 904cc Power and Torque Barrier
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Having had another look at the Dyno Table, I couldn't help but wonder when the magic numbers of: 80hp and 60 ft/lbs of tq were going to be eclipsed? From what I can see from the Dyno Results Table then, here were/are the current contenders: Dinqua’s 1st dyno was verified on June 08 with 75.8 hp & 61.2 ft/lbs of tq but Pat being our consummate pioneer on the subject at the time (or should that be our resident despot LOL), who was paving the way for all of us decided to change his carbs to mikunis. I'm not sure, but it appeared this brave move appeared to create perhaps more problems than solutions. I'm only assuming here so correct me if I'm wwwwwwrong. I was once before  Progressively then, a few others have since been slowly but surely catching up and even surpassing Pat's numbers including: Mag10: Who has already achieved the hp milestone with 80.4 hp and 57.3 ft/lbs tq,, then there's, Roadworthy with 77.5hp & 57.1 ft/lbs tq, and finally. Piper with 71.49 & 57.44, That's about it I think? If I've missed someone, you'll have to email me your numbers with printout verification cos I'm only working off the Dyno Table. Of course there's also quite a few (14 or so) who have got some really descent Hp figures into the 60's area, however the ever increasing realisation and acceptance how torque now plays at least an equal factor of importance in the total equation hasn't been so impressive.  Don't get me wrong, most of us know how much work and cost goes into improving a bike's power characteristics so any increases someone has achieved deserves credit. So, as I watch the live telecast of the races pre Casie Stoner's win in the Australian Motor Bike Grand Prix (on Phillip Island here in Aus)  , I can't help think who will be the first to break that elusive 904cc power barrier. Ride safe fellas. staffo
Staintune Pipes, K&N Pods, 45 pilots, TBS needles and 145 mains.
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Re: 904cc Power and Torque Barrier
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Joined: Aug 2005
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Loquacious
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Loquacious
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My max. torque on the table is 65.54 ft. lbs. but we stopped the dyno at about 6100 rpm so I didn't get a max. hp figure. There have been a number of changes since the dyno run and the bike is running stronger since then. I don't see hitting 80 hp as a major obstacle at 7500 or higher rpms if that is your goal.
I still contend the best way to compare performance is what is happening at 5250 where the torque and hp curves cross. My dyno chart is just under 60 at 5250 rpm. I haven't seen one that beat that yet and I still even have an airbox and stock carbs. I'm no longer trying to get more power, but I do intend to get an update dyno run in before long that would be current and run to 7500 rpm.
Bob
2005 America, 904cc - sold. 2014 Trophy SE.
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Re: 904cc Power and Torque Barrier
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Joined: Mar 2007
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Check Pants
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Check Pants
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My eyes keep searching the Dyno thread and comparing the "what if" scenarios.
I agree .... IF looking at HP numbers it seems 80ish is a max and Tq seems to peak at the mid 60s.
Too bad we cant get everyone on the same dyno, tweaked and then compare all the results...
The other thought here is that:
1)There truly is a max for the 904.
2)Breaking out of that elusive 80Hp number is going to require A LOT OF WORK. Every 100hp number Ive seen/heard of comes from a motor that is at or over 1100cc with lots o mods.
SOLD: 07 Black BA, 39mm FCRs, TPUSA stage 1 head, TPUSA 813 cams, TPUSA 10.8:1 pistons, TTP #3 igniter, Specialty Spares Long Cannons, Tsukayu Hard Bags. 82HP/55tq
NEW: 19 Goldwing Tour DCT
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2005
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Oil Expert
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Oil Expert
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Quote:
Too bad we cant get everyone on the same dyno, tweaked and then compare all the results...
Agreed. That would be the best way if you wanted to compare mods and their effect. Everyone knows that different dynos show different numbers. Main reason for putting your bike on a dyno though is to diagnose it. To really see what effect your tinkering have made and to see if you're running it with a proper a/f mixture. And to get the best answers it's important to use the same dyno and preferably the same operator every time and run.
"Wise men speak because they have something to say, fools because they have to say something."
