I have always believed that there is no substitute for displacement. Anybody agree? If so what does it take to make that happen on a RZR?

I agree, there's no substitute for cubic inches

i agree but if you do a piston you need to do a cam if you do a cam you need to do valve springs get my drift im trying to make the most of what i got and stay deppendable i put mountain performance cdi box on and its not giving me all thay said it would all it did was raise my rev limiter from 6500 to 7000 no timing advance the only cdi box that i have had any luck with is dyna tech i put it on my 650 v-twin articat. it did everything mnt said theres would do i will call mnt on monday my point is be vary carefull with your money keep asking and dont buy anything until you have all the anwsers if you dont have big money the box is the way i hope mnt can deliver on monday if not i will wait for dynna tech if you have big money i hope it gos well for you i hear alot about dragon fire give them a call

Thanks mdevans. I think alot of people spend alot of money on the " outside of the motor". Maybe it starts with the "inside" . (B+S). I have to be honest though this is all new to me so I am still learning.

you got the idea if you open up the exhaust and up the fuel delivery you can cause the engine to be detuned if you add some extra air to that you can gain a little more bottom torq but top speed will go down just because you open the exhaust on the outside dont mean you can flow all that air and fuel the air fuel mixture go into the engine intake manifold as the engine is cranked over it pulls it into the engine through a intake valve thats in the engine head. piston comes up spark plug fires air fuel blows up piston gos down exhaust valve opens up WAIT we have bigger air fuel and more exhaust going out smaller valves so if we rework the engine head we can put bigger valves in and keep our top speed maybe gain a little but we spent alot of money and were only a little faster on bottom and a little faster on top WHY because the piston is still little make that bigger and the engine will be stronger. NO it will be more powerfull the engine is still bilt to be smaller this could be a bad deal for the engine crank shaft most of the time if you keep rpms stock crank will be ok but if you want to go fast on top end you need more rpms BIGGER CAM the cam opens and closes the valves if we keep the intake valve open a little longer we get more air fuel mixture. and the motor can run at higher rpm but will it NO it will hit the rev limiter so we need a cdi box with a higher rev limiter but we still a stock crankshaft. if you rev crank above what it can handle its over if you want go big you need to go all the way

you got the idea if you open up the exhaust and up the fuel delivery you can cause the engine to be detuned if you add some extra air to that you can gain a little more bottom torq but top speed will go down just because you open the exhaust on the outside dont mean you can flow all that air and fuel the air fuel mixture go into the engine intake manifold as the engine is cranked over it pulls it into the engine through a intake valve thats in the engine head. piston comes up spark plug fires air fuel blows up piston gos down exhaust valve opens up WAIT we have bigger air fuel and more exhaust going out smaller valves so if we rework the engine head we can put bigger valves in and keep our top speed maybe gain a little but we spent alot of money and were only a little faster on bottom and a little faster on top WHY because the piston is still little make that bigger and the engine will be stronger. NO it will be more powerfull the engine is still bilt to be smaller this could be a bad deal for the engine crank shaft most of the time if you keep rpms stock crank will be ok but if you want to go fast on top end you need more rpms BIGGER CAM the cam opens and closes the valves if we keep the intake valve open a little longer we get more air fuel mixture. and the motor can run at higher rpm but will it NO it will hit the rev limiter so we need a cdi box with a higher rev limiter but we still have a stock crankshaft. if you rev crank above what it can handle its over if you want to go big you need to go all the way

I would have to disagree on the mp cdi box i would say it's the best money i have spent so far. Just my 2 cents.

h&k: What differences have you seen with the mp cdi? Also have you tried any other hp mods?

well i put the dfr full pipe, clutch kit, air box and there programmer and it hit the rev limiter at 62. to 62.2 mph.(stock cdi)

Next all i did was install mp cdi box set up with a 7,000 rpm max range and it did 66 mph at 6820 rpm with no bogging. I don,t think it,s as good as they claim out of the hole but I it is faster in the midrand and faster to top speed. I,m not trying to hype them up but to me it was worth it.
Hope that helps.

I called mpi and told them my cdi box not working as thay said it would. only to find out that thay were going to put me through a lot of testing thay said my 27 inch tires were making the clutch slip and that the box is for 25 inch tires wish i new that before i bought the box. however the tires wont make your clutch slip unless thay are to big for it and if my clutch was slipping i would have higher rpms this is not the case. what thay made me do is time the car for 100 feet with the 27 inch tires and with the 25 inch tires at 100 feet thay were the same 30 mph but i got 4 seconds with 27 inch and 1 tenth maybe 2 tenth faster with25 inch tires. like the other guy said no change out of the hole if this box was working as soon as you pushed the throtle you would feel the differance.and thats what it says on there web site i have a freind with a brute force that has 27 inch itp 589 (heavy) i sold him my cdi box that i had on my v-twin articat. my articat had 26 inch 589 my articat pulled the wheels like you wouldent beleave.as for the brute force he beat my sons stock kfx 700 with me riding it and i pulled a better hole shot. this is how advance timing should work. by the way the cdi box im talking about is a dynna tech. my rzr runs just like a stock one all the way to 58 mph than if your going down hill the engine will go to 6850 rpms this is because the timing is not advanced on my box if it was i would have more torq to get to 7000rpms my rzr engine is bone stock it even has a clutch spacer.it dont even have 1000 miles on it and i changed the air filter 4 times the inside of my engine has sean no dirt. also i won a mud bog with 27 inch tire my belt is still stock.the only thing a clutch kit would do for me is back shift faster and it would do the same for 25 inch tires if you go to big 28 or 30 inch 589s outlaws yes you will need clutch work and you will feel your clutch failing. im waiting for mpi to aprove me to send there box back that is not doing what thay said it would do. also im not the only one that has a rzr with a mpi box that dont advance out of the hole. why cant i just send it back let them look at it . in case anyone is woundering i took neg off than pos installed box put pos on than neg. im not saying it yet but it looks like all thay did was pulled the chip out and programed it for 7000 rpms. if this is true i want my money back. i hope i can send it to them and there on the up and the up. i would rather have a box that works than my money back .

