UNI Filter Achievement unlocked. What next?

Scalpel · Post by **Scalpel** » Wed Sep 16, 2009 8:05 pm

I've been really happy with the UNI filter mod I did a few months ago, but I'd like to get a little more top end speed from my little Rattler. In pursuit of those extra mph, my current plan is to add the following to the bike:

Dr. Pulley 9.0 gram sliders
Malossi variator
Either the 2000 rpm spring, or a 1500 rpm spring

Although I think I'm on the right path on this, I have a few questions before I start madly spending money:

Will 9.0g sliders work well for better top end, or should I be looking at a different size?
Should I go with the Malossi variator, or is there another brand that would work better?
Should I even bother replacing the stock variator?
1500 rpm spring, or 2000?
Is the Prima pipe worth the money, or should I try a different pipe for the Rattler? Or stick with stock?
Will this buy me a decent amount of speed at the top end? I'm not really interested in drag racing; the aim is to go faster.
Is there something I'm missing that should be on my parts list?

Ray Knobs · Post by **Ray Knobs** » Wed Sep 16, 2009 8:17 pm

For the record my prima added some low end and took nothing off the top.

Scalpel · Post by **Scalpel** » Wed Sep 16, 2009 8:21 pm

Ray Knobs wrote:For the record my prima added some low end and took nothing off the top.

Good to know. I've thought about trying the V8 pipe from Scooterworld Guam, but I haven't called them to see exactly how much it is they want for it. I suspect that the Prima pipe will be a bargain in comparison...

Ray Knobs · Post by **Ray Knobs** » Wed Sep 16, 2009 8:24 pm

I would check with the other guy that bought one before spending money on it.

nissanman · Post by **nissanman** » Thu Sep 17, 2009 2:01 am

The Malossi Variator will need heavier weights than 9g. It comes stock with 12g

Liquidkool · Post by **Liquidkool** » Thu Sep 17, 2009 2:59 pm

the multivar by malossi is not going to add any top end, in my testing i found that it hurt my top end. That variator geared more toward racing on a track where little short bursts of acceleration is needed. it doesnt work well for cruising around or at a constant high rpm. keep your stock variator and go with the sliders, either the nines or you could try the tens for more top end

B02S4 · Post by **B02S4** » Thu Sep 17, 2009 5:15 pm

The stock variator is just fine, maybe just polish & slot the ramp tracks.

The stock torque spring is OK. You don't need the heavier spring unless you change to a Malossi or similar variator that uses heavier roller weights.

DP 9g sliders may be too heavy in the OEM variator, at least they were for me. I step-drilled the DP 9g slider cores to drop the weight down to approx 8.75g's & found a good balance with that.

Scalpel · Post by **Scalpel** » Thu Sep 17, 2009 11:31 pm

B02S4 wrote:The stock variator is just fine, maybe just polish & slot the ramp tracks.

I get the polishing thing, but what is slotting, and how is it done?

B02S4 wrote:The stock torque spring is OK. You don't need the heavier spring unless you change to a Malossi or similar variator that uses heavier roller weights.

Since my intention is to move to heavier weights for better top end, wouldn't the upgraded torque spring help preserve the low-end acceleration? Or am I completely misunderstanding the point of that upgrade?

B02S4 wrote:DP 9g sliders may be too heavy in the OEM variator, at least they were for me. I step-drilled the DP 9g slider cores to drop the weight down to approx 8.75g's & found a good balance with that.

Are the Dr. Pulley sliders that different from the stock rollers of the same weight? Since the stock Rattler weights are 8.5, I figured that the 9s would be a fairly minor change. Honestly, I was tempted to go for 9.5s.

B02S4 · Post by **B02S4** » Fri Sep 18, 2009 3:12 am

Scalpel wrote: I get the polishing thing, but what is slotting, and how is it done? ...Since my intention is to move to heavier weights for better top end, wouldn't the upgraded torque spring help preserve the low-end acceleration? Or am I completely misunderstanding the point of that upgrade?...Are the Dr. Pulley sliders that different from the stock rollers of the same weight? Since the stock Rattler weights are 8.5, I figured that the 9s would be a fairly minor change. Honestly, I was tempted to go for 9.5s.

"Slotting" means extending the roller track out a mm or so to the outer edge with a Dremel. It must be done uniformly to preserve variator balance.

It is the relative balance among the variator, weights/sliders, & torque spring that really matters. Unless you do major mods the stock torque spring is fine, it is strong enough. Just tune the rollers to work with it so you achieve what you want.

Believe it or not, the factory really did get the roller weight pretty much right. The OEM roller weights are 8.5g's. IMO, unless there are special circumstances, if you run a lightly modded bike (air filter & exhaust mods & carb tuning) then the "sweet spot" tuning range with the OEM variator is primarily in the 8g - 9g range (imagine that!).

Others may disagree & that is OK with me. I'm just sharing what I know that works. I have gone as light as DP 7g sliders (great acceleration to 30 mph, lousy cruise) to DP 9g's, with various combinations. I did not see any need to go heavier than DP 9g sliders with the stock variator & torque spring.

Personally I think the 9.5's will be too much. Remember the relativity thing. If you want to try the DP 9.5g sliders then you might as well also get a set of 8.5g sliders at the same time; that would give you 3 viable combinations to try (8.5, 9 [if combo staggered], & 9.5).

nissanman · Post by **nissanman** » Fri Sep 18, 2009 12:56 pm

It will also depend on how much the rider/gear weigh. A heavier rider may need lighter weights to run the engine higher in the rpm band (and theoretically produce more power). A lighter rider can go with heavier weights. If you're in the 150-180 range the stock weights are fine. I'm 200 + gear... a little lighter works better for my riding style. But I do have to live with more noise since I keep the engine at higher rpms.

Scalpel · Post by **Scalpel** » Fri Sep 18, 2009 8:22 pm

After reviewing all the advice here, on Genuine Rattler, and Voodoo Buddy, I think I've come up with a final parts list:

Dr. Pulley 9.0 gram sliders
Dr. Pulley variator
1000 or 1500 rpm clutch spring (I'll probably get both)

The question is, where should I buy from? No site seems to have all the parts, and I don't want to pay double shipping...

P.S.: If you have any case to be made against this upgrade package, speak now or forever hold your post.

B02S4 · Post by **B02S4** » Fri Sep 18, 2009 9:24 pm

As previously stated, IMO the torque spring/s isn't needed, & if you get the spring/s then the advice that I gave you for slider weights does not apply. The DP variator also uses different size sliders than the OEM variator.

Scalpel · Post by **Scalpel** » Fri Sep 18, 2009 9:54 pm

B02S4 wrote:As previously stated, IMO the torque spring/s isn't needed, & if you get the spring/s then the advice that I gave you for slider weights does not apply. The DP variator also uses different size sliders than the OEM variator.

So let's assume that I am getting the DP variator, and would like the fast take-off of the springs. What slider weight size would you suggest?

B02S4 · Post by **B02S4** » Fri Sep 18, 2009 11:42 pm

Scalpel wrote: So let's assume that I am getting the DP variator, and would like the fast take-off of the springs. What slider weight size would you suggest?

I don't know what you mean by "fast take-off of the springs".

Scalpel · Post by **Scalpel** » Fri Sep 18, 2009 11:46 pm

B02S4 wrote:I don't know what you mean by "fast take-off of the springs".

From what I understand, the higher rpm spring causes a quicker "jump" off the line when starting from a stop light or whatever. I'd like to have that boost, without an impact on the top end. That's why I'm thinking about the 1000 rpm spring rather than, say, the 2000 rpm spring.

B02S4 · Post by **B02S4** » Sat Sep 19, 2009 1:20 am

As a person of science, think this through a little more. A "1000" or higher spring has a higher spring rate than the stock spring. The stock spring provides enough force as it is. If you place a higher rate spring (lbs per inch or metric equivalent) all other things equal then all you have accomplished is to require heavier rollers/sliders in the variator to get the same relative CVT balance as you had before.

If all you want is to pull hills better or accelerate faster, then you can accomplish that with lighter rollers/sliders.

It's your money and you should of course spend it any way you want to, but the reality is all you need to do to accomplish "better acceleration" is to go to lower weight rollers. Nah, it ain't sexy, but it works.

But wait...you say you want better acceleration and higher top speed? Sure. No problem. Get a BBK, a bigger carb, port the reed cage, a RRGS V8 style pipe, a DP HIT clutch or Koso Racing clutch, & THEN get the higher rate torque spring & test roller/slider weights, & maybe new final drive gears. You want to play in that arena, then you've got to pay the price. Remember that "fun" runabout scooter? Now it's a race monster.

But higher rate torque spring for a Unifilter and pipe? Umm, no.

Scalpel · Post by **Scalpel** » Sat Sep 19, 2009 7:25 am

So to make sure I understand correctly...

Slightly heavier roller weights are the only mod that would help get more top end on my Rattler, without resorting to the list of mods you described? The DP variator and/or the performance pipe will have no effect on the performance of the bike?

I guess I'm confused why people buy these performance parts, if it's as you say and the parts don't really change the performance of the bike at all.

Is it because the Rattler is already maxed out, performance-wise? The Voodoo Buddy site seems very encouraging about some of these mods, but it sounds like either they're misguided, or that the Buddy is more mod-able than the Rattler.

B02S4 · Post by **B02S4** » Sat Sep 19, 2009 1:08 pm

Scalpel wrote: ...I guess I'm confused why people buy these performance parts, if it's as you say and the parts don't really change the performance of the bike at all...

That is your interpretation of what I wrote, & either you missed the point or I didn't explain very well, or both.

Of course the "performance" is changed by performance parts. And to a certain extent Buddys and Rattlers are apples and oranges.

Why don't you restate specifically what you want to achieve and then you can get more specific recommendations.

Scalpel · Post by **Scalpel** » Sat Sep 19, 2009 6:51 pm

B02S4 wrote:
Scalpel wrote:Why don't you restate specifically what you want to achieve and then you can get more specific recommendations.
I'd like to get a little more top end speed from my Rattler. The bike currently has a UNI filter and a bigger jet, but everything else is stock.

What would you suggest I do to get a higher top speed, without seriously degrading the acceleration? I've read several comments and reviews that claim that the Dr. Pulley variator and sliders add both acceleration and a higher top speed, due to a longer variator face. That's why I was considering going to route.

Will the variator and sliders produce the results I expect, and are there any other mods (short of the BBK and bigger carb) that might help?

B02S4 · Post by **B02S4** » Sat Sep 19, 2009 7:56 pm

Everyone wants more top end from a Rat! The choices basically boil down to finding a way to make the engine rev higher, increasing the variator face diamter, or changing the final drive gearing. A performance pipe & good carb tuning will increase the revs a bit & get a few mph more top end. The DP variator that fits the Rat has the same face diameter as the 0EM does, but has a thinner drive boss (so you get more low end). That combined with a final drive gear change might get you where you want to be. The DP variator alone, probably not.

bigbropgo · Post by **bigbropgo** » Sat Sep 19, 2009 8:42 pm

so sorry to threadjack but has anybody sourced final gears? I can handle some of the other mods but what does the swap entail? I think timone ninja had some. sbl is no longer a source for anything rattler

B02S4 · Post by **B02S4** » Sat Sep 19, 2009 9:38 pm

The only source for gears that I know of is Scooterworld Guam.

mojobuddy70cc · Post by **mojobuddy70cc** » Tue Sep 22, 2009 3:22 pm

i have a uni filter, prima exhaust,.21m jetting and stock roller for top end ( genuine tech sourced) after running hot with heavier rollers. clutch spring and stage 2 kit, 70cc. ok the prima pipe needs to be cleaned( the packing for a 2T) out w/ brake cleaner i do it about 800-100 mi. this makes a big difference.!! the uni will flow much smoother and i hit 55mph easy ( i`m 200lb) 60ish on the dream-0-meter. but to get the full bene`s from the UNI it needs to breath all the way thru the intake/outake to make the bike respond like it was intended to do. i found this out after loss of power and it was as simple as keeping the baffle packing cleaned out.
i`m installing a new ameche 19mm carb, can`t wait to see the diff. i`m getting about 65mpg now so that will go down wif performance. i`m also buring a syn-marine 2T blend (3.99) qt @ auto-zone but does burn much cleaner than the regular oil. being tuned comes wif a price but i just smile when i`m cruising @ 50mph.