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Re: 904cc Power and Torque Barrier
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Joined: Jul 2006
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3/4 Throttle
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3/4 Throttle
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All I can say is Wow...the old Hardly rule of thumb was 1 hp per cubic inch then it got real $$$$$$$$...so we are at about 1.5 hp for every cubic inch
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Re: 904cc Power and Torque Barrier
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Joined: Aug 2007
Posts: 10,730 Likes: 5
Should be Riding
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Should be Riding
Joined: Aug 2007
Posts: 10,730 Likes: 5 |
I don't think 80hp and 60ftlbs is out of reach with the 904, it's just a matter of cost. Go with a stage 2 head with +3mm oversize valves, cams, 12:1 comp pistons(or even 11:1) and some 42mm carbs with a remap of the ignitor and watch it go past 80 easy. The thing is, everyone has a different setup and a different budget. I doubt there is conclusive evidence of which exhaust pipe works best with the 904, too many variables. If I could have 65+ ftlbs of torque, I wouldn't care if I only had 70hp. If Bob is near 60ftlb at 5250rpm, then that sounds like it is a near perfect setup. The power is in these little motors, we just need to figure out how to get to it. I still want to get new cams in mine, but not to the point where I need to go shim-under bucket. Too costly. I feel like Fast Fred's carbs and intakes are a worthwhile purchase, way less than a new set of carbs for a good gain in hp and torque. If ProCom comes out with a new ignitor, then I will definitely get one and send it off for a remap. I don't want to put money in my stock unit when it could possibly fail. I also think my motor is already capable of reaching 80hp, but the rev limiter is preventing that. My torque is still climbing at redline, so the power is there to have, I just can't get at it yet. I would love to see someone go all out on one of these motors and post numbers. I'm still disappointed in the Wiseco pistons not being the claimed compression, that affects the torque directly.
Always remember to be yourself. Unless you suck. Then pretend to be someone else.
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Re: 904cc Power and Torque Barrier
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Joined: Mar 2007
Posts: 5,616
Check Pants
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Check Pants
Joined: Mar 2007
Posts: 5,616 |
Quote:
I feel like Fast Fred's carbs and intakes are a worthwhile purchase, way less than a new set of carbs for a good gain in hp and torque.
Any word on how Freds doing? Theres been a bit of chatter on NBR, T-rat and on the Delphi forums about folks trying to get a hold of him.
Quote:
I'm still disappointed in the Wiseco pistons not being the claimed compression, that affects the torque directly.
Precisely why Im looking at TPUSA kits instead of the Wiseco route.
SOLD: 07 Black BA, 39mm FCRs, TPUSA stage 1 head, TPUSA 813 cams, TPUSA 10.8:1 pistons, TTP #3 igniter, Specialty Spares Long Cannons, Tsukayu Hard Bags. 82HP/55tq
NEW: 19 Goldwing Tour DCT
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Re: 904cc Power and Torque Barrier
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Joined: Dec 2006
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Oil Expert
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OP
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Really interesting responses, and yep I agree on just about everything said. It's all about being a combined effort really. This way eventually the best changes available are worked out with trial and error. Then the rest of us who are interested (how could you not be) and who don't have the moolah together can down the track, be lucky enough to pretty well know what needs to be done. That's why I appreciate the efforts of you bloke's and how you share your experiences  Sure makes it so much easier and cheaper, than re-inventing the wheel. thanks for your feedback  cheers staffo
Staintune Pipes, K&N Pods, 45 pilots, TBS needles and 145 mains.
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2005
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Oil Expert
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Oil Expert
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Quote:
All I can say is Wow...the old Hardly rule of thumb was 1 hp per cubic inch then it got real $$$$$$$$...so we are at about 1.5 hp for every cubic inch
Maybe harley, but for 2 cyl japanese bikes the rule of thumb was more like 1 hp per 10cc. that's closer to your 1.5 per cubic inch.
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2005
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Oil Expert
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Oil Expert
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Quote:
I still contend the best way to compare performance is what is happening at 5250 where the torque and hp curves cross.
You're right. All these numbers and mods are hard to compare (if that's what you want) with for example top hp at so many different rpm's. Some have raised the rev limiter and some haven't and so on. Your numbers are so impressive. What make them even better is the fact that you still have the air box and stock carbs.  
"Wise men speak because they have something to say, fools because they have to say something."
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2005
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Oil Expert
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Oil Expert
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Quote:
I'm still disappointed in the Wiseco pistons not being the claimed compression
But it's still unconfirmed, right?
