my mods are 3200 stall 3.783 cc306 pretty much full weight madz28 tune shift at 6600...
in the 1/8 mile my mph is almost 86...in the 1/4 i was 108...doesnt that seem a lil low for a cammed car? when i set up my rockers is was abour 5/8 past lash but im thinin of backing them to 1/4 or less bc my oil pressure is 80psi at 6000...any opinions

 

Low mph, nope. Your car weighs almost 3600lbs, and there are also other factors. Traction. And when did you let off at the end of the quarter? The timing lights for speed go the last 66 feet to the finish line, so you may have let off? Who knows. The track can be slower one day then the next. Elevation and air quality play a part too,..

 

Id back them till they tick and to a 1/4 turn. My friends CC306 auto camaro turns 110mph but his car is only about 3300lbs race weight. Mine is a CC306 car also but Im running a stick and they tend to be a few MPH faster per given e/t than an auto. My best MPH 1/8 mile MPH has been 88.5 and my best 1/4 has been 112.4mph but I generally average about 111.5mph. Mine is also about 3600lbs race weight.

Jeremy

 

well my 60' on that run was a 1.73 or so..on m/t drag radials ii spun about 10 feet...i was jut wondering i think ill readjust them anyways...

 

My 60s are only in the 2.00 range. But my car dead hooks then boggs because my horrable gear ratio. My friends car pulls similar 60s and turns 110mph.

Jeremy

 

when i said "my friends car pulls similar 60s" i ment they were similar to yours. In the low 1.7 range.

 

well my run after that was a 1.64 60' but i ran into obd1 high stall problem..otherwise id have more number to compare...

 

what do you mean OBD1 high stall problem??

 

wont shift to 2nd at the track..in an automatic with a stall

 

Ahhh. I didnt know that was a commen problem everyone ran into. Two of my friends are having that problem but I just though it was becuase one of them tunes the others car. Does yours just beat the out of the rev limiter?

Jeremy

 

yea...bam bam bam bam..on the street ts fine...you need to get it switched to obd2 most likely...

 

Your wasting your time spinning it to 6600 RPM's ...

Your on stock heads. Im sorry, but MadZ28 did a bad job with that one if he set the shift points that high for a stock headed car. Stock heads kill power at 6000RPMs and you shouldnt be shifting ANY HIGHER than 6300ish.

That oculd be half your probilem right there. Over revving it. Your not staying in the ideal section of the power band. Also, your lash is too tight. On stock lifters, with 7/16's studs, you only need a little more than 1/4 turn past. On 3/8" studs, you would be best with about a 1/2 Turn.

 

Right. Tell that to all the people running 11s on stock heads, shifting at 6700+.
If you shift where your car makes peak power, you will have lower track times. Ideal powerband is right, except that if you shift at 6000 where your peak power is, after a shift, your RPM will drop UNDER your power band and it will take longer for the car to get back into the power band than if you shifted ~600 RPM later than where your peak power occurs, which for a 306 cam on stock heads is ~6000 RPM. Solution - either don't go with a cam that needs to be reved this high, or shift where it should be shifted -- 6600-6700 RPM.

 

Also, the power drop is not caused by stock heads. If you put ported heads on a 350, it will still drop at 6000 RPM for a 306 cam.

I have two videos showing a 3 MPH and 4 tenth difference between shifting at 6000 RPM and 6800 on a cam similar to the 306 which also peaks at 6000 (233/239/112 .569/.577 lift). I will post them when I find them.

 

Amen brotha! I have the CC306 and I know what your talking about first hand. Im dealing with a 6-speed car with stock heads. But a power band is a power band no matter what trans your using. I shift my car as 6500-6700rpm and thats where I get my best mph. I know you know what your doing and anyone who questions that doesnt pay much attention to the threads. my $.02


Jeremy