- Fri Feb 01, 2008 9:15 pm
#40431
The bottom end of the GSR and ITR are quite different actually. The rods and pistons are not the same. ITR rods are stronger, built of a different material, and the pistons have a special coating that reduces heat.
The B16 head is the same casting as the ITR head. The difference again, is the internals, such as cams, springs and retainers. ITR heads are ported at the factory. The 96-97 heads were hand ported, while the 98+ heads were ported by computer-controlled machine work. All ITR motors were hand assembled at the factory under very tight tolerances.
I've talked to a few honda engineers, and they have stated, the ITR motors are practically the only motors Honda has developed that were primarily to be used on the track, but released for production use as well. They have stated that they took a GSR motor, and maximized it to its full potential without comprimising reliability.
As for a B16 head outflowing a GSR head, that's totally untrue. They flow either the same or a difference of 2 cfm's. Nothing to write home about.
In my opinion, a STOCK poor mans ITR can never be an ITR, not to insult your build Greased. I've driven a poor mans ITR setup and in no way does it feel as strong as a pure ITR motor. I'd compare it to a stock GSR motor with bolt on's. The power was approximately the same between the two that I've driven.
Greased, I'd highly recommend getting your head ported, either by Alaniz or Portflow. Alaniz will get the most power out of the porting, comparing street port vs. street port between the two companies. Problem is that Alaniz takes forever to get his porting done, but portflow's turnaround time is short.
A portflow street port, plus S2 stage II's with springs and retainers, and your setup will be just as fast as an ITR motor, or faster depending on the tune. Add a nice hytech replica header, my DIY ITR box, and a full 2.5" exhaust, and you'll definitely push 200whp. That setup I just pointed out, is a setup for reliability, which is what I'm all about. I don't like to build something that will blow up after 10-20 passes down the 1/4. For example, my setup on the ITR should last just as long as a stock motor, just because I didn't even touch the internals. I have basically a stock motor.
Good luck with whatever you decide.