"Wise men speak because they have something to say, fools because they have to say something."
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Re: 904cc Power and Torque Barrier
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Joined: Aug 2007
Posts: 10,730 Likes: 5
Should be Riding
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Should be Riding
Joined: Aug 2007
Posts: 10,730 Likes: 5 |
Quote:
Quote:
I'm still disappointed in the Wiseco pistons not being the claimed compression
But it's still unconfirmed, right?
As far as I know they haven't admitted it. I may have to call Bill Gately and see if he found anything out.
Always remember to be yourself. Unless you suck. Then pretend to be someone else.
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
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Learned Hand
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Learned Hand
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I have not had a chance to get back to the dyno, but I am fairly certain that I have higher number (sure feels like it) after making the carb adjustments indicated by the dyno run and the timing adjustments to address the knock. I am planning to send my carbs off to fast fred for the over size treatment in the next week or so (riding season appears to be done for me this year). Spring should yield some interesting numbers. Past conversations with fast fred indicate that 100hp should be doable for a 904. And that is what I would like to see.
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
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Quote:
I have not had a chance to get back to the dyno, but I am fairly certain that I have higher number (sure feels like it) after making the carb adjustments indicated by the dyno run and the timing adjustments to address the knock. I am planning to send my carbs off to fast fred for the over size treatment in the next week or so (riding season appears to be done for me this year). Spring should yield some interesting numbers. Past conversations with fast fred indicate that 100hp should be doable for a 904. And that is what I would like to see.
You will not get 100RWHP out of 904 for a street bike.
Maybe, and I said maybe for a full race motor but will not be easy.
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
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Learned Hand
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Learned Hand
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Quote:
You will not get 100RWHP out of 904 for a street bike.
Maybe, and I said maybe for a full race motor but will not be easy.
WHY? what do you think is the limiting factor? And what would you consider makes a bike not a 'street bike'?
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Aug 2007
Posts: 10,730 Likes: 5
Should be Riding
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Should be Riding
Joined: Aug 2007
Posts: 10,730 Likes: 5 |
I think he means that if you can get 100hp out of it, it wouldn't be until very high in the rpms (over 9000), and torque would be insignificant in the lower rpm range where it would be used in a street application, say under 5000 rpms. Basically, it would start off the line like a turd, and not make any power from one block to the next.
Always remember to be yourself. Unless you suck. Then pretend to be someone else.
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
Joined: Apr 2009
Posts: 48 |
Quote:
Quote:
You will not get 100RWHP out of 904 for a street bike.
Maybe, and I said maybe for a full race motor but will not be easy.
WHY? what do you think is the limiting factor? And what would you consider makes a bike not a 'street bike'?
You will need to pull 10000 RPM's. 500 lift cams which implies a ProStock head(SUB), racing fuel,etc,etc.
At that point you'll have a non streetable bike and a hand grenade under the seat.
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
Posts: 1,174 Likes: 15
Learned Hand
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Learned Hand
Joined: Jan 2008
Posts: 1,174 Likes: 15 |
Quote:
Quote:
Quote:
You will not get 100RWHP out of 904 for a street bike.
Maybe, and I said maybe for a full race motor but will not be easy.
WHY? what do you think is the limiting factor? And what would you consider makes a bike not a 'street bike'?
You will need to pull 10000 RPM's. 500 lift cams which implies a ProStock head(SUB), racing fuel,etc,etc.
At that point you'll have a non streetable bike and a hand grenade under the seat.
as my wife would be quick to point out, it would not be the first time that I kept messing with a bike or car until it was undriveable on the street. But I will still ride it aways.
Your math on the HP is interesting. Obviously, the easiest way to get the high HP is more revs. (10,000 seems like too round of a number to be realistic) The most productive way would be more torque, then see where the revs fall. I may not get to 100 hp but I am not stopping at 80 just because you think it can't be done.
As for sitting on a hand grenade, if you are afraid to scatter a motor or two then this is a bad game to play.
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2005
Posts: 3,753
Loquacious
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Loquacious
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not sure you understand who you are talking to, he has exploded motors and has done some pretty extreme things with these motors
(Former)05 BA tbike pipes, ai removed, Freak, mikuni hsr 42's, 904, ported/polished head, 1mm oversized valves
NOW-2010 silver and black tbird
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
Joined: Apr 2009
Posts: 48 |
Quote:
Quote:
Quote:
Quote:
You will not get 100RWHP out of 904 for a street bike.
