SWAPPING E.C.U'S R1 TO RX1

[rightarm]

Was curious if any gear head's out there have swapped the stock E.C.U from the RX1 for the E.C.U from the R1 which allow's the motor to spin up to 12,500.Thanx.

 

[Srxspec]

Not sure why you would want to spin the motor up to 12,500 as all your efficiency would be gone through the clutching & it doesn't make any more power there unless you have changed cams & done some other things as well.

 

[rightarm]

Thank you srx I guess your answer is no?I will be changing cam's,head work and different comp piston's,as well as rod's and crank work.As well as clutching.thanx for the reply.

 

[Srxspec]

At 12,500 rpm on the engine your clutch would be spinning 10,375 rpm going down the trail WFO. Most people don't like to have a trail machine running much more than 91-9200 rpm because 1-it wears out the clutches faster due to more heat being created, etc 2-it's alot less efficient because of all the heat being created.

I would assume your new cams will be designed to run at close to the stock RPM so I don't see a need in it, but I don't think it would work any way due to the fact that the sled has hand warmers, the bike doesn't, etc etc. Just too many differences.

 

[rightarm]

Srx what if the gear reduction sprockets were changed so that the clutches were brought back to proper or tolerably rpms.

 

[Srxspec]

It could be done, but I don't think there's enough room in the gear housing to make up the difference. To get the clutches back to the same operating rpm as stock you'd need a 32% (would bring clutch down to 8500 rpm at 12500 rpm on the engine) reduction & the stock reduction is only 17%. You could get away with a 25% reduction which would make the clutch spin 9375 @ 12500, but like I said, I don't think there's room for the gears to make that reduction number.

 

[rightarm]

Thank you SRX for your insight and knowledge I will definately take your words into consideration during this project much appreciated.

 

[QCRider]

What would be the horsepower gain by going to 12,500? Is it really worth the time and money you are looking at? I would think a turbo would be the best performance option for the money..

 

[rightarm]

QCrider if everthing comes together right,the rpm change could probably be worth anywhere from 5-10hp,with all the other mods anywhere from30 to 40hp,no lag instant responce.As far as the turbo yeah it would would probably be easier to do but to build a turbo motor properly you need to split the cases put in heavy duty cylinder studs as well as rods turbo pistons etc,etc.By the time all is said and done boost gauges ,pop off valves,yada,yada,yada I can build two of these naturally aspirated motors,they may only produce about 170- 180hp but theres no lag, no extreme under hood temps,awesome torque #'s, and will definately last a whole hell of alot longer than a turbo motor as well as being a lighter package.As far as time and money thats irrelavent.

 

[kviper]

One of the reason's Yamaha camed and tuned this motor the way they did was to build a better torque curve, needed in a snomobile app. If you set it up as you specified in an earlier post i am quite sure you will loose a lot of low end torque and would be mutch harder to clutch even with the reduction, and the extra RPM will use up the motor quicker than a turbo at 10500. I don't think that you will have to do any motor mod's at 8 lb boost with a turbo and 8lb will get you a sold 190 HP. Another thing to think about is all of the oil you will use. On my RX the more peak RPM i ran it would use a little more oil. Just my .02 so take it for what ever it is worth but it may be some thing's to think about.

 

[rightarm]

Thank's for the responce's guy's I really thank you guy's for your kind word's and support,even if the ECU thing dosen't work out. It's great to have the support and info this site provide's.So again thank's to MR.SLED for a great forum and last but not least all the terrific people and mind's that this site contain's.YOU GUY'S RULE!