knock sensor and 20hp loss - a myth?

[Lex]

Hey guys,

Reading the GTR manual, it says that the failsafe for not having a knock sensor is a reduction in timing by 1 degree! 1 degree, is that the cause of the claimed 20 hp power loss? Or is this 20hp power loss without a knock sensor another myth?

Can someone with first hand experience confirm? Jordy? Charles? Dave?

EDIT: If it is 1 degree retard, can't we just advance timing using the disty by 1 degree and be done with it?

[D323]

Hey guys,

Reading the GTR manual, it says that the failsafe for not having a knock sensor is a reduction in timing by 1 degree! 1 degree, is that the cause of the claimed 20 hp power loss? Or is this 20hp power loss without a knock sensor another myth?

Can someone with first hand experience confirm? Jordy? Charles? Dave?

EDIT: If it is 1 degree retard, can't we just advance timing using the disty by 1 degree and be done with it?

good info, but isnt the GTR ecu completely different from the GTX one? Is there a greater decrease in timing since the GTR could probably handle more abuse than the GTX one?

Good find d00d.

Bump for more info.

[charles]

Not sure but my GTX is running super rich. i don't have the knock sensor or 4th wire for the TPS.

[D323]

if you get a knock sensor hooked up take it to a dyno, and unplug it and see how much HP you lose from a base pull.

[Lex]

The Ford Laser guys also said it was 1 degree (they have BPTs) - if anyone has a GTX FSM, we could figure it out easily.

[BuGS]

What should your timing be for a N/A Turbo'd BP??? Right now I have it at the stock 10 degree but an thinking of lowering it to 9 or 8. BTW running 92 Octane from 76.

[Lex]

If it's a turboed NA, you have a few things to consider.

1. Your na block has a higher compression

2. if you're using an na ECU, it advances the timing much more than a BP26, or 55

So in your case, you should take those things into consideration when setting the base timing - however, there isnt much you can do about the way the ECU advances timing unless you go standalone ignition.

[Tazman2]

I'm betting thats a misprint and suppose to be more like 10 degrees not just 1! :ARCADE:

[Lex]

I doubt it. It seems to be in the GTX and GTR manuals

[redfox]

i hooked up both wires on my knock sensor and didnt knowtice ANY difference... 20hp is just another myth

[Lex]

dammit, I hate how these myths are born

[D323]

dammit, I hate how these myths are born

at least we have disproved them slowly but surely.

[Bax]

Is there anyone that can understand the way the GTR knock sensor works?
The GTR wiring manual has it's equivalent circuit so I think that it will be pretty easy to build a simple circuit to monitor knocking.
As I saw, it is a hell to understand how knock control box output (2J pin on ECU ) reacts to knocking as there is no schematic of it, nor the manual says what voltage we get on knocking on 2J pin. It only says that on idle we have 4 Volts.
One other way to see if knocking occurs is on the diagnosis connector. It outputs 5 sequential pulses which represents knocking but i don't thing it's realtime. It's like a log.
What do you all think.

P.s. 1 degree retard would be able to hurt so much the performance (20hp)?

[Lex]

I am not sure what is inside the knock sensor control box without opening one up and I don't have one on hand.

Yes, I am quite sure that 1 degree will not result in 20 hp loss. That seems to just be a myth

[EscortNation]

My guess would be its not the actual knock sencor. Its probly a difference in the timing curve between the bp05 and bp26 ecu's. People who have driven with the bp05 ecu then change to the bp26 and find they have a bit less power. Then they just make the asumption that they dont have the knock sencor which changes timing so that must be why