b18c1 vs b18c5 into eg

Hi, I'm maybe planning on swapping either the a b18c1 or b18c5 in to my 92 hb eg civic vti (currently a b16a2).

Which would be better in the long run for maximum power for a street application? e.g If i wanted to supercharge the engine after the swap, would the b18c1 be better for boost or will the type-r engine handle it better? Bascially i'm looking for well over 200hp and I'm not sure which engine can get me there easiest!

I know the b18c5 is more powerful from stock, but could i get more out of the gsr engine?

I have heard that the b18c5 doesn't like boost, anyone got any ideas?

On the other hand, does anyone recommend sticking with the b16a2 and tubo-charging or supercharging that? or even a compound?

Any suggestions much appreciated.

Bert

[TeriyakiBroccoli]

Go with the b18c1.. the type - r has higher compression and does not like any kind of boost.... You can basically do anything to a b18c1.

[slowEJ6]

keep the b16a and turbocharge it....there is absolutely no sense in swapping out to a b18c1 when you already have a b16a.

But wouldn't I be able to make more power (in the long run) from the B18C1 than from my B16A2?

Could I turbo/supercharge my current engine no problem?

What sort of power do you think I could get out of my B16A2 then realisticly?

Oh, and can you run a turbo and a supercharger on a VTEC efficiently?

Thanks

[slowEJ6]

you could make more power probably but thats only if you are completely rebuilding the motor to be an all out drag racer. otherwise you could simply upgrade the pistons/rods and add a thicker headgasket - with the proper fuel/ignition/ecu mods and youd easily be in the 12's with proper tuning on the B16A.

no you cannot run a turbo and an SC.

So I could seriously be running 12s from my current engine?

Is that with a turbo or what?

Ok, say you had $5000, what would you do, step by step, with this engine if you had it?

p.s this engine has just hit 100,000 miles so i'm a bit worried about the condition of it. Can I find out by checking the compression? If so, how the hell do I do that? Sorry, i'm a bit new, i know what i want i just don't know how to get there!

[silver]

just because the c5 has high compression does not have anything to do with being bad for boost. Having a lower compression means you will need to raise the boost to have equal power made.

One main concern in power production with forced induction is effective compression. Effective compression is the sum of the motors static compression, plus the additional compression added by the forced induction tool. A B18C1 (also B16A) motor will have a higher effective compression than a B18B motor will, on the same boost...therefore, pound for pound, it will make more power.
The next argument that people usually bring up is that a higher compression is bad for turbocharging. Well, if you understand the concept of effective compression, then you should understand that this statement is entirely incorrect. A higher compression engine makes more power in NA form. So, why do you turbo guys think that a lower compression turbo motor makes more power? Does that make any sense when you really think about it? A turbocharger is a power adder? So why deplete power that was there to begin with? The answer I usually get to that is "So I can run more boost!" Well, sorry to rain on your parade, but more boost does not always equal more power. Check out this mathematical example of effective compression:

A motor with a 10.0:1 static CR boosting 10psi
10psi/14.7psi = .68
.68 + 1 = 1.68
1.68 x 10 = 16.8 effective CR

A motor with an 8.5:1 static CR boosting 10psi
10psi/14.7psi = .68
.68 + 1 = 1.68
1.68 x 8.5 = 14.28 effective CR

Now tell me who is going to make more power? The higher CR motor, or the lower CR motor?

So, maybe add more boost to the lower CR motor, right? Wrong...

A motor with an 8.5:1 static CR boosting 13psi
13psi/14.7psi = .88
.88 + 1 = 1.88
1.88 x 8.5 = 15.98 effective CR

Now you see, even adding 3psi of boost, still does not equal the effective CR of the higher compression, lower boost motor.

Effective compression is not the only advantage of the B16A/B18C1 either. The B16A/B18C1 has a stronger, better flowing cylinder head. It can rev much higher, making it that much more effective, and it flows great to handle all of the extra volume. The block has oil squirters to help support the bottom end assembly at high RPM. It takes more than a valvetrain upgrade to make a B18B safe at 8k. The higher compression also aids in spooling the turbo faster too.

Both motors have similar tolerances though. Both motors pretty much top out at around 350-400hp on stock motors, very well tuned. The B18C1 will make it far more efficiently for you though. It takes less boost to do so, it has more safeguards...and the bottom line on any Honda motor is tuning. If it is well tuned, you will be set. That goes for both motors. YOU ARE A FOOL if you think for one second that just because your B18B has a lower compression, you can substitute that for proper tuning.

