RCU Forums - View Single Post - 90 jett LX full pipe stinger diameter
View Single Post
Old 12-14-2017, 03:37 AM
  #7  
1QwkSport2.5r
 
1QwkSport2.5r's Avatar
 
Join Date: Oct 2006
Location: Cottage Grove, MN
Posts: 10,414
Received 76 Likes on 69 Posts
Default

I just couldn’t ever compare a ringed OS to an AAC Jett. Regardless of what makes more power, piston seal is paramount. AAC trumps ringed any day in my book.

FWIW - I run boats and trucks too. I run my truck engines at 34/60 crank timing and bored crank, 120 transfers,
122-127 Boost, and 170-182 exhaust.

Most of the engines I’ve measured (surface, air, and marine) have had at minimum 118 for the transfers - many in the 125-130 range. Boost is no different. Where I see most influence is in th crank timing, crank bore, and exhaust timing. If the transfers get too much higher than 130, you’ll likely get some blowback through the transfers.

I just checked my notes on my ringed ST S90K; Exhaust 150, Transfers 124, Boost 120, crank 32/50 (198 by my sleep deprived brain)

Last edited by 1QwkSport2.5r; 12-14-2017 at 03:52 AM.