L98 Underrated?
09-30-2003, 09:31 PM
#16
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Originally posted by kraftopia02
"some were made better"
That's not really true, though...
In a factory setup you should assume that all motors are built equally. Their only differences being the break-in drive period.
The motors are not "built differently," they just have differing wear patterns after the first 5,000 miles which determines the motor's lifetime power and torque.
Every L98 that came out of the factory had the same potential (within reason) to be just as powerful than the most powerful L98. Just get a good driver behind it for the first few miles and you will see the difference in any engine.
If every car was driven the exact same way for the first few thousand miles, then it would be pretty easy to assume that they all would have the same power and torque.
"some were made better"
That's not really true, though...
In a factory setup you should assume that all motors are built equally. Their only differences being the break-in drive period.
The motors are not "built differently," they just have differing wear patterns after the first 5,000 miles which determines the motor's lifetime power and torque.
Every L98 that came out of the factory had the same potential (within reason) to be just as powerful than the most powerful L98. Just get a good driver behind it for the first few miles and you will see the difference in any engine.
If every car was driven the exact same way for the first few thousand miles, then it would be pretty easy to assume that they all would have the same power and torque.
09-30-2003, 09:53 PM
#18
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about the l98 being underrated...
i think it was always like 10 short on the vette
andthe reason they gave on thirdgen.org...
vettes had aluminum heads while the fbodies had cast iron
i think they mightve given another reason too, not sure
but when you're thinking abotu the narrow horsepower ranges back then (10 hp was a bigger leap then, than it is now) it might be underrated for the camaro, might not be
think about it
i think it was always like 10 short on the vette
andthe reason they gave on thirdgen.org...
vettes had aluminum heads while the fbodies had cast iron
i think they mightve given another reason too, not sure
but when you're thinking abotu the narrow horsepower ranges back then (10 hp was a bigger leap then, than it is now) it might be underrated for the camaro, might not be
think about it
09-30-2003, 09:58 PM
#19
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Actually, if you use the formula hp= torque x the RPM where max hp is supposed to occur divided by 5252 .
345 x 4400 = 1518000
1518000 divided by 5252 = 289 @ 4400 RPM
So according to the laws of physics the L98 actually produces 289 hp at the crank. Or 300 hp @4500 RPM for the dual cat option.
LT1 = 320 hp @5000 RPM
LS1 = 345 hp @5400 RPM
345 x 4400 = 1518000
1518000 divided by 5252 = 289 @ 4400 RPM
So according to the laws of physics the L98 actually produces 289 hp at the crank. Or 300 hp @4500 RPM for the dual cat option.
LT1 = 320 hp @5000 RPM
LS1 = 345 hp @5400 RPM
09-30-2003, 10:57 PM
#20
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The Corvette is a lighter car, so they could get away with not having a large HP difference and the vette would still outperform an fbody to an "acceptable" degree in the hands of a good driver. I had a C5 vette run a 13.5 next to me as I ran a 16.xxx the first time I ever ran at the track. Back then it just looked really bad getting smoked like that, but when I think about it now 13.5 wasn't very impressive.
It's mostly insurance reasons as well....that's pretty much why HP is underrated. The government nitpicks car companies to death over things like that.
It's mostly insurance reasons as well....that's pretty much why HP is underrated. The government nitpicks car companies to death over things like that.
10-01-2003, 08:36 AM
#21
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I doubt the TPI and LT1 cars are under rated. I know when I dynoed my 96 WS6 it was 274rwhp which comes out to about 310-315hp. With the K&N, thermostat, and airfoil might have made up the difference from a rated 305. Same for the TPI cars I've seen dynoed that were stock. I haven't seen a stock 350 TPI dyno higher than 210 rwhp.
The LS1 is definitely underrated. Its pulling rwhp numbers the same as what its flywheel rated. The turbo Buick in the turbo TA was under rated by about 40 hp also.
The LS1 is definitely underrated. Its pulling rwhp numbers the same as what its flywheel rated. The turbo Buick in the turbo TA was under rated by about 40 hp also.
10-01-2003, 09:34 AM
#23
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Originally posted by mako350Z28
Yea, but if I remember correctly, wasn't the LT1 camaro rated at 275-285 hp in 1996?
Yea, but if I remember correctly, wasn't the LT1 camaro rated at 275-285 hp in 1996?
10-01-2003, 10:30 AM
#26
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Yes it would since the ram air does just that - it rams the air into the intake when the car is moving, providing denser air for the combustion process. Even if the hood is open, there is nothing forcing the air into the engine. It's getting pulled in instead of pushed in.
10-01-2003, 10:52 AM
#27
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Air is always getting pushed in, it never gets pulled in.
Ram air does not make the air denser, cold air provides a denser charge, and therefore more horsepower. Though many will argue it, there is no significant "ram air" effect on an automobile.
All you want it is unrestricted cold air. Ram air on a dyno is restrictive, since the car is not moving. Keeping the air element exposed removes the restriction, most places have some way of keep the air cool that is going into the engine for best performance.
Ram air does not make the air denser, cold air provides a denser charge, and therefore more horsepower. Though many will argue it, there is no significant "ram air" effect on an automobile.
All you want it is unrestricted cold air. Ram air on a dyno is restrictive, since the car is not moving. Keeping the air element exposed removes the restriction, most places have some way of keep the air cool that is going into the engine for best performance.
10-01-2003, 11:05 AM
#28
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Wish I could remember the web site that explains the way it works but it does work. There is only one catch though - it works in the higher rpm range at high speeds (usually at 90 mph and above).
It works because it provides denser (hence more) air to the engine. Atmospheric pressure is lower inside an engine than it is outside and actually gets lower the faster the car moves. A good ram air system evens out this inequality and, on a really good system, provides about .156 psi of positive boost over atmospheric pressure.
It works because it provides denser (hence more) air to the engine. Atmospheric pressure is lower inside an engine than it is outside and actually gets lower the faster the car moves. A good ram air system evens out this inequality and, on a really good system, provides about .156 psi of positive boost over atmospheric pressure.
10-01-2003, 01:03 PM
#29
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You have to be going like 150MPH for 1 PSI of pressure, you get .1-.2 PSI at 100MPH....this is under PERFECT ducting of the sytem and a perfectly sealed airbox.
An engine at WOT has 0 vacuum, ram air does not change any inequality, the theory is if the system is designed correctly that pressurization occurs in the airbox....at automobile speeds it's almost worthless....stock ram air isn't correctly designed, it brings COLD air in, nothing more.
An engine at WOT has 0 vacuum, ram air does not change any inequality, the theory is if the system is designed correctly that pressurization occurs in the airbox....at automobile speeds it's almost worthless....stock ram air isn't correctly designed, it brings COLD air in, nothing more.
10-01-2003, 03:51 PM
#30
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Originally posted by mako350Z28
If you have the ram air then that would account for the loss of power. It's kind of hard to use the ram air when you are sitting still.
If you have the ram air then that would account for the loss of power. It's kind of hard to use the ram air when you are sitting still.
The only problem I ever had was heat soak because of it being right over the radiator. The summer took its toll on that car on back to back runs.