Port my current M1 single plane or install the RPM Air Gap?
It's not a drag car although it's been to a few tracks, its not an autocross car however I will do more of them in the future but what it must do more of is highway miles due to my rural location.
The Combo is a 422ci la, 11.2:1, stock RPM eddies, M1 intake, 750 BG, 242/[email protected] 109LS 105IC hyd roller, TTI 1-5/8-1-3/4" step header into 3" tapering to 2.5" on the exit of the X full length mandrel TTI exhaust. Lightweight aluminum flywheel and single disk clutch, manual trans 3.2 gear .068 OD and 3.23 rear gear.
The previous hydraulic flat tappet cam is very similar to the above roller cams specs and the engine idled easily at 800, vacuum was 8" to 10" at idle, at WOT vacuum fluctuated between 1 and 2". The combo had plenty of torque and throttle response was great, mpg a tick over 20 highway cruising with the M1 single plane. The M1 is just damn ugly inside, being a spread bore with the sharp radius into the front intake runners. I cannot stop thinking its killing allot of power, yet I like its exterior look and lower height for hood clearance. How much torque is the M1 down, is the RPM down on HP at 5500 to 6200 and by how much if at all? I don't see M1 dyno results let alone ported results to determine if porting it would be worth the money. I've seen the M1 is mid pack in the Motor Trend LA intake ranking. What are your thoughts and experiences?
My vote is RPM air gap for autocross and drivability.