Hi kids. I was wondering if anyone has an opinion on mods that will get me some more hp on a efi T-100. My mechanic doesn't seem to think the air-box removal will do much, except at the top end. Any thoughts? P.S. I have tors silencers at the moment, and am open for any performance suggestions that would cost around a grand.
Air box removal on EFI
- Thread starter crikket44
- Start date
Easy13
Street Tracker
I'm not an expert on EFI, but the principles remain the same: If you can increase airflow both in and out, you'll net performance.
It's not that tough of a job to chop up your stock airbox, just research a bit at the T-rat site under the "good source of info" sticky and know that it's really easier than it sounds. UNI pod filters flow very well and can be had very inexpensively:
http://www.oemcycle.com/Item/product/5261/PU/1011-0758/ANGLED_ID_2.5in_LENGTH_OF_FOAM_4in
There are lots of mufflers in the aftermarket, most of which will outperform the TORs and make a pleasant sound doing it, so look for the style you want and get to it.
It's not that tough of a job to chop up your stock airbox, just research a bit at the T-rat site under the "good source of info" sticky and know that it's really easier than it sounds. UNI pod filters flow very well and can be had very inexpensively:
http://www.oemcycle.com/Item/product/5261/PU/1011-0758/ANGLED_ID_2.5in_LENGTH_OF_FOAM_4in
There are lots of mufflers in the aftermarket, most of which will outperform the TORs and make a pleasant sound doing it, so look for the style you want and get to it.
Speed3Chris
I like Dick
There are many that have removed it and many that have modded the box. I have an EFI bike and kept the box and removed the restrictor. There is no question that removing or modifying the box will help the motor breath a bit.
To me removing the box is about:
1. Sound
2. Opportunity for more dirt or water ingress
2. is not a problem with proper parts.
But...sound is very different without the box. Before you decide pull the snorkel and ride the bike for a while. This will give you an idea what the bike will sound like without the box. I prefer the box in place for sound mostly...removing the restrictor frees up flow and adds just a bit of sound at WOT which to me sounds perfect but I don't like excessive induction noise...prefer to hear the pipes.
Cheers.
PS: The Tors is a separate discussion and or debate. Other peashooters do not flow better than Tors and virtually all are louder...like Togas, Sleepers etc. Reverse cone mufflers like Predators flow better but are louder. There is no free lunch with mufflers. To me Tors are perfect and in many ways changing Tors is just like the airbox. Removing each will free up less than a handful of horsepower up top and the bike will be a LOT louder. So pick what you want. A good muffler choice is the Dominator Tourings which are reverse cone and not as loud as Predators. It also comes down to the look you are after. Some like the reverse cone look and some prefer the vintage peashooter look. The good news with all this stuff, is you have a lot of choices. It mostly comes down to sound. If you want a faster bike, you need to go into the motor. These motors are low compression and have a very mild intake cam and a good place to start.
To me removing the box is about:
1. Sound
2. Opportunity for more dirt or water ingress
2. is not a problem with proper parts.
But...sound is very different without the box. Before you decide pull the snorkel and ride the bike for a while. This will give you an idea what the bike will sound like without the box. I prefer the box in place for sound mostly...removing the restrictor frees up flow and adds just a bit of sound at WOT which to me sounds perfect but I don't like excessive induction noise...prefer to hear the pipes.
Cheers.
PS: The Tors is a separate discussion and or debate. Other peashooters do not flow better than Tors and virtually all are louder...like Togas, Sleepers etc. Reverse cone mufflers like Predators flow better but are louder. There is no free lunch with mufflers. To me Tors are perfect and in many ways changing Tors is just like the airbox. Removing each will free up less than a handful of horsepower up top and the bike will be a LOT louder. So pick what you want. A good muffler choice is the Dominator Tourings which are reverse cone and not as loud as Predators. It also comes down to the look you are after. Some like the reverse cone look and some prefer the vintage peashooter look. The good news with all this stuff, is you have a lot of choices. It mostly comes down to sound. If you want a faster bike, you need to go into the motor. These motors are low compression and have a very mild intake cam and a good place to start.
