My dyno vid
Thread Starter
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
My dyno vid
I figured I'd create a thread for this so that you wouldn't have to open the thread-o-200-pics to get to it...
http://youtube.com/watch?v=v5nka4ska-c
It didn't put down the numbers I expected, but I figured out why (they dynoed my car as an NA, so the wrong final drive ratio was used for calculations).
http://youtube.com/watch?v=v5nka4ska-c
It didn't put down the numbers I expected, but I figured out why (they dynoed my car as an NA, so the wrong final drive ratio was used for calculations).
Thread Starter
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
GRD dynoed my car as an NA, so the computer assumed a 4.08 rear end. I don't have a 4.08 rear end, so the numbers are not representative of what the car actually does. Thus, I did not post them. I just like how mean the car sounds. =p
Last edited by ZLover4Life; Jun 9, 2008 at 07:34 PM.
Thread Starter
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
ok, so here's my adjusted dyno chart.
If you're interested in knowing how I got the correct values, here you go.
Horsepower is calculated by a simple formula
RWHP = (RWTQ*RPM)/5252
RWTQ = (measured torque)/(gear ratio)
So I took each torque reading (approximated from the graph), multiplied by the 4.08 gear ratio, and divided that by the correct 3.692 gear ratio to obtain my correct RWTQ numbers.
Then, I took my new RWTQ numbers, multiplied by RPM, divided by 5252 (it's a constant, look it up if you want to know where it came from).
For example, the original chart showed a peak of 424.6ft-lbs @ 5245rpm.
424.6 = (measured torque)/4.08
424.6*4.08 = measured torque
1732.368 = measured torque
rwtq = 1732.368/3.692
rwtq = 469.222
rwhp = (469.222*5245)/5252
rwhp = 468.59 @ 5245rpm
Considering I did 431rwhp/416.6rwtq before, a gain of approximately 37rwhp with intercoolers, test pipes, and a better intake on a hot day is perfectly reasonable. The type of dyno has also historically given lower numbers as well (another TT owner who was there had done 490rwhp on GRD's dyno, but over 500rwhp on every other dyno he used).
P.S. There was a vacuum hose that they tapped into for a boost reading that blew off at 6100 rpm, so that contributed to the drop of power beyond there.
If you're interested in knowing how I got the correct values, here you go.
Horsepower is calculated by a simple formula
RWHP = (RWTQ*RPM)/5252
RWTQ = (measured torque)/(gear ratio)
So I took each torque reading (approximated from the graph), multiplied by the 4.08 gear ratio, and divided that by the correct 3.692 gear ratio to obtain my correct RWTQ numbers.
Then, I took my new RWTQ numbers, multiplied by RPM, divided by 5252 (it's a constant, look it up if you want to know where it came from).
For example, the original chart showed a peak of 424.6ft-lbs @ 5245rpm.
424.6 = (measured torque)/4.08
424.6*4.08 = measured torque
1732.368 = measured torque
rwtq = 1732.368/3.692
rwtq = 469.222
rwhp = (469.222*5245)/5252
rwhp = 468.59 @ 5245rpm
Considering I did 431rwhp/416.6rwtq before, a gain of approximately 37rwhp with intercoolers, test pipes, and a better intake on a hot day is perfectly reasonable. The type of dyno has also historically given lower numbers as well (another TT owner who was there had done 490rwhp on GRD's dyno, but over 500rwhp on every other dyno he used).
P.S. There was a vacuum hose that they tapped into for a boost reading that blew off at 6100 rpm, so that contributed to the drop of power beyond there.
Last edited by ZLover4Life; Jun 10, 2008 at 12:06 AM.
Über User
Joined: Sep 2005
Posts: 9,532
From: lemont, Illinois
damn, i dont know if i woulda been able to do those calculations. also it was cool finally putting a person behind the screen name. still bummed out i missed the run in person though 
and that GRD n00b'ed out on yah there lol.
and that GRD n00b'ed out on yah there lol.
Thread Starter
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
Originally Posted by snwbrderphat540
damn, i dont know if i woulda been able to do those calculations. also it was cool finally putting a person behind the screen name. still bummed out i missed the run in person though and that GRD n00b'ed out on yah there lol.
and that GRD n00b'ed out on yah there lol.And it was good to find out that you weren't who I suspected you were. =p
Last edited by ZLover4Life; Jun 10, 2008 at 12:15 AM.
Thread
Thread Starter
Forum
Replies
Last Post
Bookmarks
