kingtigg
New member
Current setup:
Primary: Yel/Sil/Yel, 8DN-20s, 4.5g in both holes.
Sec: grn wound to 80, 54/44 helix
Me: ~175lbs...
Off the line and mid-range is FANTASTIC.
But there are 2 things id like to correct:
1)The machine seems to "top out" around 130kph with a max of only 140kph at a WAY high RPM of ~8800 according to tach.
2) backshift is a little slow...about 1s before RPMS get up where they should be.
Anyway, I understand adding weight to the tips would be the best thing to do, but I cannot get any larger rivets...AND...wouldnt this make the backshift even slower?
The buttons on the secondary are original and most likely need replacing, is there anything on the primary other than rollers that should be replaced as well? Would this help the top end?
I don't believe the sled has been geared down...and I am going to check to ensure I am getting full shiftout as soon as I can get into the garage again...
Any other obvious things I can/should look at or do?
Thanks!
Primary: Yel/Sil/Yel, 8DN-20s, 4.5g in both holes.
Sec: grn wound to 80, 54/44 helix
Me: ~175lbs...
Off the line and mid-range is FANTASTIC.
But there are 2 things id like to correct:
1)The machine seems to "top out" around 130kph with a max of only 140kph at a WAY high RPM of ~8800 according to tach.
2) backshift is a little slow...about 1s before RPMS get up where they should be.
Anyway, I understand adding weight to the tips would be the best thing to do, but I cannot get any larger rivets...AND...wouldnt this make the backshift even slower?
The buttons on the secondary are original and most likely need replacing, is there anything on the primary other than rollers that should be replaced as well? Would this help the top end?
I don't believe the sled has been geared down...and I am going to check to ensure I am getting full shiftout as soon as I can get into the garage again...
Any other obvious things I can/should look at or do?
Thanks!
what happens to the tach when you take off from a dead stop, does it rev smoothly up to 8800rpm or does it go up to 8000, then stay there for a short while and begin to climb?
kingtigg
New member
The RPMs jump to ~8000 and rises nicely from there.
does the tach lose rpm anywhere in the upshift? It would seem to me you need more tip weight, you can simply install a washer on the tip rivet. Have you tried to loosen the rear secondary spring tension? you might be able to run it at 60-70 and this will let it run more mph up top, but it comes down to if you can control the shift with the helix start at 54, thats kinda steep.
kingtigg
New member
yeah, i figured it was kind of steep too..
no, the rpm continually rises throughout acceleration.
i will try playing with the wrap within the next week and post results back here.
I never really thought about using washers...I guess I could always try that...im just worried that if I add much more weight then my upshift would be too fast with this helix...
buttons and/or bushing wouldnt play a part in this would they?
Thanks!!!
no, the rpm continually rises throughout acceleration.
i will try playing with the wrap within the next week and post results back here.
I never really thought about using washers...I guess I could always try that...im just worried that if I add much more weight then my upshift would be too fast with this helix...
buttons and/or bushing wouldnt play a part in this would they?
Thanks!!!
kingtigg
New member
ok, i went out and played with the clutching yesterday.
my original wrap was at 90!...i lowered it to 60 and took out the screws in the secondary that adjust the width since my belt measures about 1/2-life left and needed to be adjusted to sit higher.
I managed to hit about 170kph on a packed road....MUCH better...but I was still overreving to 8800 rpms throughout the shiftout!
I am going to add heavier weights by using washers in the tips...i figure an extra 1g in each weight should do it...or should I go higher....1.5g each?
Thx again!
my original wrap was at 90!...i lowered it to 60 and took out the screws in the secondary that adjust the width since my belt measures about 1/2-life left and needed to be adjusted to sit higher.
I managed to hit about 170kph on a packed road....MUCH better...but I was still overreving to 8800 rpms throughout the shiftout!
I am going to add heavier weights by using washers in the tips...i figure an extra 1g in each weight should do it...or should I go higher....1.5g each?
Thx again!
Rambunctious
New member
I have been chasing the same exact issue with the low finish angle helix ( 54/42)
I have 5.5g tip bolts ( someone in the industry sells them, can't think of it right now) and still over rev on top end
I ran my stock 47 this last weekend and with green at 90 wrap I was right at 8500.
I bought a 53/45 and am waiting for it to arrive
I may also try a 51/47 . my theory is this will shift fast for the first half shift out and then shift sufficiently , but not too fast ( with 47 finish) to keep to 8500 instead of the 42 finish over reving
just my observations
Ramb
I have 5.5g tip bolts ( someone in the industry sells them, can't think of it right now) and still over rev on top end
I ran my stock 47 this last weekend and with green at 90 wrap I was right at 8500.
I bought a 53/45 and am waiting for it to arrive
I may also try a 51/47 . my theory is this will shift fast for the first half shift out and then shift sufficiently , but not too fast ( with 47 finish) to keep to 8500 instead of the 42 finish over reving
just my observations
Ramb