b16 or b20 for turbo

I know this is a very broad question, I was just wondering which engine likes turbos better? I’m thinking I can get either engine fairly cheaply and spend around $2000 on piecing together a turbo kit. I know lower compression is better for turbos because it prevents detonation but as far as I know the CR would only be a factor when you raise the boost to 12lbs or more. So, I think the CR of the engine doesn’t really come into play since I’d only boost around 5-7lbs. Plus, I’d be doing all this work next summer, and the following summer I’d be able to afford turbo pistons and cams and etc. to build up the block. I think the b16 has a better r/s ratio as well so maybe it would be better for turbo? then again if I put a b17 crank into the b20 it would have a near perfect r/s ratio.

Basically I would prefer the b20 but are there any overwhelming reasons to get the b16 instead since it’s about half the price? BTW, either block would be mated to my ls tranny. Sorry for rambling, TIA.

Go with the B20 for more displacement. I think you would be safe to boost 7-9 p.s.i. for a daily driver for a long time. My CRVTEC dynoed 224 at 4 p.s.i. and
298 at 10 p.s.i. If you run about 9.5:1 comp on the B20 you will have plenty of low end torque until boost.

Thanks AMERIKAN. You’re one of the key members I was hoping to hear from. I won’t have to worry about any major wiring when swapping in a b20 would I? I mean nothing like wiring my car for VTEC with the b16.

Whitey… I would recommend www.Honda-Tech.com and do a search under Forced Induction before you post redundant questions. Some of these boards aren’t too lurker friendly so you kind of have to ease yourself in.

Good luck:D


Come on man I’m not a lurker here if that’s what you’re implying, I’ve been here since I got my car in June.
Do I have any advocates for the turbo b16?

Whitey, I am NOT implying you are a lurker. I am only trying to tell you that some pages are not as friendly to newcomers as G2IC is:)

OOoohhh OK. Just checking. That website is very informative. I used to frequent h-a.net before I got my g2 and now the only one I ever go to is g2ic.com. But h-t has lots of info, thanks for the tip.

Originally posted by whiteyg2RS

Do I have any advocates for the turbo b16?

I’ve had mine for about a year. Like you said the 10:2 c/r of the B16 isn’t really in too much danger of detonation at levels at or below 10psi- especially with an intercooler. Actually, higher compression FI car is better for everyday driveablity- alot more responsive at lower rpm’s (Tuning is the key though, when boosting with higher a compression engine) I run 8 psi on the street and 10 at the track, haven’t hit a dyno yet- but at 8 psi I was pulling 104mph trap speeds with full interior in 100 F weather. That probably puts me at about 230/wheels…
I’m not saying B16/Turbo is better. But like AMERICAN said, the torque is a HUGE advantage in the B20/Turbo setup. I’m just not a big fan of LS/VTEC Turbo cars- Probably cause guys I’ve seen with em have sloppy installs and a heavy foot = Bad Combination. You’ll be happy either way you go. HTH

PS-dont let the sig fool ya :wink:

This is probably a redundant set of questions but I don’t know the answers so BACK-OFF John! :stuck_out_tongue:

Hey, anyway, I’m wondering where a stock b20 makes it’s power. Does it have a similar power curve to the b18a? What is it’s peak hp/torque stock and what RPM’s does it achieve those maximums.

One day I’m gonna build a monster non-vtec turbo set-up and I’m trying to determine whether a b18a or b20 would be the best block to use. I’m not planning on building a pure drag machine by any means. Just a mean, practical, daily-driven street machine, that can run mid 13"s on slicks, and pull away from almost any car on the highway:)



I simply got these numbers off of honda’s web-page for the 2002 CRV. Not sure if that is accurate for the b20 we can pick up used.

Horsepower @ rpm
(SAE net)160 @ 6000
Torque (lb.-ft. @ rpm)
162 @ 3600
Compression Ratio

So I’m assuming redline is about 6,200 or 6,500. This might be a dumb question but does a 6K RPM engine give enough range for the turbo to spool? Do my concerns make sense? It seems like a vtec engine would would be great because you could be in boost a couple thousand RPM’s longer.


The 2002 CRV is a whole different beast. Go to www.crvtec.com for some info on B20s…:smiley:

Cool, thanks John


97-98 B20B 126hp @ 5400 rpm
133 ft-lbs (18.4 Kg-M) @ 4300
8.8:1 CR

99-00 B20Z 146hp @ 6200 rpm
133 ft-lbs (18.4 Kg-M) @ 4500
9.6:1 CR

Those specs on the b20b are quite troubling to me. Would it be a wise idea to get a b20b and slap on a b18a head? Or even the b18a cams? Otherwise it seems like the b20z is the only choice if one plans on running the stock head specs.

B20b/z 84 mm bore

Also it looks like the b20 comes stock w/ much thicker sleeves than any other bseries motor. Remember that post that was all about re-sleeving? In theory shouldn’t a non-bored out b20 block be sufficient for years or moderate boosting (10psi)?


Leif, You’ve got hotmail…

the redline on my 2000 CRV is about 6,700. just trying to help.