fmf MegaMax # of plates

[bakerboyz]

I was wondering how many plates each of you run in your Mega Max II exhaust.

I bought this 300ex, it has 4 plates on and another 9 in a bag. I do not have the FMF manual. was wondering how many I can use without re-jetting.

Thanks

[UglyMotha™]

it doensn't matter how many plate you run "rule of thumb, the more plates you use the more gas you need" so test a couple out put six plate on see how it runs, if it runs like crap your either gonna have to up the jet size or take the plates back of your choice but i would go ahead and just slam all the plate on it and see what jet acomodates *sp that combination

IM CURENTLY RUNING MY MEGAMAX WITH NO DISCS, WILL ADDING DISCS ADD POWER?

[frogburner]

I have a 400 and I have 10 plates in mine... But it is rejetted with a 170 main..

[UglyMotha™]

Originally posted by sportraxx2001
IM CURENTLY RUNING MY MEGAMAX WITH NO DISCS, WILL ADDING DISCS ADD POWER?


when you run it with no discs you will gain top end but loose bottom end in other words you loose torque if i was you i would run 8-12 discs that way you have the best of both worlds

[300exryder]

I have a megamaxII on my 300 and this is the rundown:
I never bothered with that quiet core insert -- it's like having a stock exhaust. They say not to run less than 8 discs but hey who cares? I used to run it with nothing on and runnning it like that will give you the best top end. The less discs you have the more backpressure and therefore the better bottom end. Putting more discs on will slowly increase your top end but at a sacrifice to your bottom end. It is really noticeable after having it run with nothing on to having 8 discs.


BTW -- im in need of a 130 main jet.......

so, i think i got it, the more discs on the more top end you will have???

[300exryder]

yup, i think you got it -- anyone correct me if im wrong-- I would recommend running it with nothing on if sound isnt a problem. I think it sounds best this way and it gives more top end.

before you said the more discs the more top end, now your saying no discs for more top end, wich one is it??????:huh

Adding discs increases the exhaust size and increases exh flow, then this will allow the motor to breathe better in the higher rpms. The neg side is that it will take away from your bottom end torque.

Decreasing the number of discs will add bottom end and take away the higher end. So its a compromise, and better be carefull with the jetting, too lean = run mean but rebuild soon, run rich= be safe but loose a little power.

BTW Froggburner, Your running 2 less plates with your 400 than I am with my 440 and your a jet size above me? 170 vs 168. I have no obvious problems and the plug looks right both times I checked after changing the jet. My question is what do your plugs look like, right after you put them in and run for a few minutes??
Just curious.

Thnx

[bakerboyz]

This is from the FMF web site FAQ, How many discs to run?

Keep this in mind. Having less backpressure (louder), the more top end power you'll have. More backpressure (quieter), the more bottom end power you'll have. This is true to a certain extent until you get out of the tuning range of the motor. A 250cc motor will only flow so much exhaust. If you're looking for an all around power increase we recommend running 11-13 discs with the quietcore out. For more top end, add more discs and for more bottom end, run less discs with the quietcore installed. Don't run less than 8 discs though.

Any under the jetting guide:


99-01 PILOT MAIN 87-01 PILOT MAIN
TRX 400EX TRX 300EX
TRX 250X
STOCK 38 145 STOCK 38 122
FMF 40 150/152 FMF 38 128
FMF/K&N 42/45 155-170 FMF/K&N
OPEN AIRBOX OPEN AIRBOX 40-42 130-135