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Before and after dyno numbers (headers)

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Old Dec 4, 2010 | 03:24 PM
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Default Before and after dyno numbers (headers)

Finally made back to the dyno last night to see how much improvement the headers made. Baseline numbers were as follows: 238.95hp/250.71tq

After the headers and tune the numbers look like this: 259.45hp/270.78tq

20fwhp and 20fwtq, I'm pleased with the results, I was more pleased with the track times the mods produced (13.504@102mph). Now it's time for an intake swap, already have the LS1 intake just need to start getting all my ducks in a row (research) before I begin the swap!

Just wanted to share.

Joe.
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Old Dec 4, 2010 | 03:30 PM
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What type of dyno was this on? I had almost identical times (13.45 @ 102.9) making 280/300 in a lighter car.

BTW, that's really impressive for otherwise stock exhaust. I was headers, truck coils, full 3" mandrel bent, and intake tunning those times.
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Old Dec 4, 2010 | 03:40 PM
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I like the improvement,I didnt get a chance to dyno mine before the mods.Im lookin forward to doing the intake swap as well,and hopefully see some higher numbers.
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Old Dec 4, 2010 | 05:55 PM
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It was a dynojet, but it reads lower than other dyno's in the area. We compared quite a few different cars that dynoed on this dyno and then on another dyno in the area and it was basically ~7% lower. If you do that math it works out to 277/289, but the lower numbers really dont bother me, I think it's track performance makes up for it. I'm really looking forward to the LS1 intake swap and running it again!
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Old Dec 5, 2010 | 11:05 AM
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Nice! I need to get my heap on the dyno and see what it does!
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Old Dec 8, 2010 | 07:09 AM
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better be a low reading dyno.
I put down 258/272 with a downpipe and tuning. My dyno operator told me his dyno reads lower then others too. I wish I would have got tuned with my headers and made a few passes down the track. I was unimpressed with my headers but I wasn't tuned. Thanks for sharing your resaults.
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Old Dec 8, 2010 | 07:13 AM
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Also... I just swaped out my custom 3" exhaust for the magnaflow kit due to the leaks and noise. I lost a bunch of midrange power! 0-60 in mid 5.5's and I was at 5.0-5.1. Car is much more civil now and the part throttle response is insane. There's just nothing there when I mash the gas.
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Old Dec 8, 2010 | 10:23 AM
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Originally Posted by DavidGXP
Also... I just swaped out my custom 3" exhaust for the magnaflow kit due to the leaks and noise. I lost a bunch of midrange power! 0-60 in mid 5.5's and I was at 5.0-5.1. Car is much more civil now and the part throttle response is insane. There's just nothing there when I mash the gas.
That's disappointing! I don't like my magnaflow, too much drone.
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Old Dec 8, 2010 | 06:57 PM
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I could honestly care less about the overall numbers of the wheel horsepower/torque ratings, because they dont mean jack if it doesnt back it up at the track. I'd rather have lower numbers on a dyno sheet and run decent at the track than have dyno queen that runs like a turd in the 1/4. To me a dyno serves as a good tool to measure before/after info as well as a very valuable tool for tuning. I'm just happy the headers/tune did show some improvement over stock.
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Old Feb 6, 2011 | 03:39 PM
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Originally Posted by crazyjoe
Finally made back to the dyno last night to see how much improvement the headers made. Baseline numbers were as follows: 238.95hp/250.71tq

After the headers and tune the numbers look like this: 259.45hp/270.78tq

20fwhp and 20fwtq, I'm pleased with the results, I was more pleased with the track times the mods produced (13.504@102mph). Now it's time for an intake swap, already have the LS1 intake just need to start getting all my ducks in a row (research) before I begin the swap!

Just wanted to share.

Joe.
Were you tuned before the headers?
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Old Feb 6, 2011 | 05:24 PM
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Originally Posted by crazyjoe
I could honestly care less about the overall numbers of the wheel horsepower/torque ratings, because they dont mean jack if it doesnt back it up at the track. I'd rather have lower numbers on a dyno sheet and run decent at the track than have dyno queen that runs like a turd in the 1/4. To me a dyno serves as a good tool to measure before/after info as well as a very valuable tool for tuning. I'm just happy the headers/tune did show some improvement over stock.
Thank you!!!! I feel the same, it doesn't matter if you dyno 300whp if you run high 13's@99mph. Peak HP #'s pretty much don't mean **** as long the car performs.
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Old Feb 7, 2011 | 09:45 PM
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Headers are worth about 6hp on a stock LS4.

Last edited by DavidGXP; Feb 7, 2011 at 09:53 PM.
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Old Feb 7, 2011 | 11:35 PM
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Them are some good gains. The percentage gain is whats important, not actual hp tq numbers. Now you need more intake air!
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Old Feb 8, 2011 | 06:35 AM
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I wasnt tuned prior, so obviously some of the increase is thanks to the tune, but even still, the car feels night and day different compared to stock-----I would recommend the headers to anyone look for a few extra ponies (accomonied with a tune that is).

And I have an LS1 intake just sitting here, but I cant find the time to put it on. I still need tires, so that will probably set my plans back as well. I'll definitely keep you guys posted when I dyno after the intake though.
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Old Feb 19, 2011 | 08:29 AM
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Default DT headers and tuning?

Hello, i recent purchased a cat-back Magnaflow exhaust and debating whether or not I should also get the DT headers. But I'm reading allot about tuning the LS4. What exactly is this required tuning and who and where can I get this done?




Originally Posted by crazyjoe
I wasnt tuned prior, so obviously some of the increase is thanks to the tune, but even still, the car feels night and day different compared to stock-----I would recommend the headers to anyone look for a few extra ponies (accomonied with a tune that is).

And I have an LS1 intake just sitting here, but I cant find the time to put it on. I still need tires, so that will probably set my plans back as well. I'll definitely keep you guys posted when I dyno after the intake though.
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Old Feb 19, 2011 | 10:41 AM
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Originally Posted by flyturbo
Hello, i recent purchased a cat-back Magnaflow exhaust and debating whether or not I should also get the DT headers. But I'm reading allot about tuning the LS4. What exactly is this required tuning and who and where can I get this done?
I hate to do this to you man...
Try a search.
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Old Feb 19, 2011 | 04:47 PM
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dang i should run well into the 13s then only mods done are the fwi, res delete and had wicked hp dyno tune it and i topped out at 250hp/278tq at the wheels on a dyno jet with the sae number not the bull **** numbers people massage
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Old Feb 22, 2011 | 07:24 PM
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In what gear are our cars suppose to be dynoed? Im going to get my car dynoed tomorrow.
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Old Feb 22, 2011 | 07:51 PM
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Should be third gear for the wbodies. (or whatever gear is closest to 1:1 depending on the vehicle) Some dyno operators don't like to run their machines to 160 mph and want to use a lower gear.
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Old Feb 22, 2011 | 08:04 PM
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I made one pull in 3rd gear and the numbers were pretty much identical so I didnt see any point in spinning to 140mph+ on multiple occasions. Hell, I cross the traps at the end of 2nd gear in the quarter anyhow, so why should I care what 3rd gear shows lol.
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