Latest OCMD project: modded airbox lid
Thread Starter
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
Not to rain on yer parade guys, but it never really was... 
Yes, I'm running a variation of this on my race bike... But then again, it made a nice chunky 150+ bhp before that mod, and the change in outright hp is pretty marginal really... Most of the gains for me, is the peaky top end, and the fact that I finally can get that and keep the meaty midrange that I so love from this engine...
But no, the air box isn't the limiting factor for the horsepower on this engine... You hit the ceiling on a number of components around the 160-165 bhp mark or there abouts... I'm pretty sure Im skimming the edge of reliability with that engine, but damn, it's worth it every time I flog it out of a corner, and down a straight... Even better when you chase down newer bikes...
Yes, I'm running a variation of this on my race bike... But then again, it made a nice chunky 150+ bhp before that mod, and the change in outright hp is pretty marginal really... Most of the gains for me, is the peaky top end, and the fact that I finally can get that and keep the meaty midrange that I so love from this engine...
But no, the air box isn't the limiting factor for the horsepower on this engine... You hit the ceiling on a number of components around the 160-165 bhp mark or there abouts... I'm pretty sure Im skimming the edge of reliability with that engine, but damn, it's worth it every time I flog it out of a corner, and down a straight... Even better when you chase down newer bikes...
on a more important note|: pics.... we need pics Markus!!!!!!!!
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
Small change today to try to sort the mid throttle. Drilled out the blocked holes in the slides. Needles are set with 4.25 and 4.75mm lift. See what that does during the week.
Oh and changed the idels back to 42/45.
Oh and changed the idels back to 42/45.
Out of my mind, back in 5
MotoGP
Joined: Nov 2006
Posts: 6,109
From: Skurup, Sweden
That bike looks pretty much stock really, apart from the rat-bike fairings held together by duct tape and zip ties... Oh, and the swing-arm and forks... But they are pretty ratty too to be honest... Partly because I have made a few visits to the gravel trap at the end of the last season when I started to get a bit braver than my skill set allowed... The damned engine has so much torque that it just flings me off if I provoke it too damned much...
The fit and finish is second to everything, and the engine looks bone stock unless you open it up... I could be damned honest and tell you its because it a low budget build to begin with...
But I prefer to say it's to further **** off the new bike owners I run circles around at the track... They seem to take offence when being passed by something that could fall apart any minute, but goes like stink...
Thread Starter
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
Ehh... Well... I'll snap a pic someday... But its not going to excite you very much...
That bike looks pretty much stock really, apart from the rat-bike fairings held together by duct tape and zip ties... Oh, and the swing-arm and forks... But they are pretty ratty too to be honest... Partly because I have made a few visits to the gravel trap at the end of the last season when I started to get a bit braver than my skill set allowed... The damned engine has so much torque that it just flings me off if I provoke it too damned much...
The fit and finish is second to everything, and the engine looks bone stock unless you open it up... I could be damned honest and tell you its because it a low budget build to begin with...
But I prefer to say it's to further **** off the new bike owners I run circles around at the track... They seem to take offence when being passed by something that could fall apart any minute, but goes like stink...
That bike looks pretty much stock really, apart from the rat-bike fairings held together by duct tape and zip ties... Oh, and the swing-arm and forks... But they are pretty ratty too to be honest... Partly because I have made a few visits to the gravel trap at the end of the last season when I started to get a bit braver than my skill set allowed... The damned engine has so much torque that it just flings me off if I provoke it too damned much...
The fit and finish is second to everything, and the engine looks bone stock unless you open it up... I could be damned honest and tell you its because it a low budget build to begin with...
But I prefer to say it's to further **** off the new bike owners I run circles around at the track... They seem to take offence when being passed by something that could fall apart any minute, but goes like stink...
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
Its rain season here so hard to get a dry run. May check my plug gap tomorrow and possibly open it a bit.
über-n00b
Superstock
Joined: Dec 2011
Posts: 257
From: S. WI
OK. I have the bike prepped to take in for tuning!
Where are you guys at, as far as mains/pilots/schims/turns out??
Does it matter which brand of these items? DynoJet vs Factory Pro vs HRC...?
last I recall seeing:
mains = 205 front / 210 rear
pilots = 42 (45?) / 45
Fuel screws (turns out) 2F & 2.25R
Where are you guys at, as far as mains/pilots/schims/turns out??
