[farlsincharge]

I have a problem for you guys to try and figure out. A 97 670 summit with 145 pounds of compression both sides. Both clutches have been taken apart, cleaned, inspected, and had the stock springs replaced with new stock springs (purple/yellow, and beige).
Now as I understand it the primary clutch is the one that deals with rpm (spring controls engagement, weight determines peak rpm). The primary in this sled is setup stock except for the pins which weigh in at 13.8 grams and I have no idea what they are supposed to actually be but 13.8 seems like it would be light enough to really rev?
I want this thing to rev out at 8200 rpm at 6000ft on clicker 5, and right now it is reving about 7200 at 2000ft on clicker 3. Also I am running a factory tach which I know aren't that accurate but in the ballpark, but I have relocated it and in doing so have shortened the wires about 5 feet. Also the deflection of the belt is right and it is a new belt but a gates extreme.
The rpm testing was done on a flat road with about 2 inches of snow, abd the rpms hit 8000 spinning out on the ice as I started but then held 7200 the rest of the pull (power seems good and sled runs fine, plugs look good)

So my questions are these:
1. Shouldn't 13.8 grams be light enough to get me the rpm's I want, and is going any lighter okay
2. Did shortening my tach wires screw with the accuracy
3. Would the gates belt have that much of a bearing in this situation
4. Will going to a stiffer spring in the primary affect my peak rpm AT ALL
5. Is there something that could be wrong with the cluches that I may have missed, or even something wrong not clutch related

Any help is appreciated, I know there are a lot of smart people on this website and I apologize for my ignorance on the whole clutching subject.

p.s. I know the tach sucks but a digitron isn't in the budget till next year

 

[Thumbdoctor]

Are your RAVEs functioning correctly Summits from altitude have lighter springs than sea level installed. Order one OEM hollow pin and weigh it for a starting point. If you want accurate clutch testing results you need to install a fresh OEM belt then go after market for comparison. Tachs are generally 200 ~ 300 rpm higher than true rpm.

 

[farlsincharge]

Thanks Doc, I will pull my raves apart tomorrow and I have ordered the hollow pins (hoping they are about 11 grams). Just one more thing if you have a second, The spring I pulled out of my primary was about 1/4 to 3/8" shorter than the new one, is this normal?

 

[Thumbdoctor]

I checked the racing manual for the steel hollow pins and P/N 420429140 is listed at 10.3 grams. The OEM P/N for steel pins for your sled is 417004303 no weight info provided. There doesn't seem to be any high altitude kit listed for the Summit either. The V/Y spring for the primary is correct and should measure relaxed at 157.9mm (6.22"). The secondary beige spring preload should be 15.4 lbs. Your RAVE springs P/N 420239948 should measure 38.0 mm.

 

[farlsincharge]

Okay, so I cleaned the Rave's and they weren't that bad, and installed the stock pins 10.3 grams. The clutches are now totally stock with new parts and the engine runs strong. I am now revving 7800 rpm on clicker 3 at 2000ft and I want to be about 400-500 rpm higher than that. Any ideas on how to go about doing this, as I'm pretty sure my pins are about as light as you can get.