New Top Speed

[Macheater]

I was always in denial of how dated my Attak was becoming until I purchased my Winder.
The Apexs are still great sleds especially with the numerous updates most of us have done to them, but they are not in the same league as the newer modern chassis sleds.
I kept my Attak but it just sits while I ride my Sidewinder unless riding with my wife as then she rides the Winder and I ride my Attak.
All good things eventually do come to an end.
JM.02c

Yea Bob you hit it on the head. I think I've been in denial as well. With all the numerous mods and changes I've made, I do believe the sled is better in every way than when I purchased it. But, its really hard for an individual to keep up with the newer technology that the factories are putting out. Especially with a 15+ year old chassis.

I've begun to think about what I want out of my next sled. I still love HP, but, at 54, comfort and ride is becoming more important than speed. Especially when the rides are longer and the trails are beat-up. I like the cornering of the lower slung chassis as opposed to the taller more bump oriented sleds, provided the machine has decent suspension. The longevity is also becoming less important as I don't put in any where near the miles I used too. So going back to a 2-smoker might be a better fit.

Dunno, may have to wait and see what's available for next season.

 

[Macheater]

I'm not defending the apex but you know I'm a ape lover. For me the SC sled which uses the stock tank but having a performance suspension like the ZX2 made the sled so much more fun to drive. Its heads and tails ahead of the mono. THEN I got the turbo, which makes a significant change, moving the fuel back, this is CRITICAL IMO. I think the 'wooped feeling' from riding a ape is where the fuel sits stock. After I corner balanced my sled and focused on matching a pro ski weight (135lbs - see my garage thread if your curious on this) the sled drove easier then any ski doo I rode (all my buds have doos). Even they couldn't argue that. It was amazing. Not trying to sway you on saving the ape but IF you think you want to try it, look into a doo XP tank and seat combo. It saves significant weight and moves the fuel weight to a better location. Every new sled has the fuel under and behind the rider. Looking back if I had to rank the effects from 1-10. I would say the ZX2 was a 7/8 and the fuel tank was a STRONG 10. I actively searched for whooped out trails, it was amazing how the sled would skip and hop seemingly effortlessly over them. Now this is performance riding/driving, I was not sitting on the seat and trying to cruise over them like a cloud, that would be M20 air territory. I was riding it like I stole it with a huge smile the whole time. I felt a XRS 850 was a lumber wagon in the same trail.

Just my $0.02 keep in mind this is a 330hp, custom suspension, sled ultra light compared to stock. Doesn't apply to a stock suspension, and weight sled. Good luck!

As I said, still weighing my options. Was thinking about swapping out the entire rear suspension with possibly a RTX Winder rear skid, or a Doo skid. But, of course I'd be experimenting, so there are no guarantee's, and at the end of the day, I'm still on a 15 year old sled.

I agree with you about load and where its placed etc, just don't have the desire to keep modding an older design. I'm already at the point where I would get more money out of parting the sled as opposed to selling it as a whole. Its really hard to consider parting out a perfectly good sled.

 

[kinger]

I hear ya. If your impressed with a 600 doo it may be your riding style has changed and something new may be a better fit. All depends what you want out of the ride! Myself I'm still on "I want the sled to try and kill me" mode A boosted apex is always trying to kill me and I love it LOL.

 

[Macheater]

I hear ya. If your impressed with a 600 doo it may be your riding style has changed and something new may be a better fit. All depends what you want out of the ride! Myself I'm still on "I want the sled to try and kill me" mode A boosted apex is always trying to kill me and I love it LOL.

Sick!!!
I used to be like that. Not anymore.

 

[Macheater]

Ok, now that I've had several days and a long ride home to think about things, I believe I have a reason for the lack of improvement in my top speed.

So, for years now I've been running Ulmers clutch kit set to his specs. It always shifted at about 11,000-10,800 depending on conditions, when the sled was stock or slightly modded. If I nailed the throttle, it would immediately hit about 11k and slowly drop to 10,800 or so on a long run. So, a year ago when I added the Yamacharger along with the ported head, now its shifting at 11 grand.

