Compression ratios...

[CT_the_AZN]

Okay, so I'm still a little confused with on this. Now, with N/A builds you want to shoot for a HIGH compression ratio right? What compression ratio would be most beneficial to an N/A ITR? (with a moderately upgraded internal setup.....valvetrain, forged pistons, rods) Where can i find rod bearings that are capable of handling higher HP/RPM's? Or will new OEM one's be good enough?

And another questions is the head gasket. Does a thinner head gasket equate to lower or higher compression? Thanks again guys.

one more thing. This will be my DD, weekend warrior car. So nothing too radical...

[heel_touge]

higher compression always makes power. the problem with higher compression AND boost is that it puts tremendous amounts of additional stress on the motor. lower compression = moore room for boost but the boost generates less power per square inch than it would with a higher compression.

cam choice/ headwork/ bottom end assembly will dictate what will be the best compression ratio for your motor. OEM bearings will work well.

thinner headgasket = more compression

[CT_the_AZN]

so there's no real "optimal" compression ratio i'm shooting for with the N/A build? Just the higher the "better"...within reason. What's stock comp ratio?.....is there a thread on here that has all the specs for the ITR? i.e. HP, TQ, curbweight, tire size(s), front/rear weight dist, mpg, skidpad g's, gear ratio's, etc, etc. I'd like to know (mechanically) as much about the ITR as possible. I love knowledge....

[DCR26]

is there a thread on here that has all the specs for the ITR? i.e. HP, TQ, curbweight, tire size(s), front/rear weight dist, mpg, skidpad g's, gear ratio's, etc, etc. I'd like to know (mechanically) as much about the ITR as possible. I love knowledge....

FAQS section bro. Most questions you have can be answered there.

[Bbasso]

If you are going to DD it, I'd leave it stock with some bolt-ons... the car is pretty damm good in stock trim.
for more info on the caR, check out this http://itrsport.com/specifications.html

[Dave_B]

Higher compression does NOT always yeild more power.

It all depends on the supporting mods behind it. That's like saying you can put stage 4 cams in your stock motor and make more power. Just isn't going to happen.

Personally, I'm against the grain here. IMO, the best internal build is one of OEM quality (for street apps, and very mild runnings)

I have JDM P30 pistons, (thinner) Mugen Head Gasket.

To support this, I also ported and polished the head and am running Skunk2 Stage 2 cams.

You have to think bigger picture when building your motor. Think about realistic power goals. Figure out your budget and go from there.

[CT_the_AZN]

I was looking at shooting for somewhere around 250hp at the motor (wheel would be nicer ).....now that being said, is that a realistic goal for an N/A ITR build? Or would just be better off going with a small trim turbo route? I have reservations on another boosted car. I have a supercharger Focus hatchback that put down 198fwhp with an 11lb pulley on stock internals. And to make a long story short, it's on it's second motor right now...and it needs a 3rd (spun bearing). I just want something that's quick and (more) reliable than that.

[Dave_B]

I was looking at shooting for somewhere around 250hp at the motor (wheel would be nicer ).....now that being said, is that a realistic goal for an N/A ITR build? Or would just be better off going with a small trim turbo route? I have reservations on another boosted car. I have a supercharger Focus hatchback that put down 198fwhp with an 11lb pulley on stock internals. And to make a long story short, it's on it's second motor right now...and it needs a 3rd (spun bearing). I just want something that's quick and (more) reliable than that.

IMO that's a bit much (even at the engine) for a DD car. While I'm pushing the envelope in my car, I wouldn't recommend it to anyone. It certainly doesn't idle stock at ALL.

220 to the wheels is about it, and that's really pushing a DD car. I wouldn't so much be concerned with forged internals, I would save that money for headwork/tuning. I also wouldn't run a turbo either (I like the NA powerband myself)

What costs are you looking to spend?

[CT_the_AZN]

....to be honest i'm really not sure on how much i want to spend. But $3k is absolutely the MOST i want to spend. Now keep in mind, i'm planning on pulling the motor out and refreshing just about everything. i.e. new gaskets, bearings, valve cover's chipping a little bit so i need that repainted/powercoated. And that $3k isn't going to be just in the motor. a few other small things with the interior too. Like i said, i'm don't want to go uber-insane with the setup. Just something clean yanno......

[Dave_B]

If only 3k... I say rebuild to stock and get a really nice I/H/E cause you'll spend close to 3k on a good setup.

[CT_the_AZN]

okay so the type-r has 10.6:1 compression ratio....would stock internals be sufficient enough to withstand say 12.5:1? or is that taking it a lil too high?

[Dave_B]

Your question is a bit confusing...

Stock internals yeild the 10.6:1 compression ratio.

So I guess I'm confused when you ask would stock internals be sufficient to withstand 12.5:1 compression ratio.

I think what you mean is will the stock rods/crank/sleeves hold 12.5:1. And the answer is yes, to a point.