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Speed3Chris
I like Dick
For the record OP, Pieman is one of the most knowledgable tuners of these bikes but that doesn't mean I agree with everything he says. He sells custom tuneboy tunes for EFI bikes so he looks through a particular lense.
You don't have to look at the airbox in all or nothing terms or whole hog as he writes. This binary way of thinking in many ways is the antithesis of tuning which tends to be quite subtle. Pieman knows that removing the restrictor will improve the breathing of the box, in fact he taught us that.... just not as much as gutting it which will make it a lot louder and if you look at Pieman's dyno runs, removing the box adds hp ABOVE redline. My comments are in no way an afront to Pieman's words...just an attempt to clarify some of the nuances in the decision process as there is a fair amount to the complexities of changing your bike and tune. For example, running hot and lean on an EFI bike is also a myth...even if you gut the box and run a Arrow 2-2 or Arrow 2-1 map...the bike will run close to stoich with no airbox. Also for less than 6% of throttle openings, the EFI motor is adaptive and will run close to stoich independent of changing the map unless you disable closed loop which is a good option if tuning the bike. Is stoich best for performance? No but it is not a bad compromise if you want some fuel economy as well, so depends what you want. Stoich certainly won't make the motor hot or burn up...otherwise 80% of bonnies sold that never get modified would all burn up...lol. An Arrow 2-1 EFI bike with airbox has an AFR of 13:1 +or- in open loop and removing the box will move it closer to stoich but not any leaner. If you want to "optimize performance" however at some detriment to fuel economy and do decide to gut the box, you do need a custom map and if you are not a tuner by nature, Pieman is a good man to contact for one of his tunes.
Good Luck.
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Bigted
Two Stroke
Save a few more bucks and get the 904 kit from TPUSA. You're almost there now. Your TORS will get louder after you put some miles on them, .. I think they are a nice compromise between too loud and not loud enough. I also understand that they will provide 90+% power of the most free flowing pipes so it is likely you may not even be able to tell the difference anyway.
Ted
Ted
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Speed3Chris
I like Dick
+1 and 813 cams if your budget will tolerate. TPUSA also sells a HC piston + 813 cams kit which is a good value if wanting to increase hp which is never cheap on any bike. If you want to skim the head you can also rival the CR of the BB kit with the HC piston kit...just will give up 39cc's...tough choice really. I wish TPUSA sold the HC pistons as 11.5 CR like the big bore kit but they do so I presume as an incentive to purchase the BB kit which requires new cylinders.
PS: As a footnote, Tors will also be louder with either HC pistons or BB kit because of higher cylinder pressures.
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Thank you so much, I will talk the 904 kit (and the other suggested) with my man. Any ideas of cost with labor. I would love to get new shocks, brakes, and some engine preformance mods all coming in under 2000. Maybe its a pipe dream to get it all done for that. As a sidenote, I feel smarter just reading all the posts on this site.
Speed3Chris
I like Dick
I as well as others prefer the TPUSA big bore kit to Weisco for the simple fact that it uses Nikasil cylinders just like the factory bores. Go to their website for pricing and see the various go fast parts. Labor really depends. Many of us will do it ourselves. If you know a good wrench maybe you can barter with him something he may need.
It also depends if you do cams which require exchange and/or head work which helps these motor breath. The Hinkley motor is a very strong motor that is conservatively tuned from the factory. It really needs cams and compression to bring it alive if stock performance isn't enough. There is also debate on whether the motor really needs any more performance with basic tuning like opening the airbox and decent pipes. An EFI bike in this form will generate up to mid 60 RWHP which for many is really enough on the street if you run the bike like intended which is up near redline where these motors start to produce hp. I have owned my bike for over a year now and honestly the bike does not feel underpowered to me hitting redline quickly in each gear and one of the best aspects of the bike is how easy it is to ride fast because of its very gradual power onset with no surprises. If you build the motor, you really have to watch your power out of turns so in effect you aren't really much faster on the street. For the track you may want a different bike anyway....like a Daytona.
