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BB vs SB on 10 cub


kshoulde35

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lol I just did it cuz green did.. I really didn't say anything..   My take is.. Leave it up to the builder.  More then one way to skin a cat.  Just cuz the guy made the pipe dont mean he knows everything.  I got dyno's that show SB and BB both setup optimal with proper domes/timing and they made same HP but BB had better torque curve.  Peak HP is meaningless to me.. its about usable power.  I'll take a motor with 5 less peak HP  but makes peak HP across a wider rpm range and better front side curve any day.  JMO...

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That fucking post is clear as mud..

 

What I gather is that on different motors, in different applications, with 100 different variables, BB or SB could be the winner.

 

Which is basically what I've been saying all along.

 

There are far too many people winning with both pipes to determine a clear winner for all set ups.

I agree.  FWIW I run the SBs on that motor now. 

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John, are you referring mainly to peak HP?

 

In some types of riding/racing, peak HP means little or nothing.

 

I know that in hillclimbing, I am a lot less concerned with peak HP than I am a good strong curve off the bottom.

 

Cameron dynoed the 18DM and it made anywhere from 136-141HP with my custom in-frame set up. The out-frames made about 6 more peak HP.

 

The in-frames came on better and the curve was stronger down low. To me, that's more important than the peak.

 

Is it possible, that in some instances, the BB may be better than the SB and vice versa?

 

I'm just trying to think outside the box here and outside the realm of peak HP, which we all know is what most people are interested in.

No I am NEVER one to give a crap about a peak number. Those are for braggers. My involvement with dyno testing is only about finding the best overall combo. If people would really give Mat's suggestions on the topic a listen...they would begin to understand that he's talking about the small bores on a 421-465 making 5 more Peak HP as well as a stronger overall curve. (So more mid and low torque as well.) 

You are correct. In most forms of racing a peak number means nothing. Even in drag racing, having all your focus on a top peak number is only going to hurt your potential.

 

Part of what I'm speaking about is in addressing the culture of the sport. The industry is kinda split 50/50 on some of the paths to power. For a long time people chased HP by simply raising port timings, compression and timing to the moon. This is ingrained in more that a few builders engine building style.

Part of what a some builders do is based on sales. (Do you really want your builder to tell you that your newest build needs small pipes? No, you want to hear that your new build is the best out there and needs Big Bore pipes to work......just like beginner guys want to hear that their motor needs race fuel.)

Some of what they do is based on feeding into what are common practices. (If your one of those people who think that +14 timing is what it takes to win, are you going to listen when your builder tells you to keep in a lot lower?)

Too many build practices are just a series of reactions to starting with the wrong pipe. (A big pipe is tried and the motor needs more bottom end, so they raise compression, close the squish, design a squish band for added torque, raise timing, etc.) Yes these are the hundreds of factors that muddy the real discussion.

OR...it makes a killer top number on a dyno, so they run it not knowing they are throwing away a large amount of useable power band. But at least they have a big brag factor.....

 

It comes down to this..... Do guys want to just leave the motor they have the way it sits and continue to tune as they always have, or will they be willing to tune the overall combo?

If someone fits into the "My builder built it like this and I'm not changing a thing" category......then have custom pipes made for that exact combo because that is the only way to get the most from it.

If someone fits into the "I wanna get everything I can from a motor this size" category.....then you can get an off the shelf pipe and with slight adjustments to your domes and ignition timing, make way more power than if you slapped standard pipes on it.

 

The pipes and motor have to work together because it is a Resonance power plant. If they don't work well together....then they aren't working well.

I respect track results. But take this into consideration. I have a 63HP bike in my stable that has never lost to a particular 421 cub powered bike. Does that mean my 63 HP bike is working great? Does that mean his 421 isn't? Is it rider? His bike is nicer.....so even though on the track I win....that doesn't really prove anything as far as a debate about either of our combos. This is why I find dyno information useful. A dyno will 100% show you if you have more power vs another motor or engine combo. It is then on the racer to make the most of it in the bike set-up as well as his riding. The track proves that you made the most of what you loaded in the trailer. I'm trying to address making the most of what you have BEFORE it's trailer time. LOL

 

 

 My take is.. Leave it up to the builder.  More then one way to skin a cat.  Just cuz the guy made the pipe dont mean he knows everything.  I got dyno's that show SB and BB both setup optimal with proper domes/timing and they made same HP but BB had better torque curve.  

My take is the pipe builders have seen EVERY major builders work and know what the builders are doing. They have feedback from almost everyone. So I think a pipe builder has a better cross section of information about what works and doesn't (in respect to the details that their pipes like) vs. a builder who can only afford to try a limited amount of changes.

I guess the way I see it, if the pipe builder specifically went back and re-designed his SB OOF pipe to zero in on the massive interest the 421-465 Alky Drag motors were getting, I would want to hear just what factors lead a particular motor to favoring a different pipe choice.

 

I'd be interested to hear more details about the motor you spent the time to "Set up optimal" and tested with both pipe sizes. (Not only because my dyno testing on my 472-492 Cheetah and 465 Cub showed the exact opposite, but because I'd like to hear what factors lead to that.) Was that your 10 mill Cub? What all did you do and what ended up being the reason it favored the BB's?  (Genuine questions. Not asked with a "Tone".) I know how some of you hate the smileys, so I thought I'd clarify. LOL

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This topic is beat to death...go figure.

 

Todd...my 10 cub ran very well on BB OOF pipes.  I ran 165 to 175PSI compression, and timing from 8 to 12 degrees with 20cc domes.

Would it have run better with small bore with less compression and less timing as Windy said?

Never know...

What I do know is after the quality control issues I had 3 years in a row, I wasn't about to drop my hard earned coin on another set to find out.

 

J-Madd...

You were at Planet Sand in 08 and raced against my old motor when Frank jockey'd it.  Can you confirm please it was in a stock lightened chassis and not a rigid frame that was previously reported (I had to laugh at that one...)

I guess the pictures that were posted at that time were forgeries....

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Tyler could you share a portion of what you've gathered from your builder? I think it would help hearing all sides

 

I doubt it, but let's look at it this way...

 

Member A says SB are the way to go and has dyno runs to prove it. Member A is also a keyboard racer and has never won anything except the longest post award on BansheeHQ.

 

Member B is a racer and ran a 10mm Cub for 5 years winning many races, setting records and accomplishing things no other ATV hillclimber ever has.. He runs BB pipes.

 

Which pipe do you want?

 

Secrets are no fun

 

Yes they are, especially when you know the secret.

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the only problem with member B is that we know to achieve that kind of success there are some very fine details that were left out in why it worked so well... which may cause one "Member C" to attempt to duplicate this success to no avail... Member A is offering a quick here it is on a platter solution but how real world it is none of us know? therein lies the dilemma lol

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the only problem with member B is that we know to achieve that kind of success there are some very fine details that were left out in why it worked so well... which may cause one "Member C" to attempt to duplicate this success to no avail... Member A is offering a quick here it is on a platter solution but how real world it is none of us know? therein lies the dilemma lol

 

What fucking fine details? Redline built 10mm Cub on race gas. 39PWK with BB in-frames.

 

And for the record, I didn't consult with Cameron before I bought and installed them. That set up started out with Rockets.

 

Like I said, it doesn't matter what who said. People like you are far more concerned with a number than what the bike will do in the real world.

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