running open headers ?
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From: Valdosta Ga.
Yeah thanks Elliot haha. Im not going to drive it anymore until the Y-pipe gets installed. It should be here Fri. I'll post back with results for people who might have this problem in the future.
I was wondering something though. I installed the mailorder tune today and was wondering when the car is in open loop does it still use the mailorder tune configurations or does it go back completely stock? If I unplugged my O2's would the tune still be helping any or would it bypass it? Kinda hard to explain. Im not going to do it but I was just wondering.
I was wondering something though. I installed the mailorder tune today and was wondering when the car is in open loop does it still use the mailorder tune configurations or does it go back completely stock? If I unplugged my O2's would the tune still be helping any or would it bypass it? Kinda hard to explain. Im not going to do it but I was just wondering.
Yeah thanks Elliot haha. Im not going to drive it anymore until the Y-pipe gets installed. It should be here Fri. I'll post back with results for people who might have this problem in the future.
I was wondering something though. I installed the mailorder tune today and was wondering when the car is in open loop does it still use the mailorder tune configurations or does it go back completely stock? If I unplugged my O2's would the tune still be helping any or would it bypass it? Kinda hard to explain. Im not going to do it but I was just wondering.
I was wondering something though. I installed the mailorder tune today and was wondering when the car is in open loop does it still use the mailorder tune configurations or does it go back completely stock? If I unplugged my O2's would the tune still be helping any or would it bypass it? Kinda hard to explain. Im not going to do it but I was just wondering.
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From: Valdosta Ga.
I see. Thanks for all the help. If the Y-pipe doesnt cure it the next thing I was going to do is unplug the O2's and if that works it should rule out the rocker arms not being adjusted right. Then I will probably need O2's. We'll just have to see.
^^ Yeah, hopefully you can get it running correctly here soon so you can see how them headers changed the feel of your ride. Them Macs really give the car good low end and mid range power.
The backpressure thing is a myth.
90% chance it's the O2 sensors reading fresh air and telling the computer to dump in fuel. I had this exact thing happen when I drove my car home from the shop with open Hooker LT's. Added a y-pipe and re-set the computer and all problems were solved.
90% chance it's the O2 sensors reading fresh air and telling the computer to dump in fuel. I had this exact thing happen when I drove my car home from the shop with open Hooker LT's. Added a y-pipe and re-set the computer and all problems were solved.
After a tune open headers will have more hp and tq then a full exhaust every time. "Backpressure" costs power, scavenging is what makes it(and where the myth comes from)...anything post collector will not aid scavenging and will only hurt power on a tuned car.
My car felt like it lost a lot of torque down low running open headers. . Felt about like what the op described. Low rpm's loss of power, high rpm's felt normal. It was a night and day difference when I got the rest of my exhaust on
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I agree with the o2 sensor theory. If it was the rockers it would have fallen on its face before the headers wouldent it? Let me know how that tune is after you get it running right, im gunna have them do mine here in a bit for 22# to 23# injectors, lower fan temps, and pacesetter lt's.
Your also playing with fire running open headers in cold air, you could warp valves......that would pretty much suck lol.
Your also playing with fire running open headers in cold air, you could warp valves......that would pretty much suck lol.
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From: Valdosta Ga.
Well Im 10 miles from the Florida line so the air down here is pretty warm and I waited until it was a hot day before I even drove it so I dont think I could have hurt it with what little I did drive it. Its crazy how some of you say it didnt affect driveability but some say it did. I think if I had LT's if might have been different. Im anxious to see what happens with the Y-pipe installed. I have driven a car with the rockers too tight so I kinda know what to feel for and this didnt feel like that. I have also driven a car with bad O2's (my old 94 Z28) and it did feel quite similar to that so Im leaning toward bad readings on the O2's myself.
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From: Valdosta Ga.
Well the MF'rs (C.U.N.D. racing) sent me the wrong Y-pipe and so I called Mac and they said it would take 4-5 weeks and they have to make it!! I cant believe I have to wait this long for 1 pipe. Anybody have one laying around? I will pay good not to have to wait that long!!
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Probably has to do with how far the O2 sensor is from the header collector on the particular set being used. If they're furher forward on the pipe, it may not be an issue. With Hooker LT's, it's definitely an issue.
That is why I bought two 12" 3" diameter pipes from Autozone and clamped them on to the end of my PS headers until I got my Y-pipe in the mail. Doing that helped keep my o2 readings in check. Damn, the car was LOUD! After I dialed in the rocker adjustment, car ran like a beast. Put the full exhaust on and the car ran the same, just what I was expecting. Back pressure is a myth!
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From: Valdosta Ga.
UPDATE!! Well after what like 5 or 6 weeks now I finally got the Y-pipe from Mac after they screwed up numerous times. They had already screwed up 3 times and when it came they forgot the studs and nuts so I had to run all over town to find some after I called them 3 times to make sure it was included. My experience with MAC was without a doubt the worst I have ever had. The parts are great but the way they do business is horrible!! I will never order from them again.
Enough ranting back on topic. I bolted the Y-pipe up and took it for a test drive and its still running rough below 2,000 RPM,s and doesnt feel like it has much power. So I unhooked 1 O2 sensor and drove it again and it felt a little better but not quite right yet. The car idles perfectly though and revs nice while in park or nuetral. Do I need to unhook both O2's or would 1 unplugged be the same as 2? Thanks.
Enough ranting back on topic. I bolted the Y-pipe up and took it for a test drive and its still running rough below 2,000 RPM,s and doesnt feel like it has much power. So I unhooked 1 O2 sensor and drove it again and it felt a little better but not quite right yet. The car idles perfectly though and revs nice while in park or nuetral. Do I need to unhook both O2's or would 1 unplugged be the same as 2? Thanks.
