Head comments:
FOR TRAIL & PUMP FUEL; Regardless of year 99 through 2006, for engine safety and reliabilty to run on as low as 87 octane, I recommend The low-comp head insert to be used with as thin as a #3 base gasket. The #3 has 3 holes in it.
Spending many hours on an inertia dyno, I found most hp and torque with spark plug gapped @ .022"~023".
On up to 2003 models many owners get away with the hi-comp head inserts however they use the #6 base gasket to avoid detonation.
The power results are nearly the same as low-comp setup with the difference in exhaust port timing because of the thickness of the base gasket. Using the thick gasket you may find the clutching likes to be around 8600 rpm or just a little bit more on the tach. I personally prefer the low compression inserts with thin basegasket to offer reliability.
I had a lot of help from some friends to test and build the kit against their sleds. I put 1800 miles in total on it. We used MXZX's to test with ranging from 1999zx to 2002zx & 03 REVs.
The initial building of the kit was done using 92 octane fuel. The '99 & '00 sleds used a Rotax #2 or #3 base gasket with low compression head inserts, 260 & 270 jets.
The '02 sled used a Rotax #6 base gasket with low compression head inserts and 310-320 jets. Compression for both engines were between 125#-130#s. I know of some guys using 280-280 in their '02 sleds. The two REVs we have been using are running 310-320 jets @ 135 lbs compression.
Competition Drag racing, high compression inserts were used with #3 base gaskets @ 165 lbs compression in the '99 and '02 engines with 220 & 230 jets.
***High compression heads for '99 sled need minimum 108 octane.***
***High compression heads for '00 to '03 sleds need minimum 100 octane.***
***The fuel that worked the best was VP Fuels C-12. We could add the most flyweight. ***
Original ignition timing was used. During one test session in drags we used a timing box programmed by Ski-Doo for Sno-X condition. Using a Portatree system with printouts for 0-90', 0-300', and 0-1000', we measured the programmed ignition decreasing the 0 to 90' time by up to 2-10ths of a second consistently. The difference in times between the other markers were almost negligible.
The kits have been tested under the following conditions:
2 mile long snow covered Lake for top end runs in heavy loads. (4 inches of powder)
2 mile stretch of rolling hills where max possible speed is approx 60mph because of steep grades and 2' to 3' dips/bumps. (tough workout in Sno-X conditions)
62 miles of extreme bump trails with small creek crossings, 50 deg hills, low pitch deep bumps and some open water.
4 mile long river straight for W.O.T. running narrowing down to 2 miles of extreme corners of "Point/shoot".
The point/shoot ability is fantastic and leaves larger cc sleds in the dust. In it's stock clutching trim with experienced driver, the larger cc sled cannot sustain a rhythm to "track" an efficient course around a point/shoot trail when trying to run against the 440Zx.
For lake testing with stock gear 21:43 [89mph@8500] w/1.25" track:
In 660 feet, averaged 6 lengths over bone stock clutches.
1300' 81-82mph (stock trim) 86-89mph (with kit)
River run with kit got up to 93mph on hardpack.
Stock clutch trim was measured up to 86mph.
* All tests done with sportchek radar.
MOST TACH'S ARE OUT....a simple check:
We tested the tachs against radar and had improved all measurements every time we turned the engines higher on the tach needle.
My Zx made consistent runs in 1300' of around 89mph with 8700rpm, 86mph @ 8500rpm, 86mph @ 8800-8900. My sled runs a little better than 8700 rpm when cold and pulls hardest at 8650-8700 when hot after warmup.
Tested with top drive gears of 21, 22, 23 & 24. In our area and the way we drive, the stock gear trim was best suited and had the most performance for all around hill climb, twisty trail, point/shoot and all out top end. The feedback from owners is that they enjoy the "toggle switch" style of riding as the clutching backshifts very quick and the upshift is right there to accelerate when the fuel is applied.
The kit has been used for trail riding, drag racing and 1000' hill climb event (50+ degree hill). Most impressive holeshot over stock with very hard "roll on the throttle" midrange pull.
THE JIST:
The cam uses a blend of angles that are used in speed runs and drag racing.
When you look at the cam, you can see it starts very steep and smooth out to a low angle.
You know that: 1] low angles produce great backshift 2] Large angles produce great upshift.
The cam provides an angle that the sled "Needs" at the speed it is going.
You punch the fuel, it accelerates hard...let off the fuel the clutches backshift quickly, you punch the fuel again, you accelerate hard.
The clutches have a fantastic ability to grip the belt all the way to and past 1:1 ratio.
The low temperature is the clutches telling the tuner that the system is very efficient.
I have actually got 20%+ into overdrive with it on river runs @ 93mph.
I am not a high volume clutch kit provider. I am only a nobody who has passion for clutching more than I can measure. All I have is my word but especially my reputation to back my kit.
Like the 440 & 800 builds we tested compression in all of the engines. There are big differences in values from one engine to the next. The Test mule had 155 lbs compression; the other mule had almost 150 lbs compression. Did side to side running from these speeds 30mph, 50mph, and 70mph to top end. The sleds we used were 600 H.O. & Gade SDI.
