We finally got a chance to test a Stage I Cam only install thanks to Eric who drove all the way from Tyler TX. to be the volunteer. We didn't have a stock Rhino with MSD and Muzzy pipe to test on. He also brought us some deer meat!!
To the test!!
As I said this was a stock engine 09 700 Rhino with a MSD and Muzzy full exhaust and our 20gr. overdrive sliding weights with stock sheave. Eric had some Terracross tires, front hood rack, yamaha roof and two gun boots.
We put on his set of stock tires for all the tests and then when done put his 26x9x14 and 26x11x14 Terracross tires back on. We left all the other accessories on it. When we would test on speed and time Eric rode with me every time so we were consistent.
Before we did any work we did a 0-50 run time and a top speed run. The 0-50 time was 11.16 and top speed was 58.
We also did a dyno run as is and the peak HP was 28.83 at 26 mph and over at 50 mph we were getting right at 13 to 14 hp.
By the way stock HP with no muzzy is 22.62 at peak and would not run 50. This test result was from a dyno run on a totally stock machine a while back.
So we did the install and I want to explain something on the install. You have a choice when doing the install. If you choose to remove the bearing off the new camshaft and install it in the head you won't have to have any special tools other wise you will need a blind bearing removing tool and a rocker arm shaft removing tool just to get the cam bearing out plus you will need to remove head to do the install. From a liability stand point this is the way you need to go but I will tell you what I do and then you make the decision.
If the engine is relatively new and has never been ran low of oil then I re-use the stock bearing which makes for a much easier install that most anyone can do.
Now some more liability statement crap!! This cam is not our cam it is one that is available to anyone, you are modifying your engine and you must take the responsibility of modifying it and what possible damage may occur on your own. Hunterworks will not be responsible for bad installs or any engine damage that may occur from the install. We simply provide the cam, gasket and fuel map for the MSD to match the cam.
To put your mind ease, we have ran this cam and one with more lift in a stock head with stock valves and springs for at least three races and one was a 8 hr race where our race rhino ran for 6.5 straight hours because our teammates vehicle went down. By the way, we won two of three races racing against Teryx and RZR's.
Ok back to the testing!!
We made the cam swap and then put the rhino on the dyno to get a fuel map made. I took the fuel map from my race rhino that has same mods except for a high compression piston to give us a good starting point. Interestingly the cam only, took slightly more fuel than with piston reason is less volume in cylinder with high compression piston taking up space.
The trouble with other cams is the fuel maps between part throttle and full throttle are so far apart you can't make a fuel map that works in both cases so you end of with a rhino that runs good at part throttle but is running too lean at full throttle so you think you have a good running rhino until it quits. In the other case you get it right at full throttle and it will miss at part throttle running a steady speed due to being too rich. This is the reason we are doing the Stage I cam because the Stage II and Stage III would not run right in both areas.
After we got a fuel map made we did a on road run and no missing and it ran great. This does not mean you might get a slight miss somewhere running a steady speed but this is a small quirk you may to deal with. It will be a rich miss which won't hurt anything. Hopefully no one will get the miss.
After Install results:
Peak HP went up about 5 hp but the most amazing area was at 50 mph there is about a 13 hp gain.
Our 0-50 times to 8.5 secs which is almost a 3 sec difference which is big!! Top speed went to 62 mph. You might say, that is not so much but the reason why it was 62 was it was hitting the rev limiter and we were able to hold 62 with about 3/4 throttle. Also to hit 58 before it took about a 1/4 mile and we hit 62 in about half the distance.
Got to thinking about the fact that we moved the peak point of the engine higher so we put a set of 18 gr. over drive weights in the clutch and our 0-50 times dropped another 3/4 second but top speed still didn't change which it shouldn't. This is not the place to explain clutch weights but lighter ones are needed when you do engine work.
Going by the seat of the pants dyno it was a vast improvement.
We put the heavy Terracross tires back on and re did our 0-50 test and top speed test. We didn't redyno though. Our 0-50 times dropped big time to 10.16 and top speed to 60 and we went the full quarter mile to get that. We didn't do a 0-50 run before with the big tires but Eric said top speed was 52 mph before.
So with those heavy tires we only gained one second 0-50 and 8 MPH, not bad but it does give you a idea of what bigger tires do for you. The moral of this story is that if you want to accelerate quickly and run fast you need light tires period. This does not mean you have to run stock tires there are several good choices for lighter tires for mud such as the Maxxis Zilla and all terrain tire such as Maxxis Bighorn 2.0 which we run on race rhino that will get the job done without losing much if any power.
You can watch our install video on the site. This install is very easy and is the most HP per dollar you can do to your Rhino. Yes you can get bigger better faster etc. but we are talking about a mod that is less than $200 and get 13 hp that most anyone can do.
All future MSD's will have this fuel map and our piston/cam combo map in it and if you already have a MSD we can simply e-mail you the map and you download it in your MSD.
By the way, you get about a consistent 5 more HP with piston but it comes at a higher price tag and harder install where most people would have to pay to get it done and it opens the possibility to something going wrong on the install too. We are all about reliable gains that are easy on the wallet and easy to install.