Hi,
In my ill-informed, un-educated past(pre Saab owning days!) when it came time to change the spark plugs I usually went for the bosch super 4's.
I found them to actually be better than normal plugs (or was I simply trying to convince myself that £20 for 4 plugs was ok?)
Anyway, I'm going to change the plugs on my '91 2.3turbo and I was wondering if anyone has any recomendations?

Thanks.
Dave

A number of dealers and Saab specialists I know strongly recommend only using NGK plugs on 9000's.

I'd be glad to hear of any recommendations for enhanced plugs, especially regarding the multi electrode units, etc.

Highlander

the recomended plugs for your 91 2.3 turbo are NGK BCPR7ES you must use resistor plugs otherwise you will right off your DI

AYM

use only NGK !

Use only NGK and if the car has Trionic engine management this is essential since the voltage required to ignite the mixture is measured at each cycle and the spark timing for the next stroke is adjusted accordingly. The spark plugs are in fact one of the sensors used by the ECU for engine management so it is important that you use exactly those specified.

Trivia:
I read somewhere that 1000 NGK plugs a minute are sold worldwide. So somewhere some machinery is working like mad!

Good point Derek.
I understood that the DI Pack only applied the lower voltage to all 4 plugs to measure resistance, (in order to identify which one was on the compression stroke), prior to the engine actually running. The objective is to know which cyclinder to fire first, and then it follows on in the normal firing order (1;3;4;2).

Anyway, I have never had a problem with NGK's, so will stick with them on the popular opinion of Saab experts and enthusiasts!

thanks guys...it'll be the NGK's then

AYM

When you say use only NGK fair enough,but do the plugs you suggest 'BCPR7ES',will they 'do' the 89' 2.0 turbo too.
I mean is it basically the same plug for just about all the 9000's.

I read somewhere that 1000 NGK plugs a minute are sold worldwide. So somewhere some machinery is working like mad![/b]

And you thought that [i]I{/i] would win mastermind??

Intersting DI article I found once..... Long!


Saab Direct Ignition
Part 1 of 2: Multi-Spark Firepower!

"We have ignition!" is an exciting phrase in this era of space
exploration. Now exciting automotive ignition systems are evolving
with that same space age technology which are sparking new levels
of engine control and performance.

SAAB, the Swedish automaker, realized the limitations of
conventional inductive-type ignitions were restricting further engine
development. So they created the innovative Direct Ignition (DI)
system to surpass present day requirements and allow
enhancements well into the future. DI may have the most intelligent,
powerful spark in the realm of ignition science. This first of a 2-part
article takes a look at the power and tremendous reserve capacity
of the Direct Ignition system.

DI is presented in a simple, powerful package. There is no ignition
distributor, no cap and rotor, no visible coil. There are no
secondary wires snaking over the engine, no fragile spark plug
boots, no moving parts. The source of DI power is the Ignition
Discharge Module (IDM) which is bolted between the overhead
camshafts and is mounted directly on the spark plugs. The brain of
the system is the Ignition Control Module (ICM) which interprets
signals from the unique sensing circuitry in the IDM and responds
with appropriate commands. The 1989-1991 ICM is located under
the driver's seat. 1992 and later ICM's are located in the engine
compartment under the plastic bulkhead cover. In Trionic systems,
the DI is incorporated into the fuel/turbocharger management
computer.

Within the IDM is a 400-volt transformer which charges a bank of
primary circuit capacitors. When the ICM triggers the release of
this charge, it races through the primary windings of the ignition
coils mounted atop each spark plug developing 40,000 volts or
more. The cast aluminum housing of the IDM shields the complete
ignition process and prevents the powerful electrical circuitry from
interfering with radio and computer operations on the car as well as
protecting wayward humans.

