some apex sleds are fast and some are not why?

[snowbeast]

I never really thought my 06 attak/apex was any kind of monster for top end speed,as it only would run 117-118 gps on glare ice,and around 110-112 gps on groomed r.r. beds. As some of you know i traded mine in mid season for the 07 rtx,and we stripped most of the goodies off,but my dealer in caribou,Maine has been loaning it out,in hopes of selling it,i guess,and every time when it returns whoever was riding it,exsplains to john my dealer whats up with this apex,what has been done,and he asks why not running good,and the driver exsplains no its smoking everything we have to run,5 other apex sleds of 06 and 07 and some other brands,guy stated it is 7 mph faster than the next closest apex on the same conditions,last weekend on fresh snow,guy stated it ran 127 speedo,and i told john thats about right,when i had my cut speedo gear in,it would read 110-112 and my gps the same,so what is the big surprise,both of our other 06 apex sleds run the same or even a little better,now the big guy who now wants to trade in his 06 rtx for my old 06 attak/apex shortie stated he was like 300# and loved my set up,and he is one who ran 127 at his weight,so i guess my old sled ran preety good,considering the rest of the pack of apex sleds only ran 120 speedo at best,but now my 07 rtx will not run that fast on ice,but real close on snow,so maybe i really dont miss it as bad as i thought,and they are still grooming in parts of the county for this up coming weekend,wow what an ending to a so so winter!!

 

[justinator]

I bought my 07 rtx from John as well. I traded my 06F7 for it. It was his demo model. Best I have seen on the speedo was 122 or 124 on hardpack. I never tried on ice. Sled will run prettty consistent though, it'll read 110-112 on the speedo in lousy #*$&@ conditions so I'm not complaining. I love this sled!!

Did cutting your speedo gear down make your low and mid speed more accurate too or does it screw up one to better another??

 

[Turk]

Luck of the draw. My 07 Attak was faster;quicker;better on fuel then my 06 Attak so I traded it off!

 

[snowbeast]

I bought my 07 rtx from John as well. I traded my 06F7 for it. It was his demo model. Best I have seen on the speedo was 122 or 124 on hardpack. I never tried on ice. Sled will run prettty consistent though, it'll read 110-112 on the speedo in lousy #*$&@ conditions so I'm not complaining. I love this sled!!

Did cutting your speedo gear down make your low and mid speed more accurate too or does it screw up one to better another??

Yescutting two teeth off works great,on low,mid,and top,but it does effect your milage,it will read low,but i can live with that.

 

[snowbeast]

Luck of the draw. My 07 Attak was faster;quicker;better on fuel then my 06 Attak so I traded it off!

Yup thats what i figured to, turk. I just hope with more miles my 07 will perform as well as my 06 did.

 

[justinator]

I bought my 07 rtx from John as well. I traded my 06F7 for it. It was his demo model. Best I have seen on the speedo was 122 or 124 on hardpack. I never tried on ice. Sled will run prettty consistent though, it'll read 110-112 on the speedo in lousy #*$&@ conditions so I'm not complaining. I love this sled!!

Did cutting your speedo gear down make your low and mid speed more accurate too or does it screw up one to better another??

Yescutting two teeth off works great,on low,mid,and top,but it does effect your milage,it will read low,but i can live with that.

Is the mileage just reading low because of the speedo being accurate though because if stock you rode 55mph for 2 hrs and racked 110 miles on the odometer but in reality if the speedo was off 10% and you really cruising 50mph then your true mileage was 100 miles and obviously the faster you average for speed the larger margin. 1 or 2 teeth off the drive gear. Not trying to hijack the thread.....sorry

 

[snowbeast]

I bought my 07 rtx from John as well. I traded my 06F7 for it. It was his demo model. Best I have seen on the speedo was 122 or 124 on hardpack. I never tried on ice. Sled will run prettty consistent though, it'll read 110-112 on the speedo in lousy #*$&@ conditions so I'm not complaining. I love this sled!!

Did cutting your speedo gear down make your low and mid speed more accurate too or does it screw up one to better another??

Yescutting two teeth off works great,on low,mid,and top,but it does effect your milage,it will read low,but i can live with that.

