What s up guys

I have an 06 mt with hondata, ct icebox, headers and rt cat for power mods. After installing comptech headers with rt cat (hondata and icebox were done before) i notice that in 1st gear the car wants to knock or die earlier.

lets say 800 rpm was when the car started to shake a little before now it starts around 1000-1200 rpm. I notice because i have to use the gas and clutch to get out of my apts up hill driveway.

I was thinking that i may need bigger injectors since the headers and cat were installed? has anyone experienced this with their mods?

searched already

any responses appreciated

Dom

 

If you do a search you will see many poeple have the normal comptech vibration/rattle this could be the same thing.

I think it has to do with the AC being on, in gear, and in and around the idle speed that the amount of air flow hits a natural resonance with either the header or the CAT that causes this vibration. I ordered my headers and they should be here in the next few days and i really hope that i don't get this problem with mine. If i do, i'm selling them and picking up a Topspeed header.

 

Headers have to be designed very well to minimize amount of pulsing just behind the valves. This is a lot more important at low RPMs where the exhaust gases are moving slowly and don't have much inertia to resist getting pulled backwards by pressure gradients caused by the closing of the exhaust valves. Low end torque is hugely effected by the velocity of the air moving through the intake/engine/exhaust. If when the exhaust valve opens there's a pressure wave moving in the opposite direction that the gases leaving the engine are trying to move, the piston has to push harder against the air in the cylinder to shove it out and into the header. This robs inertia from the turning motor which is not very high to start with around idle.

Most performance mods are going to be less engineered for the very bottom of the RPM range. The stock Honda exhaust and header are going to pay much closer attention to the low RPM characteristics because that's where the average driver is going to spend the majority of their time. So in response to your question, I doubt what you are experiencing has anything to do with the injectors being too small. The duty cycle of the stock injectors should have plenty of room to supply the required volume of fuel near idle. You just need to get used to your torque curve starting a bit higher up in the revs. On the plus side, it should peak sooner and stay flatter across the range with those mods.

 

Soon after I had my Topspeed header installed I noticed a "pulsing" when at idle. It has not led to rattling, at least not in the sense that is attributed to the Comptech header. It may idle a little rougher although it may also just be my imagination. My best description is that the engine seems to "pulse" about every 1-2 seconds. I don't feel it in the steering wheel and its not reflected in the tachometer (the tach is steady) but I do detect it in the sound.

I'm thinking that this may be the result of the ECU trying to, but not quite succeeding, adjust for the different flow characteristics of the header. At idle, every 1-2 sec. = 60-120 revolutions, just enough IMHO for the ECU to adjust the timing+a/f mix, sense the resulting engine output, and then make the adjustment again.

 

AHH great! I really don't know if i feel like dealing with that, i'm anal when it comes to that especially since i spend a lot of time at idle due to my commute and sitting in the parking lot and such. I am debating on even installing the CT headers....they should be at my house today so we'll see. If it rattles or pulses, i think i'll sell them and just save the money to put down on a 2nd edition of the new TSX turbo

 

check for exhaust leaks as well

 

I had a leaky flex pipe which I fixed. Maybe I need to get under the vehicle again.


Jordan, If you're anal about such things then you'll probably hear it but, trust me, it doesn't bother me.

 

If the performance is enough to make me forgive the noise then i'll let it go! If its not, then off it comes!!....lol

Do i need any additional gaskets or anything before installing it?

 

I believe the header comes with all the necessary gaskets. If not, I wouldn't reuse the exhaust manifold gasket. A new one costs $15-$18 at the dealership.

 

thanks everyone


its not the a/c rattle. i have that one and its easy to deal with. think thats just from the headers one piece design.

probably should check for leaks