TRA Ramps

Nobody has the two ramps to compare? The race manual has the 427 profile, but I want to compare the two side by side. 05's came stock with 435, but 04, 06 and 07 all have 427 stock? Anybody able to shine some light on the matter? Tom, D-joe, anyone?

RJH said:

I don?t have Doo clutch experience ? so just wondering?..

It was mentioned, one set of ramps is more aggressive. To me that means ? they shift harder.

Then, my way of thinking ? they are better ? like for coming off a turn on an ice oval, no drag.

Then, it?s mentioned ? they are good in the tight section of the track.
Then, my way of thinking, we would want an angle that would let the thing shift up easy - rev faster not harder. Harder would pull the engine down ? if it tried to shift up too fast.

Until I see one..I?m guessing?.. that, the deeper the moon shape?the softer the shift?

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Hey RJH,

Correct. I did intend "aggressive" to mean a harder shift.

Not quite right about the "softer shift" in ratio's with the deeper moon shape though. In general terms, just like your Yamie, a deeper moon shape of your arms would give you a harder, more "aggressive shift". But, in the TRA's case the profiled ramps are located on the governor cup (like a spider in your case).

Same rules of physics apply, the further the mass is from the axis of rotation the more centrifugal force it will create and vise versa. The TRA just happens to be a lot more adjustable then your Yamie...

I guess I should have waited to see one before commenting. Cool ? thanks.

After years of working with a ?male mold? so to speak?. The doo is simply opposite then?

So.. you wouldn?t have to weld material on (tricky with oil impregnated metal) ? to get the same affect as the ?arm? clutch, we take away, on the doo, rather then make the profile bigger ? this is good!!!!

What year race sled did the 435 come as standard issue?

As anyone invented a ramp holder (to hold all three the same for griding) or do I make my own?

Converted ????in my old race days we had Cat clutches on the Yammie. I can tell you there is more issues with the Yammie then even Yamaha is aware. On my trail sleds we machined the spider to tuck the weights under more. I couldn?t weld the weights so Thunder products supplied some profiles we wanted that were just not available and on and on and on!

mxzx313 said:

Hey stokes, sorry i got back to this so late. I don't have any experience with the 422. I agree with what Tom and Gasman are saying, but personally, i didn't see too much difference between the 435 and 427 for trail riding besides the higher engagement. I run waay low finish angles in my secondary (Team TSS-98) so i never had any problems with getting good backshift. I just didn't like the trenching i got with the 435. I know what GasMan is saying though, and if i remember he runs something like 21g of pin weight which i just couldn't get my engine to pull.

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Very observant MXZX313!

I get 156 to 160 PSI per jug with LC domes and 190 to 195+ PSI with HC domes pending on which BG's I use. - That's how I run 21g+ weights. I get re-nicked every year w/ some extra plating to tighten up the piston / jug clearance.