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Tuomo, when did you drive your beastie last time and when will we see the latest dyno figures?
Åke
It’s been a couple of years since I drove the car last. Luckily, it’s like riding a bicycle!
The car is being shaken down on John's dyno. There are loose connections and some minor faults to hunt and fix, so it’s being shaken down without putting down any significant power. 600 rwhp runs just to check everything and bug hunt. Dyno sensor calibrations to do, and there’s probably one more loose connection in the car.
One thing to note is that at constant boost (and massively retarded timing) as in those shakedown runs, the engine really wants to make good torque in the 4500-6000 rpm range. This is exactly as expected, given the exhaust blowdown interference with exhaust manifolds. These Elgin 65-6 cams on 114 LSA would really benefit from long-tube headers in a normally aspirated car, the mid range would get boosted up a lot and the torque curve would extend further. In the turbo case, as long as we can deal with knock due to large residual exhaust fraction, it'll be easy to just tailor the boost profile per rpm to create a flat torque curve. Today, we should find out how much the cylinder specific ignition timing helps in keeping the knock counts down with higher boost.
It will not want to go to 870 rwhp with pump gas. Just not enough octane.
On the positive side, the turbine outlet pressure is down a full pound per square inch with the new exhaust. And the new exhaust is quieter than the old, more restrictive one.
More debugging at the Kuhn lab... the wideband oxygen sensor is malfunctioning. One boost pipe needs to be tightened, popped out and made a small dent to the car. John’s notebook also having some issues, so new computer coming tomorrow. John’s calling it a day today.
No oil out of the breather system at all.
The next order of business tomorrow is to try to extend that torque curve as flat as possible past 5800 by suppressing knocks in cylinders #1 and #6 and then possibly upping boost.
Here is the setup to simulate the air flow on the road. With the hood open, one doesn’t really get the ram pressure in the filter but other than that it’s probably pretty realistic:
05-02-2018, 11:40 AM
