bronx

i bought a set of gsr pistons,

im gonna put them into my ls/vtec motor

should they connect right onto the ls rods?

do i need to buy stronger rod bolts? or are stock ls rods and rod bolts fine for the gsr pistons?
thanks

zeeman

iTrader: (1)

Yes, using ARP rod bolts is recommended if you plan on revving past the stock redline of the LS....which is kinda the point with lsvtec's. It is also recommended that you use a 22T water pump, which is any dohc vtec water pump (b16, gsr, itr), but you would also need to use the gsr/itr timing belt if you use a 22T water pump. Its also a good idea to use the gsr/itr oil pump if your budget allows.
The gsr pistons will fit but you need to narrow the wrist pin end of the rod to accept the p72 pistons.
Now, are you using p72-A0 (usdm) or p72-00 (jdm)?
Because if you are using a pr3 (b16/itr) head then you will only yeild a 10:1 CR with the p72-A0's and 10.5:1 CR using the p72-00's.
I personally would use the p30 piston in a lsvtec b/c it gives a very streetable 11.5:1 CR which is enough compression to run some itr/ctr cams, or any stage 1 or 2 cam of your choice, but keep in mind that while using any stage 2+ cam that it is necessary to upgrade the valve springs and retainers.
The whole point of swaping out the pistons is to significantly raise the compression ratio. If you only wanted a little bump in compression then you can mill the head or use a thinner head gasket. Why go through all the trouble of ripping apart your bottom end to put in different pistons for such minimal gains?
JDM ITR (p73-00) 11.2:1 is another streetable choice and are nice because of the coating they have on them.
Of course PCT (civic type R) pistons are the best OE piston to use for maximum compression, but IMO thats really pushin' it for a daily driven street car. I mean, you would need some good tuning and 94 octane to run those during the heat of summer.
However, if you are using a gsr head then you can add about .3 to each of those CR's above.

bronx

thanks man....
i had bad pistons in my motor so im just gonna put in new gsr pistons, a small upgrade but nothing radical

i wont be doing any crazy racing so i still got the oe pumps, belt, rods and rod bolts....
the head is cdn sir top with arp head bolts

i think the cr should be 10:1 and it should be making 155whp
since the ls pistons were making 145whp

thanks again for the helpful info