Hello all, I'm new here... Although I've lurked for awhile >.>

On to the point... I have a 93 dx coupe with a JDM B18C swap (SiR-G) that I've been driving for almost a year now with no upgrades except a K&N air intake and a MagnaFlow cat-back exhaust. I now have some friends that are trying to talk me into hitting the track with them, so I decided to start working on upgrades and I require the expert advice of some HT members.

I'm trying to start basic with just bolt ons, and so far I'm looking at a dc sports 4-1 header and a skunk2 intake manifold. I'd just like to know what kind of issues I'd be running into, if any, by going through with this. From what I've read, I'll have better top end going with 4-1 headers, but my low end will suffer. My swap already has crappy torque to begin with, but I'd still like to have some oomph. Would going with 4-2-1 hurt my top end much? Also, what should I expect from the intake manifold?

The main reason I'm concerned about all this is because of seeing several posts regarding problems with backpressure...

Any advice would be greatly appreciated, thanks.

Edit: It's worth adding that I know enough to get around, but am not a professional nor expert by any stretch of the imagination when it comes to performance parts... So I'm trying to keep things as simple as possible and sticking with an NA build while avoiding any engine rebuilding.

 

if u do a skunk2 intake mani with a 68mm throttle body a dc 4-2-1 header with 2 1/4 piping the car will feel alot faster i went from a 4-2-1 to a 4-1 on my fully built ls vtec and i noticed a difference low end

 

What about drivability? This car is still gonna be a daily driver... And what about the sound with your build? My exhaust sounds nice and deep until I really rev it and it has that nice, race-like sound. I don't want it to sound ricey :/

 

Here's my advice from my shop doing many different installs on 94-01 GS-Rs.

<U>Header:</U>

IMO the 4-1 should not hurt any low/mid range power and/or torque. A good 4-1 should increase numbers across the board. Funny thing is that even the crazy $1,200.00 custom headers that are often referred to as "4-1" are actually often a different sort of 4-2-1 with the collectors going to two tubes right before the flange at the convertor.

<U>Skunk2 manifold:</U>

This is a "slippery slope" mod IMO. What do I mean? Well it's a slippery slope because once you do it you'll NEED to do other mods just to capitalize on the potential gains. If you do not then you will actually lose drivebility, low/midrange power, and maybe gain just a few extra whp at the very very end of your rpm range/rev limiter.

You must upgrade your ECU first to take advantage of the different manifold. Honda designed the stock GS-R manifold with the 4500rpm VTEC point and then the secondary butterfly opening up at 6200rpm or so. A Skunk2 manifold models itself after the ITR manifold which has a much higher VTEC point at say 6200rpm or so. In other words a Skunk2 manifold with a GS-R/SiR-G ECU = shitty.

Also keep in mind that Honda designed the SiR-G/GS-R engine/manifold to be ran with the taller SiR-G/GS-R tranny. The VTEC is set low to accomdate not only the cam/intake manifold, but also so that the VTEC doesn't drop out when you shift at redline with the taller GS-R/SiR-G tranny.

So really ideally you'd want a rechipped ECU and a ITR/B16A shorter geared tranny in order to take advantage of the Skunk2 manifold.

Also ideally you'd want cams that are more Type R like, but I digress.

IMO the Skunk2 manifold sucks ***** if done as a stand-alone mod. As part of an entire package that includes cams, tranny, ECU, etc. it's great as it mirrors the ITR manifold, and Honda put engough R&D in the ITR engine/manifold to make me think it's a worthwhile upgrade if done along with the other components.

 

...Wow. That's the kind of advice I needed! If I could afford tranny work and all that other jazz, I would be all over it. But unfortunately I'm working and going to school, trying to finish up my last year and graduate so I don't really have the time nor money for major work like that. Still, I'll definitely still get headers but the thorough explanation for the manifold has forced me to shy away from it.

Ideally, I'd like to get an RSX Type-S a few years down the road (the B18C has made me fall in love with the high revving vtec builds), but civic has been very good to me and will stay in the family for years to come (after all, the engine only had 40k on it when it was swapped in last year).

Anywho, thanks for the advice thus far... Any suggestions for minor mods are more than welcome. After all, I just want the car to have a little more pep so it can compete with the SIs at the track heh.

 

Well a cold air intake and a decent header would be starting points IMO. you can mod a few things around to use a Integra GS-R CAI kit such as relocating the coolant overflow bottle since the Integra intake piping routes right there and bends around the right side frame rail rather than the intake piping going through the hole by the right headlight.

There is a guy in GA that seels some really nice replica HyTech style headers. You're in GA, right? I'll see if I can find his info and PM it to you.

 

Yeah, I'm about 3 hours south of Atlanta. I did have an older AEM CAI, but it had to be bent to fit and even then I had issues with water getting on the filter... So buying a cheap short ram replacement from advance auto was the quickest and easiest solution at the time. If I could find a cover of some sort fort the filter then that'd work... The cheap plastic splash guards really never helped keep water out.


Modified by arterial_black at 12:30 PM 10/13/2008