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Discussion Starter #1
Hi all! My first post on these forums although i've been lurking for a while.

I have a few questions and figured i'd throw them out on the board.

All questions pertain to my 2000 929 which currently has a PC3, hindle bolt-on, and the headers/mid from a '02 954.

1. Does anyone anywhere have a map for a stock 00 929 with a hindle bolt on? i've seen a bunch of references to using other maps, currently i'm using the 2bro map. Could I get some opinions on what map is the way to go for this?

2. I am planning on getting a custom map in about a week (i know this negates the importance of question 1, but i'm still curious) and am making the mods i would like to have for the mapping. I will be removing the flapper and was wondering if locking open the HTEV might help as well. I am a bit vague on the whole backpressure thing as it works in the exhaust. I've tried to read a lot on this but i haven't found any clear cut answers. perhaps locking open the HTEV would be bad for stock fuel injection, but will the low end power that i lose (i guess) come back with a custom map? or am i just better off not worrying about that.

3. does anyone know of any ill effects of removing the pair valve? i couldn't find any, but figured i'd toss that one out too.

thanks a ton, now that i've finally registered i guess i'll have to post more =P



more on question 2. i sent this in an email to couple of friends i was asking opinions on about this. it pretty much sums up my logic and better than i explained above i think.

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it seems like if you are removing the flapper (air in) it would effect the effectiveness of the HTEV itself (air out) since you have more air in at the low end, you will have that added backpressure already.
 

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Removing the pair valve won't present any problems and all you need is the block off plates. If memory serves me right, any good dyno guy would need to block off the pair system to do a good custom map. I'm sure you will get better answers to this and the rest of your questions.
 

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'it seems like if you are removing the flapper (air in) it would effect the effectiveness of the HTEV itself (air out) since you have more air in at the low end, you will have that added backpressure already.'

The above is not necesarily correct as it is not a 'Ram Air' system, the engine can only take in as much air at a certain rpm as its volumetric efficiency will allow (100% volumetric efficiency is when an idividual cylinder of for example 250cc draws in 250cc's of air/fuel mixture) most normally aspirated engines do not acheive 100% VE, Im not sure what a fireblades VE is But would not be suprised if it was somewhere around 100% and this would be produced at the point where the engines peak torque is made but at 5000rpm I would be supprised if 60% VE was acheived because of the cam timing and overlap, so below 7000-8000rpm when the flapper is usually closed you will not see to much if any improvement from removing or pinning the flapper open, some engines for example prostock drag cars can produce greater than 115% VE by having cams with massive duration and tunned length intake runners that creat a pulse effect to actually create positive presure in the intake manifold just as the inlet valve opens to create a supercharging effect, so as it isnt a ram air or positive presure type system basically as long as it isnt too restricted which it isnt at those lower rpm you will not really gain any power from having it removed! Although if you can modify it to make it a ram air system you will gain power if it is mapped to suit the extra air flow! Sorry about the long reply, I just have trouble explaining things simply
 

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Discussion Starter #4
long replies are what i want to see. =)

even if the increase is slight, it seems like it would still be an increase of some kind with the flapper gone. the htev is another story. i'm not sure what kind of effect the backpressure has on the power of the engine.

it seems that if you had a ram air system it would be hard to build a good map for it with a dyno. you would be running leaner than needed for max power the fast you went because your fuel/air ratio would be off (more speed, more air pushed in, less fuel to mix with it since map is made standing still) or is this something they accomodate for?

i would like to do a ram air mod but i don't feel like investing in that right now. i would also like to just put a full hindle on the bike then i don't have to worry about the htev, but if i can just open up the htev and map out some of the dips and get close to a hindle, i'll be pretty happy.
 

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Sorry I didnt mention anything about the HTEV before, Thats an intresting Idea about locking it open! although the reason its there is to vary the routing of the exhaust gases not so much as to alter the amount of back presure, but 'when' the presure waves return to the exhuast port (as it isnt constant, it returns in waves back to the exhaust valve/port in pulses, both -ve and +ve presure waves) and ties in with camshaft timing, as a camshaft is a compromise that works best at a particular rpm and works in symphony with tuned exhaust and intake pulses to help fill the cylinder and help scavenge on the exhaust side, therefore a long exhaust header will work better at low rpm as the presure waves take longer to return and a short header is better for high rpm where they will return much more quickly, and this is more what the htev is about than the the amount of presure, hope this helps a bit and sorry if any thing isnt as clear as it could be but its getting late and the brain is going off line!
 

