thunderstruck507

iTrader: (18)

Also being 1 year apart and "the same type of day" without having the weather data from the dyno doesn't mean anything. I dunno about you but I can't tell you the barometric pressure just by walking outside. Nor the humidity.

Also on the new graph the HP could have still be climbing when the run was cut.

The torque plot on the first graph looks strange.

Curious if the tuner adjusted timing or only fuel.

Was this done with the cutout open or closed? Wondering if it was closed and causing turbulence in the exhaust (I'm not familiar with the layout and where the cutout is, could be disruptive to flow when closed though)

dave04da

iTrader: (2)

The cut out was closed on all the runs.
I have the Macs back on and scheduled another dyno tune for Thurs. the 20th. I guess well find out!

dave04da

iTrader: (2)

I don't know what he may have adjusted. I do remember that he said it was running rich on the tune for the first graph. What looks strange about the tq graph? Yea I also noticed that it seemed like the hp was still climbing when he stopped. The first graph it seems he took it further into the rpm range.

jimmyblue

iTrader: (11)

Re my Y merge comments - here's an image showing
two different Y-pipes that TSP sells. The one on the
right is good, the one on the left not so much.

dave04da

iTrader: (2)

Here is a pic of the SE y. It looks good to me.

JoeNova

A lot can happen in a year.
More miles on one oil than the other, more build-up on pistons/valves, different plugs with different gaps, etc etc.

The fact that one is Standard and the other is SAE means you should just throw any and all assumptions out the window completely.

ddnspider

iTrader: (26)

this has been my point all along, not apples to apples and jumping to assumptions.

JoeNova

He doesn't seem to be getting the point. You didn't call for backup but I'm here to lend it

ddnspider

iTrader: (26)

sxc Z28

Just so people don't get confused. STD and SAE are correction factors. This means they have a premeditated outside temp, humidity, etc. already factored in. STD and SAE are interchangeable using this formula:

STD - (STD x .026) = SAE

SoFla01SSLookinstok

Good spot spider.

The SAE/STD thing is not on his side here anyway. It would make the numbers with the LT headers even lower.

One other thing I notice is the hp/tq split. With the macs it's even tq to hp. The long tubes shows more power to tq.

ddnspider

iTrader: (26)

It's interesting cause I've seen the std to sae conversion go either way where sometimes it's higher and sometimes it's lower, ll depends on the weather. I know temp was the same but didn't check on baro

dave04da

iTrader: (2)

I'll get the print out next week when I go back. I should have took it but I wasnt real happy at the time. Don't get me wrong I'm glad I took it in and found this out rather than think I made an improvement in power when I actually don't think I did. I'm not saying good reputable long tubes aren't better, I think this MAY show that all long tubes are not created equal. Its one thing to just bend up some tubes in a jig, weld it up and say this is a great looking header but don't know how it performs. Without any real dyno testing and tweaking to the design to achieve maximum power all you have are some pretty pipes. I think you get what you pay for!

wannafbody

iTrader: (2)

Torque and HP should be the same at 5250 rpm, which the graphs show.

tech@WS6store

iTrader: (2)

OP can you email me the pics you have on here of the dyno graph?
Rpmspeedtech@gmail.com

I brought my popcorn too!

P.s. ive never seen sae track more than std on the same dyno.

If it were mw between the 2 runs id look everywhere on the overlay for any power gains at all. Seems like all the excuses are being thrown out, but at some point youve got to say with all the claims out there X should have outdone Y but this is prob really the first comparo between them at the same place with the same car and the same tuner. Trying to say youd just need a cam better designed for those headers isnt an excuse at all. If they are better they should have added power. No ifs ands or butts about that.

On an unrelated note (read shameless plug) our mac headers are here
Htth://www.ws6project.com/user_stor/catalog/index.php?cPath=235_82_43&sort=3a&filter_id=78

Most of this post is in good fun of course, but there are some very good questions that come up from it.

I dig it!

ddnspider

iTrader: (26)

I'm skeptical because there are plenty of other people who've shown significant gains. I've got these longtubes in my 700fwhp Camaro with no signs of choking....does that mean I would pick up by going to Mac mids.....I think not.

JakeFusion

iTrader: (7)

That's correct. The difference from SAE to STD is 2.6%.

So, if you apply the SAE correction to the STD numbers... he drops about 10HP. And I'm not sure about you, but dropping 30HP by swapping headers doesn't seem likely.

This makes me think there is another issue with the car that needs to be troubleshot. Of course, swapping back in the mids with either show the power restored or a continued trend in lost power.

I bet you see power down from the 391 number last year. Meaning you may have an issue with any number of things. But then I'd do a leakdown and see. You may have an issue with a ringland, valve seal, etc. If you drove the car hard in the last year, you could have hurt the motor.

If the power comes back. Set the headers on fire.

ddnspider

iTrader: (26)

It could be as simple as a weak spark plug or Crack in the porcelain, or a plug wire slightly melted. It will definitely be interesting to see what happens.

dave04da

iTrader: (2)

Email sent! Thanks for the help.

dave04da

iTrader: (2)

Man, anything is possible! I only put about 3,000 miles on her last year and I really don't beat it. I'm 40 yrs old not a kid. Not that I don't like to run it, I just do it smart! No bouncing the rev limiter or power shifting. I checked all the plugs and regapped them when I put the Macs back on, they all looked perfect and exactly the same burn on all 8. I was at the track once last year and it ran great. I did a 12.7 at 113. It was about 50 degrees out and the track was slick so my 60' weren't the greatest. It feels just as strong as ever. But who knows man, I guess we will know more on Thursday!