pipe length of the cmb 90

[Darren smith]

i dont know if any one can help , but what is the the best pipe lengh to run with the cmb 90

thanks guys

regards

Darren

 

[BigChuck]

seeing as how you are .............running Dave's pipe would it not be best to as him???

 

[ids987]

i dont know if any one can help , but what is the the best pipe lengh to run with the cmb 90 thanks guys

regards

Darren

Darren, If it's the goldhead, and you're setting the boat up for OMRA racing, I'd start off at something around 13" - maybe 13.5".

It depends to some extent what prop you're using - and how much nitro.

When I ran a 90 gold top in a Magnum, it wouldn't reliably come back on pipe much shorter than that. Going up from 10% to 20% nitro helped give it more torque to stay and come back on pipe - especially when the pipe got hot. Gets pricey when you need almost a gallon of fuel for a half hour race though.

The engine shouldn't be so heavily loaded in a Sigma, so you should be able to go a bit shorter when you've got it running well. Always better to start off on the long side of a good setting. It makes everything else less critical.

Ian