Maybe, and I said maybe for a full race motor but will not be easy.
WHY? what do you think is the limiting factor? And what would you consider makes a bike not a 'street bike'?
You will need to pull 10000 RPM's. 500 lift cams which implies a ProStock head(SUB), racing fuel,etc,etc.
At that point you'll have a non streetable bike and a hand grenade under the seat.
as my wife would be quick to point out, it would not be the first time that I kept messing with a bike or car until it was undriveable on the street. But I will still ride it aways.
Your math on the HP is interesting. Obviously, the easiest way to get the high HP is more revs. (10,000 seems like too round of a number to be realistic) The most productive way would be more torque, then see where the revs fall. I may not get to 100 hp but I am not stopping at 80 just because you think it can't be done.
As for sitting on a hand grenade, if you are afraid to scatter a motor or two then this is a bad game to play.
The figures that I gave you are real, not interesting.
Do you have an idea how many 904's, 988's,994's and 1087's we did?
I'm trying to help you save money and headaches, been there than that more often that you may think.
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Mar 2007
Posts: 5,616
Check Pants
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Check Pants
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Mag10...sorry dude. No offense but read on... Quote:
not sure you understand who you are talking to, he has exploded motors and has done some pretty extreme things with these motors
Links:
turbo bonni.
1147 Mirage
988 Thrux ...110 hp but holly crap look at the list of mods...
Last edited by Zmilin; 10/20/2009 7:34 PM.
SOLD: 07 Black BA, 39mm FCRs, TPUSA stage 1 head, TPUSA 813 cams, TPUSA 10.8:1 pistons, TTP #3 igniter, Specialty Spares Long Cannons, Tsukayu Hard Bags. 82HP/55tq
NEW: 19 Goldwing Tour DCT
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Re: 904cc Power and Torque Barrier
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Joined: Dec 2006
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Oil Expert
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OP
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Personally I would prefer we discuss the general motor and carb modifications that still delivers great tq at lower revs. I know I didn't specify that in the original question and yes, I think we are getting to the point where the best mods have been trialed, and the limits are being reached. for most of us though (I'm assuming here) full blown race bike mods aren't my thing. Defeats the purpose IMHO of having a cruiser doesn't it. Go on with it if you want, it's still interesting reading but I'd prefer we didn't go in a direction in this thread where most of us won't be taking part. Btw, when I was younger I once had a older model car where I had a lumpy cam put in but I after a while I just wished I had my nice smooth idle back. Similarly, I wouldn't want to fiddle with my bike to the point where I regretted having the more bum dyno performance because my bike didn't seem to run as smoothly or continually needed adjustments. Not my thing anymore. I'd rather keep what I've got ie a nice smooth running motor without any risks of problems. Just my personal opinion.
Staintune Pipes, K&N Pods, 45 pilots, TBS needles and 145 mains.
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2005
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Learned Hand
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Learned Hand
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You can alway turbo charge it or spray a little NOS'. Some folks may think of this as cheating to get horsepower. But It would seem the most cost effective and practical way of getting 100hp.
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Re: 904cc Power and Torque Barrier
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Joined: Mar 2007
Posts: 5,616
Check Pants
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Check Pants
Joined: Mar 2007
Posts: 5,616 |
Quote:
Personally I would prefer we discuss the general motor and carb modifications that still delivers great tq at lower revs.
Good enough.
I can only speak from research thus far but Ill say it again then...it looks like the 904 has limitations. That doesnt make it bad...its just limited in how much can be got.
Reflecting back on my conversation with Carlos about the limitations of the 865 High Compression kit I beleive the same factors will apply to the 904 upgrade.
Once the carbs are opened up (bore or biger carbs), the head is opened up (oversize valves, port and polish), the breathing is improved via cams the last limiting factor is how much air can those pistons compress.
The limiting factor in going with a higher compression is simply valve clearance. There is a balance in how much compression you can gain before you start banging against the valves.
Now...all we need is for Dave to add those cams and get dynoed again OR for someone to go ballstothewall with one of these and post some results...