Now according to my dyno sessions, I'm making peak power in the 10,3-10,4 range. So I started adding washers in an attempt to get my shift speed down from 11 grand to 10,400. I haven't added enough weight yet as I'm still shifting out at about 10,600.

So here's where things get interesting. On subsequent runs I'd watch the tach and as I approached 125 mph, the rpm's would slowly drop from 10,600 to 10,500 and stay there. Previously, before I started adding washers when the sled was much closer to stock it would drop to 10,800 at top speed.

So now it would seem that I can attain the same speed but, at a lower rpm. This would seem to indicate that the over-driven primary may be doing its job. If I can run the same speed now at 10,500 vs previously at 10,800. But now that the clutch is over-driven and possibly shifted out all the way, the only way to gain speed would be for it to over-rev. Since it has peaked at 10,400, it may be starting to make less power when it needs to be making more to continue picking up speed.

If with my current setup I could pull another 300 rpm, (back to 10,800) this would give me an additional 4.6 mph. Which is about what I was expecting to gain.

If my speculation is correct, the only way to go faster in the same conditions would be to gear it taller to run max speed at 10,400 (peak power) and hope it has the power to pull the taller gearing to a higher speed.

Thoughts?

 

[sideshowBob]

I have had little luck gaining speed by installing an overdrive clutch. As your belt speed goes up and the shift ratio goes beyond 1:1 your hp being transferred to the chain case starts to drop dramatically.
You are better off to gear for the max speed you realistically think you can achieve at a 1:1.
JM.02c

 

[Macheater]

I have had little luck gaining speed by installing an overdrive clutch. As your belt speed goes up and the shift ratio goes beyond 1:1 your hp being transferred to the chain case starts to drop dramatically.
You are better off to gear for the max speed you realistically think you can achieve at a 1:1.
JM.02c

I'm not disagreeing but, it would seem that the road to higher speed would be taller gearing. I'm going to break out the calipers to see if it really is going beyond 1:1 and if so, by how much.

 

[Stubbs]

Bob beat me to it. Lol
Overdrive isn’t all that efficient, and needs perfect conditions (read: very low drag) to work at all. Unless you are geared very low, the odds of shifting into overdrive on snow are very very low. Like Bob said, the best top speed will be found by gearing the sled to a theoretical top speed at 1:1, while you keep your Engine at RPM for best power. You’re observations this week about lower RPM and the relative speed staying the same make perfect sense.

 

[Macheater]

Again, I agree, but I still believe that the clutches are beginning to overshift. The only way to run the same speed at lower rpm. I am geared shorter than stock but, only by a little bit. Gonna actually measure the belt od on both sheaves to see EXACTLY where things stand.

BTW my testing has been done on an icy road, not hardpack. But not PURE ice either.

 

[Justin W Wiseman]

Yes, the one I use is called Speedometer 69.
Download for free from google store.
Fairly straight forward to use.

Just downloaded for races tomorrow.

 

[Justin W Wiseman]

I am usually on my Winder now but my Attak would always beat the 850 Renegades I ride with in a drag race and top speed.
I have run a RipSaw 2 and now an Ice Attak with no significant difference on top speed, but the Ripsaw 2 was definitely better off trail...I actually regret removing the RipSaw 2
Rpms are always consistent.
Pc5 ignition module
Pc5 fuel controller
PC Autotune
Pod 300 for data logging ect
Stock exhaust
ect ect

 

[Justin W Wiseman]

How many feet were u racing?

 

[Macheater]

How many feet were u racing?

Not racing, and don't know how far. I would estimate 2,000+ feet. Just a long stretch of flat road and a pinned throttle.
If my tach and Hurricanes speed calculator are correct, I was in OD at .97. I plan on going back to stock gearing at seasons end and trying to get a little more OD ratio out of it. Maybe as much as .95.
Rockerdan had a great post when he had his Apex and went 120+, he was well into OD.

 

[rtx moose]

fix ram air and overdrive on my 07 RTX

 

[rtx moose]

fix ram air and overdrive on my 07 RTX