Some things don't require an engineer. It is a simple matter of whether it works or not. Some may have tried it, and some may have not. I persoanally haven't.

Here's the setup:
-B16 bottom end
-GSR head decked .008"
-PR3 pistons
-GSR dual stage manifold
-GSR cams (may soon upgrade to Blox spec B's or C's; not sure yet)
-well that's about it.

The motor is rolling with approx. 10.75:1 static compression. So it has at least some pop. I don't reeeeeaaaally (lol, it's a B16. So what can I really say?) expect it to have too much badass'ness down low. It doesn't even seem responsive UNTIL about 6500 to 7000 rpm's.

The way I see it, a 2.5" exhaust came on a stock ITR, which to me is only as good as stock.

I'm more into going down the racetrack faster, and not necessarily making the worlds greatest numbers on a dyno. Yes, there's a difference.

Overall, what have you guys seen, and how would you approach the deal? Kteller looks promising with their piping kits.

 

you're not going to get any responsiveness at 6500-7000 rpms because you ARE a b16 and have the lowest torque/weight ratio of the B-series.

you're not making enough exhaust energy to warrant a 3" exhaust to eliminate backpressure.. because you haven't created any with that power level at that compression.

ITRs did not come with 2.5" exhaust piping. you're better off with something a little better flowing like a 2.25" skunk or T1R, or kteller. But untill you put some real "ummph" in the engine, (better compression, cams, valvetrain, etc) you'd actually be pissed by putting a 3" exhaust on an NA car like that, as you'll take even MORE rpms to get the car moving down some drag strip.

this is a situation where MUCH bigger is NOT better

 

What if I put a set of meaner cams in it?

By the way, it doesn't do **** until it gets past 6k rpm's. You have to buzz it. Nitrous makes just about anything haul *** otherwise.

Overall, your recommendation seems accurate to me. I was very doubtful about the 3 inch stuff.

 

Again, "meaner cams" don't do anything for you in 90% of the cases unless you increase compression at least with 11.0:1-12.0:1 and in some cases, additional displacement. Even then, it may cause a lot of overlap beyond what your Nitrous is set for.

You're at a point where its time to turbocharge with the purpose you continue to describe.

 

I feel like my compression ratio is far too high for anything over 5 psi @ 250 whp approx 300 hp.

Maybe I could stack a thick copper head gasket in there to dive the compression back some. Lol, I see my **** going no where.

PM me if you'd like. I'm sort of running out of ideas with my **** right now. Makes me think I need to pick up a B20 bottom end, trim the pistons a little bit for clearance, and roll with a B20 vtec setup. It'd cost ME a lot less than a turbo combo, but i'd run slower than a turbo setup. I'd still be limited by the stock cast pistons. I just keep going back to the fact that a Subaru Impreza WRX rolls with a static compression ratio of 8.0'ish. Hey it lasts. I should be particular, but smart about things as well. Nitrous isn't really smart I might add since there's too much that can go wrong. I've seen this before.

 

Turbo will be fine with 10.75 compression, there are plenty of turbo r's out there. Just make sure you get it tuned well. Since we are in the all motor forum, your b20 suggestion would probably be a better idea if you are trying to stay on a small budget.

 

that's because you're thinking that N/A tuning and turbocharged tuning is similar. They are vastly different. A subaru WRX has 8.5:1 compression because it uses a small enough turbocharger to only get up to about 225hp (about 203AWHP) to be in its efficiency range. Don't think like a subaru or a DSM or any other factory turbo car, as a B-series honda build is completely different with completely different thinking.

10.75:1 compression (which sounds fishy to me, as a stock B16A2 is about 10.4:1) is fine for over 300whp on the stock engine block with no "head work" or "cams" and can last for years, provided that you don't cut any corners. Stock cast pistons have done over 300whp on about 8-12psi on your run of the mill QUALITY turbocharger kit with good engine management and supplemental equipment.

I know that you want a "fast car" that you can daily drive, but you have to determine what your power goal is and what budget you have available to get to that power goal. Yes, this is the all-motor forum, but for a lot of what you're trying to doesn't FIT this side of the forums. staying with a B16 block is not a bad thing, necessarily, as there are several ways to skin a cat to be "fast". But remember that no matter what road you take (Boost, nitrous, NA) you need to make sure that you plan accordingly and not be in sucha a big hurry worrying about everyone else. In the end, only YOU can determine if you're fast enough and if something goes wrong you can repair it.

Think more about what you're trying to acheive (no E.Ts, please) and let's work to get in THAT direction.