gearing,clutching,hp=speed

[apexfx]

it seems that the stock clutching is pretty good,and also the gearing 24/38,the engine has a fairly broad power band,it looks like if you do not go over 10800 rpm you are still in the pwer band,if you could get the clutches shifted out and lower the gaering a bit that might help,the Apex has 150 hp and a 1 1/4 track,the 1 1/4 is great for hole shoot and hook,but not for top speed,in the passed I have done many tests,and there is only 2 ways for the most part to gain speed.More HP or a 1 inch track,1 inch track will gain you as much as 10 mph,once you get over 110mph you need a lot of power to go a little faster,on average a 150hp sled will do 115 mph,170 hp will do 120 mph,200 hp will do 125 mph and a 230 hp will do 128 mph.these numbers are on hard packed snow,you loose top end with a 1 1/4 track,to much drag.If you are looking top speed the best track is a Comoplast Chalenger track 1 inch,but you will loose hook,and mid pull,so if you are looking to beat your buddy in a long run get that track,if you are looking to beat him in 1200 feet keep the stock track.We have been testing tracks for over 10 years,also you may find that a F700 that has only 140 hp will have more top end than you,why,cause they have a narrower track.the speeds posted are on radar,the speedes posted hold true for Ski-Doo,Arctic cat,Polaris,Yamaha.If you have ever race a Vector,you will see that for the most part you will have 5-6 mph on him on top ,and both of you will get to 100mph at a bout the same time.

 

[87gtNOS]

I agree, except aboout the smaller 1" track not being as 'quick'.

This past weekend, on lots of snow, my Apex vs. 04 RX1 vs. SRX700...both other sleds having 1" tracks.
The SRX would walk me, the RX1 would hold with me. This is on powder on the lake, like 1+ foot of snow, some sluch underneath, top speeds I would see on my speedo was 100mph(my speedo pickup is cut one tooth).

The difference the 1" track makes is not noticable.

 

[SRXSRULE]

Your hp to speed theory dont work out. my old 98 SRX with 140'ish hp was clocked on a stalker pro gun at 126. And an F7 is fast because power to weight ratio, not just because the narrow track. ===SRXSRULE===

 

[SledFreak]

I agree, except aboout the smaller 1" track not being as 'quick'.

This past weekend, on lots of snow, my Apex vs. 04 RX1 vs. SRX700...both other sleds having 1" tracks.
The SRX would walk me, the RX1 would hold with me. This is on powder on the lake, like 1+ foot of snow, some sluch underneath, top speeds I would see on my speedo was 100mph(my speedo pickup is cut one tooth).

The difference the 1" track makes is not noticable.

Of course you would not notice in soft snow, but you would notice o hard packed snow or ice.

 

[apexfx]

The speeds were based on hard pack snow,2000 ft,no picks,on those conditions I have never see a 140 hp sled do 126 mph on radar,the best we have ever seen was 128 mph with a 240 hp sled.this is over 10 years of over 150 sleds.

 

[snowbeast]

The speeds were based on hard pack snow,2000 ft,no picks,on those conditions I have never see a 140 hp sled do 126 mph on radar,the best we have ever seen was 128 mph with a 240 hp sled.this is over 10 years of over 150 sleds.

We have some bad srxs around that are stock,but set up for all out top end radar running,i have seen the 01srx run 126 on the clock in about 2500-3000 bare ice,now this is not box stock at all,it is slammed 1/2" speed track,clutched and geared,and just the right amount of picks installed with a lube system,and another same condition 98 srx run 123 on the gun and now the guy who ownes the fast 01 has the apex er slammed and running a speed track,and he is at 123+ on the clock and he may have by now hit 125 not sure on that one,and there is a guy in ontario running a stock motor in the 03 f-7 at 130+ in 3000 ft. of course all set up for just that top speed. But in general you are very close about trail running sleds,to date sense i came over to yammi i had my 03 rx1 run 117 in 3000 ft gps on perfect conditions and have had my 06 attak with bare track run 114 gps on snow just before it blew its track,again!!

 

[suburban]

Easy now, the F7 that's running 130 may be stock motored but it is also running a proline suspension and 10" track. That track and susp on any sled would add 5 plus mph.

 

[ROCKERDAN]

I removed the ripsaw right off the bat last week and installed a new full clipped predator 1 incher,same as a mach track...this one has every 3rd clip has holes in it to hold ice....

with 20 miles on the sled my buds 800 mile GT jumped me outa hole,then after 30 feet i go by hime like hes standing still..and just keeps pulling ontop...we havent radared them yet but im guessing at leasst 4mph on top end if not more....

Im assuming this is all the track...or else his GT is just slow??..

Dan

 

[RED800]

i did a few adjustments to my rtx(bone stock) and raced my bro(he has attack) and my buddys sno-pro f7....my bro's attack crushed my rtx every time previous to yesterday...first race was at shoot out track in woodgate,loose snow conditions,f7(which is studded) jumped out ahead of me(rtx no studs) by 3-4 sleds lengths,1/2 way down, i blew by him like he was standing still,bro's attack no where in site...many races after that at a local strip and same result,f7 jumps out and 1/2 to 3/4 down im flying past him with ease..bro's attack no where in site.....my RTX pulls like a son of a beach now!! when it gets hard pack my rtx is only gonna get better,so if your getting beat by a f7 something is wrong with your sled,they have no chance against an apex

 

[snowbeast]

Easy now, the F7 that's running 130 may be stock motored but it is also running a proline suspension and 10" track. That track and susp on any sled would add 5 plus mph.

No the f-7 i am speaking of,has stock suspension that spenc used to achieve 131.9 that is quite a feat,for a stock motored f-7,all he has done is a speedwerk single pipe and air mod added,of course not trail rideable at all under those conditions,but impressive at any rate.

 

[Mighty]

red800 what adjustments did you make to gain that much of an improvement?

 

[welterracer]

I agree with red800

If a apex gets beat by a stock F7 there is something wrong with the apex..

My buddy has a very fast 05 SP F7 with Pipe mod and cluching... He is 50 lbs lighter than me and i still beat him by 1-2 sled lengths..

With the HP to weight ratio, he should be killing me.. but doesnt..

 

[pro116]

when it come's to f7's clkutching is everything.I have two buddies with stock exhaust they have ice pick's and 1/2 lug track's with the ecu reprogrammed and clutching only running 114-116mph in a 1000ft.Yes a stock f7 is slow but you get them clutched right and they fly,so do the piston's,lol

 

[RED800]

i fixed my belt deflection by adding shims,i had alot of excess shavings that kept my clucth open(dremmel works wonders) and my belt was sitting down in my secondary,also put in 3 shims and tightened my straps up one hole.i picked up at least 6-7 sled lengths...my rtx pulls so hard now i cannot believe what i was missing,my brother crushed me with his attack by 3-4 sled lengths and i had no chance in hell of catching him,now he's 3-4 behind me....no bullshit,he was absolutely amazed!!!...the only place im loosing is the holeshot,we were on 6-7 inches fresh snow with ice under it.f7 snp-pro has studs,i dont....about 300ft out my rtx is realling the f7 in very very fast.....i myself am amazed with how much i gained,but thats all i did to it,i just broke 400 miles yesterday...144 woodys in the back and i find it very hard for any sled to go buy it......

 

[MyOutdoors]

Very cool red, did you clean up the primary and secondary with a dremel? Do you have any pics? What hole are you in now with the lmiter straps...it seems some are different from the factory. Also what are you running for psi in the floats? Thanks. Craig