Does it matter which brand of these items? DynoJet vs Factory Pro vs HRC...?
last I recall seeing:
mains = 205 front / 210 rear
pilots = 42 (45?) / 45
Fuel screws (turns out) 2F & 2.25R
Last edited by Spoot; Jun 3, 2015 at 08:55 AM.
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
OK. I have the bike prepped to take in for tuning!
Where are you guys at, as far as mains/pilots/schims/turns out??
Does it matter which brand of these items? DynoJet vs Factory Pro vs HRC...?
last I recall seeing:
mains = 205 front / 210 rear
pilots = 42 (45?) / 45
Fuel screws (turns out) 2F & 2.25R
Where are you guys at, as far as mains/pilots/schims/turns out??
Does it matter which brand of these items? DynoJet vs Factory Pro vs HRC...?
last I recall seeing:
mains = 205 front / 210 rear
pilots = 42 (45?) / 45
Fuel screws (turns out) 2F & 2.25R
in saying that I am seriously considering blocking the air bleeds for the main circuit and running smaller mains. I would be interested to know what size mains the guys with HRC kits run.
über-n00b
Superstock
Joined: Dec 2011
Posts: 257
From: S. WI
oops, do I need to tell him to block the hole on the slide?
(how, where, why...)
also, he broke the news that Staintune pipes aren't normally known for HP gains.
Bike is at the shop - probably won't be done this week, so I'll keep ya'll posted.
(how, where, why...)
also, he broke the news that Staintune pipes aren't normally known for HP gains.
Bike is at the shop - probably won't be done this week, so I'll keep ya'll posted.
Last edited by Spoot; Jun 3, 2015 at 09:00 PM.
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
Had a long talk with our top dyno guy. Told him the mod and the problem I have been having.
His response was that being as Im trying to tune a CV carb with an open airbox the problem is the resonance or shock wave the carb needs to function is not there. So the slide blasts open and creates a lean condition. Not enough vacuum or signal to the main circuit for it to draw a mixture. His comment was that is a very dangerous condition for the motor. He said as I have used it on track he would have expected it to drop valves by now.
I spoke to him about blocking the air bleed to the main circuit to which he said this would be a very good idea to strengthen the signal to the circuit. Even tapping it to take a jet could help. I guess those running flow commanders have this resolved already.
He suggested returning it to stock for the time being until I can get it to the dyno. His quote for dyno time was $1000 plus tax.
Another point he made was our jet sizes here are normally 15 points or so below the US due to atmospheric differences.
So Im returning to stock. But not for the reason above. I have been finding the intake noise has been giving me nausea. This is something Im prone to. There is no medical fix for it. I had to stop racing cars due to it. Its a mix of sound and motion. I may have to give up track for the same reason.
Im looking forward to hearing dyno results from this. I would say from the above blocking or controlling the air bleed is the way forward and I guess the reason the HRC kits have the blocking plugs.
His response was that being as Im trying to tune a CV carb with an open airbox the problem is the resonance or shock wave the carb needs to function is not there. So the slide blasts open and creates a lean condition. Not enough vacuum or signal to the main circuit for it to draw a mixture. His comment was that is a very dangerous condition for the motor. He said as I have used it on track he would have expected it to drop valves by now.
I spoke to him about blocking the air bleed to the main circuit to which he said this would be a very good idea to strengthen the signal to the circuit. Even tapping it to take a jet could help. I guess those running flow commanders have this resolved already.
He suggested returning it to stock for the time being until I can get it to the dyno. His quote for dyno time was $1000 plus tax.
Another point he made was our jet sizes here are normally 15 points or so below the US due to atmospheric differences.
So Im returning to stock. But not for the reason above. I have been finding the intake noise has been giving me nausea. This is something Im prone to. There is no medical fix for it. I had to stop racing cars due to it. Its a mix of sound and motion. I may have to give up track for the same reason.
Im looking forward to hearing dyno results from this. I would say from the above blocking or controlling the air bleed is the way forward and I guess the reason the HRC kits have the blocking plugs.
über-n00b
Superstock
Joined: Dec 2011
Posts: 257
From: S. WI
I have the pair valves blocked, so I hope that my guy can see the A/F mix and know if something looks off at the top-end.
