I decided i would fit the header myself this morning as i got tired on the guy i usually get to do stuff like this being so busy and not being able to fit me in till next week. Anyway had it fitted in approx 1 hour which wasnt bad as i was on my own. It went on simply but the only problem had was i wasnt able to use the stock bracket on the 2-1 section as the bracket on the 5zigen header didnt reach, so i just left it off (hopefully this wont cause any vibration problems)

Anyway i took the car out for a run, I didnt notice any noise difference in my exhaust for a start. Once the engine was up to full temperature i found some lonely stretches of road and slowed way down, dropped it into second and gunned it.... :shock: where's my VTEC gone?????????? Before at 5800rpm there was i'd estimate an 80% increase in noise once vtec cut in, now its more like 25%, its so much more subdued in sound...its still working and i still get the same pushed back in the seat feeling but i have lost the noise (which i loved) :-(

I'm guessing that due to the larger piping size of the header that the exhaust gasses escape quicker which in turns allows the engine to spin freer and so there is less difference in the before and after (vtec) velocity of the exhaust gasses...i hope this is what it is anyway :-?

VTEC does come up a lot faster now though but as i said its more subdued noise wise...i'm not sure i like this. I loved the huge increase in noise beforehand along with a big kick and top end feels exactly as it did beforehand. I know i went for the 4-2-1 primarily because i felt the ITR was lacking in the low end, and the header has increased low end power (i believe) and i also knew that i was going to gain very little if anything at all top end which didnt bother me, but i wasn't expecting my beautiful VTEC roar to be lessened by the whole thing.....so now my stupid head is thinking on getting a 4-1 :-?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mugenracer &raquo;</TD></TR><TR><TD CLASS="quote">so now my stupid head is thinking on getting a 4-1 :-?</TD></TR></TABLE>

just b/c of the sound difference....???

 

Are you sure you don't have an exhaust leak?

 

I dont think so, i dont hear it blowing out anywhere and the exhaust note sounds as it did before hand.

 

A header itself won't add much noise. If you want noise you should get an open intake and an N1 exhaust.

 

I wasnt looking for it to increase noise, but i didnt expect it to supress the noise i already had. I have an open apexi intake and so the noise at vtec was pretty loud, but ist now so much less than it used to be.

 

I didn't like the sound of my Mugen 4-1 header when I got it.

I had a resonance at 3-4K rpm that sounded like a loose heatshield.

I liked my Spoon 4-2-1 better but dented it on a speed bump.

Since then I've had a Hytech and that sounds different too.

Suffice it to say that each header will have its own sound characteristics.


Modified by Big Phat R at 10:36 AM 3/17/2005

 

isn't it possible that it is helping your motor to run more efficiently, thus feeling smoother engagement. sounds stupid but just because you don't "feel" it doesn't mean you aren't going faster.

 

From what I have read here when Vtec is less pronounced it's smoother therefor a faster car... but that is usually with tuning.

I had the oem jdm 4-1 with testpipe and stock exhaust and the Vtec sounded the exact same now with the same header and test pipe but with the BCIII cat back the crossover is smoother and much quieter. But the caR does pull much much harder.

 

With a aftermarket 4-2-1 you get more midrange, so the vtec doesnt kick as hard as a 4-1. Im having the same feeling with my current 4-2-1 header. Vtec is so smooth you cant even tell its on -_-

 

I understand what everyone is saying and i agree with you hadboosttroy on the reason it may be happening...but what suprised me was that i went from a 96spec 4-2-1 which has a 2.38" collector to the 5zigen which has a 0.12" larger collector and the same 4-2-1 configuration and i just wasnt expecting the vast difference in noise at VTEC x-over. The car definitely definitely is quicker up to vtec, i cant say there is any difference after it though, and it does pull smoother in the higher gears when i floor it. I guess i'll run it for now and hopefully it'll grow on me. I have had the car just over a year now and was used to the noise i got when i hit 5800rpm, its a little disappointing to think that that is now gone, even though the car is possibly better for it. I'm going to book it in for a dyno run next week as the header is the only mod i have added since the last one in november so it should show me exactlywhere the improvements are in the power band etc etc

