Quote:
Originally Posted by forcefed7
Hey Ted,
The torque curve looks strange because of two things.
-Tire/clutch slippage when the vehicle comes into boost
-Boost dropping off at higher rpms.
Dyno runs were done in 4th gear using a stock FD trans. Tire circumference is about 79"
The graph in the middle shows calculated gear ratio, this line is fairly straight if there is no slippage. Peak torque output is actually in the 530-560 range.
The bottom graph is the boost, near the end of the run the boost is only about 28psi. The wastegate being a 66mm unit with a 12-13 psi spring has a lot of surface area, and once you get up in the higher revs/power output the exhaust back pressure starts to go a little over 1:1 and pushes the valve open, limiting the boost.
If you were to calculate the average acceleration rate (now that you know the engine rpm) I don't think you'd be too disappointed  |
On the road in the real world with quick transient conditions that thing would not develop full boost till 6k rpm or more in 2nd or 3rd gears especially, so far as 4k to 5k forget it.
It's a really nice set up for high power dyno competitions though
If you send me the vehicle run weight along with a VBOX .vbo or .dbn file, I'll see what power it makes on the street when you do an acceleration test with it, with that gearing though to do 100kmh to 200kmh you will probably be using 2nd and 3rd gears at a guess, rather than 3rd and 4th like we do.