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Discussion Starter #6
where is the 'end' of the pressure wave in the exhaust?

i'm basing my assumptions on the image below on how the air flow works in the htev:


in that image it would seem that if longer pressure wave returns are better at low rpms, you would lock it open. thus creating one long pipe. perhaps not full open as it is above 7k but just with all 4 pipes routed straight through to the exhaust creating the longest possible exhaust header. wouldn't the htev essentially become part of the header at that point?

just trying to understand =)
 

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Sorry ilikesilver that I cant give a very good explaination relating exactly to the htev diagram ill have to look at it for a while to figure out what is going on, as once you start having junctions etc things start getting a bit complicated and I have some notes on exhuast design that also has formulas for working out exhaust lenghts and diameters but they are at my parents house, although the example I gave was for primary header length which is easiest to understand when thinking of a 4 into 1 type exhaust system which I was mainly intrested in when I was reading up about this as that design gives the most peak/topend power! opposed to 4-2-1 which gives better mid range power and a better spread and as at the time I was studying up about this, It was for an engine I was planning on building (still will one day as I already have most of the parts) that has a massive cam with 322 degrees duration so I was chasing top end at all costs! But back to your question about were does the presure wave end? The easiest way to explain it is if you have a strait piece of pipe with an open end and you send a presure wave down it, when the wave reaches the open end it will turn around and come back (strange but true) so anywhere in the sytem there is a junction or in the case of of 4-1 the collector where the 4 headers dump into collector this will occur although I would have to read through my notes again to refresh myself as to exactly what happens with the secondary pipes espeacially in the tri-y design (4-2-1) although you can see in the htev digram that above 7000rpm that when when they are all completely open they are also open between the top and bottom and I think when the wave reaches this point it will turn around acting like a shorter primary even though it looks like a longer pipe all the way to the junction just before the muffler (just remember the presure wave turns around not the exhaust gas itself ( heres a strange example but it might make some sense! just say you had a little boat in a pond and you throw a rock in the middle, you can see what are essentially presure waves eminating concentrically from the the center so these wave are moving out although the little boat could be simoultaneously floating towards the middle seemingly against the flow! so when you see these rings moving outward the water molecules arnt actually moving outward just shock waves, like if you stand in a cue and shoulder barge someone you can transfer your force to someone ten positions down the cue but you dont actually have to go down there! Hope Im not raving too much, just my way of explaing things, and Im sure there will be others on the forum who maybe able to explain things a bit clearer than me and add to this or correct what Ive said to a degree, but I think what Im saying is essentially correct! maybe just not put the best way!
 

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Discussion Starter #8
well dang i was hoping for more responses. i can't believe no one has ever locked open the htev on a 929. i guess i'll be the first =P pair valve is off. flapper is out. i didn't have that little filter that was used to block off the crankcase air in the faq buti just ran that back into the airbox where it was before so no biggy. now if i gas it from zero the engine bogs until about 3k then it takes off like a rocket. i never really paid attention before sadly but i don't think it bogged like it does now. only if i break like 60% throttle, under that it seems fine.

had to switch out my right rearset tonight and now it's dark so no htev tonight, but probably tomorrow. i'll let everyone know how it goes. =)
 

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Kind of a sidenote question here, but the flapper - isn't it generally accepted to have virtually zero to do with real performance as opposed to it being there simply as an EPA noise reduction device?

I pinned my flapper and found no change in the way the bike runs, but I get a nice intake growl now that I didn't have before.
 

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Discussion Starter #10
Quote Kind of a sidenote question here, but the flapper - isn't it generally accepted to have virtually zero to do with real performance as opposed to it being there simply as an EPA noise reduction device?


i wouldn't say that. there appear to be different opinions on it. i have heard/read that it makes a much bigger difference on the 929 than on a 954. i don't know why though. a friend of mine has a 954 with a full micron and a custom map. i believe it was dynoing at like 147 or so after all that. he said my 929 has more low end power than his ever had any any config. i don't know if that's just because of the flapper (i doubt it) but it couldn't hurt.

don't they gut the airbox in racing configs? i would assume more air in = more power. since it's by default closed under 7k, i would assume opening it gives more air and more air = more power.

some of that was what i wanted to learn from this thread.
 

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Hey ilikesilver, just read your thread.  I'm no expert, but if you've been doin alot of reading I think you'll find those who have either A) Dumped the flapper and HTEV and went with a full Hindle system (you already have the PCIII), or B) left the HTEV and flapper and went with a 1/2 or 3/4 system.

