B20 VTEC vs. B20 Turbo

[ahzab33]

Hi,

I'm building up a 1990 Honda Civic project car and I was wondering which would be better in your opinion. I'm hooked on the idea on using the B20B engine because of its torque and supplimenting it with some kind of high-end power. Which would be best, a B20VTEC or a boosted B20B? I'm kinda leaning towards the boosted B20 because it already comes with low compression 8.8:1 pistons. I know about the weak sleeves and plan to treat the bottom end to a good reinforcement. Please post your opinion and why.

This car will be daily driven and built for the street.

[SRV BOY]

how about a boosted b20vtec??

[91lxdreamer]

I personally think you should go with the boosted B20. With the small gains you might get from the VTEC, you'd be much better off just reinforcing the bottom end and boosting that. It all depends on what youre looking for, I mean a B20 setup is going to deliver quite a kick, but what are you looking at accomplishing? In my honest opinion, I think you might, if you choose the VTEC option, get done with it, and then wish you'd gone with the boost, since the boost is going to offer more power. And with boost you can always replace some other components, such as your rods, rod bolts, pistons, retainers, springs, and like you mentioned earlier, sleeves, to really add to the punch of your motor. In the end, its up to you, and what youre really looking for. But IMHO, boost is the way to get the more aggressive power gains.


P.S. Hey, hope theres no real hard feelings bout earlier, we both spit off at the mouth, and I know I said some things that we probably could have lived without. So I'm tryin to call truce man, make everyones experience a little more pleasant. Take care man, any more ?'s, ask away...

[SRV BOY]

Having a boosted vtec, opose to having a non vtec boost in my minds is not as fast, unless of course like the guy mentioned is gonna be built from the bottom up

[lotusonwater19]

all motor is more respectable and more reliable usually. but if youre not gonna boost that much its coo, just dont over do it with the turbo and end having to start over rebuilding it again.

[ahzab33]

Originally Posted by lotusonwater19

all motor is more respectable and more reliable usually. but if youre not gonna boost that much its coo, just dont over do it with the turbo and end having to start over rebuilding it again.

True... All motor is a bit more respectable. An all-motor monstor will definately having you blowing past a lot of other import drivers, but may not go far enough when facing off against domestic car racers. The simple fact of the matter is that even with VTEC, a honda engine can only flow so much air, which means you can only burn so much fuel, which will determine how much power you can make. With a turbo, you can at least eliminate that problem.

I mean think about it. Aren't both turbo and VTEC desinged to the exact same thing? Provide additional flow to the engine at higher rpms? The only difference is that with VTEC you will always be limited by nature (atmospheric pressure). Your car may go faster in CA. than in CO. or UT. Whereas with a turbo its adjustable. You can always compensate for nature or throw away nature altogether. Am I right?

[ahzab33]

Originally Posted by SRV BOY

Having a boosted vtec, opose to having a non vtec boost in my minds is not as fast, unless of course like the guy mentioned is gonna be built from the bottom up

Oh for sure! I wouldn't build any serious engine without changing the guts. Whether I decide to go with a B20VTEC, Boosted B20B, or even a Boosted B20BVTEC (messy) I would rebuild the insides to handle at least triple the original hp output. Here's what I have in mind:

1. Head studs
2. Block sleeves
3. Forged Pistons & Rods
4. Tougher valve springs
5. Crankshaft Bearings
6. Whatever you might recommend

[jcrx]

The blind leading the blind, good stuff. Fuck all the bullshit, and build a CRvtec,an then boost the fuck out of it. There isn't any point to building an engine and not making it the best it can be, just useless.

[darkerdayz]

finally someone said something i agree with. why not just build a boosted crv-tec? that would produce much more power than an all-motor crv-tec. secondly, i think that just the boosted b20 wouldnt really work. i'm not too positive, but arent the clearences much taller on a crv than on a civic (90 at that). i'm not trying to start a flame war either because i think those are pointless because i dont want to try and be an internet thug. so i think that really only leaves you with 2 choice...crv-tec or boosted crv-tec, and personally, i would go boosted. with a generally flat torque curve, that motor boosted would be a monster, but hey, that just my

[liquidflame8]

boost that mofo (crvtec)

[op012503]

IF this is gonna be a street car I think you should just swap in a b18 a or b engine because you wouldnt have to treat the bottom end and the compression on a b 18 is 8.9 if im not mistaken.
A boosted b20 with a treated bottom end would be great for a turbo. Im sure you can run like 25 psi on it but there is one problem--its not going to pass emissions~!

[YOUNGSTER]

yeah i agree if you could build your motor first than go turbo so you know what to match your turbo with hey jcrx i have almost the same car as you look in my gallery i even have the same jdm cluster lol

[Hybrid_Sol]

Originally Posted by ahzab33

I'm hooked on the idea on using the B20B engine because of its torque and supplimenting it with some kind of high-end power.

Keep in mind that a lot of that low-end torque is from the way honda already tunned the engine, such as the cam profiles. I haven't seen any dynos for the engine, but I can't imagine that it makes much power in the upper rpm band.

If you went all motor and did a crvtec, you would probably loose some torque, but gain a ton of power. I've seen dynos for crvtecs (I'll see if I can find them again and post them). They showed between 150 and 170whp and like 125lbs torque I assume depending on the cams. Keep in mind that the VTEC head will probably change the compression ratio.

If you have money, I would think you'd want to do a boosted crvtec, but you would need to resleve the engine.

Either way you'll want to tune the shit out of it.

This is the direction I was thinking of going too.