just installed my new JDM 4-1 header and carsound cat on saturday (thanks carlex!), with the proper gaskets. i had to go to the parts store to get longer bolts for the header/cat connection, and new bolts for the cat/exhaust connections. ai also reset the ECU.

anyway, after installing, i took it out for a test drive. it was about 9pm, about 65 degrees (cool), and the car felt great . . . VTEC pulls MUCH harder.

but, what i noticed is that i hear a lot of air 'rushing' sounds . . . kind of the hissing sound you get partial-throttle with an AEM CAI. my header/cat bolts are tight, and the connection is tight, and my cat/exhaust connection is very tight as well. so, i don't think i'm leaking anywhere.

i guess what i'm wondering is, is this typical? or should i not be hearing this?

the car has these engine mods:
-comptech icebox with filter
-JDM 4-1
-2.5" carsound cat
-60mm thermal cat-back

any thoughts? or am i nuts? thanks in advance...

 

I had the same thing happen when I put my Spoon header on. Its normal due to the increase of airflow. As long as it is all bolted on tightly you should be okay.

 

yeah, i assumed it was due to the increased airflow . . . the car was 'breathing' better . . . everything is VERY tight. i made very sure of that...

thanks!

 

The header is responsible for a lot of the way a car sounds. The JDM has a very characteristic sound on an R, as does the cat and the b-pipe. Since you are not using the stock b-pipe & muffler, I would say it is the header and cat.

I have almost the same setup, except I have an adapted stock b-pipe, a-la SMSP. It sounds close to stock, but the gains are very noticable. Will dyno in a few weeks.

If you had a leak, you would know it. poor gas mileage, loss of power, possibly check engine light...that loud sound...


[Modified by FBP_1171, 9:14 AM 8/20/2001]

 

The "Rushing" sounds are normal after adding the JDM header and High-flow cat. Don't worry, however, when you said "Everything is tight" I hope you left some slack in the springs for slight movement.. You don't want to tighten the springs all the way down. If so, you're fine.

 

cool. my 60mm thermal just got louder with the header and cat, and it was too loud already, so i will be SMSP-ing my stock b-pipe as well, and re-installing it with the stock muffler. i can't wait! it's so loud now...

well, i went out and bought some new bolts and springs, and the springs i got were about 1-2 coils shorter than the regular springs, and they are pretty much cranked all the way down; i can move the cat a little, but not much right now. is this a problem?

i would've used the stock header/cat springs, but one of my bolts was seized (only 6K miles on it, too!), and i didn't have the tools to cut the bolt off, so i had to fully remove the header and cat in one piece . . . what a pain!

 

Next time: WD-40 all the key bolts the night before the install. They will come off much easier. Not that that helps you now...

 

yep typical sound(s) as you mentioned is normal. but you might want to have another car buddy check the tightness of the bolts around the cat/header area!

Wouldn't want you to snap anything too far from home!

 

oh, they're definitely tight enough. it's not going anywhere. and i'm glad i also got the JDM lower header bracket . . . more peace of mind . . .

 

Which bracket? Isn't it the same as USDM?

 

nope.. Mike at IPS has them.

 

How about the JDM DC 4-1? Do I need this bracket? Mine is still not installed yet...

 

yep, that's where i got mine . . . it's slightly different in shape than the USDM one, about the same weight and a hell of a lot stronger!

 

Not sure about the DC.. but the JDM Honda has the provisions for the rear bracket.

Test to preform... once you have everything bolted up and inspected... grab the header near the O2 sensor... push up and down... I did on my car... 1/4" 1/2" movement....

= I will put one on my car.

William

 

I think the lower bracket is a MUST for the JDM 4-1. I had the header for a MONTH before I put it on because I was waiting for the bracket. The fact that it uses the lower bracket at all is one of the main reasons I went with this header. Another was the upper heatshield (I bought the lower also, but haven't put it on yet)...also supplied by Mike at IPS Thanks Mike!


[Modified by FBP_1171, 8:44 AM 8/21/2001]

 

I am still not sure which bracket you all are talking about. Is it where the two bolts goes near the O2 or the one in the middle of the header like the USDM one.

 

yep, that one . . . here's a pic: (sorry mike! )

 

It is not the 2 bolts that hold the 2 pieces of the USDM header together.

Nor is it the bracket on the front of the block.

It is right near the drivers side c.v. joint.

Sould be 2 nuts that you have to remove before the factory header can be removed. The bracket is held to the back side of the block with 2 bolts.

Look up at your oil filter from the underside... it should be right there.

Willis

 

This one? http://www.c-speedracing.com/howto/h...s/dsc00004.jpg



I hope the DC JDM doesn't need this bracket.

 

yes... that one.

It will not work with the Honda JDM header...

Will

 

The DC JDM uses the stock bracket

 

I just got a DC JDM and testpipe from godspeed. I believe i will need a new donut gasket to mate the two. Anyone know where to get one without paying the money for a jdm one? I figure an auto parts store must sell one that would work... but what size?

 

Peter - glad you like it!

sackdz (ed), if the collector is the same size as the JDM 4-1 header (I've heard conflicting accounts) I can supply you with a perfect-fit gasket.

 

Thanks for your info, Ninjaman.

SMSP said (if I remember correctly) that the OEM JDM uses a 65mm donut and the DC just a 2.5 inch one.


[Modified by EuroITR1689, 11:10 PM 8/21/2001]

 

back to the original question..i have the EXACT same setup..and that hissing sound your hearing is not the increased airflow....check the Cat- Bpipe connection with the three bolts...on mine, between the two bottom bolts there is a SMALL( emphasize SMALL) leak that does hiss sometimes...its leaving black residue and is visible on winter mornings when u can see the exhaust fumes....to find out for real hold a balled up shirt and plug up the rear muffler for a hot second or two and listen there and u should hear it. im probably gonna fix mine with a gasket or weld it closed.