speedtigger

iTrader: (16)

Down at the bottom of the dyno sheet there is data called boost pressure. The first run is over negative 1 pound and the second run is nearly positive 1 pound. That is a 2 lbs difference. Any guesses as to why the manifold pressure was different on the 2 runs?

01 ss vert

iTrader: (1)

The difference in area of the 2 diameters is only .354 square inches. However, that converts to a 14.75% increase in square area. In those terms, I can justify an improvement, but I'm still shocked at the amount gained.


I agree with this.

redtan

iTrader: (5)

What was the weather like during these two runs?

What exactly was touched up in the tune between these two runs?

Certainly there was power gained from simply switching to a bigger primary, but I would bet that a good portion of that power difference came from the tune adjustments and/or any variation in weather.

ScreaminRedZ

iTrader: (3)

Good point, I'm curious as well.

Nick@Straightline

We have a 3BAR map sensor built into our dyno that we hook up only on force inducted cars. So when we pulled his car the vacuum hose was not hooked up to his car. The hose is just rolled up hanging on the dyno. At WOT the manifold pressure is 98-99kpa on the HPTuners scan. Same as it was on the run when he had 1-3/4 headers.

I agree the gains were great for a header swap! I just think with the new headers everything compliments each other on his car. I would say a 5-10 hp gain would be the norm on a bolt on car. He did the install himself and did a very nice job! This car is beautiful in person! Very well kept

Nick@Straightline

Good questions! The car was previously tuned on March 29th of this year. Temp was probably close but the humidity might have been higher back in spring. As far as what was changed in the tune, I had to add anywhere between 3-4% fuel WOT to get to a 12.8-12.9 AFR average across the pull.

bozzhawg

Very interesting

BrntWS6

iTrader: (7)

Yeah, I live in Minooka which is down by Joliet.

LASTOFTHEBREED02T/A

iTrader: (15)

Those are some crazy numbers! Nice gains for sure. Makes me want to swap to 1 7/8 Lt's.

MikeWS6

Those are some great gains. These numbers are not the norm right? I would have guessed around 10 hp gain on your setup.

HCI2000SS

iTrader: (2)

So same dyno with similar weather conditions correct? Very nice!

RAMPANT

iTrader: (17)

BrntWS6, not sure if I missed it, but I wanted to know if your original 1 3/4" header had a Merge collector and does your new 1 7/8" have a merge collector?

You can see it here in this picture below. The one on the left is an older Kooks and the one on the right is the newer Kooks design.

Just curious, as I changed from an older Kooks to a newer larger header myself.

Thanks in advance.

litle88

iTrader: (20)

Congrats on the gains!

But the real question Nick, is it cleaner than mine? lol JK.

Looks like a nice car.

Detoxx03

iTrader: (14)

Pleasant surprise.

vettenuts

iTrader: (4)

Curious when the fuel was purchased for this latest dyno pull. Was it just before the dyno or a while ago?

Nick@Straightline

Wow Zeke way to put me on the spot haha! They are both super clean. Yours would be harder to keep clean since its black. I'm no car show judge but they both would win awards in my book!!

BrntWS6

iTrader: (7)

My old Kooks were bought in 2006 and the new ones were just ordered weeks ago brand new. I don't remember the collector flaring out like that but if that's how there coming now then they should be the same.

BrntWS6

iTrader: (7)

Car is not a DD but wasn't that long ago. Why?

BrntWS6

iTrader: (7)

Here's some fap material for ya...or new wallpaper for your computer. LOL J/K....thanks

1989GTA

The merge collector could be part of the difference along with the size increase. I hope so because that is what I am putting on my car.