 

yeah please get back to us with the dyno numbers, im pretty anxious. ive always liked the 5zigen header, blown away why more people don't use it as it is a really good deal

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mugenracer &raquo;</TD></TR><TR><TD CLASS="quote"> from a 96spec 4-2-1 which has a 2.38" collector to the 5zigen which has a 0.12" larger collector and the same 4-2-1 configuration and i just wasnt expecting the vast difference in noise at VTEC x-over.
</TD></TR></TABLE>
In that case I think the difference is very small. The primary tubes of the 5zigen header looks kinda small. What is the diameter of them?

 

dimensions are:
42.7mm
50.8mm
63.5mm

The dimensions of primaries and secondary pipes is the same as the majority of JDM made aftermarket headers for the ITR/B18C

I have only done approx 40miles since fitting it and it has gone a sweet gold/bronze colour now...i'd love if it stayed that colour

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mugenracer &raquo;</TD></TR><TR><TD CLASS="quote">dimensions are:
42.7mm
50.8mm
63.5mm
</TD></TR></TABLE>

The primaries of the Toda are a little bit bigger. The Honda JDM 4-1 has 44 mm primaries.

 

Hence the word <u>majority</u> and not 'all'. Apexi spoon mugen HKS and GReddy use the same pipe size for primary/secondary/final pipe diameter in their 4-2-1 headers. I know from reading numerous threads that the Toda header seems to be the daddy of them all, and believe me if i had he funds i would have bought one. I done as much research on the 5zigen as was possible and i found the piping size was the same as most other 4-2-1 headers...budget was also a consideration and the 5zigen was also a very reasonable price. I will get a dyno run done in the next week or so hopefully and then i will be able to show a proper comparisson (whether good or not). Its sort of growing on me at present, i can feel the lower end gains quite easily, and i know the noise was mainly a placebo thing but for me the placebo worked and truthfully i would be willing to sacrifice whatever gains there is from this header for the way the car sounded and ran prior to fitting it. That comment probably runs against the grain of many ITR owners/enthusiasts but what the hey, its my car, money, time and decision at the end of the day


Modified by mugenracer at 3:34 AM 3/19/2005

 

I think it might be possible you are doing all your testing with a broken, or at the minimum, a faulty Butt Dyno. Seriously, the sound of the VTACK makes as much power as well applied spoon stickers. 4-2-1 Headers are best suited for the GSR powerplant. Any R owner that does about 5 minutes of research on this board knows that a 4-1 header with a 2.5" collector and long runners makes the best power on the C5, be it a JDM DC2 header, DC Sports or SMSP.

 

LoL!!! Yeah i know a 4-1 header makes better power but the car is lowered and i had a DC JDM 4-1 on my last integra which was also lowered and i knocked the crap out of that thing on ur crap roads at least once a week, that is the only reason i went for a 4-2-1 header.

 

It's completely normal that you get less sound when changing to a better header/exhaust due to less backpreassure. This is particulary noticable when running an aftermarket air intake. My J's intake became much more quiet when I put on the Toda header. Less backpreassure = less intake noice.

Your exhaust noice should not be much different though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Pompiuses &raquo;</TD></TR><TR><TD CLASS="quote">It's completely normal that you get less sound when changing to a better header/exhaust due to less backpreassure. This is particulary noticable when running an aftermarket air intake. My J's intake became much more quiet when I put on the Toda header. Less backpreassure = less intake noice.
</TD></TR></TABLE>
It was the opposite for me. It became a bit louder with my JDM 4-1 header. I also have an open short ram intake.

 

Exhaust noise is pretty similar, a bit deeper if anything, but no louder (which i didnt want anyway)