Originally Posted by
sherwood
The best avalible option for acceleration and highway driving would be an LS transmission with a modified final drive. By scaling it to the same top gear ratio as the GSR you're left with something that hits 35mph at 8k rpm in first and 160 at 8k in 5th. Though I find it utterly pointless, just stick with a GSR transmission.
The major gains for the a VTEC conversion utilizing an LS crank come from the extra compression, not the displacement. Though the extra displacement does net higher gains, the "miracle" worker is just the taller stroke pushing the pistons closer to deck height.
if you use stock ls pistons in an ls/vtec your not getting that much more of a C/R over a Stock LS set-up! you will get a slight bump in the C/R because of the GSR head but not much more. If you use gsr pistons in this setup you will get a bump in the C/R but again not alot.
JDM ITR pistons are best for this set-up if you want big dent in the C/R, 11.5:1 with an OEM headgasket, higher if you use a 2 layer HG with the set up!
About the tranny now, a GSR tranny is fine, BUT you still have to offset the extra weight of the LS crank and rods. A lighter flywheel is the cheapest route but a Type R tranny i feel is a better way due to the closer gear ratios, final drive, LSD couple that with a lighter flywheel if a person chooses to get the any LS/vtec running the way people intended. I understand especially now how important Gas mileage is, and that is the reason why you switch to a gsr or even an LS fifth gear.
Not trying to start an arguement!! This is just coming from driving an LS/vtec for the past 3 years on a daily basis and figuring these things out by driving other peoples lsvtecs and seeing the same issues. For me spending the $900 on a ITR tranny with a gsr 5TH (which will also be used on my stroked GSR block) was a very good investment.