[CT_the_AZN]

^my bad . yeah i meant the last thing you said...I'm not sure if i've ever stated this before but, i'm currently running the JDM B18C Type-R motor. I've been scrambling around trying to figure out whether it was, in fact, a JDM Type-R or just a GS-R. Because, if i'm not mistaken, they are both B18C...Some people told me the difference is in the IM, others said look for 'P73' of the ECU. Still other said to disreguard either of those because either is easily changed out. And some said the only true Type-R was a B18C5...but after an exhaustive quest, i'm confident in saying that it is, without a doubt, (now) a JDM Type-R motor

Now one thing no one seems to be able to figure out is what kinda tranny i have in. I running 17"x7's all around with 215/45/17R tires, and it will drop out of VTEC EVERYtime i shift into 2nd...it drops to about 5500RPMS and there is a lot of wheel hop, anyone have any ideas?

[Dave_B]

^my bad . yeah i meant the last thing you said...I'm not sure if i've ever stated this before but, i'm currently running the JDM B18C Type-R motor. I've been scrambling around trying to figure out whether it was, in fact, a JDM Type-R or just a GS-R. Because, if i'm not mistaken, they are both B18C...Some people told me the difference is in the IM, others said look for 'P73' of the ECU. Still other said to disreguard either of those because either is easily changed out. And some said the only true Type-R was a B18C5...but after an exhaustive quest, i'm confident in saying that it is, without a doubt, (now) a JDM Type-R motor

Now one thing no one seems to be able to figure out is what kinda tranny i have in. I running 17"x7's all around with 215/45/17R tires, and it will drop out of VTEC EVERYtime i shift into 2nd...it drops to about 5500RPMS and there is a lot of wheel hop, anyone have any ideas?

Did the trans come with the swap? Are there any markings on the case of the trans?

[CT_the_AZN]

From what i was told from the dealer...when the owner before me traded the car in, it had a fully built B16C (or whatever teh GS-R is) in it because he had blown the original B18C5. When the dealership found this out, they immediately had it replaced with another Type-R motor. I have paperwork given to me from an Acura dealership verifing this. Apparently they only ordered the engine and not the engine/tranny combo...there's a paragraph somewhere in the stack of papers stating why. I'm guessing, when the dealership swapped out the motors they just used the "old" tranny...Now here's the tricky part...pay attention...

shortly after i bought her, i had to have to the tranny replaced (hideously trashed synchro's) since i decided to use the 'extended warranty' to cover the tranny replacement, the tranny shop said they could only replace what had already been there...this is what didn't make sense to me at first...they told me when i came to pick up the car that the car had a GS-R tranny and not Type-R. I asked the guy if he still had the old tranny at the shop. He showed it to me, and upon inspection of it, it in fact, was a non-LSD, GS-R tranny....which now that you sit and think about it, makes perfect sense.....

i expectedt that whenever the previous owner blew the B18C5 he'd have swapped over the ITR tranny when he installed the built GS-R...i mean, that only makes sense wouldn't it???...But i guess he didn't...must've sold the ITR tranny to afford the GS-R build.............i guess we'll never know.

and no, there is no LSD stamp on the tranny housing...

[CT_the_AZN]

okay here's another question that i have. If i were to buy 'hi-compression' pistons that bring compression to 11.5:1 (JE 81.5mm, .020" oversized) ...and i bought a 1mm head gasket (TODA B-series VTEC head gasket) which is suppose to bump compression up to 11.9:1 on a stock motor....would the end result be a 11.4:1, stay at 11.9:1 beacuase of the head gasket, or go up to 12.4? basically i guess what i'm trying to ask is, is compression additive?

[Dave_B]

okay here's another question that i have. If i were to buy 'hi-compression' pistons that bring compression to 11.5:1 (JE 81.5mm, .020" oversized) ...and i bought a 1mm head gasket (TODA B-series VTEC head gasket) which is suppose to bump compression up to 11.9:1 on a stock motor....would the end result be a 11.4:1, stay at 11.9:1 beacuase of the head gasket, or go up to 12.4? basically i guess what i'm trying to ask is, is compression additive?

My guess without specifics would be this.

The Pistons your looking at are described around the OEM head gasket. So if you put in a thinner head gasket, it will up the compression even more.

HOWEVER, all that said, IMO I wouldn't go with that HG, or at the very least I would have the motor clayed to make sure you have enough clearence.

[King-Tuning]

You keep asking about high compression. Going from 10:6 to high 11 or low 12 compression ratio does not always make power. On a stock motor raising the compression will only gain a few WHP and will raise a whole lot of cylinder pressure. Which might cause the motor to knock. Plus you have to factor in labor cost to put in the piston. IMO a nice I/H/E and Crome, hondata, neptune, might yield you some nice gains. It should cost under 3g.

If you really want high compression piston. I would send your block to a shop, get it sleeved and go with some 84mm high compression piston. Get it hondata or some thing so you can get it tune with. Tuning will allow you to make a lot of power and safety of your motor.

Making all motor power is not cheap. For every thousand you spend, you might just pick up a few horse power.