Maybe a Flow-Commander is a 'recommended' addition for this mod?
Hey - if we don't have the OE (or replacement) filter in between the lid and base....do we need a gasket or something to complete the seal?? I forget how that fits together.
Maybe a Flow-Commander is a 'recommended' addition for this mod?
Hey - if we don't have the OE (or replacement) filter in between the lid and base....do we need a gasket or something to complete the seal?? I forget how that fits together.
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
I have the pair valves blocked, so I hope that my guy can see the A/F mix and know if something looks off at the top-end.
Maybe a Flow-Commander is a 'recommended' addition for this mod?
Hey - if we don't have the OE (or replacement) filter in between the lid and base....do we need a gasket or something to complete the seal?? I forget how that fits together.
Maybe a Flow-Commander is a 'recommended' addition for this mod?
Hey - if we don't have the OE (or replacement) filter in between the lid and base....do we need a gasket or something to complete the seal?? I forget how that fits together.
über-n00b
Superstock
Joined: Dec 2011
Posts: 257
From: S. WI
Before I could get to the donor filter to seat the lid....I got a reply from the shop.
This is interesting:
"Hello Dave,
We have tested your Superhawk as delivered and it made within 4 hp of one with cams, pipe, etc.
The third highest tested and only 4 hp less than the one mentioned above.
Putting in the air cleaner you supplied made it so lean it wasn't able to be tested.
To try and bring the jetting to usable may get us a few horsepower, and if you would like, we can attempt it. I don't feel; it is worth the time for the possibility of gaining a few horsepower (if at all).
If I was to try anything, it would be to see about exhaust mods, but when there is so little difference between yours and a much more highly modified one, it points to a non-responsive platform.
So there you have it, just let us know what you would like to do."
Do I spend the extra $$ ??
This is interesting:
"Hello Dave,
We have tested your Superhawk as delivered and it made within 4 hp of one with cams, pipe, etc.
The third highest tested and only 4 hp less than the one mentioned above.
Putting in the air cleaner you supplied made it so lean it wasn't able to be tested.
To try and bring the jetting to usable may get us a few horsepower, and if you would like, we can attempt it. I don't feel; it is worth the time for the possibility of gaining a few horsepower (if at all).
If I was to try anything, it would be to see about exhaust mods, but when there is so little difference between yours and a much more highly modified one, it points to a non-responsive platform.
So there you have it, just let us know what you would like to do."
Do I spend the extra $$ ??
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
Before I could get to the donor filter to seat the lid....I got a reply from the shop.
This is interesting:
"Hello Dave,
We have tested your Superhawk as delivered and it made within 4 hp of one with cams, pipe, etc.
The third highest tested and only 4 hp less than the one mentioned above.
Putting in the air cleaner you supplied made it so lean it wasn't able to be tested.
To try and bring the jetting to usable may get us a few horsepower, and if you would like, we can attempt it. I don't feel; it is worth the time for the possibility of gaining a few horsepower (if at all).
If I was to try anything, it would be to see about exhaust mods, but when there is so little difference between yours and a much more highly modified one, it points to a non-responsive platform.
So there you have it, just let us know what you would like to do."
Do I spend the extra $$ ??
This is interesting:
"Hello Dave,
We have tested your Superhawk as delivered and it made within 4 hp of one with cams, pipe, etc.
The third highest tested and only 4 hp less than the one mentioned above.
Putting in the air cleaner you supplied made it so lean it wasn't able to be tested.
To try and bring the jetting to usable may get us a few horsepower, and if you would like, we can attempt it. I don't feel; it is worth the time for the possibility of gaining a few horsepower (if at all).
If I was to try anything, it would be to see about exhaust mods, but when there is so little difference between yours and a much more highly modified one, it points to a non-responsive platform.
So there you have it, just let us know what you would like to do."
Do I spend the extra $$ ??
What pipes do you have?
Ive changed back to Hawks carb setup.
Not thats Hawks setup is bad but I miss the midrange.
über-n00b
Superstock
Joined: Dec 2011
Posts: 257
From: S. WI
I have Staintune high-mount.
I'm debating between borrowing a different exhaust and 'taking one for the team' to see what the FIL can really do on my bike and spend whatever cash is needed to get it dialed in.....