Did "running" side-to-side drag racing with two REV 600 H.O. SDI's. One driver would hold his hand up while operating then throw the hand down and pin throttle to the bar. Every time, the kit would pull away from the stock setup, but even more so in the higher mphs and especially in deep snow.
On flat river running with hardly any snow (2-3") the S6X Mule sled could not outdo the stocker by more than a few mph of around 94mph. Start to get some snow (4-6") on the ice, the S6X could hold a high mph longer. We tested the kits on a river with up to a foot of slush in 1km drag races and pulling off into the deep snow doing side-by-side throttle response tests.
The angle of the helix near 1:1 ratio is smaller than most tuners are used to. This from my experience leaves capacity to gear up and still have a great amount of belt squeeze at the top to get a higher mph on flat low load surfaces. Leaves the capacity to gear down and maintain high mph in rough terrain, blanket snow conditions with the benefit of increasing midrange acceleration. We did not test with a taller gear. I wanted to test bone showroom stock. My guarantee that the S6X kit is a HUGE improvement thru the whole midrange for acceleration and back shift over stock helix and gearing. I also guarantee that the owner will be light on the fuel trigger at speeds of 80~90mph running for long periods of time. The S6X will help to consume less fuel than stock clutch.
Because of my experience selling clutch kits, there are more novice tuners who just want to put a kit in and drive the sled. They do not want to know much about the system other than it will take minimum setup and usually they take kit to a friend to install it. Most guys do not even gap their new plugs. I have even been told of people trying to pry their belt off with a screwdriver. Because of this, I wanted to test with absolutely bone stock and touch nothing other than make sure brand new plugs were gapped at factory setting. We never even tested with changing jet size.
On the 600 H.O. the shock valving was adjusted in the high-speed valve stack so the sled could be beat as if running in an x-country race. Where the stock suspension would bottom out to nearly breaking parts, the sled could now run with higher speeds in 2-foot whoops and 1-foot deep chatter bumps. The clutches are heavily loaded getting on and off the throttle and the sled is much more responsive to double big bumps. The point/shoot ability is fantastic and leaves the stock clutch in the dust when accelerating on corner-to-corner tight river running where you can only achieve midrange speeds before braking. When the engine gets hot the clutching does not get lazy if the flyweight is correct. With stock clutching and the engine getting hot, rpm loss starts to happen and the engine response is slower.
Sled owners who have this kit are running about 8100 on their tach. The OEM tachs are reading high as the 600 engine is an 8000 rpm engine.
The S6X helix uses a blend of angles that are used in speed runs and drag racing.
Speed run clutching uses low degree angles.
Drag race clutching uses high degree angles.
When you look at the helix, you can see it starts very steep and smoothes out to a lower angle.
We know that:
1) Low angles produce great back shift
2) Large angles produce great up shift
I make this helix as a blend of both disciplines. The helix provides an angle that the sled "Needs" at the speed it is going. You punch the fuel, it accelerates hard...let off the fuel the clutches back shift quickly, you punch the fuel again, you accelerate hard. The clutches have a fantastic ability to grip the belt all the way to and past 1:1 ratio.
**NEW, Stock factory installed belt is a must.**
Supplied are DALTONPRO Ultimate Stainless Pins 14.5g ~ 25g. General feedback is to use approx 24 grams on clicker 4.
Success with 600 is impressive with around 23~24 grams of pinweight depending on engine fitness.
So far, most need about 23~24 grams of pinweight, a few are using up to 26 grams.
Depending on your engine fitness the 600 has responded better to other springs than the stock black. Some have required the Doo green or Doo purple secondary spring to straighten out rpms in the bottom end of the shift range.
What happens is with weaker engines the rpms are low in the start of the shift and as midrange speed increases, so does the rpms.
Rpms are climbing. When a tuner is using a black 160/300 spring they can goto a green 180/300 or right to the purple 225/300. The rpms pull straight right on from stop to full speed. Ive seen engines from 125 lbs to 155 lbs so this kit is easily calibrated to suit engine fitness. I like to change the secondary spring for improved results rather than change the clicker to a lower number and pull flyweight out. I like to improve the clamp on the belt in the secondary to build engine rpms on the bottom end and the tuner finds quicker throttle responce in addition to correct rpms.
To get a snapshot of your engine's fitness, cold engine, start let run for 5 seconds then kill engine, take 8 pulls at wide open throttle.
The present 600 "Trail" kit comes with:
1 Primary spring
1 S6X Helix
1 Pkg of DALTONPRO Ultimate Stainless Pins 14.5g ~ 25g
1 Manual
Can calibrate with stock gears, Purple Doo secondary spring PT#414 978 300, stock TRA ramp.
Just like the 440 excercises, once again testing compression in all of the engines, there are big differences in values from one engine to the next. The Test mule had 125 lbs compression, the twin sled "stocker" had almost 155 lbs compression. Did side to side running from these speeds 30mph, 50mph, 70mph to top end.
