Discussion and questions related to the course Road Tuning
I do some infrequent tuning - and this weekend I’ve been playing around with the sprint car again following a turbo upgrade.
My equipment is a Smiths Racing “The Knock Box” and a Phormula KS3.
I’m seeking some advice on the settings for the KS3 and also some general advice.
The engine is a 3SGTE on an MR2, with a Garrett GT30 turbo; forged and all the other whatnots you’d expect for an uprated engine.
The question is: for anyone who has mapped a 3SGTE and used a KS3 (/4), what settings have they found useful?
I have The Knock Box sensor mounted in the standard factory position. The KS3 is mounted on the top surface of the cylinder head.
The pistons are standard sized - 86mm - so the Phormula web site suggest 6.7ish frequency.
I have a choice of 6.5 or 7.0 on the KS3, so I’ve chosen 6.5. I have gain of 6 and on regular pull get about 35 on the readout.
Now then... here’s the reason for my question...
I’ve worked UP TO the ignition values provided by Andre for a turbo charged engine. I’m working at about 1.2 bar (220 kpa) ... based on the suggested startup figures I should be on about 15 degrees advance at 200, a bit less at 220.
At these figures, the car drives fantastically on a pull. Some research on similar engines suggest these starting figures are actually a general sweet spot for these engines (my research may be on flawed data!)... in the headphones I can’t hear anything major - although paranoia make me think I can... but the KS3 sometimes registers a 50 readout and a warning.
Now I could be missing the sounds. While I do think I know what det sounds like, I found that advancing even a further 6! Degrees made no difference to what I heard, nor what I see on the KS3.
Sorry for the long intro - but I would appreciate any experience on these engines, which I’m pretty sure are knock limited, and also any experience in successfully configuring the hardware mentioned.
This is a hobby car, so the objective is not to push the boundaries and to be safe to the engine.