[MatT3T4]

You will actually have better numbers from the B18C5 than you will from the B18B or the B18C1. The higher compression is good, quicker spool, earlier power, etc. Retard the timing a bit, maybe purchase yourself an oil cooler, and you should be fine.

The only problem that turbo ITR's run into is the rods and pistons. Now, it's not the compression that is the problem with them, it is the lightweight construction. One trick for NA motors is lighter components. Now, as you can probably guess, the lighter the compound, the weaker it "probably" is, unless we are talking about expensive materials...not OEM Honda parts, of course. So, you will have a slightly higher chance of breaking something in an ITR.

Still though, go for it. You will enjoy it greatly. If, by chance, something does happen...if you rebuild it, keep the stock compression, don't lower it.

 

[MatT3T4]

Most people don't understand the dynamics of compression and boost. For a street car, compressionc an be very beneficial.

 

[MatT3T4]

maybe for low boost applications, lower compression takes away some power, but it gives less chance of detonation, which IMO is more important, i know i said this before, lower compression only gives you a little more room to work with when tuning...

You're absolutely right. However, there are plenty of alternatives to lowering compression...timing retard, methanol injection, aquamist type water injection, oil coolers, etc. In the end, it's up to the individual.

 

[MatT3T4]

We have seen that there are limits on what can be done running pump gas on an engine with a relatively high compression ratio. High compression engines are therefore poor candidates for high boost pressures on pump fuel.

And on the flipside, the lower boost plus higher compression equals the higher boost plus lower compression. It's where the whole effective compression comes in to play. There is no need to run really high boost, especially in street cars. The peak power evens out, the difference is in the middle of the powerband, and the one with higher compression usually has a more efficient one.

 

[MatT3T4]

As well, that article you posted is only "one way" to go about relieving detonation. Obviously, if they have to drop the compression to 7.0:1 to run a measly 8psi, they haven't done anything to the fuel system.

Fuel upgrades extend the amount of boost and/or compression you can run. So do ignition upgrades. On top of those standard upgrades, there are cooling measures. The detonation is being caused by heat. Water injection (although not my favorite), methanol injection, oil coolers, etc...can ALL stop detonation in it's tracks. But you have to ask yourself this...Which one will be more efficient? The doggedly low compression motor, or the higher compression motor? The low compression motor will have trouble even spooling the turbo, unless you launch at 8000rpm. The higher compression motor will feel good right off the line.

 

[MatT3T4]

I totally agree. The thing about Hondas, though, is the fact that the stock compression, which is what people usually refer to as "high" compression, really isn't all that high...and in reality, doesn't warrant the use of such drastic measures to remedy detonation. When I speak of the "high" compression, it is usually in regards to low compression motors...so I speak of the stock compression. Now, if we were bumping it up to 11.5:1 or so, then HELL yeah...gimme some methanol.

You are absolutely correct though, low compression is easier, overall, but makes less power pound for pound, and high compression takes more effort, but is more efficient.

 

[MatT3T4]

MatT3T4
what comp. where you running in your coupe? what was your max boost (track psi)?
I have a built b16 10:6:1 comp going turbo.
You have been there done that, so your in the know.

Stock compression. KICKED ASS for 2 years. Built it to 9.5:1...sucked, sold it.