Did "running" side to side drag racing with two REV800's. One driver would hold his hand up while operating then throw the hand down and pin throttle to the bar. Everytime, the kit would pull away from the stock setup, but even more-so in the higher mph's and especially in deep snow.
On flat river running with hardly any snow (2-3") the Mule sled could not outdo the stocker by more than a few mph of around 104mph. Start to get some snow (4-6") on the ice, the S8X could hold a high mph longer.
...Deeper snow and the stock clutching is not even competition.
The angle of the helix near 1:1 ratio is smaller than most tuners are used to. This from my experience leaves capacity to gear up and still have a great amount of belt squeeze at the top to get a higher mph on flat low load surfaces. Leaves the capacity to gear down and maintain high mph in rough terrain, blanket snow conditions with the benefit of increasing midrange acceleration. We did not test with a taller gear. I wanted to test bone showroom stock. My gurantee that the S8X kit is a HUGE improvement thru the whole midrange for acceleration and backshift over stock helix and gearing.
I wanted to use the secondary spring that come with the sled and make a huge improvement over stock with little items as possible. I also gurantee that the owner will be light on the fuel trigger at speeds of 90mph running for long periods of time. You will find that there is barely any squeeze on it to run and maintain a cruising mph. This means better mileage. The stock setup you are more into the fuel trigger to maintain a high cruising mph. On a long trip when all sledders are driving the same speeds, the S8X will help to consume less fuel than stock clutch.
Because of my experience selling my S4X clutch kits, there are more novice tuners who just want to put a kit in and drive the sled. They do not want to know much about the system other than it will take minimum setup and usually they take kit to a friend to install it. Most guys do not even gap their new plugs. I have even been told of people trying to pry their belt off with a screwdriver. Because of this, I wanted to test with absolutely bone stock and touch nothing other than make sure brand new plugs were gapped at factory setting of .018". We never even tested with changing jet size.
We installed 1999 MxZx440 sno-pro shocks in the 800 to go beat it like a race sled on the trails. The suspension ability to suck up the bumps is increased several times. Where the stock suspension would bottom out to nearly breaking parts, the sled could now run with 440's on extreme trails. The sled could now actually run fast in extreme bumps and at high speeds so the clutches are heavily loaded getting on and off the throttle to keep from getting "death air". The S8X is so much more responsive to throttle position in heavy clutch loads over stock.
The point/shoot ability is fantastic and leaves the stock clutch in the dust when the sled has the capacity to suck up bumps. In it's stock clutching trim with experienced driver, the stock helix does not much help the driver sustain a rhythm to "track" an efficient course on extreme bumps when trying to run against the 440zx. The rpm loss is always there and takes time to catch up. The fuel is let off and got back on then the sled is low in rpm. This can be disastrous as may "case" a hill instead of clearing it. Since we put the Race shocks in the 800 sled, I now do believe that a 600 or 800 can keep up to a 440 in the twisty bumpy trail. Bad thing is though that the driver of a larger sled still only drives with one hand safely on the brake side handle. The fuel hand you cannot grip fully the handlebar for long as you would understeer off the trail.
Many sled owners who have this kit are running 8000 to 8100 on their tach. The OEM tachs are reading high as the engine is a 7850 engine.
The kit has been used for trail riding and sno drag racing. In sno drag racing, the kit clobbers the stock setup. More midrange than I care to elaborate on. The sleds we beat had either stock clutching or aftermarket kits. It was very hard to beat some sleds as thru analysis we saw these tuners had their chassis dialed in for holeshot to stay on the snow instead of digging a trench.
I knew most of the racers we were pitted against and most I consider are masters at tuning for snow. I have to say that a Renegade, Legend and Summit are absolutely the hardest sleds to beat on snow if their suspensions are tuned for this application. The differences in the longer track and placement of the rear swing arm and pivot arm on the non-sport sled is sometimes better for snow drags compared to the shorter skidframe on the sport chassis models.
This 800REV sled has some serious capacity with a little suspension tuning.
The S8X helix uses a blend of angles that are used in speed runs and drag racing.
Speed run clutching uses low degree angles.
Drag race clutching uses high degree angles.
When you look at the helix, you can see it starts very steep and smooths out to a lower angle.
We know that:
1) low angles produce great backshift
2) Large angles produce great upshift
I make this helix as a blend of both disciplines. The helix provides an angle that the sled "Needs" at the speed it is going. You punch the fuel, it accelerates hard...let off the fuel the clutches backshift quickly, you punch the fuel again, you accelerate hard. The clutches have a fantastic ability to grip the belt all the way to and past 1:1 ratio.
**NEW, Stock factory installed belt is a must.**
Not too much to say other than we took a lot of time with it and made several custom helix's to come up with one that loads the engine heavily at the start and has a useable angle for high speed running/taller gears.
The present "Trail" kit comes with:
1 Primary spring
1 S8X Helix
1 Pkg of DALTONPRO Ultimate Stainless Pins 14.5g ~ 25g
1 Manual
Use the stock gears, stock secondary spring, stock TRA ramp.