It also depends if you do cams which require exchange and/or head work which helps these motor breath. The Hinkley motor is a very strong motor that is conservatively tuned from the factory. It really needs cams and compression to bring it alive if stock performance isn't enough. There is also debate on whether the motor really needs any more performance with basic tuning like opening the airbox and decent pipes. An EFI bike in this form will generate up to mid 60 RWHP which for many is really enough on the street if you run the bike like intended which is up near redline where these motors start to produce hp. I have owned my bike for over a year now and honestly the bike does not feel underpowered to me hitting redline quickly in each gear and one of the best aspects of the bike is how easy it is to ride fast because of its very gradual power onset with no surprises. If you build the motor, you really have to watch your power out of turns so in effect you aren't really much faster on the street. For the track you may want a different bike anyway....like a Daytona.
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A lot of labor you can accomplish yourself. Pretty much everything aside from machining bores or pressing sleeves can be done in your garage.
On motorcycles, even if you pay someone supposedly qualified to do work, the margin of safety is so slim you must know enough about your bike to check every bolt and fastener when you get your bike back from the shop. It's your ass.
So, if you're going to go to that much attention/trouble anyhow, save some money, gain some experience, and do the work yourself.
Good thing to also include brake and suspension upgrades when increasing engine performance. The stock setup is acceptable for average riding, but if even if you're riding spiritedly with the stock engine you'll want better fork springs and rear shocks. Add more 'go fast' and you'll definitely want better braking, and also consider a steering stabilizer.
I don't know if you can do all that for sub-$2k, but just do a bit at a time, spread it over a couple years. No need to rush it, you'll have the bike for a lifetime right? Plus, we're always too impatient with our wants and purchases; sometimes it's nice to have a project that you drag out over many months or even a few years. It gives you lots of time to daydream and drool over parts catalogs, and the planning and the chase is a big part of the fun anyway. That's why we never stop modding, it's not always just about the result.
I've got lots of things I'd love to do with my bike, but with college and work some things go on the back burner.
-K
Stars&Bars
Two Stroke
Hey Crikket44, Remember if you want to sell your pipes there are folks out here that are looking for good used TORS, So don't forget to let us know their for sale here first!
airbox mods
Speed3Chris,
Would you relate to me what you have done to your engine as far as mods to the intake, airbox, and exhaust. Especially with the airbox. I have a 2009 Bonnie Standard with the factory TORS which are loud enough for me. I've removed the snorkle and ordered a UNI filter. I naturally have the factory TORS map in it now and it runs great. I also removed the AI as soon as I got it home from the dealer using your excellent writeup. I don't want to lose any of the motors flexibility at low end. I was thinking of removing the restricter plate and drilling out the other side of the airbox to match the main intake. I'm like you in that I don't want to lose my airbox for the same reasons you give. I'm not looking for that last horsepower at the top end, I just want to make the most out of what I have without losing a great amount of flexibility.
Will the map I have in it now work with the mods I have in mind? When I ride real conservatively I have gotten as high as 59mpg.
This bike was made for me. I love the way it drives.
Bill
Speed3Chris,
Would you relate to me what you have done to your engine as far as mods to the intake, airbox, and exhaust. Especially with the airbox. I have a 2009 Bonnie Standard with the factory TORS which are loud enough for me. I've removed the snorkle and ordered a UNI filter. I naturally have the factory TORS map in it now and it runs great. I also removed the AI as soon as I got it home from the dealer using your excellent writeup. I don't want to lose any of the motors flexibility at low end. I was thinking of removing the restricter plate and drilling out the other side of the airbox to match the main intake. I'm like you in that I don't want to lose my airbox for the same reasons you give. I'm not looking for that last horsepower at the top end, I just want to make the most out of what I have without losing a great amount of flexibility.
