Aftermarket Engine Knock Control (F3 Engine Content)

Is anybody using Knock Control on their MS1 V3 ?

Are you using it with standard VW sensors

cheers

 

im sure eddie did some work on this a while back with a seperate knock control system

also i vaguely remember trev16v with a set of ear defenders hooked up to the engine ?

 

That's det cans trev had!

Nigep did a thread on them too.

i was wanting to install knock control on the ECU for safety more than anything.

 

Are you concerned about det when running nitrous? Do det detectors work in the same frequencies for different fuels? Or is knock always the same?

Really interesting if the OEM ABF knock sensors can be simply hooked up to the MS.... cue a more aggressive spark set up + more power.

 

They can't be just connected up. They need some form of filtration. Or knocksense that can connect up to MS. If its mapped right tho , it shouldn't need it.

 

Map it right and you will have all the 'safety' that is needed.

 

i always thought that's why OEM Management had knock control , because VW didn't map them from the factory correctly

LMFAO

 

Yes Eddy very Whitty , you know you have done a complete map on the MS1 if we have lived closer.

Diffent Fuels are probably the main reason for the question but won't go into too much detail on that one.

 

Eddy as in Eddy Current dyno?

OEM det sensors are a production failsafe, and can't be compared with aftermarket ECUs. There are 2 OEM det sensors on an ABF, yet 4 on a BTCC engine. One lives on det, the other stays off it most of the time.

 

We havn't had a thread on the Different Fuels which is what will probably follow on from this thread.

i.e. 109 Ron , E85 etc.

 

There are a few goes at E85 threads around the forum - I've just put 'E85' into the search.

I don't think we've had a concerted go though, but have a look first. I believe consistency of fuel is the issue with that, cue straight back to the knock sensor topic, and how practical it is to get aftermarket ECUs to work with det sensors, and retard the timing when needed.

Potentially fascinating, though sounds horribly complex!

 

but worth it if you get the Power from the Fuel especially when you have the flow limitations of a 051 / 027 Head.

 

Agreed - it's down to the effectiveness of the control systems which are actually available and how cost effective they are to set up safely on a closed loop system.

It can't result in pistons pock marked with det, or the consumable nature of that rules it out.

 

My take on it is that knock control is more important on production engines because of the high likelihood of people running the engine on stale or low-grade fuel, or because of increased knocking through high engine mileage (carbon buildup, etcetera). In other words, the basic map is good, but you have to have a failsafe knock system because the average person is likely to shove any old fuel into it.

I think Eddie's and Tshirt's comments about 'mapping it right' are quite valid, because once mapped, a 'tuned' engine is most likely to be fed decent grade fuel and generally looked after. I feel confident with my 16VG60 (running on MS1) because we used a Bosch wideband knock sensor via a hearing amplifier while tuning on both the road and rolling road. I keep that setup in the car so it can always be checked again from time to time. I have a mate who is very good at listening for detonation amongst all other noises in the headphones, so I take him out in the passenger seat while I concentrate on driving.

 

Thanks Trev


Whats the part number for the Bosch Sensors, my ABF had Sensors (not connected) fitted many years ago but that's another story.

 

There seem to be quite a few types of knock sensor Brooky.
I got a load here that came off various 6A, ABF and ADR 20v engines.
Can get part numbers in a few minutes for you.

 

Various sensors:

Black connector 037 905 377

Brown connector 037 905 377 A

Blue connector 054 905 377 G

Green connector 054 905 377 H

 

Found a US Company that do a Knock Sensor unit that is designed to be connected to MS ECU's

http://www.viatrack.ca/

Nice Price too.

i will ask if they ship to the uk or i might have to ask BrokeVW to do his deed

Group buy anyone ?

 

Also i've been pointed in the direction of J&S Safeguard knock control.

This system is alot more advanced than most others i've seen.

The best aftermarket standalone Knock Sensing ignition in the world, is the J&S Safeguard:

http://www.jandssafeguard.com/Vampir...S_Vampire.html

http://www.jandssafeguard.com/SafeGu...timonials.html


http://forums.maxima.org/general-ma...nitrous-all-motor-forced-induced-maximas.html

 

Quote from F3 Engine Builder regarding Knock Control. hope this is of interest, i found it to be a good read.

Ian Whiiteside's review, after testing on his F3 engine:

To: jands <jpizzuto@jandssafeguard.com>
Date: Monday, October 31, 2005 3:52 AM
Subject: RE: Dyno results with Safeguard

I sold the car a few weeks ago, I however had no problems with the
controller. When I was on the dyno, the operator seemed quite impressed but
I wouldn't tell him what make the system was - the dyno was also used by an
engine builder who builds most of the engines in my race series, so didn't
want to give away my secret weapon!

I'll check out the Forum. I have posted on these type of things before but
find it very frustrating when people start quoting folk-lore at you and
disagreeing with the basic laws of physics - I normally just let them
carry-on in ignorance. I have attached the actual dyno results for you to
look at, now I have sold the car then you can post them on the forum if you
like. The dyno control was a little poor which is why the torque curves look
so 'bumpy'. First test was with 98 RON fuel without the controller and the
EMS calibrated to 2? clear of knock, next test is again with 98 RON fuel but
with 4 deg spk adv added to the previous map. Next two curves are using the
102 RON 'control' fuel for my race series, this was tested at +4 and +6
degrees from the base map ( i.e. 2 and 4? beyond detonation ).

