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I found this RC51 dyno chart and was wondering what is the rev limiter extender he is talking about?

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Full Yosh, Thorsten airbox, ported heads, VP fuel, PC3R, Carmo extended rev limit, Wiseco high-comp pistons, Carrillo rods, Falicon Supercrank, etc. (vs. 100% stock bike)

 

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Street and Track Moderator
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I think he is just referring to the removal of the "soft" limit!
 

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I happened to be talking with a guy that used to tune Steve Crevier's RC51. I asked about doing the soft rev mod on my bike and he said there is a way to elevate the point at which the soft rev and hard rev limiter kicks in, thereby leaving them both intact but being able to hit higher rpms. I didn't ask about details as it was getting over my head.
 

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HRC ECU in either the basic racer or the complete racer, but of course you know what that'll do to the service interval on the motor! You also need more than the ECU alone. The Honda Canada bikes were complete racer level I think, and the American Honda bikes were more than a few notches above that.


Bunch of talk about this over at the other spot.
 

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The original graph looks the same as my one (UK bike) so there is definately no soft limit on it.

As for the higher rpm limit still I would guess along the lines of a different ECU too. I doubt our standard engine internals could take the extra rpm all the time though hence why the guy has different pistons, rods and crank. Those are nice hefty gains though, wonder how much all the engine work cost to get done?
 

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Thats some power :rockon

Even if you didnt move the original hard limiter @10200rpm I reckon it would still have the same peak as it just flattens off there. I'd love a go on that beast :woot:
 

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Looking at the dyno...the rev limiter it only 200-300rpms more than the stock. Thats not that much extended, my guess it the factory ECU could do that.

As for the stock internals...yes I think they would be pushed at a higher RPM, but I believe he raised the compression ratio and that is the reason for the upgraded pistons/rods.

Anyhow that is a sick ass RC motor they have there!
 

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You Know What's Really Crazy!...??

Just think what kind of boost she'd have on the road
track with the RAM AIR Working!:clapper
Another 10% FOR SURE......+/-15%....???

I also 2nd the question, by "Paul_SP2" How much would/did it cost, to build that engine?

SWEET!


Peace Jeff
 

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That engine snapped a cam during that last run.

Also, he is using a aftermarket ECU similar to a Motec (i dont remember which one). I looked into buying one but it was close to $2500 iirc.

How about hi-comp pistons + Stage 1 cams + Thorsten airbox for 140HP? Seems like a better way to go, imo.
 

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How about piston speeds at that level? A bit scary high? For a twin, our bikes spin pretty hard as is.
 

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Nearly 80, and ATE A CAM. Never mind what happened to the valves, guides, piston etc as it spun down with a dead motor.

No real worries, Dale here probably still has some billet ones left for sale.
 
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