It looks like S2 engines have 2 knock sensors fitted whereas my 91 turbo only has 1, despite the block being drilled and tapped for 2. Is there any benefit to running 2 sensors on a turbo and would it be a simple splice job on the wiring ?

 

Not unless you rewrite the code. The s2 has a hall sensor to detect which cylinder is knocking and can retard ignition for individual cylinders.

Then there is a problem with mounting on the crankcase.

 

It looks like the crankcase mounting is already there for a 2nd sensor between cylinders 1 and 2 on both my late turbo and 2.7 blocks.

 

My 89 turbo had 2.

 

Really? Was that a ROW thing? Mine has only one on top that I know of.

 

I am able to detect knock by putting the Bosch sensor at the boss where the 951 intake support bracket (the long black, sort of sword shaped one by the AOS) attaches to the block.
Not ideal location but works well enough for my use.

 

I don't know how the S2 deals with knock. Maybe the KLR doesn't need 2 sensors ?

 

I thought it was normal.. My turbo was rhd 952 so maybe it was UK thing.

 

Not unless mine is missing something.

 

All turbos came with one single knock sensor and if you disagree then I would like a bottle of whatever you folks drink in Slovenia

 

Im almost 100% sure my turbo had 2. I'll check harneas when I find it. It also didnt have o2 sensor. It was modified by bbr/gti but that was probably just chips.

We like our wine here

http://www.nytimes.com/2013/01/30/di...anted=all&_r=0

 

By the way,(been wondering about that for a long time) why standalones like Motec M84 that are used in very high profile cars like 917 and 962 do not have knock control at all?

Its strange to find it in ultra cheap ecu offerings like MS, EMU, Vems, but not in Motec, Haltech etc..

 

Probably because the fuel is consistent as it's race fuel. and probably because the threshold of peak power output per cylinder (there's a word for it which i've forgotten) vs when it'll knock is large enough that it wont knock.

That's my thought anyway.

 

Do you think there was any EFI system back in the days of the 917?

Full race cars are a lot less subject to see fuel of varying octane than street cars that must be able to fill up anywhere.

ETA : Pauly was quicker.

 

No, they had super complicated 12 port bosch fuel pumps. But if I remember correctly I saw a video of one converted to efi with motec.

It was also used on street/regular fuel 962s such as this one:



It does not make sense (to me) that cheap units would facilitate this function yet 3x more expensive units with reputation that are oriented as much on the road as any standalone, does not.