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DISCLAIMER: I am asking this purely because of all the questions the answer to my question will in turn answer. I would never do this to my bike.

I have always been told that the 1999 Daytona 955i engine is identical to the 1999 Sprint ST 955i engine with the exception of tuning. So does that mean that if you uploaded Daytona mapping to a Sprint ST that your Sprint ST engine will behave like a sport tuned Daytona engine?

Almost obviously, no, but if so, what are the hardware constraints that make that so?
 

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So does that mean that if you uploaded Daytona mapping to a Sprint ST that your Sprint ST engine will behave like a sport tuned Daytona engine?
Yes.
How is that?
Lets say the bike is identical in all bore/stroke/cams/etc. So will the FI telemetry. So what will be the difference? Probably ignition curve and a slight fuel AFR adjust.

Will it hurt the engine? No. Will my torque curve come on sooner or later? ST means sport-tour, so low end torque is most likely the swap or loss changing to a Dayton map. The Daytona would have more torque up the rpm band and would be set there.

You did not change cam timing, bore size, stroke, so the ignition will just move the same torque up or down the curve range we watch a dyno run.
 

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Bottom end of engine has forged crankshaft, pistons, rods etc. Can rev 1,000-1,500 rpm higher than Sprint engine. Cams are more aggressive to take advantage of this & make 149 HP instead of 118. There's no magic to it...
 

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..... Cams are more aggressive to take advantage of this & make 149 HP instead of 118. There's no magic to it...
That's the 02+ engine - 99 Daytona 'only' makes 128 hp (vs 108 for the 99 Sprint)
But yes, the main difference in all the generations is the cams which is what predominantly accounts for the map. The rotating components are upgraded vs the Sprint/Speed Triple engines to accommodate that extra power and higher red-line.
 

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Hi, I'm sorry to revive this but it easier than starting a new thread.
Dcosse you mentioned the differences being the cams.
I have a 98 daytona to which the engine has given way as all the coolant system now doubles up as the oil system its time to rebuild the motor.
Is it possible to transplant a sprint St engine in its place while I do this work or am I pissing in the wind.
Fact is I've aquired a 50k good running St lump for £100 and its from same year as my tona.

Will it just go bang on the current map?
Is it possible to throw the sprint map on?

Just like to say at this point I'm not to bothered about losing 20 hp as long as i can still use it reliably?

To say it's in speed triple mode now aswell so the extra hp isn't a prob massive lol (he says with gritted teeth)
 

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As other people have said, the difference between Daytona and non Daytona 955 engines is a stronger crank, rods and pistons to allow a higher rev limit. There is also different liners to match the pistons, and different cams to take advantage of the higher rev limit.

2nd gen (2002+) Daytonas have more differences but that's a different kettle of fish.

You can drop a 1st gen 955 Sprint engine straight in and it might run on your current map, not well though as it's not the right cams. Your Daytona map will also allow the engine to rev too high (10,800rpm vs 9,700rpm), it might not fail immediately but every time you rev it out past the Sprint's red line you are playing with fire.

You can load the appropriate Sprint map on your ECU and it may work, there may be differences in the wiring/instruments etc which throw error codes. I'm not sure. A sure fire way to run the Sprint engine in your bike is to copy all of the tables and parameters from the Sprint map into a Daytona map and upload that.

Another option (of questionable value) is putting the Daytona cams in your Sprint engine, using the Daytona map and dropping the rev limit in your map to match the Sprint engine. I don't know how this would compare in performance to the Sprint cams over the rev range or if it would be worth it. You'd be losing the top end which is kind of the point of the Daytona.

I think this is all moot as from your other thread it seems the cracked head is your problem. Your best option is to put the Daytona cams in the Sprint head on the Daytona bottom end and you have yourself a running Daytona engine, no map changes required :)
 
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