OR
Bail now and do the mod/tune myself on a backroad in the country, with a guy named Crux.
über-n00b
Superstock
Joined: Dec 2011
Posts: 257
From: S. WI
ok. I'm gonna bail.
I had a 105.x hp pull.
The "other" bike had 109 with a port/polish/cam/pipes/jetting.
I'd like to pin down what else NZ & Crux have going to see if I can find some common ground b4 trying again.
Otherwise, maybe I get Crux to run on this same dyno to see where he is at?
I had a 105.x hp pull.
The "other" bike had 109 with a port/polish/cam/pipes/jetting.
I'd like to pin down what else NZ & Crux have going to see if I can find some common ground b4 trying again.
Otherwise, maybe I get Crux to run on this same dyno to see where he is at?
Banned
MotoGP
Joined: Aug 2007
Posts: 5,942
From: Lake View Terrace, CA
That is the only way to know what is really going on.
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
ok. I'm gonna bail.
I had a 105.x hp pull.
The "other" bike had 109 with a port/polish/cam/pipes/jetting.
I'd like to pin down what else NZ & Crux have going to see if I can find some common ground b4 trying again.
Otherwise, maybe I get Crux to run on this same dyno to see where he is at?
I had a 105.x hp pull.
The "other" bike had 109 with a port/polish/cam/pipes/jetting.
I'd like to pin down what else NZ & Crux have going to see if I can find some common ground b4 trying again.
Otherwise, maybe I get Crux to run on this same dyno to see where he is at?
So What you know is a base number. Where the FIL seems to work is mid range. Max HP is not important. How good is this dyno op? Bunch of guys in Aussie did a group dyno run and they were all 110 to 118hp.
For me the mid range helped it rip out of turns. It comes on hard. Now Im back at Hawks set up it has lost some of that. Im confident the plug in the air bleed is the way forward.
No I dont believe this mod will find 20hp. But it seems to find a real nice chunk of very handy mid range.
European Member
Back Marker
Joined: Mar 2013
Posts: 194
From: Netherlands
Has anybody tried, a double filter ??,
double layer, stock filter in stock position and one in the lid ??
i am gonna try this, also the FIL mod like you guys.... also gonna do some dyno time, wondering what HP i will see, considering we have better fuel here (98 octane or V power 100 in germany
) and also different atmospheric conditions
double layer, stock filter in stock position and one in the lid ??
i am gonna try this, also the FIL mod like you guys.... also gonna do some dyno time, wondering what HP i will see, considering we have better fuel here (98 octane or V power 100 in germany
) and also different atmospheric conditions
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
Has anybody tried, a double filter ??,
double layer, stock filter in stock position and one in the lid ??
i am gonna try this, also the FIL mod like you guys.... also gonna do some dyno time, wondering what HP i will see, considering we have better fuel here (98 octane or V power 100 in germany) and also different atmospheric conditions
double layer, stock filter in stock position and one in the lid ??
i am gonna try this, also the FIL mod like you guys.... also gonna do some dyno time, wondering what HP i will see, considering we have better fuel here (98 octane or V power 100 in germany
) and also different atmospheric conditions
Rex Kramer-Thrill Seeker
SuperBike
Joined: Jan 2011
Posts: 2,312
From: Brookfield, WI
I just don't understand why you would want to do that. You are purposely making it harder for your engine to breath. You are now going backwards with the FIL mod.
Spokes, for the noise issue, I could see making some kind of shield above and on the sides of the filter and lining it with foam, but space is the limiting factor. Not sure if there is even enough room for that. You could also maybe make some kind of large snorkel, like the stock airbox had. That might quiet it down a little.
Spokes, for the noise issue, I could see making some kind of shield above and on the sides of the filter and lining it with foam, but space is the limiting factor. Not sure if there is even enough room for that. You could also maybe make some kind of large snorkel, like the stock airbox had. That might quiet it down a little.
Senior Member
Back Marker
Joined: Apr 2010
Posts: 219
From: Prague - Czech
Has anybody tried, a double filter ??,
double layer, stock filter in stock position and one in the lid ??
i am gonna try this, also the FIL mod like you guys.... also gonna do some dyno time, wondering what HP i will see, considering we have better fuel here (98 octane or V power 100 in germany) and also different atmospheric conditions
double layer, stock filter in stock position and one in the lid ??
i am gonna try this, also the FIL mod like you guys.... also gonna do some dyno time, wondering what HP i will see, considering we have better fuel here (98 octane or V power 100 in germany
) and also different atmospheric conditionsI see no point do to it, you will restrict the intake ane affect pressure in airbox, while stock airbox with Dr Honda stacks is performing flawlessly.
