i have installed aem cold air intake and comptec exhaust... my gas mileage has gone down about 30-50miles per full tank... this might be due to the fact that i drive my car harder but here is a question for you guys. if i were to get new comptec headers and full piping how much Hp would i get out of it and what would my gas mileage be like thanks guys mike

 

with free flowing air mods. THe flwo rate change is usually pretty small. If you are talking about changing the flow rate by forced induction that is a whole different story. I think it's your driving habits. Just think of how different your mileage is from city to highway. For example in my A4...I tend to get about 330-350 per tank. I always have some stop and go on the way to and from work every day. I took a road trip a few weeks ago and did all highway driving at 70 mph average (about 3600 RPM in my car). I hit wot a few times to pass and let my friend drive the car for a few miles at one point where he drove very agressively and at wot most of the time the RPMS were never below 3000 RPM. I still got 430 miles out of the tank. Just not having those city and stop and go miles made a hige difference. So you can see how driving habits affects mileage. When you mod, you drive harder usually like you say.

you could always reinstall your stock airbox and try to verify that your mileage is changing.

 

As you can see in previous posts there is no clear answer on HP gains for any upgrade. Gas mileage is based heavily on your driving habits so even that is something that would be tough to predict. Were you thinking of dual catalysts when you refered to full piping ?

 

Your gas mileage going down is due to you driving harder. No question.

Headers will get you about 25-30 HP at the wheel (peak) with the Competch. OBX headers may get you 2-3 more peak HP. Full piping won't do much as the stock exhaust is very free-flowing (which is why almost all mufflers for our car are axle-back).

Gas mileage would increase with the installation of headers due to better airflow, however, in reality you'll probably see a drop in MPG again b/c you'll still be driving hard...possibly harder.

 

what are some good prices that you guys came accross comptec header? i just figured i will keep all my mods comptech since acura will cover these mods

 

Since Acura has absolutely NO ties with Comptech... a mod by ANY company would be covered the same way across the board.

Cheapest I've seen Comptech's for is $1050 which can be had on this site if you are a Premium member....

FYI... OBX headers are $340 shipped and produce slightly more power....

 

this is what the guys at pasadena acura told me... that if i get comptech parts installed on to the car that they will still cover it under the warrenty,like if it causes problem wih my car due to comptech parts that they will fix it under acura warranty... any how has any one had any problem with obx headers?

 

[QUOTE]Originally posted by Ray_Khan
[. I took a road trip a few weeks ago and did all highway driving at 70 mph average (about 3600 RPM in my car).

What are you driving?? I just did two 500++ mile road trips in a week and set my cruise control at 74 mph[Wis. cops seem to ignore me at that speed] and I was barely turning 2000RPM.
I'm driving a SSM 03 TL-S.

 

Here's another possibility:

You have a small air leak on the headers, drawing outside air into the exhaust. This makes the O2 sensor think the engine is running lean, and the ECU compensates by richening the mixture. This, in turn, increases fuel consumption. This is a fairly common problem with header installs. Do you have more soot than normal in the tailpipe?

Drive "nice" for a tank or two, and see if you go back to normal. If not, look into this.

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3600rpm @ 70mph in an A4??? My friend's 99 doesn't rev that high (5 speed auto).

Todd

 

could some of you guys take time to post how many miles you get out of full tank of gas? it would be nice if you could post what mods you have on your cars also. thanks... mike

 

With just a K&N drop-in filter underhood, I get about 450 miles to a tank (max) driving all highway or about 350 mixed highway and around town. If I'm really leaning on it, it's more like 275.

 

Same on this end, K&N filter and Mobil1 0w-30. I saw no difference between Redline 5w-20 and Mobil1 0w-30 in gas mileage. FYI the K&N air filter made a big difference.

 

out of curiosity.. does that dealer sell Comptech parts? B/C if they do... that's why they're pushing you that way. Either way that's a cool deal, but you will be paying more for Comptech parts.

FYI... no one has had problems with the OBX headers, but they are still new. Either way they have a lifetime warranty on them.

 

sorry it took so long but ya the dealer does carry comptech parts
so if the headers them self come with life time warrenty does that mean it would cover any problem that would arise from headers being installed to my car? well i am getting about 270 max even if i drive very modestly... could it be that i am always stuck on 110 going though LA Downtown.... going and coming home? please let me know

 

mach3,

Are you talking about any problems a defective problem would cause. Say your headers cracked and as a result one of your exhaust valves cracked as a result. I would check into the warrantee if they cover any parts other than their own product