Oh...cant forget Triumphtwinpower ingnitors...those seem to make a difference but are the cherry on top once everything else is tweaked. Of course thats not to say you cant get that cherry right now.
Last edited by Zmilin; 10/20/2009 11:04 PM.
SOLD: 07 Black BA, 39mm FCRs, TPUSA stage 1 head, TPUSA 813 cams, TPUSA 10.8:1 pistons, TTP #3 igniter, Specialty Spares Long Cannons, Tsukayu Hard Bags. 82HP/55tq
NEW: 19 Goldwing Tour DCT
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2009
Posts: 1,228
I live in the sun downunder
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I live in the sun downunder
Joined: Jan 2009
Posts: 1,228 |
Quote:
Personally I would prefer we discuss the general motor and carb modifications that still delivers great tq at lower revs.
I know I didn't specify that in the original question and yes, I think we are getting to the point where the best mods have been trialed, and the limits are being reached.
for most of us though (I'm assuming here) full blown race bike mods aren't my thing. Defeats the purpose IMHO of having a cruiser doesn't it.
Go on with it if you want, it's still interesting reading but I'd prefer we didn't go in a direction in this thread where most of us won't be taking part.
Btw, when I was younger I once had a older model car where I had a lumpy cam put in but I after a while I just wished I had my nice smooth idle back.
Similarly, I wouldn't want to fiddle with my bike to the point where I regretted having the more bum dyno performance because my bike didn't seem to run as smoothly or continually needed adjustments. Not my thing anymore. I'd rather keep what I've got ie a nice smooth running motor without any risks of problems.
Just my personal opinion.
I have had my Speedy up to 160 KPH on the speedo.
The benefits of going faster are what?
The pitfalls are no license!!!
I can keep up with all the guys that I ride with, Harleys, BMW, Yamaha Cruisers, loosing my license is not in the equation.
FrankW
Ex Speedmaster rider, went to the Dark Side now riding an America.
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
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Learned Hand
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Learned Hand
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Quote:
not sure you understand who you are talking to, he has exploded motors and has done some pretty extreme things with these motors
I know full well who he works for. But does he know who I am? What I read is the opinion that if he has not been sucessful with an effort it cannot be done.
If the effort is made; there appears to be light weighting that could be done with the valve train. The piston profiles seem pretty straight forward so far - some options there. Lighter and stronger rods than the carillos can be ginned up. The igition system has a lot to be desired.
My point is still that more could be squeezed out of a 904. Is it worth the effort? Probably not - best to just go buy a hayabusa.
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
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Learned Hand
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Learned Hand
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Quote:
Quote:
Personally I would prefer we discuss the general motor and carb modifications that still delivers great tq at lower revs.
The limiting factor in going with a higher compression is simply valve clearance. There is a balance in how much compression you can gain before you start banging against the valves.
I think that you will run into pre ignition problems with higher compression before valves start hitting the pistons. That will move you into racing type fuels or ignition mods pretty quick.
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2008
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Loquacious
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Loquacious
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Quote:
But does he know who I am?
Probably not! 
And you may see me tonight
With an illegal smile
J. Prine
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
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Posts: 48 |
Quote:
Quote:
But does he know who I am?
Probably not!
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Jul 2006
Posts: 853
3/4 Throttle
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3/4 Throttle
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Posts: 853 |
You guys are talking about streetable bike, right...so as I see it if you open up the 988 Trux link above the bike torqe climbs to about 5500 rpm then the bike is making "power"...by the time you hit 5500 rpm you may be at the next signal...I think you want a toque curve that starts making "power" lower...I think that is why my old Harley would beat my 600 cc 636 light to light but get it on the freeway and it would be bye bye Harley.
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
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Learned Hand
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Learned Hand
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it looks like the work that 1087 has done is on the 360 crank motors. any numbers for the 270? after all that is what most of us are playing with. Not throwing stones here, but I would like to see something other than the thruxton numbers. would 1087 please post his numbers for the 904 -270s that he has built. that should add to the discussion in a more direct way.
