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.

AlabamaGuy

iTrader: (5)

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.

1CL3ANSUP3RSPORT

iTrader: (23)

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.

crazyjoe

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!

ImpSS07

iTrader: (3)

Nice! I need to get my heap on the dyno and see what it does!

DavidGXP

iTrader: (14)

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.

DavidGXP

iTrader: (14)

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.

707chance

iTrader: (2)

That's disappointing! I don't like my magnaflow, too much drone.

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.

DavidGXP

iTrader: (14)

Were you tuned before the headers?

CenTexSS

iTrader: (2)

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.

DavidGXP

iTrader: (14)

Headers are worth about 6hp on a stock LS4.

LS4SPEED

iTrader: (3)

Them are some good gains. The percentage gain is whats important, not actual hp tq numbers. Now you need more intake air!

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.

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?

DavidGXP

iTrader: (14)

I hate to do this to you man...
Try a search.

vroom_vroom

iTrader: (5)

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

smokin06impala ss

iTrader: (2)

In what gear are our cars suppose to be dynoed? Im going to get my car dynoed tomorrow.

TiredGXP

iTrader: (2)

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.

crazyjoe

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.