Is a TURBO any faster?

[Fast Jimmie]

I'm talking about top speed here.
My dad and I are having this debate yesterday and we didn't get anyware. He says if both sleds spin at 10,400 rpm's and clutches are both engaged fully for top speed (as in a top speed run), the drive ratio (from the engine to the track) would be no different for either and a Turbo cannot go any faster than a stock sled.

He says the only way to go faster is by further changing gearing or running higher rpm's.

Does every turbo guy change his gearing right away?



Waiting for the day I can afford a turbo.

 

[Turbo Tim]

UHHH..........I'm gonna go with yes.

 

[Turk]

Lets see....my particular rX-1 was turning 10,200 rpm & running about 115ish on GPS..perfect conditions. My Turbo RX turning 10,200 rpm now does 126 on GPS in about 1200' & still climbing. So...the correct answer is ??????

 

[Otis RX]

TURK........

What gearing combination are you running?
I can't recall if you're on a mountain sled or not.
Here's a what if........ say I go TURBO on a 121 w/reverse. I hear you can only change the top gear to one size up 25/38 vs stock 24/38. Can the stock chain be used?? Bottom gears can't be changed unless you get a new chain case cover and dump the reverse. Is that correct?
Thanks for the input.
OTIS

 

[Sled Dog]

Not that much of a change in top end speed but huge diff in how long it takes to get there.

 

[Simons CPR]

stock sleds don't have the power to fully close the sheaves to get all the overdrive out of them with stock gears, add more hp, and more weight in the clutch, now you can pull full overdrive and run more mph, stock gears on most stock rx-1s top out at 114mph, on our turbo stock gear tops out at 138mph, bouncing of the rev limiter, anotherwards it begging for more gear. jeff

 

[Turk]

I just changed my gearing this week from 24/38 to 25/38 & the 70 link chain still works. 24/38 is not enuff gear for the turbo. I am running a shortie with an x-pert X skid running a 9818 1.25" track.

 

[Fast Jimmie]

stock sleds don't have the power to fully close the sheaves to get all the overdrive out of them with stock gears, add more hp, and more weight in the clutch, now you can pull full overdrive and run more mph, stock gears on most stock rx-1s top out at 114mph, on our turbo stock gear tops out at 138mph, bouncing of the rev limiter, anotherwards it begging for more gear. jeff

Thanks for the first logical answer, but why wouldn't Yamaha have designed the clutch to work to its full potential from the get-go. Or is it errelevant(sp?) how far the clutches actually engage?

 

[Otis RX]

TURK..... Thanks for sharing the gearing info.

Jeff ..... Thanks for the great answer to Jimmie's question. I had a feeling there was more to it.
OTIS

 

[Buckeye]

TURK........

What gearing combination are you running?
I can't recall if you're on a mountain sled or not.
Here's a what if........ say I go TURBO on a 121 w/reverse. I hear you can only change the top gear to one size up 25/38 vs stock 24/38. Can the stock chain be used?? Bottom gears can't be changed unless you get a new chain case cover and dump the reverse. Is that correct?
Thanks for the input.
OTIS

Yes you can't change the bottom gear and keep reverse. You might be able to change the bottom gear and not change the cover. I will have to look into that. I am not sure that the 25 top gear is enough. I am told that Micro belmont, now has a 26 and it works with the 7o link chain. I know my et in the qtr improved with the 25 vs. the 24. I also picked up mph. Haven't tried the 26 yet. I guess the amount of boost you run is also a factor. My results are with 12 lbs.

 

[Turbo Tim]

Yeah what Jeff said ............I was just getting around to saying that ..

 

[hlmrx1]

Now these are good answers guys, keep it up.....

 

[black john]

gearing

micro belmont has top gears up to 27 tooth and there is a bottem 37 for the rev models avlable from yamaha

 

[Buckeye]

Re: gearing

micro belmont has top gears up to 27 tooth and there is a bottem 37 for the rev models avlable from yamaha

Are you sure about the 37? Do you have a part number?

 

[POWERHAULIC]

Micro-Belmont only has up to 25T. for RX.

I also would like to know the part# for the reverse 37T. sprocket