Will the map I have in it now work with the mods I have in mind? When I ride real conservatively I have gotten as high as 59mpg.
This bike was made for me. I love the way it drives.
Bill
Speed3Chris
I like Dick
Hi Bill,
I have an EFI bike that is close to stock and like many a work in progress. The motor is unaltered and I have a stock map in it. I removed AI like you did very early on. I had the snorkel on and off the bike on several ocassions which reinforced that I don't like the intake completely open with the Tors pipes in particular which are perfect in loudness "to me". I have made this mistake on other motorcycles and regretted it. To me the sound of the bike is almost as important as the power it produces and tuning the sound of the bike is really personal taste. The decision to remove the airbox and even modifiy it in large degree affects sound more than hp. Yes there is some hp to be gained up past 7K RPM but you really have to ask yourself which you have...how do I ride the bike? I typically shift up near 7K or so when riding aggressively so removing the airbox isn't a big help to flow anyway. So it comes down to sound. Removing the restrictor plate frees up more flow Bill and I highly recommend this change. I like the snorkel again because of sound. If you don't mind the louder induction noise, then toss the snorkel. Further, you will get more flow out of the box if you cut open the RH wall of the box...no question. You can get pretty close to the same flow as no box by opening up both walls of the box...BUT...it will be louder when you open the throttle. If you like your set up now without the snorkel relative to noise level in particular, then you are a good candidate for removing the restrictor AND opening both sides of the airbox for more flow. Keep in mind if you open the right hand wall and poke a hole in the RHS of the filter, you need to add a gasket to the RHS of the filter to seal it surrounding the added hole...much like how the left side is configured from the factory.
As to map, word is the Tors map is perhaps the least favorable map from a throttle response standpoint. If you study the air and A/F values of the Tors map and compare it to the stock map, they are pretty close...the Tors map being mapped for higher air flow values and a degree or so more ignition timing. This greater fuel disparity between closed and open loop is what gives the Tors map its snatchier personality which is common to EFI bikes across brands. Both Arrow maps are better for throttle response because they spend less time at stoich in closed loop and therefore have a less abrupt transistion to open loop. The whole subject of maps and opening up the airbox is a bit tedious and often misinterpreted without a bit of study. The best way to get proper tuning is on the dyno with your particular bike config. The Arrow 2 into 1 map is the best factory map if opening up the airbox but will not be optimum for performance without a bit of tweaking with a tuneboy or Power Commander. It will be ok for typical riding however. A last note on the EFI bikes is they have not been out that long and there will be more tuning options likely available in the future as these bikes fall into more owners hands.
I agree with you about how these bikes ride....a lot of fun. Part of the charm of a bonnie is the power delivery of the bike which has a very gradual onset making it so easy to ride and accelerate out of corners. Shift up near redline and keep the revs up above 5K RPM which is easy with Tors because they do not draw too much attention...and the bike has plenty of power with some subtle tuning as you know. An EFI bike with pipes and no restrictor plate will make low 60's RWHP which is adequate. At some point, I will likely increase compression and change the cams and flow the head which adds about 10 more RWHP...not because it needs it...just for the fun of modding it a bit more as modding these bikes to me is as much fun as riding them. For now I am tweaking other aspects of the bike that I think it needs more than the motor.
Cheers.
PS: below shows an internally shortened snorkel...an easy mod to make. I run this in addition to the restrictor plate removed in an effort to create a tone and noise threshold for the intake I enjoy at WOT with very little compromise to performance. Generally be it intake or exhaust there is tradeoff of hp for less sound otherwise everybody would run open pipes and no airbox. If you remove the snorkel for test riding, you will see it has a long internal baffle connected to its "snout" which is there to reduce resonance aka sound. Predominant squelching of intake noise level is the snout however. As to the restrictor plate, some believe the restrictor plate is in place to increase intake velocity at low RPM to preserve low end torque. This seems to be disproved with dyno testing and anecdotal accounts including mine as I don't feel any loss of torque down low and the bike feels like it pulls harder up past 5K RPM without the restrictor. I believe the restrictor is in there largely for sound abatement albeit it doesn't make a big difference in sound if removed. If it makes any contribution to low end torque, its fractional and its restriction in terms of hp lost at higher RPM is more consequential as proven by Pieman's testing.
