Port sizing for 3.0 race motor
 

Trying to finalize some details for my rally car and wanted to help solidify some port sizing. Current specs so far are 3.0 95mm JE 10.8:1 pistons, 46mm itb's, twin plug, arp rod bolts and stock rods, and more than likely DC60 cams... I was planning to port the heads to 40mm intake and 38mm exhaust...

Thanks
LP

Port shape is more important than size but your formula is pretty close.
We built 3 rally engines for a series in Europe with almost identical specs (10.4 rather than 10.8). One actually learned to fly winning the championship the first year.

http://forums.pelicanparts.com/uploa...1389671628.jpg

http://forums.pelicanparts.com/uploa...1389671743.jpg

Good looking trio... My 911 won't be ready for the Rally America season opener Sno*drift in two weeks, but I will be flying in my old open class mitsu. I hope to have the 911 ready by late 2014. Oh and my wife is co-driving!

http://forums.pelicanparts.com/uploa...1389673544.jpg

Which # do you have for the VR4? I had #1974 (white like yours) and sold it off to Connecticut about 9yrs back. Heck of a sleeper with a ported o2 housing, 3" turbo back and the frequency valve bleeder mod.

Im pretty sure its #241... I sold it a few years back, but am driving it at Sno*drift in two weeks... Car made 300hp 360tq on 34mm turbo restrictor @ 18 psi and overall a good rally car despite a slow steering rack and crapy ratios for a restricted rally motor.

PRS rally car - a set on Flickr

Just flipped through your Flickr album - gorgeous build. I used mine for commuting and time-trial ice racing with long term plans/pipe dreams to build out as you did. One trip to a 1/4 drag in Quebec and killed my second gear synchronizer... that's when we decided to part ways.