Here is a reply to post on the forum:



"Firstly I will explain my background, I am a performance development
engineer for a company called Ilmor Engineering in the UK. For those of you
how haven't heard of it, it designs and manufactures race engines for
'premier' race series and has been involved with such championships as F1,
IRL, CART, NASCAR etc. My use of the J&S knock controller was purely for
personal use and in no way is this an endorsement of the product my Ilmor
Engineering. I have mentioned my background purely so you know that I speak
on the subject with some authority.

When the spark is initiated, the fuel/air mixture in the chamber starts to
burn and the flame front travels from the spark plug to the edge of the
cylinder. This advancing flame front heats and compresses the unburnt
fuel/air mixture at the edge of the cylinder and under certain circumstances
the pressures and temperature become so high that the whole mixture
spontaneously combusts. This effect is called Knock ( or Detonation ) and
gives a very sharp rise in cylinder pressures and normally an audible
'knocking' noise from the engine. The knock causes erosion of the cylinder
head and piston if run for sustained periods of time, which is clearly
undesirable. Under extreme conditions, the knocking can also raise the
temperature of certain regions of the combustion chamber to values that
cause the mixture to ignite before the spark plug is fired, this condition
is known as Pre-Ignition and usually results in an instant melting of
pistons or head gasket failure. Both Knock and Pre-Ignition are very harmful
to the engine and should be avoided at all costs.

For any speed and load point on an engine there will be an optimum spark
advance that gives maximum torque ( this is referred to as MBT - 'Minimum
spk adv for Best Torque' ), if we advance or retard the ignition from MBT
then the engine performance will decrease. Clearly what we want to do is run
the engine at MBT all the time in order to get best performance, however
this is not always possible because of knock. From my brief description of
the knock process, it can be seen that it is the result of 'time exposed to
high temperatures', i.e. an engine will knock more at high load, low speed,
high compression ratios and low grade fuels. It is also strongly effected by
such things as high coolant temperature, high air temperature as well as
secondary factors such as oil temperature and humidity. In an ideal world it
would be possible to map your engine at all the possible conditions in which
it may run, but this will take you many weeks on the dyno due to the large
number of factors! What is normally done is to map the engine at a few
different temperatures and then retard the ignition by 2 or 3? to provide a
'safety factor' for all the other unknown conditions that haven't been
tested. This extra 'safety' spark retard reduces the performance of the
engine, what is needed is an 'active' system that detects knock and only
retard the ignition when it is present - i.e. a Knock Controller.

I hear that people are saying 'you should tune for no knock'. Sounds good in
principle but how do you do it? The only way is to reduce the temperatures
and pressures in the cylinder, i.e. close the throttle or reduce boost -
clearly not a way to maximum performance!

I understand that John has posted some performance figures from my engine, I
have now sent him the full dyno data so hopefully he can post that for you
to look at as well. My engine is a 2 litre naturally aspirated 4 cylinder F3
engine, it is fitted with a 24mm inlet air restrictor as specified by the
series rules. This restrictor has a severe effect on the engine performance
and starts to choke the engine from about 5000rpm upwards. In order to get
maximum power from the engine it needs to be very 'efficient' in its use of
this limited air supply, the main way to do this is to raise the compression
ratio - it runs at 14:1. At the higher engine speeds, the engine is not that
knock limited as the lack of airflow reduces cylinder pressures. However at
the lower speeds where it is no being restricted it is highly knock limited
due to the very high compression ratio. For instance at around 4000 rpm, the
engine runs only 12? spark advance which is approximately 10-15? retarded
from MBT. Under these conditions the gradient of engine torque against spark
advance is very steep so a 2? 'safety margin' causes a significant loss in
performance.

By using a knock controller it is possible to eliminate this 'safety margin'
and gain performance. The other advantage of the controller is that it can
retard only the actual cylinder that knocked rather than the whole engine.
Due to subtle difference between cylinders it is very likely that one
cylinder will knock before the others. With the controller in 'individual
cylinder' mode, the knocking cylinder can run a little retarded to prevent
knock whilst the others can run closer to MBT and thus give you an extra
performance advantage.

I guess this forum is about cars with after-market turbo conversions and
these are the ideal sort of vehicle that would benefit from a knock
controller. A turbo engine produces lots of power as well as low speed
torque, it also has high air inlet temperatures - these combine to make
turbo engines very knock limited particularly at low speed ( very much like
my F3 engine ). By fitting a knock controller you will not only gain
significant increases in performance but will have the peace of mind that
the engine will be safe under any extreme ambient conditions you may
experience or say if you fill up with the wrong fuel grade.

If knock control is so good then why don't production cars use it you may
ask? The answers is that many of them do, most 'high-end' and performance
cars build in the last 5 years or so probably have knock control. Bosch is a
very strong advocate and a modern car with Bosch engine management will
have knock control. The J&S unit may be an after-market item but is works on
the same principle as the OEM controllers. Go and buy one, it is easy to
install and set-up and is a very cost effective way to more performance.

I re-confirm that I have no connection with J&S - I have only purchased one
of their units and am very pleased with the way it works. I have written
this article to help people understand how it works and what benefits they
will receive - hopefully I haven't baffled you with too much science!

Ian Whiteside"


Knock sensor discussion on usenet, from 1992