You can use all the existing stuff. It just replaces the original diff.

You will need to do some careful carving to make room for the diff. The instructions tell you where to trim.

Ok, thanks for the tips on the kawahara diff guys. But perhaps I should try to get that kawahara shocktower if that can help me avoid any modifications to the original parts? Not that I'm not feeling capable to modify them, but maybe they are getting weak-spots and break easily?

Anywone know the part# for the kawahara parts?

I have ran the conversion for a couple weeks now. I haven't been running different sized tires either. I thought that the conversion was to help with the fact that the rear tires wear faster than the fronts with the stock pullies.

16/19 Questions..........and answers.....
 

Not to be harsh....but.....there seems to be a LOT of questions concerning the 16/19 conversion that indicate that MANY people do not fully understand the concept.....the above post is not the only one, simply the latest....let's see if this helps....

The stock rear drive ratio from the center shaft to the front and rear wheels is 2.526:1 (SAME front and rear....thus, you must run the same diameter tires to have a non-overdriven condition)

The FRONT drive ratio with the 16/19 conversion is 2.375:1 (while the rear remains unchanged at 2.562:1). With the conversion, the front of the car has a drive ratio that results in the front-tires spinning approximately 6% FASTER than the rear tires....therefore, that 6% difference must be compensated for by tire sizes.

The proper tire size to achieve a non-overdriven condition may be determined by calculating the rollout of the front and rears for each turn of the center shaft and picking the proper tire size to achieve the condition you desire.

To simplify things, here are some example tire combinations that achieve a near-even drive ratio front to rear.....(it is not specifically a constant split...but it's close as you will see)

Front.........Rear.........Overdrive #
50mm.........53mm............1.004
52mm.........55.5mm.........0.997
54mm.........57.5mm.........0.999
56mm.........59.5mm.........1.001
58mm.........61.5mm.........1.003
60mm.........64mm............0.997

As you can see....an approximate 3.5mm split achieves a non-overdriven condition (rollout for front and rear equal) for a large range of tire sizes. (slightly less split for small tires... and more split for larger tires)

The main thing to understand is that this conversion allows you to get more even tire-wear (Fronts and rears wear together...without having to constantly true the front tires down to match the ever-shrinking rears). You also get to run the front of the body lower over the wheels......if you like to SLAM the body to the ground. You get the benefit of having less foam on the front tires......good turn-in without excessive tire flex and traction-roll issues (and they're lighter). Finally, assuming you keep a similar rear tire-size to what you would normally run....the front roll center is changed slightly due to the suspension geometry change of adapting to the small front-tires without compromising ride-height.

One last thing to remember......the overdrive percentage of 1.000 is only one option.....you can use an overdriven condition to alter the handling of the car...especially on low-bite tracks. A number higher than 1.00 means that the front tires tend to "pull" the rear of the car.....a number less than 1.00 means that the rear tires "shove" the front around.......each has a slightly different feel. This is easier to distinguish on low-bite tracks and is not so apparent on high-traction surfaces.

If you do not run SOME split front-to-rear....then you will unnecessarily stress the drive-train and wear out the belts and pulleys faster.........recall from above that there is a 6% overdrive created with the conversion and if the tires are equal-sized front-to-rear then the front tires are trying to pull the rear along 6% faster than it wants to pull itself......:tire: :tire:

If someone has a place for me to post an image....I can take a screenshot of a chart I have created in excel for ease of tire-size selection......I can send it to anyone in excel or pdf format also. PM me if you'd like a copy. I'd be happy to answer any questions about this post....please PM me.

Re: 16/19 Questions..........and answers.....
 

Nice job

So is it a mis-print at mugenracing.com that the 0.8 conversion uses a 61 and a 57 spur instead of the 59/57 that the prospec comes with?

]-[0pa]0ng - I know all those guys very well at Phat Boyz.

Yea they are going to help show me how to setup the car and dial it in. They have pretty good pices as far as a LHS goes. Paht boyz is the whole reason I went into this on road. Never thought there was so much involved. I'll be there today figuring out the tire ratio vs the gear setup. This site has real good info. Will be picking up that Xtreme RC july issue as well.

David where you there at the track for the first race they had or tried to have? I remember someone from Austin with a blue body and a modfied mugen engine.

]-[0pa]0ng- did they ever get the pc troubles worked out? i was there the first day but we only got a qualifier in before they called it quits, nice track though.

Does anybody know where i can get the red clutch shoes online?

Todd says he will have it all worked out. It was a new program and wasn't use to it. The next race is on the 6th. to make up for the last one. So Since you were in it it's free this time. He really felt imbarrassed about it. I couldn't get over the turn out. They came from CA and did all this in a very short time. It has the our Hobby shop scratching now. Ceck this out Werks They have have 4 types of shoes.

i know they do but they are also on Vacation: Winner Circle

I'm almost certain Phat Boyz do have it.

Re: 16/19 Questions..........and answers.....
 

I sent you a PM. ;)

Quite a bit of good info in the thread but unfortunately some calculator doesn't seem to understand the first part of your post or chose to ignore it. :deathstar

Check your PM.

Change in top speed/acceleration
 

The only change in acceleration that will occur due to the 16/19 conversion is that the mass of the front tires and side belt/pulleys is SLIGHTLY smaller than without the conversion. The decrease in rotating mass will allow SLIGHTLY faster acceleration, though I doubt it will be noticable to most drivers.

Top speed is unaffected by the conversion if proper tire-sizes are chosen that eliminate an overdriven condition that scrubs energy due to one end of the car being dragged-along or shoved-along at a pace other than it's rollout. If a non-overdriven condition is used, there is no difference to top speed.

(This should be obvious to those that understand the concept of the conversion....if it is not clear...feel free to PM me and we'll discuss it)

OK I've already started to notice the accelerated rear tire wear on my mtx3. What parts will I need for the 16/19 conversion. From the searching I did I found I will need: 16t pulley, 19t pulley and the corresponding belt. Is this all? Also, I believe Kawahara offers all these parts...? Does anyone else? Thanks.

Required parts for the belt conversion
 

Yes...that is all...

The standard Mugen pulley set - (Part # T0221) has the 16T pulley you need.........the 19t pulley is already on your car....simply remove the 24T (front) side pulley and toss it....put the 19T (rear) pulley already on the side of the car up front....and install a new 16T pulley (the same size as is used in the front of the car on the mid-shaft to drive the front belt)

The best buy for belts is the guy on ebay.....you can email him for belts... his RC-tech handle is "evlhdlts" and here is the email.....


[email protected]

(he posted this information a couple of days ago)

They have FAST shipment of belts at lower prices than the Kawahara ones......