Power Gain Questions.........
#11
#12
RE: Power Gain Questions.........
what matters to you more? Simple numbers that you can flout about, or being able to whoop someone regardless of the numbers they've been throwing at you? It's one thing to talk numbers, it's another thing to do something with it.
And how do you figure that they're not very accurate? It's a computer that measures how much power your car puts to the wheels accross the entire RPM range. You can't call it inaccurate just because it's not feeding you the numbers that you don't want to see.
And how do you figure that they're not very accurate? It's a computer that measures how much power your car puts to the wheels accross the entire RPM range. You can't call it inaccurate just because it's not feeding you the numbers that you don't want to see.
#13
#14
RE: Power Gain Questions.........
Dyno's tend to be very consistent. Yes, you can pull your engine and take it to an engine dyno, if you can find one... I was assuming a good 30% loss from the powertrain, very typical (if not generous) for the 3-speed, which would put crank HP in the 145-150 range.
Numbers do matter in autocross, but not necessarily peak HP/torque numbers. You still have to accelerate the car, and that takes HP. Where you make power makes a difference; it's nice to know whether you're going to have to downshift before a turn or if you've got the low end power to pull out of it in whatever gear you're in. With the mods you've already done, you've moved yourself into a class where you can't possibly have a prayer of being competitive, much less winning, if you're talking SCCA Solo 2. Your cam, header, and CAI each bumped you out of stock class. If your header is not on the EPA's site as 50-state legal (it isn't), it's not allowed in Street Touring classes. Camshaft swaps aren't allowed until the Prepared and Modified (not Street Prepared or Street Modified) classes.
"Taking" your buddy's Si, or any car for that matter, on the street means nothing. Jumping the gun by a tenth of a second means over a car length when accelerating to 90 mph. Since most amateur drivers have a typical reaction time spread of 0.2-0.3 seconds (or more), that means that any "win" by less than 4-5 car lengths (or 8, or 10) in a street race could easily be a win for the other driver on a real track where everything is measured. Street racing is bogus, about as accurate and impressive as a race in kindergarten nose picking.
The whole point of autocross is to have fun though. Being competitive takes money, which typically means sponsors, which means you're going to need a lot of practice before anyone takes you seriously. Get out there, have some fun, and listen to what the more experienced guys tell you.
Numbers do matter in autocross, but not necessarily peak HP/torque numbers. You still have to accelerate the car, and that takes HP. Where you make power makes a difference; it's nice to know whether you're going to have to downshift before a turn or if you've got the low end power to pull out of it in whatever gear you're in. With the mods you've already done, you've moved yourself into a class where you can't possibly have a prayer of being competitive, much less winning, if you're talking SCCA Solo 2. Your cam, header, and CAI each bumped you out of stock class. If your header is not on the EPA's site as 50-state legal (it isn't), it's not allowed in Street Touring classes. Camshaft swaps aren't allowed until the Prepared and Modified (not Street Prepared or Street Modified) classes.
"Taking" your buddy's Si, or any car for that matter, on the street means nothing. Jumping the gun by a tenth of a second means over a car length when accelerating to 90 mph. Since most amateur drivers have a typical reaction time spread of 0.2-0.3 seconds (or more), that means that any "win" by less than 4-5 car lengths (or 8, or 10) in a street race could easily be a win for the other driver on a real track where everything is measured. Street racing is bogus, about as accurate and impressive as a race in kindergarten nose picking.
The whole point of autocross is to have fun though. Being competitive takes money, which typically means sponsors, which means you're going to need a lot of practice before anyone takes you seriously. Get out there, have some fun, and listen to what the more experienced guys tell you.
#15