Seems to me at the begining of the year when Dick started introducing the new Cooper QHP quiet pipe for the .45's , there was some discussion here as to lenghts being used in 40 mono's in particular. At the time, the weather was still fairly cool for our Northern members. The numbers being tossed around as I recall were in the 9 1/2 - 9 3/4 range with good results. My question to those of you that ran such a short pipe during the cooler months is- When the weather warmed in your area (summer) were you still able to carry such a short pipe ? and if not, were did you end up lenght wise in the hotter months ? Hull - motor and prop size before and after would also be helpful.
Andy .
i didn't run mine till about july. seducer sd3, purple head cmb, x450 and x450 barr cut, i think we got 56 on radar. ran the cooper and a cmdi parabolic 9 3/4 on both. both pipes run too hot for my liking want to try something else but don't know what yet.
Thanks Steve. Do you remember ballpark temps and humidity at that time of year were your at ? What nitro % are you using ??
Ive never been able to run the pipe any shorter than 10-1/8 to 10 1/4 range down here in Fla during the summer,or anytime for that matter. I cant figure out how your running yours so short with a like setup.I run a purple head cmb-x450/3 sbc 3.6 - or 3.4 and it runs out of prop. I played with a 452/3-bar cut and reduced and it hauled butt as long as the boat was scary loose. With the weather cooling down some here- humidity 40%- dewpoint in the 48% range- 65-70 degree days- Im wondering if I should start squeezing down on the pipe lenght some and try and pull the bigger wheel again ???
Im going to test in the am - the temps should be low 60's and low humidty and air density(for Fla) - suggestions ?
Thoughts?? comments??
After re-reading the old threads twice , Im still confused about were you guys are taking you actual measurement at- on the pipe end specifically. I measure mine from cylinder center-on the side of the case (not the glow plug) to the first apparent weld on the outside of the pipe- is this correct and acurate with your measurements ??