Is the mileage just reading low because of the speedo being accurate though because if stock you rode 55mph for 2 hrs and racked 110 miles on the odometer but in reality if the speedo was off 10% and you really cruising 50mph then your true mileage was 100 miles and obviously the faster you average for speed the larger margin. 1 or 2 teeth off the drive gear. Not trying to hijack the thread.....sorry

Yes two teeth 180degrees apart works good,speedo right on at all speeds,but odometer is off,at close to what you stated,but it keeps your milage down,and this speedo pick up gear is cheap,so if you want to sell the sled later on,get another stock one and it will be back to the old dreameter,my buddy did 5 teeth just screwing around with his and at 116 gps his read 34 mph lol,just some fun and cheap stuff you can do,and it is so easy to get it on and off.

 

[Riceburner]

Dyno Ray says break in procedure can amount to 3 hp difference. That should be good for a few mph on top. [ he recommends 3 good heat cycles before riding and then loading the motor well once you start riding it as I recall]

EFI calibration and proper synching etc could come in to play as well couldn't they. We also hear of differences in fuel consumption and it appears those burning more fuel are slower.

Not to mention that guys like you beast have no doubt checked all alignments, adjustable items etc to make sure they are perfect for what you are trying to achieve.

I forget the name of the member who was on here late last year who tested a number of small things as well and noted the effects of those changes. A couple of examples were the mid height windy I think was good for 2 mph more top end than the bug screen windy, clutching change was good for 2 or3 up top, windage plate 1 or two etc.

All these little things being set up perfectly add up.

Plus as Mike said above, we all know that there is also the luck of the draw. Some motors are just plain a little stronger than others for no apparent reason.

 

[1CrazySledder]

My 06 RTX stretched to 136 was WAY slower than my 07 Attak. I broke my attak in by drag racing on lake Gogebic least year. No heat cycles, just plain out dragging it down the lake. That sled rips. I'll be breaking in all my sleds that way from here on out.

-1CS

 

[welterracer]

I have checked all the alignments, along with several mods to make it faster..

Best ive ever seen was 115 on the DM in perfect conditions.. My old Rx-warrior would see 119 and i also saw 119 on my SX viper once..

I just lost 20lbs of FAT... hopefully that will make it a few MPH faster. LOL

 

[justinator]

I just lost 20lbs of FAT... hopefully that will make it a few MPH faster. LOL[/quote]

Thats the cheapest go faster technique anyways!!

 

[BA APEX]

noticed very little difference, if any, in TOP end on glare ICE.
ran tons of radar last yr and several different weight riders. no difference it pure top end. riders from 160lbs to 310lbs.
however if you have less than glare ice conditions or not more than 3/4 of a mile to get to very top then you will see differences in the speeds.

 

[snowbeast]

noticed very little difference, if any, in TOP end on glare ICE.
ran tons of radar last yr and several different weight riders. no difference it pure top end. riders from 160lbs to 310lbs.
however if you have less than glare ice conditions or not more than 3/4 of a mile to get to very top then you will see differences in the speeds.

BA i am not sure just what you are trying to say,i know you have a very fast apex,at least on ice,you have seen 120 plus,thats a couple more than i ever saw on my 06,but it would consitantly run 110plus on snow thats gps speeds,now i imagine your runs those speeds on snow as well,buy seeing it go.

 

[YAM182]

BA is saying you can get higher speeds running bare ice at a distance of 3/4 to 1 mile.Thats what BA has expierenced and I have also.
The pic below is both our sleds on Payne lake.
When BA did his 120 mph I filmed it and held the gun.
He was already at 119 mph when I raised the gun and started the camera.
Right before he went by me at about the 1 mile mark the gun ticked up to 120 mph.

How a sled is set up helps alot.
How you sit on the sled also helps alot.

Edit--The 4 runs of 122-124 mph my GT ran last year were when it had 600 miles on it,not even broken in yet.

 

[Srxspec]

From a guy who has been inside of a few of these engines and talk daily with people who have been inside them more often than me! There seems to be some slight variances in deck height and/or head volume. Just my .02!