Hello,

I recently installed a DC Sports 4-1 header on my 2000 Integra GS-R and now it is running poorly above 7,500 RPM. It's really hard for me to say what exactly it is doing but whatever it is, it's not very comforting.

Is this something that typically happens after a header install? My car has a short-ram intake but is otherwise completely stock. One of the guys at the shop where I had this installed mentioned that because the rest of my exhaust system is stock, maybe the new header is getting choked up? I don't know about that...

Thanks in advance,
Dan

 

Be more specific as to what your car is doing.

 

It almost sounds like the ignition is misfiring, but it also sounds like the fuel mixture is going too rich. Perhaps "breaking up" is the best description I can think of.

 

did you check your O2 sensor when you installed the header? was it in good shape? im not really an expert but its something you can check/replace easily and relatively cheaply.

 

The Acura dealership said that the O2 sensors had a very slight variation in their resistance level readings but they did not recommend replacing them. I am not getting a check engine light.

 

theres 2 o2 sensors on that car and you'll pick them up for 50-70 each and those are non-OEM parts. O2 sensor should throw a CEL but sometimes doesn't. poor driveability (like what you're experiencing) has so many factors that could be related. heres something to try: pull the plugs, clean them up w/ some sand paper (just a little skuff) then re-gap them (using the little circle tool they sell at autozone for like 30 cents) and put them back in. if you have a buddy w/ another gsr, see if he'll let you try his plug wires. ask him if you might be able to try his distributor.

i could understand a slight choke up high because of the bottle neck you've created w/ the dc header and stock exhaust, but it wouldn't "breaking up" it would just simply make a little less power. you're having an ignition or sensor issue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j00tel &raquo;</TD></TR><TR><TD CLASS="quote">It almost sounds like the ignition is misfiring, but it also sounds like the fuel mixture is going too rich. Perhaps "breaking up" is the best description I can think of.
</TD></TR></TABLE>

Your header isn't going to cause this problem. Also, your new header isn't even going to create any gains in hp since the rest of your exhaust is stock and is "bottlenecking" the whole system.

This is a retarded analogy, but it makes sense:

Try blowing into a coffee stirrer straw. Not easy. Now trying blowing through a regular straw with the coffee straw attached to the end of it. It won't be any easier to blow through the 2 attached straws, would it? Even though the regular straw is larger and flows better, your blowing is still restricted because the coffee stirrer straw is bottlenecking the flow.

 

Try resetting your ECU.

 

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


This is a retarded analogy, but it makes sense:

Try blowing into a coffee stirrer straw. Not easy. Now trying blowing through a regular straw with the coffee straw attached to the end of it. It won't be any easier to blow through the 2 attached straws, would it? Even though the regular straw is larger and flows better, your blowing is still restricted because the coffee stirrer straw is bottlenecking the flow. </TD></TR></TABLE>

wow were you bored at work or sumthin but good analogy or whaever they say

 

It wouldn't be the O2 sensors anyway. They do very little at full throttle.

 

Its gotta be the bottle neck. I have a dc 4-1 stock cat and a tanabe hyper catback( which i cant stand) and mines fine above 7500

 

Not retarded analogy, but you might look retarded blowing through those straws.

How hard would it be for you to re-install the OEM exhaust manifold? If that's the only thing you changed and are now having problems.....

 

I'm voting for the bottle necking. Running the DC sports 4-1 header and a Apex Catback (Beautiful sound by the way, deep and sounds like an Indy car--I'd have to look at the receipt to remember exactly which one it is)..But back to the point..I'm fine at high RPM's running the same header and an exhaust..Hi fow cat helps, and is something I'm going for next.

 

Is this done by disconnecting the battery?

 

Actually the OEM manifold cracked, that's why I installed the header in the first place (cheaper than the OEM manifold plus, well, it's a header!).

 

but wouldn't bott necking (?) be felt in the whole rpm range not just the higher rpm's

to the person with the problem, does the car run fine before 7500rpm or is it the same as stock

 

Car runs great and pulls hard before 7,500 RPM, starts "breaking up" after roughly 7,500 RPM.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j00tel &raquo;</TD></TR><TR><TD CLASS="quote">Car runs great and pulls hard before 7,500 RPM, starts "breaking up" after roughly 7,500 RPM.
</TD></TR></TABLE>

just get a new exhaust with similar size piping as the header and that should fix the problem

 

I love it when people attempt to describe the exhaust system in layman's terms by using the blow through a small straw analogy. The stock exhaust wouldn't just choke it up at 7500, it would lag it through the whole rpm range. Could be something ignition related. When was the last time you replaced/inspected you plugs, wires, cap, rotor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j00tel &raquo;</TD></TR><TR><TD CLASS="quote">Hello,

I recently installed a DC Sports 4-1 header on my 2000 Integra GS-R and now it is running poorly above 7,500 RPM. It's really hard for me to say what exactly it is doing but whatever it is, it's not very comforting.

Is this something that typically happens after a header install? My car has a short-ram intake but is otherwise completely stock. One of the guys at the shop where I had this installed mentioned that because the rest of my exhaust system is stock, maybe the new header is getting choked up? I don't know about that...

Thanks in advance,
Dan
</TD></TR></TABLE>

O2 sensor prolly installed back in?

**** i heard something u need to do after install new header like somethit with ecu omg somehow i can't remember...dann dude i'll get back to you later...

 

true, the lag would be felt throughout the whole RPM range...but 'breaking up' would not be truly noticed until your are at full throttle in the upper RPMS...where you are getting huge amounts of exhaust to get rid of....

the stock exhaust is fine for that...cause it was designed to be...but when you increase the diameter of the header piping to increase flow....all of this exhaust gas will move freely and quickly down the pipe..until it hits the bottleneck, then its gonna build up.. and back to the head...where its reverse exhaust pulse its gonna interefere with the exhaust entering the header...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ebelp &raquo;</TD></TR><TR><TD CLASS="quote">Try blowing into a coffee stirrer straw. Not easy. Now trying blowing through a regular straw with the coffee straw attached to the end of it. It won't be any easier to blow through the 2 attached straws, would it? Even though the regular straw is larger and flows better, your blowing is still restricted because the coffee stirrer straw is bottlenecking the flow. </TD></TR></TABLE>

well said.

 

Just pop the hood and you'll see the Fuse box in the top left corner of the engine bay near the battery.

Follow these steps:

1) Make sure that the car is properly warmed up to operating temperature.
2) Shut off the car. Remove the 15A and 7.5A fuses for 10-15mins (1st and 2nd fuses in the fuse box located in the top left corner)
3) Put the fuses back inside the fuse box, start the engine and let it idle for 10-15 mins W/O touching anything including the accelerator pedal. Make sure no components are operating as well
4) Take the car out for a drive.

I'm not sure if this will solve your problem but its worth a try, especially since you had a header and exhaust installed. This should fix your A/F ratio amongst other things, hopefully.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsrboi80 &raquo;</TD></TR><TR><TD CLASS="quote">Its gotta be the bottle neck. I have a dc 4-1 stock cat and a tanabe hyper catback( which i cant stand) and mines fine above 7500 </TD></TR></TABLE>

lol, that must mean his problem is the bottleneck affect if your car is fine above 7500. hell, 99% of the cars on this thread probably perform fine above 7500 rpms, so yes... its got to be the bottleneck!

 

Try running open header and see if it changes anything in the higher RPMs. If it still stumbles, then it's not a bottleneck. Did the shop have to fab anything up to get the header installed?