choinga

I'm experiencing some detonation after installing a Lindsey Boost Kit and 951Max chips.

I got into my DME today and noticed that the switch is on the 2nd position (not stock). Not sure who or why it was put there but I just pulled and replaced my plugs and there was some indication that the car is running a bit rich (as well as some possible oil in the cylinder and detonation).

Any suggestions on where to go with the FQS from position 2 to try to minimize the detonation problem?

I'm thinking "4" might be a good place? Pull the mixture down a bit and retard the ignition? I'm not sure what to look for though in terms of negative effects. Just because the detonation goes away doesn't mean something else isn't wrong...

Should I just go back to stock or should I try one of the settings that retards the ignition a bit as well? I don't mind experimenting but don't want to put it somewhere that temporarily fixes a problem but creates a bigger problem in the longer term...

rberry951

Hello,

There are a number of things to consider, firstly, what boost pressure are you running when you experience detonation, and at what RPM range? How are you determining boost, i.e. stock boost gauge or other aftermarket. And what octane fuel are you using?

The FQS conversations can be confusing, so I always use the following nomenclature, the 1st position is the #0 position, the second the #1, etc. So when you say the switch is in the second position I assume you mean the #1 position where fuel is added. But if it is in the #2 position you are pulling fuel. Either way, the #4 position which is no fuel correction and pulls timing.

There are indeed a number of things that can throw the AFR off and possibly cause detonation. When ever there is more air than fuel in the cylinder upon ignition than expected you have a lean condition. This can cause detonation. Mechanical issues such as bad intake gasket, leaky throttle body, bad cycling valve or idle stabilizer can do this as well.

You don't want to experiment by continuing to find the detonation point, something is not right. While pulling timing in the FQS setting may resolve your detonation problem, I don't encourage it as full resolution of the problem because performance will suffer substantially across the board.

On a final note, do you have all the components of the kit, 3.0Bar FPR, etc?

Regards,
Russell

choinga

Thanks Russell.

Yes, I have the entire LBE kit installed - 3BAR FPR + boost hose. Pressure seems good - idles right at 42-43 with vacuum attached.

FWIW, I've experimented with three of the settings and none of them had any signifcant effect on the detonation at high RPM.

And yes, when I first opened the FQS it was on the 2nd position from the left - so adding 3.1. I tried first position (stock) and the 5th position which is 0 fuel but pulling back timing. Once again - none of them had any signficant effect.

Using the LBE I was able to decrease the boost a few PSI as well - so on my boost gauge on the dash I never actually hit 2BAR - just one indent below that is the max. When the detonation occurs it's at 4500-5000RPM right at that point when the boost is the highest.

If detonation means I'm lean at boost, I guess it's best to get it back to position 2 which is the +3.1 fuel and 0 adjustments to the timing and work from there. I might try the 4th position (+6.3 with no timing adjustment) just to see if that does anything for me...

Any other suggestions? This is driving me nuts!!

V2Rocket

either add fuel or retard timing, or both.

toddk911

Are all MAX chips using the same FQS settings?

Rogue_Ant

No.