hmhaga

Car is a MY98 classic with an STI V4 engine transplant
VF29 turbo
Harvey ported manifold and up-pipe
H&S 3" downpipe, midsection
Remus silencer (somewhat restrictive?)
550 ccm PE injectors
Stock TMIC - Samco hose
3-port boost solenoid (GM)
Power FC ECU


Max boost is 1,3 bar
Max AFR is 11,5
Max power fc acceptable knock value is ~15

What I find strange is the peaky curves and the significant drop in torque after 4500 rpm. Is this normal?

This was the best result my mapper managed...

I should mention that the correct STI V4 airbox and inlet hose were not used during this mapping (smaller diameter). When I later added these parts, the AFR values were thrown completely off (from 11 to 12) - so I had to redo the fueling. But my "butt-dyno" didn't notice any change in performance, so I don't think this explains the peaky curves.

On the road, it pulls strong from 3500 to 7500 rpm - so the dyno curves don't reflect the way the car behaves. Is it simply real world performance vs dyno performance?

Pavlo

That fan doesn't look like the greatest for the TMIC, and you can't tune on a specific knock value, as every car is different, you need to "calibrate" the knock results by listening with det cans. With better cooling (or FMIC) and perhaps some more timing (it might be maxed out though) it might improve. But I would say that the peak figure seems about right. I would have expected it to hold on to power longer, but if the power sweep was quite long (timewise) it will have had a negative effect on the result.

Bob Rawle

AS Paul syas, it looks as though there is simply not enough ignition in it at the higher rpm's, if you change the induction after mapping it will need to be done again to be correct, and again as Paul mentions you should not map to a knock number but use det cans and correlate that.
With those mods you should be over 300 bhp for sure

best regards

bob

harvey

iTrader: (48)

Is the Dyno Pack measuring calculated Flywheel BHP???

Paul runs a dyno and I would bow to Bob's superior knowledge but this seems a very low number and it is only a number.

hmhaga

This is power at the wheels.

The guy mapping the car tried advancing the ignition to maintain torque above 4500 rpm, but didn't succeed (no improvement noticed).

Air intake temperature is monitored, it never passed 30 degc - due to very short runs and pauses in between. So the TMIC should not be a limiting factor, but I do struggle with high IAT on track days (50-60 degc), so I have to drop boost to 1.1 and reduce timing to avoid knock - so I will replace the TMIC with a FMIC.

Mapper insisted that he did not need additional knock monitoring, as he had good experience with the Power FC knock feature.

harvey

iTrader: (48)

As explained above every engine is different and even the fuel mix can make a big difference to the timing requirement. Without DET cans or similar you have no means of knowing if you have reached the point of DET because the sensor feeding the Apexi may hear engine noise as opposed to DET so there is no way your tuner can rely on the readout on the commander to indicate he is close to the DET point.
As I think both Paul and Bob said it looks like your engine needs a lot more ignition advance. As other tuners will tell you, there can be differences in very similar engines of 4-6 degrees of ignition advance and that is a lot of torque.

Andy.F

I think some missed the fact it was power at wheels and that you have already tried more ignition timing at higher rpm.
Peak power rpm is slightly low at 6000rpm although 255 bhp at the hubs should be over 300bhp flywheel and seems reasonable for this spec. Peak torque at circa 4500rpm is also normal enough. If the graph had been cropped at 6500rpm instead of winding out to 8000 then it would also have appeared more normal.
As you suggest, your silencer may be restrictive, worth a quick change out to see if it opens up the higher rpm range.

Andy

hmhaga

This is a similar car. My dyno plot is scaled differently, but from 4000 rpm our two cars have almost similar performance. Hower, the graphs confirm that I am low on power below 4000 rpm. This is noticable when driving the car and is also confirmed by the boost curve, it doesn't start to develop real boost before 3500 rpm is passed.

Any tricks I can try with the map?
Lean out in this range? Adjust timing?

Have tried to run a manual boost controller - same result.