I called mpi and told them my cdi box not working as thay said it would. only to find out that thay were going to put me through a lot of testing thay said my 27 inch tires were making the clutch slip and that the box is for 25 inch tires wish i new that before i bought the box. however the tires wont make your clutch slip unless thay are to big for it and if my clutch was slipping i would have higher rpms this is not the case. what thay made me do is time the car for 100 feet with the 27 inch tires and with the 25 inch tires at 100 feet thay were the same 30 mph but i got 4 seconds with 27 inch and 1 tenth maybe 2 tenth faster with25 inch tires. like the other guy said no change out of the hole if this box was working as soon as you pushed the throtle you would feel the differance.and thats what it says on there web site i have a freind with a brute force that has 27 inch itp 589 (heavy) i sold him my cdi box that i had on my v-twin articat. my articat had 26 inch 589 my articat pulled the wheels like you wouldent beleave.as for the brute force he beat my sons stock kfx 700 with me riding it and i pulled a better hole shot. this is how advance timing should work. by the way the cdi box im talking about is a dynna tech. my rzr runs just like a stock one all the way to 58 mph than if your going down hill the engine will go to 6850 rpms this is because the timing is not advanced on my box if it was i would have more torq to get to 7000rpms my rzr engine is bone stock it even has a clutch spacer.it dont even have 1000 miles on it and i changed the air filter 4 times the inside of my engine has sean no dirt. also i won a mud bog with 27 inch tire my belt is still stock.the only thing a clutch kit would do for me is back shift faster and it would do the same for 25 inch tires if you go to big 28 or 30 inch 589s outlaws yes you will need clutch work and you will feel your clutch failing. im waiting for mpi to aprove me to send there box back that is not doing what thay said it would do. also im not the only one that has a rzr with a mpi box that dont advance out of the hole. why cant i just send it back let them look at it . in case anyone is woundering i took neg off than pos installed box put pos on than neg. im not saying it yet but it looks like all thay did was pulled the chip out and programed it for 7000 rpms. if this is true i want my money back. i hope i can send it to them and there on the up and the up. i would rather have a box that works than my money back .

I called mpi and told them my cdi box not working as thay said it would. only to find out that thay were going to put me through a lot of testing thay said my 27 inch tires were making the clutch slip and that the box is for 25 inch tires wish i new that before i bought the box. however the tires wont make your clutch slip unless thay are to big for it and if my clutch was slipping i would have higher rpms this is not the case. what thay made me do is time the car for 100 feet with the 27 inch tires and with the 25 inch tires at 100 feet thay were the same 30 mph but i got 4 seconds with 27 inch and 1 tenth maybe 2 tenth faster with25 inch tires. like the other guy said no change out of the hole if this box was working as soon as you pushed the throtle you would feel the differance.and thats what it says on there web site i have a freind with a brute force that has 27 inch itp 589 (heavy) i sold him my cdi box that i had on my v-twin articat. my articat had 26 inch 589 my articat pulled the wheels like you wouldent beleave.as for the brute force he beat my sons stock kfx 700 with me riding it and i pulled a better hole shot. this is how advance timing should work. by the way the cdi box im talking about is a dynna tech. my rzr runs just like a stock one all the way to 58 mph than if your going down hill the engine will go to 6850 rpms this is because the timing is not advanced on my box if it was i would have more torq to get to 7000rpms my rzr engine is bone stock it even has a clutch spacer.it dont even have 1000 miles on it and i changed the air filter 4 times the inside of my engine has sean no dirt. also i won a mud bog with 27 inch tire my belt is still stock.the only thing a clutch kit would do for me is back shift faster and it would do the same for 25 inch tires if you go to big 28 or 30 inch 589s outlaws yes you will need clutch work and you will feel your clutch failing. im waiting for mpi to aprove me to send there box back that is not doing what thay said it would do. also im not the only one that has a rzr with a mpi box that dont advance out of the hole. why cant i just send it back let them look at it . in case anyone is woundering i took neg off than pos installed box put pos on than neg. im not saying it yet but it looks like all thay did was pulled the chip out and programed it for 7000 rpms. if this is true i want my money back. i hope i can send it to them and there on the up and the up. i would rather have a box that works than my money back .(soory im going to have two post again) ok three it tells me i have to wait 30 seconds then try again than it post two times ?

Ya! somethings wrong there, I asked alot of ? befor I bought mine. I told them what I was putting on my rzr and was told by them that the tires did not matter and not only do they up the rev to 7,000 but they will lean it out because as we all know rzr's run fat. And I have to say mine runs much leaner in the mid and top range. Maybe it's time to stop being nice. Let me know how it works out..

can anyone tell me how fast there rzr will go 100 feet. and how many seconds. also i agree if you have other mods that will up your engine torq a higher rpm rev limiter is a good thing (but a lot of money for 500 rpms). on a stock engine without timing advance you dont have enough torq to hit 7000 rpms. were trying to come up with a program that will give the timing advance to fly out of the hole without detenation.

I was going to call them tomorrow about the computer, and to see about the supercharger kit. I am waiting untill I find a reliable place thats somewhat close to me(I hope) that does the whole 9 yards.

Ive found doing it all at once is really the best way to go, if posible. And they seemed to be a good shop, Ive heard good things about there Rhino superchargers at least....but sounds like they rushed the cdi out?