Your question about the HTEV is valid, but it seems as though you are about set for a full system and if your PAIR valve is blocked, custom mapping to follow.  Why are you leaving the HTEV system in, and why are you custom mapping a basically stock system ( including slip on)  ?  Your custom mapping isn't going to be cheap, and with the savings (postpone custom map) you should be almost close enough to purchase the full system Hindle.

Again, if you've read alot of history, it seems there are quite a few guys and gals who either have or had the full Hindle system with great reviews.  Personally, I would not fork out that much cash to custom map a stock system with or without flapper or pinned HTEV.  I went with the 3/4 system and PCIII with obiviously HTEV and flapper system intact.  I wasn't looking for the numbers you probably are.  I'd go full system from here. Just my 2 cents.

And no problem with a 2002 954's headers fitting on the 929? Was yours wrecked or bought used?
 

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Discussion Starter #12
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Hey ilikesilver, just read your thread.  I'm no expert, but if you've been doin alot of reading I think you'll find those who have either A) Dumped the flapper and HTEV and went with a full Hindle system (you already have the PCIII), or B) left the HTEV and flapper and went with a 1/2 or 3/4 system.

yep. i would say b is mostly people with just a slip on, i didn't find that many people with 3/4 systems at all.

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Your question about the HTEV is valid, but it seems as though you are about set for a full system and if your PAIR valve is blocked, custom mapping to follow.  Why are you leaving the HTEV system in, and why are you custom mapping a basically stock system ( including slip on)  ?  Your custom mapping isn't going to be cheap, and with the savings (postpone custom map) you should be almost close enough to purchase the full system Hindle.

my questions was mainly to determine whether taking the htev and locking it open would cause an increase without a dramatic decrease in lowend power. it seems as if it would in fact, i've talked to a few more peeps since then, including the guys at the dyno shop and they seem to think it does. why map a mostly stock system? well, because i can =) it's not that expensive relatively, only 200 bucks. and if i am going to sacrifice my midrange for highend power to go to full, i don't really want to go. my bike spends most of it's rev life below 10k because i ride it on the street and not on the track so i'd rather not waste the additional 400 bucks on a full system. maybe sometime i will, but peak horsepower isn't going to affect my daily rides on it that much even when i go on long rides for fun i am still normally below the range where i would have a huge jump in hp. in short, i would rather have a properly mapped bike with the slip on than one with a full system and not. regardless of what i did with the bike, it was a given that i would have it custom mapped. i just was trying to figure out if i should do something with the htev prior. i didn't. in addition, any more custom maps done on the bike (due to changes or additions or whatever) are half priced at this shop.

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Again, if you've read alot of history, it seems there are quite a few guys and gals who either have or had the full Hindle system with great reviews.  Personally, I would not fork out that much cash to custom map a stock system with or without flapper or pinned HTEV.  I went with the 3/4 system and PCIII with obiviously HTEV and flapper system intact.  I wasn't looking for the numbers you probably are.  I'd go full system from here.  Just my 2 cents.
well i wasn't looking for huge numbers, not from this bike really. this is the first bike i've replaced exhaust components on and stuff so i was mainly looking at it from a hobby perspective. just taking my time and enjoying the experience of changing out what i did.


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And no problem with a 2002 954's headers fitting on the 929?  Was yours wrecked or bought used?
zero problems. mine was bought from a place in daytona with an ASP title. 954 headers were off an 02 model that a friend of mine had, he was putting a full micron on and the 929's mid pipe had a dent in it. so to smooth out the dent we decided we'd give it a whirl. after some research it sounded like it was going to be fine. we mounted it all and no problems. i think the htev get's stuck a little bit now and it didn't used to. when we were doing the map today the htev didn't open on about the 3rd pull at 7k (the second opening, see pic above in post) and the engine lost about 15 hp from there out. maybe starting at 10 or 12 and curving up to about 15, so if you ever wandered if that htev opening up all the way (like i did) makes a big diff at the top end, it definately does.

