How many grams of weight?

FrostBite2010 · Dec 16, 2011

My 2010 M8 is pulling 8450rpm with 71.5 weights at 0-3000ft elevation.

I was thinking of buying some 09 M8 weights as they are slightly heavier.
I am assuming...that these weights are the same as the 2010 but different grams. MDS weights are not an option as I am running an RKT secondary and already tried this combination but was unable to maintain consistent rpm's. I am very satisfied with the way the sled is running even at this rpm range, I just feel that 8450 is a bit much.

I will entertain other weight options but feel the cat weights work well with the RKT secondary.

How many grams of weight do I need to add to get to 8150-8200rpm?

09 Weights
73g
75g
77g

06m7 · Dec 16, 2011

it wouldn't be all that crazy to try a 060 belt if u are running a 046 i run the same alt as u and that seems to help

FrostBite2010 · Dec 16, 2011

Perhaps...

I get good performance out of my 046 belts right now so I wouldn't like to switch. If anything I would rather go to a cheaper belt, not more expensive.

I have considered the Carslile XS817. I have heard that they drop rpm's. Does anyone have any experience with this?

The only reason I would switch belts is for the warranty, paying 10 bucks to replace the belt is far better than paying $70 for an 046.

0neoldfart · Dec 16, 2011

Re belt / weights

The 73g cat weights should work for you. Never used an Xs817 on M8, but tried two on my M1000 - didn't last very long, and both times they exploded without warning. I would rather use the 046 belt then replace a crank or primary due to a belt failure. Just my humble opinion.

Camo-toe · Dec 16, 2011

I would say 75 grams, on average 1g=100rpm. The 73g from 71.5 would only drop you to 8300rpm where 75's should pull you to 8100 in the sweet spot.

Are you running a straight 36helix now? another option for low elevation is a 44/40.

Bocephus · Dec 16, 2011

newbee question....

changing the helix doesnt have anything to do with changing the RPM does it?

JasonAK · Dec 16, 2011

FrostBite2010 said:
My 2010 M8 is pulling 8450rpm with 71.5 weights at 0-3000ft elevation.

I was thinking of buying some 09 M8 weights as they are slightly heavier.
I am assuming...that these weights are the same as the 2010 but different grams. MDS weights are not an option as I am running an RKT secondary and already tried this combination but was unable to maintain consistent rpm's. I am very satisfied with the way the sled is running even at this rpm range, I just feel that 8450 is a bit much.

I will entertain other weight options but feel the cat weights work well with the RKT secondary.

How many grams of weight do I need to add to get to 8150-8200rpm?

09 Weights
73g
75g
77g

What did it pull stock before the RKT Secondary? Do you have a pipe kit on it?

FrostBite2010 · Dec 16, 2011

Several things...

BDX DD Lite, BDX Titanium bolts (engine and chassis), BDX Lite Recoil, BDX Lite Brake Rotor, BDX Oil Elim, BDX Intake, SuperQ can...lots of lightweight mods. I started out with a straight 38deg helix and it was a significant gain, but I toasted that helix when the retaining bolts came loose. Now I am running 40/38p. I can't say for sure where it gained the rpm exactly, but from completely stock running 8200, I added the bdx intake and superq can and gained 150 rpm, so everything else added up to the extra 100 rpm. As cheap as they are I think I will order a set of 73's and 75's and try them both.

Makes it pretty simple if its 100rpm per gram.

Apparantly I need to make an order for ice age rails as well as I bent the ever loving sh!t out of my rails today on about a 75ft drop :face-icon-small-sho. Landing was perfect, and I am not running any wheels on my kmod skid. They were stock rails btw. It didn't bottom out so maybe they need some more valve work :face-icon-small-con

acm8 · Dec 17, 2011

how many grams of weights?

I would recommend 75 grams and ordered a new spring in primary, then speed will increase when the spring loses tension.
You can also try slowing the spring a little in RKT.
I use titanium spring 122-285.:first:

Search

How many grams of weight?

FrostBite2010

Well-known member

06m7

Member

FrostBite2010

Well-known member

0neoldfart

Well-known member

Camo-toe

Active member

Bocephus

Well-known member

JasonAK

Well-known member

FrostBite2010

Well-known member

acm8

New member

Similar threads