FullBoostAhead

i wanted to know form everyone running a Ls Vtec turbo setup or anyone who knows about them, what are the pros and cons of FI ls vtec. it has lower compression than a B18c1 block so i could run a higher boost and it still has the high end power of the vtec head. right? so where would the problems come in? would it be better for me to scrap my B18c1 block the the B18b and make more power and be able to turn the boost up for additional power? what problems would i run into? how much boost should i expect to run? any first hand experience will be appreciated.

highmilehatch

IMO, the only con I see is the fact that a B18C bottom end is DESIGNED to spin higher rpm-wise. The oil squirters for the pistons, girdle are there for a reason. I'm not quite sure if the rod to stroke ratio puts less sidewall loading on the cylinders at 8 grand as compared to the B18B, but that could contribute as well. Now, does that stop people from spinning B18B bottom ends to 8 grand? Hell no. I rev mine to 7500 at 15/16 psi and I occasionally have to adjust the valves but its no big deal. I'm sure there are plenty of people who rev them higher. I made 306 whp at 16 psi on a stock LS, and I know turning the boost up anymore would not yeild me any significant gains at this point, because of the poor flowing B18B head and cams. Now, if I slapped on a Vtec head I would obviously make more power at the same boost level and would definitely benefit from more boost.

FullBoostAhead

exactly. i've heard the "rod stroke ratio" arrgument before and don't exactly understand it. i know the ls is not designed to see that high of an rpm powerband but people do it all the time and say they have no problems at all. and it would be really cheap and really easy it get a B18b block and slap it in place of my gsr.

V-SPEC 1

here's my set up. b20vtec make 540 whp and 400 lbs.torque.
https://honda-tech.com/zerothread?id=729936