unexplainable Dyno run
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 988
Likes: 14
From: Hewitt, TX
unexplainable Dyno run
Looking for input. I bought a used 2002 coupe with about 25K on the ticker about a year ago. Seems to be pretty stock in appearance (no headers or anything obvious). I added a cat back exhaust and did the "Zip-Tie" CAI mod. Now reading various specs my expectation was to see less than 350 HP at the rear wheel.
This is were it gets interesting. I ran a 376 HP at the rear and 390 ft lbs torque today. A few guys there were commenting that this particular Dyno machine was showing lower than others they had been on by about 5 horses. I ran these numbers consistantly on multiple runs. Call me crazy but I am sure that a Cat-back exhaust didn't give me these numbers.
Is there any way to determine what may have been done to the car from the previous owner?
This is were it gets interesting. I ran a 376 HP at the rear and 390 ft lbs torque today. A few guys there were commenting that this particular Dyno machine was showing lower than others they had been on by about 5 horses. I ran these numbers consistantly on multiple runs. Call me crazy but I am sure that a Cat-back exhaust didn't give me these numbers.
Is there any way to determine what may have been done to the car from the previous owner?
Last edited by vetfeva2; Sep 29, 2009 at 11:30 PM.
Racer
Joined: Sep 2005
Posts: 260
Likes: 10
From: Amarillo Texas
Safe input is that dyno is reading very very high. Your numbers should be closer to 310rwhp or so.
Looking for input. I bought a used 2002 coupe with about 25K on the ticker about a year ago. Seems to be pretty stock in appearance (no headers or anything obvious). I added a cat back exhaust and did the "Zip-Tie" mod. Now reading various specs my expectation was to see less than 350 HP at the rear wheel.
This is were it gets interesting. I ran a 376 HP at the rear and 390 ft lbs torque today. A few guys there were commenting that this particular Dyno machine was showing lower than others they had been on by about 5 horses. I ran these numbers consistantly on multiple runs. Call me crazy but I am sure that a Cat-back exhaust didn't give me these numbers.
Is there any way to determine what may have been done to the car from the previous owner?
This is were it gets interesting. I ran a 376 HP at the rear and 390 ft lbs torque today. A few guys there were commenting that this particular Dyno machine was showing lower than others they had been on by about 5 horses. I ran these numbers consistantly on multiple runs. Call me crazy but I am sure that a Cat-back exhaust didn't give me these numbers.
Is there any way to determine what may have been done to the car from the previous owner?
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 988
Likes: 14
From: Hewitt, TX
They were just about right. A few guys thought the dyno was low but for the most part the other guys that said they were bone stock ran exactly what was expected per specs.
I have quite a bit of popping in my exhaust (which I like actually) when decel. I noticed it was more that other vettes I run with but figured it was normal with my cay back exhaust. That could indicate the possibilty of a cam?
I have quite a bit of popping in my exhaust (which I like actually) when decel. I noticed it was more that other vettes I run with but figured it was normal with my cay back exhaust. That could indicate the possibilty of a cam?
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Were you at the dyno with buddies? Are you sure one of them didn't tip the dyno operator a few bucks to add some virtual hp? It would be the first time this has happened. 
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Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Could you open the hood, and look at the bottom front of the right head, and tell us the 3 digit casting #?
You might have to pop up the rail cover to see it, but it should otherwise be visible.
If you find there is no number there at all, look at the front surface of that same head (right behind the tensioner), and see if there is any logo machined on that surface
You might have to pop up the rail cover to see it, but it should otherwise be visible.
If you find there is no number there at all, look at the front surface of that same head (right behind the tensioner), and see if there is any logo machined on that surface
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 988
Likes: 14
From: Hewitt, TX
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
No, primarily at idle. Will give an indication of a larger cam overlap.
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 988
Likes: 14
From: Hewitt, TX
Could you open the hood, and look at the bottom front of the right head, and tell us the 3 digit casting #?
You might have to pop up the rail cover to see it, but it should otherwise be visible.
If you find there is no number there at all, look at the front surface of that same head (right behind the tensioner), and see if there is any logo machined on that surface
You might have to pop up the rail cover to see it, but it should otherwise be visible.
If you find there is no number there at all, look at the front surface of that same head (right behind the tensioner), and see if there is any logo machined on that surface
Last edited by vetfeva2; Sep 27, 2009 at 10:28 AM.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
241 is the correct casting that came stock on a 2002 coupe.
Had you found something else, then we would have had some evidence that it's been modified. (this is why I asked - plus, its a quick easy check).
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 988
Likes: 14
From: Hewitt, TX
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 988
Likes: 14
From: Hewitt, TX
I only knew one person there well (Dan, the owner of VetteWorks Online), the others I pretty much met there. That would be a dirty trick especially since I told the guy doing the runs from Jet City Tuning that I wanted to get a baseline before I put headers on.
Drifting
Joined: Aug 2000
Posts: 1,758
Likes: 4
From: Medford, Or
Mike you had some great numbers.
Here's pics at the Vetteworks dyno day/ open house event:
http://www.vetteworksonline.com/vett..._2009_open.htm
Here's pics at the Vetteworks dyno day/ open house event:
http://www.vetteworksonline.com/vett..._2009_open.htm
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
They were just about right. A few guys thought the dyno was low but for the most part the other guys that said they were bone stock ran exactly what was expected per specs.
I have quite a bit of popping in my exhaust (which I like actually) when decel. I noticed it was more that other vettes I run with but figured it was normal with my cay back exhaust. That could indicate the possibilty of a cam?
I have quite a bit of popping in my exhaust (which I like actually) when decel. I noticed it was more that other vettes I run with but figured it was normal with my cay back exhaust. That could indicate the possibilty of a cam?
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Perhaps I should schedule a dyno run as well.
Drifting
Joined: Sep 2008
Posts: 1,273
Likes: 9
From: O'Fallon MO
Those #'s would suggest an LS6 cam hiding out in there 
That is about exactly what my hp #'s were with just cat back, CAI, and tune. However I did not get a tq # that high. I don't know about a stock LS1(I don't think so), but an LS6 will not "sound" like a cam but at idle the car will give just a little tiny bit of a shake to it, you can feel it just sitting in the car and paying close attention.
That is about exactly what my hp #'s were with just cat back, CAI, and tune. However I did not get a tq # that high. I don't know about a stock LS1(I don't think so), but an LS6 will not "sound" like a cam but at idle the car will give just a little tiny bit of a shake to it, you can feel it just sitting in the car and paying close attention.