496 Dyno testing and myth busting!
Gold Member
04-28-2007, 11:58 AM
#64
Quote:
Originally Posted by cobra marty
What was the Torque loss thru the bravo drive? is that constant with rpm? Do you have any curves showing HP and TQ with stock and with Dana exhaust?
Torque loss as a percentage at any rpm will be the same as the horsepower loss, since they are related 1:1.
Michael
Only at 5252 rpm is TQ=HP and 1:1 relationship. When I lookid and the numbers and calculated the difference between crankshaft and propshaft HP and TQ I found that between 3500 and 4000rpm was an area of high loss for both HP and TQ but for further rpm there seemed to be about 43-45TQ loss at all rpm regardless of TQ amount and the HP loss increased with rpm and increase HP. What this means to me is that TQ is a constant loss regardless of rpm or amount and HP loss will increase with rpm which is just what will happen to HP in the HP=TQxrpm/5252 formula.
I would love to see the propshaft test repeated with the Dana's and synthetic lube-Amsoil or redline.
Great post. Thanks.
Originally Posted by cobra marty
What was the Torque loss thru the bravo drive? is that constant with rpm? Do you have any curves showing HP and TQ with stock and with Dana exhaust?
Torque loss as a percentage at any rpm will be the same as the horsepower loss, since they are related 1:1.
Michael
Only at 5252 rpm is TQ=HP and 1:1 relationship. When I lookid and the numbers and calculated the difference between crankshaft and propshaft HP and TQ I found that between 3500 and 4000rpm was an area of high loss for both HP and TQ but for further rpm there seemed to be about 43-45TQ loss at all rpm regardless of TQ amount and the HP loss increased with rpm and increase HP. What this means to me is that TQ is a constant loss regardless of rpm or amount and HP loss will increase with rpm which is just what will happen to HP in the HP=TQxrpm/5252 formula.
I would love to see the propshaft test repeated with the Dana's and synthetic lube-Amsoil or redline.
Great post. Thanks.
04-28-2007, 12:34 PM
#65
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Great stuff. I have always wondered about gains from removeing the turbulators. It's nice to have the facts.
What about testing a set of resonators?. As far as I know, Mercruiser is still insisting that they be used whenever possible to help reduce exhaust "tuning". If you read the installation sheet that comes with them it says that they do not reduce power, and it some cases actually make power. I've always wondered about this.
Dave
What about testing a set of resonators?. As far as I know, Mercruiser is still insisting that they be used whenever possible to help reduce exhaust "tuning". If you read the installation sheet that comes with them it says that they do not reduce power, and it some cases actually make power. I've always wondered about this.
Dave
04-28-2007, 09:54 PM
#66
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Join Date: Sep 2006
Location: Houston, Texas
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Now, if someone wanted to supply me with a substitute motor while Bobl continued testing my 496.....
04-28-2007, 10:29 PM
#67
Registered
Yep, I already have 15 hours on the new baby ZR. The partying has officially begun 
PS: Mark, Thanks for being the guinea pig on this deal.
PS: Mark, Thanks for being the guinea pig on this deal.
Last edited by JW in Texas; 04-28-2007 at 10:32 PM.
