Great points guys. And nope can't get it to bury the speedometer, even when it was stock, and even now that I can get it to hold 8500 with green spring wound at 70. Not sure exactly how long of a run I did to achieve top speed, close to a mile I would say.
Maybe my tachometer is a bit off and that's why when I was revving at 8800 I received greater top end speed. If the red spring at 80 held a solid 8200 with no belt slip, maybe I could wind it to 90 without belt slip to try and up my rpm? Or even the green at 80, being that it held 8500 at 70, because my tachometer could be reading too high.
Maybe my tachometer is a bit off and that's why when I was revving at 8800 I received greater top end speed. If the red spring at 80 held a solid 8200 with no belt slip, maybe I could wind it to 90 without belt slip to try and up my rpm? Or even the green at 80, being that it held 8500 at 70, because my tachometer could be reading too high.
SRX tack pretty accurate. I added a 5.5 gram nut and bolt to tip while using a 51/43 pioneer helix that I use to be revving 8700. I have 5.9 nut and bolt for you to try in tip but you running to shallow finish angle.
Change helix
Change helix
what other helix you have?
Hey Tom the finish angle is essentially 53 or 54 by other manufacturer's standards. Turk did a test on this and that's why he recommended the 48/40 advant edge with this setup, it's like a 54/44. I think I might settle with green at 70, my rpm was spot on, just couldn't seem to get past 115 mph. Not sure why if rpm is in the sweet spot and holds there.
Is gearing stock? Can you verify? drive belt is in specs?
If clutching is good and not getting the mph, something else has to be off
If clutching is good and not getting the mph, something else has to be off
Yes stock 23/38 gearing. Everything else is stock to my knowledge. Green at 70 and my rpm was spot in. If my tachometer is off, maybe if I go to 80 with the green, my rpm will raise, and if my speed does as well I can confirm the tachometer is off. However, I never knew the peak rpm that yields the greatest hp raised when your pipes heat up. Tough call. However, 108 mph speedometer in 1/4 isn't too bad is it? Would like to see more top end, power seems to be there. Could try a new belt.
What track are you running? Anything over 1 inch will scrub mph.In my experience more spring tension raises rpm.
You should be hitting 8300 out the hole for peak torque curve.
You should be hitting 8300 out the hole for peak torque curve.
Stock track with 144 studs. Right it should raise rpm if I go to 80. Since with stock clutching I was revving at 8800 and got a better top speed than with my current setup at 8500, maybe my tachometer reads higher than it actually is. In which case going up to 80 may improve speed based on Macheater's theory. Could work! Just trying to get my top speed back is all, I'm sure if I wrapped the green spring at 60 and tuned the primary around that I could achieve a greater top speed. Would like to leave the primary alone, it works well, may have to revert back to green at 70 and eat the 3 mph!
Hope you get it fixed. Right now you looking at getting beat by a SRX 600 or SXR 700.
Please post results of clutch tuning
Please post results of clutch tuning
staggs65
Moderator
rpm = speed to an extent. the extra speed was from over-reving. being in the "sweet spot" as you call it lets you get the most speed/acceleration in a set distance that your clutching/gearing allows. being at peak HP just allows you to pull more clutching and gear in said distance but in the end speed equals engine rpm and gearing. your tests need a little more control than a "long run"
It's a strong runner, I beat an 04 RX-1 3 out of 5 times in a drag race. Not sure exact distance, probably half a mile. I figured 118 on speedometer would be respectable for a trail setup. And 108 in a 1/4 mile seems decent too. I'm sure with 8bu-10 I could do much better, but 8dn-20's work well, just wish I could bury that speedometer!!
staggs65
Moderator
I've got a few sets of bu-10s if you'd like to try a set to see. not for sale though, but you can try for free. pick up and return is on you, you know where I'm at.
Yeah staggs for testing I have cones set up for a 1/4 mile. When I do a "long" run I take a trip out to a nearby lake and just run it at WOT until my speed stops increasing, not sure the exact distance but I'd rather not hold it wide open for too long anyway. Yeah I always thought more hp more speed, figured I would lose speed if over revving. In that case I'll try green at 80 for sure. However that should hinder acceleration slightly as I will no longer be at the proper rpm, but raise top speed? Bit of a compromise I see, Arghh.
Hey thanks for the offer staggs, I think I'll just stick with the 8dn-20's for this year, crappy winter as it is. Probably going to go up north with my buddy and his dad, just trying to get my clutches dialed in before then so I can keep up to their 1000 4 strokes on top end, trails are like highways they said. My whole original setup with green at 70 that I posted worked great, 115 top end just seemed a bit low. Is that uncharacteristic of an SRX? Would it keep climbing after a mile?
YAMMIEGOD3:16
Active member
SRX TACHS ARE VERY VERY CLOSE. I COMPARED MINE WHEN I DYNOED TESTED MY 2000 SRX. FREAKING THING WAS RIGHT ON. DID SEE ANOTHER THAT WAS 200 HIGH. 3:16 (yammie tony)
staggs65
Moderator
only gonna climb as far as your gear and rpm allows. pm me an email address I can send you a gearing calculator that shows you theoretical speed for rpm/gearing/shift ratio
YAMMIEGOD3:16 said:
I have tested/compared my 2002 SRX and my 2 99 SXS tachs with a digital tach I have and they have been very accurate...unlike the old POLARIS INDY 600/650 tachs usually over indicated by 200 - 300 RPM at 8500.
Bob
Thanks PM sent. When I set the red spring to 80 with this setup my track seemed to ratchet under hard acceleration. Doesn't do this with the green spring at 70, although will test this at 80. Is it because the belt is being grabbed harder, should track be tightened further even if it doesn't ratchet when I go back to the green spring? Thanks!!!
sideshowBob said:
Thanks, then Staggs is right, hp doesn't mean everything with regard to top speed, it's gearing and rpm that matter! Which agrees with my testing when I got 3 mph greater @ 8800 rpm as opposed to 8500 rpm.
staggs65
Moderator
LaPorte429 said:
it's not as simple as that, HP does matter as long as you're pulling the most gear/clutching that the HP will allow in the distance traveled. clear as mud right.