raise and lower suspension 3 to 4 inches and note if

you feel abnormal amounts of stiction... basically your front suspension should free

fall with gravity...

If it doesn't free fall then unloosen axle pinch bolts and check free fall again...

Still not free falling??? Next check fork tube alignment by unloosing the left and right

two bottom pinch bolts on the lower triple clamp only... check free fall...

Once you have eliminated the axle and fork alignment then it time to go inside the

fork...

Check the upper and lower precision rolled copper bearings and not if any of the

gray Teflon is rubbed down to the copper... replace as needed...

Edited by BusyLittleShop
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I don't see how this could've had such an effect.  If your oil level is now much higher than before it would tend to make your spring rate more progressive since the air volume is less.  However, the air volume (unless very small) should have a near-negligeable effect on your sag.

I'm ordering some 0.95 or 1.0 kg/mm Race Tech springs tomorrow.  No matter how far off my oil level may (or may not) be, it can't bring me from 50+ mm of sag with full preload, to 35 mm of sag with very little preload (preferable).

Just reporting what it did for me fallzboater.

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That's one way but I think stiction is best felt with the hand... 

First raise the bike enough to free the front suspension...

Then turn both fork caps until they're free from the fork tubes...

Finally grasp front wheel and raise and lower suspension 3 to 4 inches and note if

you feel abnormal amounts of stiction... basically your front suspension should free

fall with gravity... 

If it doesn't free fall then unloosen axle pinch bolts and check free fall again...

Still not free falling??? Next check fork tube alignment by unloosing the left and right

two bottom pinch bolts on the lower triple clamp only...  check free fall...

Once you have eliminated the axle and fork alignment then it time to go inside the

fork...

Check the upper and lower precision rolled copper bearings and not if any of the

gray Teflon is rubbed down to the copper... replace as needed...

Good post. Have you, or anyone else here, done much significant suspension development work? I have a buddy a block from my house who does a lot of high-end motocross (and Baja) suspension work, and has done development work with a few of the suspension manufacturers as well. He's definitely available to work on my forks (or rear shock), and I'd love to get the suspension really dialled in. Unfortunately, I haven't ridden enough different bikes, and I'm not experienced enough of a rider, to really know what the bike should (or could) feel like, or which way to go with the different parameters. My buddy doesn't ride street-bikes, and he's a good bit lighter than me. So if I could tell him "it's too harsh on high-speed compression" or "I need 30% more low-speed rebound control", I think he could work with that, but I'm just not sure which way to go, or how much. He'll give me decent pricing, but I still don't want to go through too many iterations (too much down time!). He can either start with Gold Valves, or work with the stock internals. I should have my RT 0.95 springs later this week (I'm 190 lb w/o gear). I'd much prefer to work with him than send my forks off in the mail somewhere.

Any particular tips for working with the stock forks? Any good references, or is it mostly trade secrets?

As far as stiction, my buddy says the fit and finish of the tubes, bushings, etc. are pretty important, and that's a lot of what you get with nice parts like Ohlins. Also the ports are better shaped to minimize cavitation and hydraulic lock, the tubes are butted (variable thickness) for stiffness, etc. A lot of this is probably more important in moto-cross, but I imagine most of it applies to the road and track as well.

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Good post.  Have you, or anyone else here, done much significant suspension development work? 

I've done all my own suspension work... including making my own internal shock

parts... to revalving... to servicing my own rear shock fluids...

Any particular tips for working with the stock forks?  Any good references, or is it mostly trade secrets?

VFRD members can advise you better than I on a number of shock shops that have

brought them joy on their VFRs... I will say that to improve the smoothness of a

fork's action and to minimize stiction there are a number of ways offered to a tuner...

Ti Ni(Titanium Nitride gold coating)...

BDC (Black Diamond Carbon)...

GOFHP (Good Old Fashion Hand Polishing)...

As far as stiction, my buddy says the fit and finish of the tubes, bushings, etc. are pretty important, and that's a lot of what you get with nice parts like Ohlins. 

As far as stiction goes your buddy is right... fit and finish are paramount... I spent a

couple of days sanding and polishing my stock RC45 fork legs to reduce stiction... I

pull the forks apart and chucked the leg up in the Lathe... I employed a 600

crankshaft polish strap around the leg... got the leg wet with Acetone and spun it at

750 rpm's... I worked the strap evenly up and down the leg until all the marks were

gone... I was mindful not to go below the surface hardness of chrome... I was

successful in establishing a smooth uniform finish over the length of the leg...

RC45ForkSanding.JPG border='0' alt='user posted image' />

I removed a number of scuff marks...

RC45ScuffMarks.JPG border='0' alt='user posted image' />

I decided to go it alone and tackle the polishing job by hand with the

help of the Lathe... I use Nevr-Dull magic wadding under a trimmed down

section of black PVC... in about a day I had one leg polished up real nice...

gallery_3131_51_4019.jpg border='0' alt='user posted image' />

In conclusion... I estimate a 25% drop in stiction as a reward for my hours of labor...

I still got hammered as a result of race track ready suspension settings but now to a

lesser degree... I can't cry about it as I prefer to sacrifice a bit of comfort for a

volume of control... that all change for the better after I swapped the stock forks for

for a set of R/T Ohlins... currently I have more control and much much more

comfort... well my version of comfort that is...

gallery_3131_51_121200.jpg border='0' alt='user posted image' />

Edited by BusyLittleShop
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Shouldn't this topic be in the mods forum? Why limit it to 6th gen only? The best cheap mods work on most any bike; fer instance....

Pair valve mod. You can buy block off plates ($$) or you can remove the hose from the pipe on the valve cover, plug pipe with an appropriate sized cork, and refit hose. Done.

FYI, the pair valves admit additional air (oxygen) to the exhaust for improved emissions but adds pops/unbalanced sound to the exhaust on trailing throttle.

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