You won´t get any HP gain from better fuel, unless you play with compression and ignition to suit new conditions. If there would be any :-)
Senior Member
SuperSport
Joined: Apr 2014
Posts: 932
From: Auckland, new Zealand
I just don't understand why you would want to do that. You are purposely making it harder for your engine to breath. You are now going backwards with the FIL mod.
Spokes, for the noise issue, I could see making some kind of shield above and on the sides of the filter and lining it with foam, but space is the limiting factor. Not sure if there is even enough room for that. You could also maybe make some kind of large snorkel, like the stock airbox had. That might quiet it down a little.
Spokes, for the noise issue, I could see making some kind of shield above and on the sides of the filter and lining it with foam, but space is the limiting factor. Not sure if there is even enough room for that. You could also maybe make some kind of large snorkel, like the stock airbox had. That might quiet it down a little.
Currently Im helping out a dog rescue place that needs to give me a couple of dogs to look after for a bit which will take some time.
Thread Starter
Senior Member
MotoGP
Joined: Apr 2005
Posts: 5,631
From: Montreal
am very happy with my lids (both of them). I have been running the second version for 2 years now with great success and my bud JackFlash is running the original FIL with success.
Junior Member
Squid
Joined: Jan 2020
Posts: 17
Sorry to drag up an old thread, are any of you guys still visiting this forum, or still have your VTR1000F's? I read 13 pages, you were chasing your tails (as l did with my race VTR back in '97), there didn't seem to be a good result from all your work?
l just bought another VTR, which l am modifying. My 97 bike was a hotty but l never got the carburation sorted. With a carb enclosed airbox, cams & pistons l had the full throttle / 6000 rpm rich stumble, HRC hadn't brought out their carb kit back then, l swear blocking the main air bleed and reducing the MJ's would have fixed it.
My current VTR specs are ......
195 mains
Factory Pro needles, clip #3
45 pilots
2.5 turns out on mixture screws
Cut & stretched slide springs (to make them stiffer)
2 x slide lift holes opened to 2.75mm
2 x short bell mouths with full radius curved ends
Pipercross airfilter
Airbox snorkel out, intake area increased 15%
2 into 1 exhaust with 2" straight thru muffler
lt runs sweet, l will get to the dyno in the next week or two, will let you know how it goes if anyone is interested?
PS, l'm near Melbourne, Australia @ 1900' above sea level.
l just bought another VTR, which l am modifying. My 97 bike was a hotty but l never got the carburation sorted. With a carb enclosed airbox, cams & pistons l had the full throttle / 6000 rpm rich stumble, HRC hadn't brought out their carb kit back then, l swear blocking the main air bleed and reducing the MJ's would have fixed it.
My current VTR specs are ......
195 mains
Factory Pro needles, clip #3
45 pilots
2.5 turns out on mixture screws
Cut & stretched slide springs (to make them stiffer)
2 x slide lift holes opened to 2.75mm
2 x short bell mouths with full radius curved ends
Pipercross airfilter
Airbox snorkel out, intake area increased 15%
2 into 1 exhaust with 2" straight thru muffler
lt runs sweet, l will get to the dyno in the next week or two, will let you know how it goes if anyone is interested?
PS, l'm near Melbourne, Australia @ 1900' above sea level.
Last edited by John Orchard; Jan 1, 2020 at 02:26 AM.
RUNLEVELZERO #99
SuperBike
Joined: Jan 2007
Posts: 2,218
From: Skokie
I'm Still Kickin
I go back to Greg's Runlevelzero VTR forum, and long, long ago sorted out my 3/97 VTR's carb "calibration". I actually may this winter get to installing the lighter flywheel and Factory Pro 3 piece shift kit I've had for a few years. But with over 110,000 miles on the original engine, which still runs like a champ, I'm loathe to make changes to jeaprodize it's realiability (despite having two spare engines and boxes of spades upon spare parts).
Thread
Thread Starter
Forum
Replies
Last Post