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
Joined: Apr 2009
Posts: 48 |
Mag; The discussion here is the ability to make 100 RWHP for a street 904 (360-270 don't matter), versus my comment that you will not get that horsepower from a 904 street motor. You already said to consider lighten rods than Carillo's, different pistons profiles,titanium valves,etc,etc, perhaps you will need a properly design brand new head from scratch. So with unlimited budget like you seems to have maybe will be doable like Fred said. Him and I spent many hours talking about that possibility for a 904 and come up to the conclusion the the expenditure will be astronomical, without any guarantees to achieve the target. Besides that how many people ( besides you) will have interest in a 100 RWHP 904, that will not last many miles. If you want 100 RWHP reliable HP street motor consider a 988 or a 1087. See my sig. So I don't need to post any dyno runs here,maybe I'll wait for your dyno runs when you can show me and the rest of the members that your target was accomplished
Last edited by 1087; 10/21/2009 7:01 PM.
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2007
Posts: 3,063 Likes: 8
Loquacious
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Loquacious
Joined: Apr 2007
Posts: 3,063 Likes: 8 |
If you guys want to go fast from corner to corner, put a 16 or 15 tooth front sprocket on your bikes. This will help with the lower torque values at low rpms. Don't forget, the bike will rev to 9000 grand. Top speed will not really suffer with the rev limit increased 1500 rpm from 7500.
12 Rocket Roadster
03 Bonneville America
69 BSA Firebird Scrambler
73 Yamaha TX 750
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Re: 904cc Power and Torque Barrier
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Joined: Jan 2008
Posts: 1,174 Likes: 15
Learned Hand
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Learned Hand
Joined: Jan 2008
Posts: 1,174 Likes: 15 |
Quote:
Mag;
The discussion here is the ability to make 100 RWHP for a street 904 (360-270 don't matter), versus my comment that you will not get that horsepower from a 904 street motor.
You already said to consider lighten rods than Carillo's, different pistons profiles,titanium valves,etc,etc, perhaps you will need a properly design brand new head from scratch. So with unlimited budget like you seems to have maybe will be doable like Fred said.
Him and I spent many hours talking about that possibility for a 904 and come up to the conclusion the the expenditure will be astronomical, without any guarantees to achieve the target.
Besides that how many people ( besides you) will have interest in a 100 RWHP 904, that will not last many miles.
If you want 100 RWHP reliable HP street motor consider a 988 or a 1087.
See my sig.
So I don't need to post any dyno runs here,maybe I'll wait for your dyno runs when you can show me and the rest of the members that your target was accomplished
thank you for your encouragement. go back to waiting. I will post as the work progresses, it will give me something to do over the winter. I like the new head idea, I happen to have a machining center sitting idle right now. ideas, ideas...and time!
05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
Joined: Apr 2009
Posts: 48 |
I like the new head idea, I happen to have a machining center sitting idle right now. ideas, ideas...and time! >>>
Excellent!
Looking forward to it.
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Dec 2006
Posts: 2,150
Oil Expert
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OP
Oil Expert
Joined: Dec 2006
Posts: 2,150 |
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Re: 904cc Power and Torque Barrier
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Joined: Apr 2009
Posts: 48
Greenhorn
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Greenhorn
Joined: Apr 2009
Posts: 48 |
1087cc's- 115RWHP-81.5RWTQ.Nuff Said
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Re: 904cc Power and Torque Barrier
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Joined: Dec 2006
Posts: 2,150
Oil Expert
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OP
Oil Expert
Joined: Dec 2006
Posts: 2,150 |
Apologies Bob (RamSound), I don't know why I missed your numbers as part of those pushing the barrier. In fact you are the one who brought my attention to the importance of tq in the first place.  Sure would like to see your next dyno though, but again just for interest considering this is predominantly an interest thread for most of us
Staintune Pipes, K&N Pods, 45 pilots, TBS needles and 145 mains.
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Re: 904cc Power and Torque Barrier
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Joined: Dec 2006
Posts: 2,150
Oil Expert
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OP
Oil Expert
Joined: Dec 2006
Posts: 2,150 |
Staintune Pipes, K&N Pods, 45 pilots, TBS needles and 145 mains.
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Re: 904cc Power and Torque Barrier
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Joined: Aug 2005
Posts: 2,726
Loquacious
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Loquacious
Joined: Aug 2005
Posts: 2,726 |
My next shop visit will include a new dyno run for info on changes and it will go to redline.
Bob
2005 America, 904cc - sold. 2014 Trophy SE.
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He's one bloke I'd like to shout a beer