I have an EFI bike that is close to stock and like many a work in progress. The motor is unaltered and I have a stock map in it. I removed AI like you did very early on. I had the snorkel on and off the bike on several ocassions which reinforced that I don't like the intake completely open with the Tors pipes in particular which are perfect in loudness "to me". I have made this mistake on other motorcycles and regretted it. To me the sound of the bike is almost as important as the power it produces and tuning the sound of the bike is really personal taste. The decision to remove the airbox and even modifiy it in large degree affects sound more than hp. Yes there is some hp to be gained up past 7K RPM but you really have to ask yourself which you have...how do I ride the bike? I typically shift up near 7K or so when riding aggressively so removing the airbox isn't a big help to flow anyway. So it comes down to sound. Removing the restrictor plate frees up more flow Bill and I highly recommend this change. I like the snorkel again because of sound. If you don't mind the louder induction noise, then toss the snorkel. Further, you will get more flow out of the box if you cut open the RH wall of the box...no question. You can get pretty close to the same flow as no box by opening up both walls of the box...BUT...it will be louder when you open the throttle. If you like your set up now without the snorkel relative to noise level in particular, then you are a good candidate for removing the restrictor AND opening both sides of the airbox for more flow. Keep in mind if you open the right hand wall and poke a hole in the RHS of the filter, you need to add a gasket to the RHS of the filter to seal it surrounding the added hole...much like how the left side is configured from the factory.
As to map, word is the Tors map is perhaps the least favorable map from a throttle response standpoint. If you study the air and A/F values of the Tors map and compare it to the stock map, they are pretty close...the Tors map being mapped for higher air flow values and a degree or so more ignition timing. This greater fuel disparity between closed and open loop is what gives the Tors map its snatchier personality which is common to EFI bikes across brands. Both Arrow maps are better for throttle response because they spend less time at stoich in closed loop and therefore have a less abrupt transistion to open loop. The whole subject of maps and opening up the airbox is a bit tedious and often misinterpreted without a bit of study. The best way to get proper tuning is on the dyno with your particular bike config. The Arrow 2 into 1 map is the best factory map if opening up the airbox but will not be optimum for performance without a bit of tweaking with a tuneboy or Power Commander. It will be ok for typical riding however. A last note on the EFI bikes is they have not been out that long and there will be more tuning options likely available in the future as these bikes fall into more owners hands.
I agree with you about how these bikes ride....a lot of fun. Part of the charm of a bonnie is the power delivery of the bike which has a very gradual onset making it so easy to ride and accelerate out of corners. Shift up near redline and keep the revs up above 5K RPM which is easy with Tors because they do not draw too much attention...and the bike has plenty of power with some subtle tuning as you know. An EFI bike with pipes and no restrictor plate will make low 60's RWHP which is adequate. At some point, I will likely increase compression and change the cams and flow the head which adds about 10 more RWHP...not because it needs it...just for the fun of modding it a bit more as modding these bikes to me is as much fun as riding them. For now I am tweaking other aspects of the bike that I think it needs more than the motor.
Cheers.
PS: below shows an internally shortened snorkel...an easy mod to make. I run this in addition to the restrictor plate removed in an effort to create a tone and noise threshold for the intake I enjoy at WOT with very little compromise to performance. Generally be it intake or exhaust there is tradeoff of hp for less sound otherwise everybody would run open pipes and no airbox.
