My question is when swaping a B18b into a 91 CRX Si, which would be a good intake to use n what kind of headers should I use with out modifing my xmember or relocating my battery? Thanks in advance.


Modified by crxguy05sir at 3:42 PM 5/26/2003

 

JDM ITR header and Skunk2 intake manifold

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by poison &raquo;</TD></TR><TR><TD CLASS="quote">JDM ITR header and Skunk2 intake manifold</TD></TR></TABLE>
with js racing intake

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by poison &raquo;</TD></TR><TR><TD CLASS="quote">JDM ITR header and Skunk2 intake manifold</TD></TR></TABLE>

I could be wrong (because I've never used these myself on a B18B), but a 4-1 header and large IM seem kinda oversized on a motor that doesn't go past 7000 rpm stock. Perhaps they would be well suited to a drag motor that is only interested in peak-power, or a motor that has been cammed to handle the extra flow capacity. For a better daily driver I would economically choose a decent 4-2-1 designed header and aformentioned J's-Racing intake. It all depends on what you want to do with the car though...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thirdvector &raquo;</TD></TR><TR><TD CLASS="quote">

I could be wrong ...</TD></TR></TABLE>
you are, theyll benefit the setup no matter.

 

you;ll need an aftermarket crossmember if you want the header to fit, unless you want to bang the **** out of the stock one
place racing has one for a good price compared to z10 and jimfab x members

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridvteceg &raquo;</TD></TR><TR><TD CLASS="quote">
you are, theyll benefit the setup no matter.</TD></TR></TABLE>

But WHERE in the rpm range will it benifit? I have no doubt that they will increase the peak-power simply by making more air available, but I do not see how parts that were designed for above 4000 rpm on a 8400 rpm (typer) motor will help a 7000 rpm (ls) motor IN ALL CIRCUMSTANCES. In addition, those parts were designed to operate during vtec engagement. A B18B motor does not have vtec, therefore it's cam specs and compression ratio were also not designed to flow the air neccessary to fill a large IM or a 4-1 designed header.

Like I said before, if you are building a drag motor (or just care about peak-power) the large IM and 4-1 header would be a great place to START, but certainly not finish.

hybridcivicvteceg- You tell me I'm wrong, but you don't tell us why I'm wrong. Where's the theory behind slapping on big-flow parts onto an engine that wasn't designed for it? Before and after dyno charts would help out alot also.

 

well skunk2 makes an LS manifold, so it is obviously designed for it, a 4-1 header will flow better regardless so that helps there, and its no just "big" flow, its how it flows. the header would probably be benefitial above 3.5k or so and the IM above 4.5 or 5k...
you have an LS motor, what did you expect. theyre not tight for allmotor, though some have made decent setups, but generally, and with a small budget, theyre not.

BTW: "onto an engine that wasn't designed for it? " to clear this up, none of our engines were specifically "designed" for all out performance, but it is the part that is made to be designed for the motor, you have it backwards.

 

Thank you, I find one-sentence ansewers woefully inadequate. I wasn't aware that Skunk2 manufactured a manifold specifically for the LS. That changes things somewhat, but I still hold the opinion that low-end torque will suffer in the name of high-end horsepower with bigger intake/exhaust manifolds and without the cams to fill them properly. I am not arguing that they will not improve high-end power.

I guess the whole reason I contended your opinion to begin with is that I find a blanket statement promoting parts that are designed for only one end of the rev-range inadequate without knowing what he wants to use the car for. Which I might add he hasn't bothered to tell us yet. I am not saying you are wrong, just that he should understand what the parts were designed for (which part of the powerband) and what kind of compromises he should expect. I would personally love to see a dyno chart of the IM alone on an LS.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thirdvector &raquo;</TD></TR><TR><TD CLASS="quote">I wasn't aware that Skunk2 manufactured a manifold specifically for the LS.
</TD></TR></TABLE>
they have different flanges, of course the LS on is diff than a b16 or gsr one

 

that is very tru

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridvteceg &raquo;</TD></TR><TR><TD CLASS="quote">
they have different flanges, of course the LS on is diff than a b16 or gsr one</TD></TR></TABLE>

&lt;--OWNED BY THE LS INTAKE MANIFOLD FLANGE KNOWLEDGE!

just kidding, but I guess I shoulda thought of that.

 

Do I have to use place racing mounts with the crossmember or can I interchange