looking to get a few ponies out of my cbrf4 2000. Have done the suspension with penske and traxxion. took nearly 2 seconds with that alone after being stuck on times for 4 track days. Just did a full 2-brothers exst and it seemed to have a bit more mid range.. nice. Motor is otherwise stock with 20,000 miles. Will have a leak down test and freshen if needed. Lots of folks are saying milling the head and running race gas will realy wake up the f4.. Called Erion racing, they advocate to NOT mill head but rather go with the HRC head gasket that is thinner than stock.. seems like a plan..
any f4 guys out there????
The Honda motors seem to really respond well to compresion. I believe the HRC head gasket is about .010" thinner than stock.
To optimize a compression change by milling or thinner head gasket, don't forget to degree the cams back in.