just tuned a 13B p-port using turbo II rotors. dynoed 242rwhp. engine is running a holley 650 cfm carburator with a custom intake manifold to except the holley 4 barrel. engine is built for ALOT of nitrous injection, reason why I used the low comp. rotors. I didn't get a chance to give the car a nitrous shot on the dyno, it was 7pm and the p-port was headers open loud as ****!. engine made power all the way up to 10,400 rpms. I Loved the way this p-port pulled up the rpms under a load right after 7k rpms. shot up like a rocket. not bad for a carbby and ignition timing set retarted for nitrous.



We will be testing this customers car very soon at the drag strip with nitrous. Looking to run 9.50 or better @ over 140mph. Is a 1/2 chassis tube race car.

 

nice. so when can we go see all this cars and your rx3 make some passes?

 

What did you have the timing at? What power would you expect without retarding the timing?





I've got sort of the same thing, pport on a 3rd gen rotating assembly, but fuel injected with a Haltech and M&W ignition, so I don't need to run the ignition retarded all the time. Also going to use the nitrous progressively.



Keep us posted on how big a nitrous shot you use!

 

timing was set at leading 10 deg. BTDC trailing at 5 deg. BTDC.. Power without retarding timing I would say 275 to 290rwhp leaning out the fuel mixture a little. a/f was at 12.8 12.9 If tuned for all motor horsepower, It could reach the 300rwhp mark putting the air fuel mixture to 13.2. you have an advantage. 3rd gen rotors are 9.0 to 1 compression. I was using 8.5 to 1 comp.



nitrous jetting it currently has is a 250shot.. using atkins 2mm apex seals. we will be testing saturday and sunday at atco raceway

 

Im using the atkins with the cryo treatment

 

That's good news, thanks.



Have you run 250+ nitrous jets much before? What kind of power limit do you expect when it comes to nitrous jetting?

 

Yes I have used 250hp before. power limit not sure. last customers race car I tuned with a 250hp shot ran 9.0@143mph with a 13B bridgeport.. car tipped the scales @ 2000lbs

 

1971 datsun 1200 model called MPH Racing. 13B bridgeport on a holley 650cfm carb. Ran 9.0@143mph stands as best time on a bridgeport engine in the nation. this was 3 years ago.

 

first nitrous run. 13B runs 9.9 with some minor problems. more test and tunning coming soon.

 

i was there. will be a fast car once its completely sorted out.