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lost low end/power after header install

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Old 05-25-2010, 10:24 AM
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if the y pipe was hitting anywhere underneath the car on accelleration, thats something I would probably be able to hear knocking on the metal right?
Old 05-25-2010, 10:30 AM
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Originally Posted by evo462
$450??? I hope it doesn't cost that much, that's more than my headers set me back.
Take this however you want it. If $450 is too much money for a dyno tune.....find another hobby. If you didn't calculate a tune into the mix of your recent set of mods, stop what you're doing, step back, and research if this is what you want to be doing as a hobby. Sorry I didn't sugar coat it, and guys will be here to help ya if you need questions, but you have to pay to play.
Old 05-25-2010, 04:30 PM
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actually.. In My opinion.. $450 for a dyno tune is too much..considering the fact that most places dyno tune is nothing more than 3-5 pulls and they typically dont stick a wideband in a bung..its just the clamp at the rear...which sucks *** and is not accurate compared to having one in an actual exhaust bung in front of any catalytic converters...
I charge less than that for a complete tune...WOT, part throttle, idle, air fuel/spark..

also you tune it on the dyno to find what it likes for air/fuel and spark... then you still need to retune it on the street for real world airflow..making the air/fuel match what you did on the dyno...


all of that also has nothing to do with a driveability tune / part throttle adjustment which is where people "think" they have lost all this low end torque...just a slight change in spark can make a huge difference at part throttle...

and putting on headers will never result in lower torque anywhere in the spectrum... it may accentuate the increase you get in the upper end...but you will never loose torque from long tube headers
Old 05-25-2010, 05:50 PM
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I'm having it hooked up to a wide band, and it will be given a driveability and WOT tune + other misc enhancements. It costs about half of that "$450" number.

As you mentioned...the "part throttle" times are where I've really noticed a change in performance (well, that and lower RPM WOT stuff)...I'm hoping the tune will really liven the car up again. I could have plenty of fun under 3500 RPM and not even need to wind it out prior to the header install. Rarely ever do I do any sort of driving that would amount to a quarter mile run, so the lower RPM part throttle stuff was really noticeable to me as it was right in the power band I most frequently used.

Last edited by evo462; 05-25-2010 at 06:00 PM.
Old 05-26-2010, 12:25 AM
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same issue here... i installed Hooker lt's, ORY, and Hooker catback and i felt like i lost alot of low end power... it does pull harder in upper rpm's but down low it's pretty disappointing.. and kickdowns aren't as stout as they used to be... quiet a bit weaker off the line than stock... of course before the install i knew i would need a tune afterwards and had planned on doing that so i'll be getting a dyno tune soon and hopefully i'll be happier about the header install than i am right now..... sounds badass, little raspy tho :/
Old 05-26-2010, 03:23 AM
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Originally Posted by Paint_It_Black
Engines don't like back pressure. It has nothing to do with low end torque. You do want the proper pipe length after the collector, there are "wrong" lengths that will cost you torque though.
Originally Posted by Paint_It_Black
Doesn't matter how it "feels," back pressure is always bad. The less power the engine has to use pushing exhaust out, the more power gets to the wheels. Gas velocity however is a different story. You can go too big on the piping and ruin your scavenging. That will kill low end torque.
^^^^correct. IDK where the backpressure=torque story started but it is myth. Ever see a NHRA, IHRA, ADRL or NASCAR running a muffler? No because it restricts power EVERYWHERE..... You guys that feel like you lost bottom grunt need a tune maybe because it did change you AFR a bit. But as stated above if you want quantifiable evidence look at your 60 ft times if you have any to compare....
Old 05-26-2010, 12:35 PM
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i installed lt's, tsp ory, magnaflo cb, and ported tb with a mail order tune. I never lost any power anywhere. Greatly improved power at all rpm's. Even friends that have only been in the car once or twice can see, hear, and feel the difference after the install. The mods, tune, and a bit of downtime was worth every flippin penny. I think youll gain as much or more from the tune as you would from the lt's and exhaust., IMO
Old 05-26-2010, 05:56 PM
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Well...I got the XR1 welded in and it made a world of difference. It's still fairly loud, which is to be expected with LT's, an ORY, and a race muffler, but it's "good loud" now instead of bad, obnoxious, ugly loud. I'd say it has about the same volume as the LM1 did when I had stock manifolds and Y, but a much better tone now.

I also got the car tuned today, and while I didn't get into it a whole lot on my way home today, I could tell it got its mojo back and it's running really strong now. I'm looking forward to taking it to the track and seeing what it'll do, hopefully I'll be into the 12's (I have no baseline as to what it ran before, though).



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