Jump to content

Redline Dyno Shootout


srp

Recommended Posts

You know I don't give a fuck about peak numbers.

 

Did you ever compare RPM/tire speed with Shearers to RPM/tire speed with Rockets?

I remember overlaying the graphs from my big bore 4mm stock cyl motor and had Mike at lakes decipher that type of stuff but I believe he had a way to show the elapsed time on said situation and I vaguely remember the rockets pulled to about 8,500 much faster then the shearers but past that the shearers pulled tire speed faster with about 4-6 mph more.

That particular test was done when claims from Mat were "My pipe will come on earlier and carry farther with equal or more torque". Needless to say I didn't buy the set of shearers at that time, as that claim wasn't totally true.

All that was done on that test was base line, then jetting was tweaked till AFR's were spot on, then the rocket run was done again before we swapped to the shearers. Once the shearers were base lined the only change in jetting they liked was a little needle adjustment. That motor was like 42 ft. Lbs. (@8300) 72 hp (@9500) on the rockets and 42 ft. Lbs. (@ 8600) 75.4 hp (9800) on shearers.

Link to comment
Share on other sites

I actually meant at a race.. The Rockets would probably pull a little more gear. So even if you were giving up 3HP and a 300RPM, you might have been able to make it up in gearing.

Yes they will do exactley that. But eventually the big tracks need a bit of over rev. The problem in D14 is every time you show up to a race they are never the same size track. So this season I am bringing the rockets and shearers to every race.
Link to comment
Share on other sites

Yes they will do exactley that. But eventually the big tracks need a bit of over rev. The problem in D14 is every time you show up to a race they are never the same size track. So this season I am bringing the rockets and shearers to every race.

 

Is this AMA racing? If so, there must be some sort of track size spec. I can't see how AMA would allow different size tracks, especially considering they could make them all the same easily.

 

Are the track widths all standard size?

 

How much more gear will the Rockets pull than the Shearers?

Link to comment
Share on other sites

Some AMA others are local organizations. Honestly the AMA is horrible here. No planning, no orginization on race day so there is mass confusion between track side staff and the booth.

 

I probably shouldn't say that the rockets really "pull more" gear on my bike, but they allow the bike to work through the taller gear on the tighter stuff. For instance on a 1/8 mile oval, I run the same sprockets as I do on there for 1/2 mile tracks. Now if I leave the shearers on I have to down shift from 5th to third to come out of the turn to keep it from falling on its face. Same set up with rockets I can just drop it to 4th and lay on it and it powers right out of the turn. So if you relate that type of load to a trail bike, that would mean you could still run steep gearing for top end bursts in the field but still be able to lug the bike in the woods.

Link to comment
Share on other sites

Some AMA others are local organizations. Honestly the AMA is horrible here. No planning, no orginization on race day so there is mass confusion between track side staff and the booth.

 

I probably shouldn't say that the rockets really "pull more" gear on my bike, but they allow the bike to work through the taller gear on the tighter stuff. For instance on a 1/8 mile oval, I run the same sprockets as I do on there for 1/2 mile tracks. Now if I leave the shearers on I have to down shift from 5th to third to come out of the turn to keep it from falling on its face. Same set up with rockets I can just drop it to 4th and lay on it and it powers right out of the turn. So if you relate that type of load to a trail bike, that would mean you could still run steep gearing for top end bursts in the field but still be able to lug the bike in the woods.

 

Yea, the AMA hillclimb series is garbage. They just now put someone that actually knows what hillclimbing is in charge of the rule book. I assume they will be consulting with me about the ATV rules because the ones already in place are ones I set up.

 

That pull off the bottom is what I am referring to basically. If you could get away with running taller gearing it could make up for those 300RPMs.

Link to comment
Share on other sites

sorry  i just had to....

 

i'm not sure how to tell if its a "brake dyno.  as far as i can rember is was the same as whats been talked about in here.  it was in a little room on an addition to a house.  built into the floor. was a sweet setup i thought.  

Link to comment
Share on other sites

im not sure on the watering system  all i know is it was obvious that they had plenty of $$$ ( the family i believe)  hell the dyno was at his brother? house.  they owned a flat track mx park drag track outside of town that was nice.  he is a great guy and really understands these things  plus he is not closed minded as much as some i talk to.  he really understands how to make these bikes work based on what has been proven in other automotive and racing fields.  nice to see that.

Link to comment
Share on other sites

from what I have seen the loading plays a big roll on power output.  the dyno I have been using is a free spin dyno so if I don't gear the bike to do 80-100 mph it shows a really low power number. at least that's what it seems like...

I think my trail bike hit 32hp.. lol

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...