If you remove the snorkel for test riding, you will see it has a long internal baffle connected to its "snout" which is there to reduce resonance aka sound. Predominant squelching of intake noise level is the snout however. As to the restrictor plate, some believe the restrictor plate is in place to increase intake velocity at low RPM to preserve low end torque. This seems to be disproved with dyno testing and anecdotal accounts including mine as I don't feel any loss of torque down low and the bike feels like it pulls harder up past 5K RPM without the restrictor. I believe the restrictor is in there largely for sound abatement albeit it doesn't make a big difference in sound if removed. If it makes any contribution to low end torque, its fractional and its restriction in terms of hp lost at higher RPM is more consequential as proven by Pieman's testing.Attachments
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restictor plate
Chris,
I did a search on restictor plate removal and all I saw was guys chopping up their airbox and no real good pics on plate removal. Could you give me any tips on how to go about removing my restrictor plate? As I said I am putting in a Uni filter soon and as long as I am that far I would like to go ahead and get that plate out. Do you have to remove a lot of other items to get at the plate? I really would appreciate any help you can give me. You seem like one of the more logical and mechanically apt persons on this forum.
Bill
Chris,
I did a search on restictor plate removal and all I saw was guys chopping up their airbox and no real good pics on plate removal. Could you give me any tips on how to go about removing my restrictor plate? As I said I am putting in a Uni filter soon and as long as I am that far I would like to go ahead and get that plate out. Do you have to remove a lot of other items to get at the plate? I really would appreciate any help you can give me. You seem like one of the more logical and mechanically apt persons on this forum.
Bill
Speed3Chris
I like Dick
If you nose around the web bill and do a search on a few sites...you will find a procedure with some pics.
Its not a tough job but there are a few good tricks to make it more painless.
1.You have to remove the stuff off of the RHS cover of the airbox which is held on with Philips screws..remove the fuse box and master cylinder fasteners and string up.
2. Best tip is remove the seat and remove the 4 bolts up top that secure the box to the bike
3. Remove as many of the philips screws as you can with a long screwdriver from the RH cover.
4. The two rear screws will be impossible to remove with a screwdriver.
5. You can either try to remove these with needle nose vise grips from a ninety degree angle from behind the frame rail (tedious)...or....remove the throttle body bellows clamps and then push the box back with rubbers in place far enough with the four bolts removed up top to access the rearward screws behind the frame rail with a philips screw driver.
6. Helps to remove the sprocket cover as well to slide the RH cover off once all screws are removed.
7. Once the cover is off, the restrictor pulls right out.
8. When you replace the two screws behind the frame rail...replace them with hex head screws so you can use a small closed end wrench...8mm I believe....on them and that way you won't have to loosen and slide the airbox rearward if you take off the cover again...say to put a hole in it.
Thats the gist of it Bill. Post if you get stuck. A camera is your friend for posting here with any questions and keeping track of your steps. You will be fine.
Good Luck.
Its not a tough job but there are a few good tricks to make it more painless.
1.You have to remove the stuff off of the RHS cover of the airbox which is held on with Philips screws..remove the fuse box and master cylinder fasteners and string up.
2. Best tip is remove the seat and remove the 4 bolts up top that secure the box to the bike
3. Remove as many of the philips screws as you can with a long screwdriver from the RH cover.
4. The two rear screws will be impossible to remove with a screwdriver.
5. You can either try to remove these with needle nose vise grips from a ninety degree angle from behind the frame rail (tedious)...or....remove the throttle body bellows clamps and then push the box back with rubbers in place far enough with the four bolts removed up top to access the rearward screws behind the frame rail with a philips screw driver.
6. Helps to remove the sprocket cover as well to slide the RH cover off once all screws are removed.
7. Once the cover is off, the restrictor pulls right out.
8. When you replace the two screws behind the frame rail...replace them with hex head screws so you can use a small closed end wrench...8mm I believe....on them and that way you won't have to loosen and slide the airbox rearward if you take off the cover again...say to put a hole in it.
Thats the gist of it Bill. Post if you get stuck. A camera is your friend for posting here with any questions and keeping track of your steps. You will be fine.
Good Luck.