A lot of people like to lower their motors compression when they build their motor. I used to think it was a good idea before I understood about tuning, and the positive aspects of compression. In the mathematical representation below, I will show you how a low compression motor must boost more to equal the output of a higher compression, lower boost motor:

Motor: stock B16A2 boosting 7psi.
Static Compression Ratio: 10.4:1

((boost psi / 14.7) + 1) x motor compression = effective compression

Stock motor (10.4:1 CR) on 7psi:
7psi/14.7psi = .47
.47 + 1 = 1.47
1.47 x 10.4 = 15.288 effective CR

Built motor (9.0:1 CR) on 7psi:
7psi/14.7psi = .47
.47 + 1 = 1.47
1.47 x 9 = 13.23 effective CR

You will lose 2.058 points from your effective compression ratio, this translates to a significant power loss.

In order to gain back that power, you have to do this:

Built motor (9.0:1 CR) on 10.5psi:
10.5psi/14.7psi = .71
.71 + 1 = 1.71
1.71 x 9 = 15.39 effective CR

Add 3.5psi to what you were boosting before, and you should be able to make around the same power as before, granted you haven't done any other kinds of modifications port/polish, cams, etc...

As you can see, considering all things stay equal (bore/stroke/cylinder head/etc...), you must add 3.5psi to make the motors perform similarly. You just spent about $2,500 to build your bottom end, and make your car slow.

By now we all should understand the positive aspects of compression, and how when teamed with the faster spoolng turbo, more efficient output, better flowing B-series VTEC cylinder heads, better low end spool time, stock oil squirters, higher redline, etc...you should see that turbocharging B-series VTEC motors is clearly not dangerous, and highly adviseable."

i hope that helps. keep the b16 and turbo if you want to go FI, you will need to replace parts on the other motors anyway if you want high hp, save the cost of a new motor and use what you have.

[ChrisCantSkate]

very true... problem is, the c5 has all motor cams, and is not designed for the added pressure on the rods. a beefed up 10:1 CR and 10psi would be awsome. but there will be too much valve overlap on the ITR cams for it to hold the boost very well.

[silver]

i may be incorrect on this but don't people switch to ctr cams when they boost the c5?

[ChrisCantSkate]

Originally posted by silver
i may be incorrect on this but don't people switch to ctr cams when they boost the c5?

i was under the impression that any *TR cam had too much valve overlap to efficiently run boost

ok so I've been pretty much convinced to stick with the B16A2 now!

Can you seriously get 350-400hp out of my little 1.6!!!? that's amazing.

I need to know what ground work to do on the engine, what sort of money to be spending on the turbo, and then what about apex-i fuel/air adjusters, would they help?

[silver]

Originally posted by ChrisCantSkate
i was under the impression that any *TR cam had too much valve overlap to efficiently run boost

you may be correct, i'll find out. I have never boosted a type-r motor, seen them, but never built one for FI.

[silver]

Greddy makes a kit for the b16a2 for around $3k(usd). It will have everything you need to get it going. Get an intercooler as well, about another $800. Then drive around for a while and get used to it and how it works. Learn how to drive your car with all of its newfound power. Remember, you just slapped on major hp on a little car, you don't want to go 150 to 350, take it slow and be safe. And make sure you do your suspension and brakes first.

[silver]

Originally posted by silver
you may be correct, i'll find out. I have never boosted a type-r motor, seen them, but never built one for FI.

didn't get as much info as I wanted, but got a nice physics lesson for anyone interested.

http://www.streetracing.org/boards/s...threadid=63936

Originally posted by slow ej6
keep the b16a and turbocharge it....there is absolutely no sense in swapping out to a b18c1 when you already have a b16a.

we have a winner

swapping out for a b18 is very pointless.

For 5,000 I wouldn't buy a turbo kit, or swap the engine. I'd piece my system together(turbo). If you can, find used parts still in great condition. Rebuilt turbo's are everywhere, Turbo manifold you might wanna buy new, other than that, used is perfectly fine. BTW, a lot of people use GS-R cams on turbo VTEC engines, unless they buy aftermarket. Keep the B16 and boost it though, a B18 is pointless unless you sell it for at least 2K, and buy an LS motor(GREAT for boosting)

Originally posted by DjBert
ok so I've been pretty much convinced to stick with the B16A2 now!

Can you seriously get 350-400hp out of my little 1.6!!!? that's amazing.

I need to know what ground work to do on the engine, what sort of money to be spending on the turbo, and then what about apex-i fuel/air adjusters, would they help?

That's been my plan for a while, get a b16a2 - and boost it. The high redline will work well with the added power from the turbo.

sport compact car february 2001 p. 80, 1999 civic si with vortech v5 supercharger (10psi), air/water intercooler, vortech FMU, comptech header, apex'i n1 exhaust puts out 272hp and 181 lb/ft of torque at the wheels at 7900 rpm

granted it's a supercharger, not a turbo, but 10 psi is 10 psi. the engine is internally stock, with only fuel system upgrades, and engine management upgrades