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What is holding me back?

4K views 21 replies 11 participants last post by  AscensionMotorsports 
#1 ·
Car is an 08 Si. Vibrant header. Injen cai. Apexi ws2 exhaust. High flow cat. Tuned on flashpro. Car only put down 200whp on a dynojet, which is super low, isn't it? If that was on a dyno dynamics, it'd probably barely be 190whp from what I've seen. Does it sound like there's an issue here, since the numbers are so damn low. Wondering if the high flow cat and apexi ws2 are really holding me back that much? I believe the ws2 is 2.36" but could have read wrong. Either way, what can I address to get some more power? I assume cams and a 3" are my only options. Just wondering why my numbers are so low.
 
#2 ·
Do you have a dyno plot of the car stock, compared the tuned w/mods plot?

A good header and exhaust can go a long ways on the stock motors. They respond well to bolt-ons.

What elevation are you at? What is your injector duty cycle looking like where you are seeing max power?
 
#3 ·
I don't have any of that info around. Not sure where the dyno sheet went. The tune was over a year ago. Really conservative tune, and it was nearly 100 degrees that day. I care a lot more about how the car drives than getting a high dyno number. I just want another 30whp or so and I'll be happy. I don't go to the track or beat on the car much, but it just feels boring. 200whp may be fun in an eg, but an 8th Civic is so heavy it needs a bit more power.

What does the average k20 put down with basic i/h/e?
 
#7 ·
I almost wonder if something is wrong or I got a dud of a motor lol. Injen CAI is one of the best intakes for an 8th gen. The Ws2 is small, and I'm not sure how the header stacks up. I'm really trying to avoid cams if I can. Just wondering where you gain the most whp on a k20 between the intake, exhaust or header.
 
#11 ·
My friend recently installed the apexi worldsport exhaust to meet sound requirements for Lime Rock. He was making 230whp with a 3.0" exhaust & power dropped to just about 200whp (with no tuning). After tuning he was making 210whp with the worldsport.

other mods were
-K20z3 86.5mm 11.5:1 CP & 100 octane fuel
-itr/z1 cams
-RRC
-stock 60mm DBW TB
-skunk2 header (probably marginally better than vibrant)
-only thing that changed was the cat-back exhaust
all on a 2008 civic si

the apexi WS actually chokes down to 2.25-2.3" at the muffler - which is not straight thru further impeding flow :cool:
 
#20 ·
well if you dont want to have a loud exaust, i know alot k swap cars are running this set up, its low deep tone and yet pretty quiet! at idle when engine are warm, you cant barely hear the exaust. but at WOT it opens up and gets decent loud but still very low deep tone.

3" k teller piping, 2-20" resonator (3"), vibrant 2.5 or 3" black muffler.

of course your gonna need to take to someone knows how to weld. i cant chime in how loud most other off shelf exhaust are. maybe someone will.

this is quick videos of my cars i recorded for my forsale thread but you can get a decent idea how deep tone this set up is, no rasp at all!

WOT 1st and 2nd, 3rd and 4th i didnt shift to redline

http://www.youtube.com/watch?v=-1Ic...DvjVQa1PpcFMFSJ975IRP-l8ak6Npcu1vBvdoDPzw9M0=

skip to 55 second to hear the exaust at idle, it was still warming up. not fully warm'ed yet, but its usually little quiet'er

http://www.youtube.com/watch?v=OA-a...DvjVQa1PpcFMFSJ975IRP-gLyvWBAF0HcQzObbRMPW_o=

cold start, its pretty deep tone

http://www.youtube.com/watch?v=ugrP...DvjVQa1PpcFMFSJ975IRP-qBOKQKjeQWSFHos5BzFG2c=
 
#21 ·
oh ya your gonna make at least few more ponies across whole power band with the set up i mention'ed since its pretty much straight through 3" without a cat. i dyno'ed at 216whp on mustang dyno, so it should read 3-7 more on a dynojet.

all stock motor, crappy 3" SRI, ssr race header, 3" exhaust.

good luck! :up:
 
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