Searched w/ no helpful information,(might belong in FI) looking for some intelligent input on this...
Friend bought a 90 CRX Si, he has a choice between a b18b(LS) and a B16a1. We all know HP figures, but lets here it, is VTEC REALLY that bad for turbo applications? What are some pros/cons between boosting the 2 different engines?


[Modified by GSxRated, 6:37 PM 8/9/2002]

 

More displacement to begin with.

Less displacement to begin with.

 

1.8 litre producing 140hp
1.6 litre producing 160hp

 

Horsepower sells cars.
Torque makes them move.

 

Not the old turbo and VTEC don't mix argument. Believe me VTEC and turbo mix beautifully. As far as advantages of each. The advantge of the B16 is that it has more power to begin with and is a very strong motor. The advantage of the B18 is it's cost lower compression ratio, and availability of turbo oriented aftermarket support. That is not to say that there isn't support for the b16 but there are more options when it comes to the b18. Except of course for the fact that the b16 and b18 have the same bore.

 

There is plenty support for both engines for turbo applications. So finding a kit for either wont be a problem.

VTEC is always a plus no matter the application, but with the LS it can be added(but with the added cost)

Compression is always an issue but that can be fixed with a thicker head gasket. The thing that might suck is the b16's short gearing might cause traction problems with high horsepower application(well make it worse, fawkin FWD). But for low boost it shoulnt be that bad if you can drive it.

So, to answer your question....VTEC + turbo =

You choose...Mike D

 

i have been wondering this as well. i mean all the fast drag hondas use vtec but i have heard that when boosting vtec has to much overlap on the cam. anybody else ever heard this?

 

here is what I heard from a questionable source (any truth?): the valve overlab that occurs with vtec depressurises the comb chamber. Any truth in this?

 

dial that overlap out and you are good. or get turbo cams, massive lift no overlap. there is always a way out. most people consider VTEC a "boost" as turbo or more closely, nitrous. it isn't. VTEC is an advantage in both the NA and FI application. do you really want to blip you engine every 10-15 sec while idling. that what you get if you run hi speed cam profile all the time. or 2500 RPM idle. and so much emmissions, diesel will look clean next to you. i had a zcar with carbs and a pretty wild cam, and my idle sucked, my emmissions were terrible (thank god for year discrepancy here in CA), and i had to rev my engine at idle so it won't die.
that is my 2 pence of n00b info. BTW i am planning to boost my future B16.
stan

 

Any other opinions?

 

Happpened on the dyno to me recently, Vtec wire came loose and vtec did not work on a pass. Instant loss of 100 whp. This was with stock gsr cams and 25 lbs of boost. Run the vtec because the ability to make hp is greater.

 

yes, mine. a friend here has a 99 civic si turbo B16 and of course he wants more power. The "easy" way is to swap out the bottom end in favor of a B20 or B18 bottom end... more displacement = much more power.

I think you need to think about real world power, not just "B16 = 160 hp" on paper.
There is no argument against a properly built B18 oir B20 against a B16. Those who know whats up would always want more displacement.

There is no reason you cannot get good gains from a B16. BUT you need to think about the other options, and I know a B20vtec will romp on a B16 whether you are talking all motor or turbo.... and a B18B can do the same as the B20 but without as much *** kicking to the B16.

 

Aside from displacement issues, is there any real danger in turbo'ing a VTEC-equipped engine?

 

fueling. but that is a real danger on ANY FI motor, VTEC or not. make sure you get adequate fuel to the boost levels. most people blow up their B16 due to pretty damn high static CR and leaning it at 8K while boosting. i would really worry about that 10.6:1 CR than VTEC.

 

i am curious about vtec on a single cam motor. they arent many cam option out there and how can you dial out the overlap with only one cam?

 

ill throw my .02 in
if you get the engine enough fuel and tune out and blowby that could be happening vtec is GREAT with a turbo.

 

there is not that much overlap on SOHC VTEC motor to begin with, not nearly as much as DOHC. and they do make turbo cams for D16Z6/Y8.
stan

 

If a man knows how to drive, hp is what moves a car.

Give me a lever long enough and I'll have the torque to move the world. I won't move it quickly though. You need power for that.

 

yes but were talking about a dohc motor

and the overlap can be dialed out with the aid of cam gears.

 

i thought we were talking about all motors actually. or is this just a dohc debate?

 

I have never had a problem. Proper air/fuel mix and low backpressure are the keys to a happy turbo. Spools at 3500rpm, VTEC at 4500, Peak torque at 5500, peak HP at 6600. I wouldn't have it any other way.

 

vtec+turbo= lots of fun...


whassup hadji...i live in south bend...come down to tha fort alot to party...


[Modified by forcfedcivic, 3:43 PM 8/11/2002]

 

you have similar internals
you wont get much more HP or torque out of either engine.
One is just safer to do in my opinion because of lower compression.
I went Ls turbo. I have not seen anyone do a B16A1 turbo set-up really. Not when they can do a b18B1 set-up that is usually safer because of the lowered compression. Plus, you can always do the frankenstein conversion later on. And not everyone who is doing good times runs VTEC.

Plus, look at the difference in power to the WHEELS, where it matters, maybe what? 5-7 HP difference? WHO cares.

I think it is more impressive to have a non-vtec motor that is runin fast. PLus the mods that I have seen for LS motors are cheaper.