Ok im doing an ls/vtec and im going to rebuild my bottom end but not sleeve it. I want to be able to rev high so do i need to get a gsr crank or will the ls one be able to. Im changing the pistons to cp 9:1 and eagle rods. Im going to slap a sc61 turbo on it. So my question is which crank is overall better to rev high or does it matter

 

ls crank will be ok if everything is balanced. i reved my turbo street car up to 11,000rpms with a ls crank this year

 

A B16 has the best ratio. But you IMO I would use the LS and rev it to about 9000 just to stay on the safe side.

 

use the ls crank. with good rod bolts you can go 8500-9000 or maybe more. i rev my ls cranked lsvtec to about 8400

 

If you don't use the LS crank, then it wouldn't really be an ls/vtec, you wouldn't be getting the benefit of 40CC of extra displacement.

Also, if you already have LS rods, LS rods will not fit on GSR crank, too thick.

 

i have an ls/vtec in my car. i was running an ls crank, but now im running the gsr. the only reason being that we upgraded cams and de-stroked the motor with the gsr to see if it lasts any longer.

as far as the extra displacement, it didnt make any difference negatively on the car. we compared my boost/power to another ls/vtec with almost an identical setup, and i made more power with less boost and 800rpm faster. granted my turbo has a ported shrowd, so that could contribute.

either one can rev 9k with no problems

 

didnt any of you not read my first post i guess not

 

GSR crank with 5pt girdle FTW

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Supacharge &raquo;</TD></TR><TR><TD CLASS="quote">i have an ls/vtec in my car. i was running an ls crank, but now im running the gsr. the only reason being that we upgraded cams and de-stroked the motor with the gsr to see if it lasts any longer.

as far as the extra displacement, it didnt make any difference negatively on the car. we compared my boost/power to another ls/vtec with almost an identical setup, and i made more power with less boost and 800rpm faster. granted my turbo has a ported shrowd, so that could contribute.

either one can rev 9k with no problems</TD></TR></TABLE>

If you made power and boost 800 RPM's sooner than an LS/VTEC with your GSR cranked motor, there are obviously some differences in the setups contributing to that, not just the crankshaft, why would you even post this for a garbage comparison to make some newbies think that their shorter stroke motor will make more power/torque?

DSM'ers usually report about a 500 RPM difference in spool when moving from a 2.0 to a 2.4L stroked motor, that's 10 times the displacement difference we're looking at here between the GSR and LS cranks!

 

Thanx guys were do u know some online stores that i can get parts cheap.. bottem end stuff.

 

I would stick with the ls crank but I would look into new valve springs and retainers to handle the high revs. You dont want to drop a valve.