Car: 03 STi PPP Fuel: Optimax
Driving home from Brands Hatch on Saturday I noticed a bit more activity on the Knocklink than usual, so I thought I would try a simple test.
6th gear steady 2600rpm press pedal to approx 2/3, wait for turbo to bite, boost gauge showing around 15psi No knocklink activity at all until approx. 3300 then all lights inc. brief red! - close throttle!
It seems the problem (if there is one) occured as the engine started to unload? (and mixture leans and ignition advances?)
Haven't driven it since but need to re-fuel and will try again. Has anyone else noticed more activity lately (especially with similar car and set-up as mine)
JohnD

 

John,

I notice more blinking on the Knocklink when on 2/3 throttle compared to 100% throttle.

I've got a box of millers on order to see what happens, plus I'm now pressing the water spray button more often....

 

I get the occasional det spike showing on my KL usually between 5000 and 6000 rpm on WOT. I have a MY02 STi Type UK remapped by Merv at Ecutek and using PE's sports cat exhaust system - so similar to PPP. I took the car back to PE for them to look at. They said it was perfectly normal. The ecu runs the engine on the edge of det and when it detects det it alters the timing to eliminate it, hence the spike only. The next time the ecu uses that part of the map it remembers what happened last time and uses the corrected timing so that there is no det. However, after that it alters the timing again towards det conditions. Merv was able to replicate the det (verified on det cans) on PE's rolling road and watch the ecu altering the timimg in real time using the Ecutek software. Evidently new age STi engines are more prone to det between 5000 and 6000 rpm, classic Scoob engines at lower rpm.

My ecutek remap was done over a year ago, so if my det spikes were significant the engine would have melted by now. Evidently a Scoob engine will withstand det spikes. I do have my KL set at max sensitivity so it may be exagerating the situation.

Also I have found that there is no difference in the occurence of the det spikes with Esso SUL, Optimax or Esso SUL + a bottle of Millers octane booster. I believe this substantiates what Merv told me.

Incidently, whilst I was there Merv downloaded the latest ecutek software into my ecu and tweked the VVT parameters to give me a few more horsepower.

Alan

 

My KL is also set to max and as a check on sensitivity, provides a show of both greens when operating the starter (sensor is mounted on the block quite close to the starter motor) I've now got just over half a tank of Optimax and half a bottle of millers in, so I'll give it a try sometime this week.
Talking of PE, both me and my son have spent a few bob there over the years (RS's Cossies etc.) knew Merv well back then!
JohnD

PS On the subject of det. have a look at http://www.zhome.com/ZCMnL/PICS/deto...etonation.html May be American but still worth a read!