World's first FT86 Anti-Reversion,(A/R) Header

[poorsche]

Originally Posted by KoolBRZ

I'm going to dyno test it in the next few weeks. Have to find a dyno that will test down to 1000 RPM's to show improvement in low-end torque. All the headers I've tried before made it run like a 2-stroke dirt bike, no power down low, but once it's wound up it moved OK. Just OK. Remember I'm driving an A/T so my gearing is way taller than a manual's. I'll post video's once I get them. It's hard to believe this isn't FI the way it drives now. The torque dip is gone completely and it accelerates like it's supercharged. I'll have to find someone else in the Portland/Vancouver area to bear witness to my claims. Who should I ask to test drive it?

I should have gone this route instead of blowing my wad on a supercharger.

[KoolBRZ]

Why not have both, a super exhaust, and a super charger. I'm actually on the list for the Full throttle electric supercharger. You aren't still running the stock exhaust are you? Is yours an auto or a manual? Your supercharged low-end torque would work well with an automatic.

[Wayno]

Originally Posted by KoolBRZ

Let's clarify a few things. I'm driving an automatic BRZ. It's geared much taller than the manual. It takes a lot more umph to break a tire loose in an automatic. My 4th gear is equal to the manual's 6th gear.

AT 4 and MT 5 are both 1:1, not 6th. You can manually shift down to 1st in AT which you wouldn't manage very well in MT so apart from launches, you have the same number of usable gears. Ratios are different but no it doesn't take any more effort to break traction in AT, you would just be doing it at a different ratio/speed.

I still don't know why you'd want more torque below 2000rpm or even 3500rpm. Shift down or put it in auto mode and press the loud pedal, it takes 0.2 seconds. You're going to give other AT drivers a bad name.

[OkieSnuffBox]

Come back with empirical data if you want anyone to take you halfway seriously.

[Koa]

Originally Posted by KoolBRZ

Oh, and when was the last time YOU lit up your TC dashlight?

I don't light that thing up. Either they stay on the street, or I pedal dance/holdtrac in the course or lot.

Can you blame us for wanting some logs/data? Most of us are engineers or scientists in one way or another, if not for the profession

[KoolBRZ]

Originally Posted by Wayno

AT 4 and MT 5 are both 1:1, not 6th. You can manually shift down to 1st in AT which you wouldn't manage very well in MT so apart from launches, you have the same number of usable gears. Ratios are different but no it doesn't take any more effort to break traction in AT, you would just be doing it at a different ratio/speed.

I still don't know why you'd want more torque below 2000rpm or even 3500rpm. Shift down or put it in auto mode and press the loud pedal, it takes 0.2 seconds. You're going to give other AT drivers a bad name.

The ratio is the amount of leverage the engine has over the wheels. A stock manual has more wheel horsepower then an automatic because it has more leverage. Dyno tests have proven this over and over. You're telling me to get MY facts straight?

[Wayno]

Every time you say something else you come off worse. You obviously haven't seen dynos for AT and MT taken the same day for this car and base all your assumptions on shit from all kinds of older slush boxes. Unsubscribing, no point getting trolled by this joker any more.

[Hoosier Daddy]

Originally Posted by OkieSnuffBox

Come back with empirical data if you want anyone to take you halfway seriously.

Quote because that's funny. A butt dyno is empirical.

[OkieSnuffBox]

Originally Posted by Hoosier Daddy

Quote because that's funny. A butt dyno is empirical.

Empirical - capable of being confirmed, verified, or disproved by observation or experiment.


And while it does say "observation," common usage tends to associate "empirical" with "quantitative" or "verifiable."


A "butt dyno" doesn't provide a useful measurement, you can't quantify it.




Now if he said, his 40-70 times dropped by 0.X amount, that would be useful.

[Hoosier Daddy]

Cherry picking part of the definition that fits your argument doesn't make it the only correct answer.

His empirical evidence is your anecdotal. You can chose to ignore it if you so wish.

[Hyper4mance2k]

No engine in the history of 4 stroke internal combustion needs backpressure. The exhaust needs velocity to scavenge all the spent energy from the combustion chamber. There are may ways to do this, but back pressure is not one of them. You are parroting misinformation and a lack of understanding of fluid dynamics.
For an engine to make peak torque at any RPM it must expell as much exhaust as it can at any given RPM. The key to doing this is exhaust gas velocity, not back pressure. Correct diameter pipes that maintain exhaust gas velocity, at the desired RPM and throttle position, are the key to making power.
The reason the back pressure myth continues is bacuse of people putting on too large of an exhaust system which is only effective at a small and high RPM range. At other RPMs and throttle positions too large of an exhaust pipe will cause the exhaust gas to have little to no gas velocity, and can add turbulant exhaust flow which will ultimately cause low RPM drivability issues; it's the reduction in velocity and flow rates that casue problems, not the reduction in back pressure.

[zooki]

Originally Posted by Hoosier Daddy

Cherry picking part of the definition that fits your argument doesn't make it the only correct answer.

His empirical evidence is your anecdotal. You can chose to ignore it if you so wish.

"You keep using that word. I do not think it means what you think it means..." 😂

[ame]http://youtu.be/G2y8Sx4B2Sk[/ame]

[arghx7]

The effectiveness of this mod would be a lot easier to prove with more equipment, something that can't really be done on a hobbyist budget. You would need an engine dyno with crank angle resolved pressure indication in the intake and exhaust port for understanding scavenging, and software to calculate residual gas fraction.

You also need to sweep the AVCS positions (tune the cam phasing). Changing the blowdown pulses (by changing exhaust valve opening timing) or the overlap volume will affect the pulsation dynamics.

Originally Posted by Hyper4mance2k

No engine in the history of 4 stroke internal combustion needs backpressure.

Generally true, yes, but just an FYI: backpressure has been used as sort of free pumping action by manufacturers to drive auxiliary devices to improve performance in gasoline engines. Two examples are variable induction systems (Mazda, specifically older rotary engines) or low pressure EGR (new Nissan Juke engine).

[zooki]

Originally Posted by arghx7

The effectiveness of this mod would be a lot easier to prove with more equipment, something that can't really be done on a hobbyist budget. You would need an engine dyno with crank angle resolved pressure indication in the intake and exhaust port for understanding scavenging, and software to calculate residual gas fraction.

You also need to sweep the AVCS positions (tune the cam phasing). Changing the blowdown pulses (by changing exhaust valve opening timing) or the overlap volume will affect the pulsation dynamics.

"You don't understand, bro, my TC light comes on....it comes on....in a corner.....on, bro, on."
(: