Bad KS affect Startup or Idle?

[Mint Q45A]

Can a bad KS affect the startup - making it harder to start the car, or the idle - making it high/unstable?

I understand the KS function is to detect knock and signal the ECU to adjust the timing to "correct" it; in the Q it is able to do it for each bank of cylinders, individually. This I assume is more prone to happen when you are accelerating....but not sure if it also works at startup or idle or even, decelerating.

Just curious...

[qsiguy]

I don't believe so. I've had one and it was only noticeable at higher power ranges as it retards timing. Horsepower was down about 70 hp on the dyno.

[qship96]

I had mine done last month at T3-biggest difference I feel is around town tip-in acceleration-before it felt "flat",especially coming out of slow turns or curves at moderate speed then accelerating.

[MR. Q]

Horsepower was down about 70 hp on the dyno.

So that means you had about 208hp when your ks was bad? Also what is brake horse power? I always hear it on car shows like the one on BBC i thinks its top speed with the British guy.

[Q45tech]

Brake HP is measured on a water brake dyno..............the water is used to cool the power absorbing unit ...............aka brake.

The engine is run against a load until it won't accelerate any more steady rpm...............................kind of like a top speed run. Very very stressful on engine unlike a chassis dyno.

[Q45tech]

No on a chassis dyno the Q would noramally read about 220 rwhp and with bad KS the advance would top out around 15 BTDC [instead of 28] and yield weird peaks and valleys and maybe show 150 rwhp.

At WOT advance at 4,000 is ~~ 20-22 so the effect is less until you exceed that rpm.

[MR. Q]

Thanks for the knowledge.