aside from replying to you, i have the update. i left the htev intact after the research. it seemed that whatever the technical reason that backpressure increases the hp on the low end (which i couldn't find specifically), the fact remains that it does work. my bike pulled 131.something with the jardine map on it and 131.something with my new custom map. they smoothed out the powerband a little, but it was relatively unchanged. i haven't looked at the map file itself to see if there are any dramatic changes in the numbers but it didn't feel like it. it did feel a little smoother though. we compared my pulls to some other 929s they had and i was pretty happy. they had a guy with a full system.... um... yoshi i think and some new cams and he was pulling almost 142. to me, that's not worth it. he spent almost 2k on the cam work and the full system, plus the custom map etc etc. his powerband was identical to mine up to about 7 or 8k rpms then he steadily went up to his peak and left mine behind by 10hp. he had 2 more lb of torque across the band after 7k. on the track, that's definately worth it, but on the street, i don't think so. if i was gonna spend that kind of money i'd trade up to a newer 954 and do similar work on it to what i've done on the 929. i would probably get a lot closer to 140s and still spend less. however, that's all about the deal you get.

my conclusion, if you have a hindle, just use the jardine map. it's not as smooth but it had virtually identical dyno graph. i need to get the graph's as jpgs from where i took it and they are supposed to be emailing me the file which i'll post up if anyone wants to use the map.

I got it done at Stock Mild to Wild in Jacksonville, FL. it was high 90s when we did the map (per the software). The bike is a 2000 cbr 929. flapper removed. pair valve removed. stock air filter. 2002 954 headers and mid with about 8k miles on them (929 only had 6500 at dyno time). the crankcase breather tube (or whatever it's called in the knowledge base article on removing the pair valve) is still running to the airbox rather than having that hole plugged as they do in the fact and running a seperate filter on that hose.

and other than a follow up post to post the maps and graphs, that's all i have =)
 

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I've had my HTEV locked open since last October. I definitly noticed a bit more low end power. Seems to have linear power all the way through. The only negative is a slight decrease in MPG. I now get about 120 miles per tank.
 

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Discussion Starter #14
if that's true, why does the htev exist. it seems it's sole purpose is to create more low end power using backpressure. if it doesn't work, why put it in. also, why do the 929s with full systems (also w/out htev's) seem to generally lose low end, but gain top end? what other mods do you have on your bike? how did you lock it open? is the more low end power you feel just a feeling, or have you had it dynoed? by low end power do you mean sub 3k which is where the htev is pretty much closed up or do you mean between 3 and 7 where it's halfway open.

thanks and sorry for the tons of questions.
 

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Here is my 2 cents. Two weeks ago I purchased a PCIIIr from Dan Kyle at a killer price. Can't afford a full system yet, so I locked my htev open, yanked out the flapper and programed the PCIIIr for a hindle full system since I do have the hindle bolt on. It ran a bit lean do to the flapper being gone so I manually adjusted the PCIIIr up one richer on the low side, up two on the mid, and up one on the top.next I will be unplugging the pair valve. As far as how I locked open the htev, I disconected the three cables from the servo made a little cable clamp and am hoping the clamp doesn't fall off. That would suck trying to tie a not in the cable to make it home.
 

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ilikesilver : where is the 'end' of the pressure wave in the exhaust?

i'm basing my assumptions on the image below on how the air flow works in the htev:


in that image it would seem that if longer pressure wave returns are better at low rpms, you would lock it open. thus creating one long pipe. perhaps not full open as it is above 7k but just with all 4 pipes routed straight through to the exhaust creating the longest possible exhaust header. wouldn't the htev essentially become part of the header at that point?

just trying to understand =)
hello. may I ask where this image came from?

So the flapper is all the way open up to 7000 (8000, or whatever) rpm and all the way closed above 7000 (8000, or whatever).

When putting in a new air filter and plugs this weekend I noticed that my flapper is about half way between UP and DOWN at idle. As the revs come up it moves toward the UP position doesn't get there until just before it slams DOWN at around 8000 rpm.

I guess at 20,000 miles it's about time to do the checks in the manual for the HTEV and the HVIX systems.

Any words of wisdom/confirmation/correction/whatever regarding this?

as always...TIA.



bW
 

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Discussion Starter #18
link

the flapper is full closed until 7k+, then it opens up.
 

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ilikesilver : link

the flapper is full closed until 7k+, then it opens up.
right around 7000 my 929's exhaust note becomes 'fluttery.' That is to say the sound changes a bit and then starts to scream. Have any of youse other bolt-on can folks noticed this?

It seems to be a bit minimized since I adjusted the flapper and HTEV cables.

bush
 

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Discussion Starter #20
as i understand it a lot of engine sound comes from the intake, the flapper opens at 7k and then you get a lot of extra sound. doesn't have anything to do with the bolt on though.
 
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