I currently have a 95 JDM GSR engine in my 95 civic and im going to do all motor. Whats the highest compression i can run on 93octane and having good reliability, could i do 12.5:1? or is that a bit to much?

 

I wouldnt go any higher than 12.5. Im doing an na setup on a b18c and Im prob gonna go 12.3-12.5. You just need to make sure its tuned right and you arent detonating. Tuned right, you can run 12.5:1 on 93 octane.

 

By tuned right, what do you mean, ECU? or internals?

 

by tuning I meant getting some type of fuel management and getting it tuned by someone that knows what they are doing. Of course the internals will have to be done right also, if you are building the block up, you want new rod bearings and rod bolts, stuff like that. Tuning also involves adjusting the timing so its not all click and go. For instance, if you arent tuned well, you might be running too lean. Running too lean could overheat the motor or blow it at high rpms. There are a lot of other things to take into consideration when tuning, thats why people take their rides to people that really know what they're doing.

 

Get a hondata and spend some time on a dyno, and you'll be fine.

 

i got a 94 LS and im debating about some pistons when is it nessecary to tune and have a FMU??

 

FMU is not what you need, that is a boost dependant fuel pressure riser for a turbo setup. It raises fuel pressure a certain amount for every psi of boost. You would need something like a hondata or uberdata that can be tuned on a dyno for your specific setup. Piggyback ECU chips won't be enough. You need something tunable so detonation doesn't occur inside your freshly built motor, and put a hole in a piston.