The DI system is designed to enhance several engine operating
parameters. Ignition system saturation time has been limiting engine
performance for years. Exotic dual ignitions have been necessary to
power high performance V6, V8 and V12 engines because a single
inductive primary and secondary circuit couldn't respond fast
enough to meet high RPM requirements. The speed of saturation is
critical to the effective power delivered across the spark plug gap
even at lower RPM. The slower inductive ignition takes much
longer to build an adequate charge. This gives the slowly building
voltage time to bleed off to ground through secondary wires,
distributor caps, rotors and dirty spark plug insulators. The DI
system's 400v capacitive primary circuit allows shorter length,
heavier gauge primary windings to be used. The lower resistance to
current flow and computerized switching allow a much quicker
magnetic field build-up and collapse. The DI system's ability to
generate the spark in 1/20th the time of a conventional system
overcomes the possibility of voltage bleed-down while also
providing enormous reserve capacity at high speed.

Spark plug heat range considerations are another major limitation to
peak engine performance. If the spark plug runs too cold, it soots
up and misfires. So, hotter spark plugs are used to prevent deposit
build-up. The hotter plug brings the combustion chamber closer to
detonation temperatures and possible internal engine damage.
Therefore, the engine output must be restricted to provide a margin
of safety. DI enables the use of a cooler spark plug which moves
combustion chamber temperatures away from detonation and
allows both higher compression and higher turbo boost to be used.
DI also uses high technology to keep the spark plug clean. The DI
system burn-off function creates a fire storm of more than 4000
ignition discharges to clean away contaminants from the spark
plugs. A technician shocked by a conventional ignition at idle
receives about seven 9000 volt shocks each second. While in
burn-off function, DI creates 840 sparks per second at 40,000
volts each ... for a constant 5 seconds! And you thought ignition
systems weren't exciting!

Most importantly, remember the DI burn-off function can occur
while you are holding the IDM in your hands with the ignition key
off! 1990 and earlier DI systems activate the burn-off function
when the key is returned from the cranking position to the RUN
position and the engine has not started. The 1991 and later IDM
will trigger the burn-off about 5-10 seconds after the key is turned
off and the engine has stopped running. For instance, if you are
holding the IDM and someone cranks the car over for you, the
burn-off will occur 5-10 seconds after the engine stops cranking.

The intense energy released can endanger the IDM itself. Don't
trigger the burn-off function without having the prescribed resistor
spark plugs installed and securely grounded. It is important that the
IDM be positioned upright when testing to avoid overheating and
electrical breakdown in the oil cooled and insulated ignition coils.
To disarm the burn-off function, disconnect the IDM. The early
style IDM has a short wiring harness which runs through two
four-pin connectors mounted on a bracket near the battery. The
later IDM has a 10-pin connector at the IDM.

In summary, the Direct Ignition System has the capacity to produce
exceptionally quick, powerful spark energy. Its impressive reserve
capacity assures a stable source of ignition and creates new
opportunities for advanced engine performance.


Saab Direct Ignition

Part 2 of 2: Spark of Intelligence!

Part One of this article (last issue) addressed the "Multi-Spark
Firepower" of the SAAB Direct Ignition (DI) system. Part Two
examines the innovative way SAAB uses the spark plug circuit to
read combustion chamber activity. The usual task of a spark plug is
to provide replaceable electrodes within the combustion chamber
to enable ignition of the fuel/air mixture. Providing spark for a brief
moment once every four strokes explains the "spark" part of the
device's name. It spends the rest its time being a simple "plug." The
DI system has upgraded the conventional spark plug's job
description to that of a spark "sensor" by utilizing the spark plug as
part of a combustion sensing and synchronization circuit. The spark
plug is literally in the middle of everything happening in the
combustion chamber, not located on the periphery as are knock
sensors and camshaft sensors. The DI uses these spark "sensors" to
determine which cylinder to fire when cranking as well as identifying
which cylinder needs more fuel or less spark advance while running.

The brain of the system is the Electronic Control Module (ECM).
This ECM is referred to as the Ignition Control Module (ICM) with
LH Injection, as the DI-APC (Automatic Performance Control)
ECM on earlier Turbos and as the Trionic system ECM in later
vehicles both with and without turbos. The ECM works with the
Ignition Discharge Module (IDM), often referred to as the
"cassette," which is the coil-pack that bolts between the camshafts
and connects directly to the spark plugs. A hall-effect crankshaft
position sensor (CKP) is mounted behind the crank pulley and is
connected to the ECM. So, how does it work?

When first cranking, the crankshaft position sensor indicates top
dead center for each pair of partner cylinders but cannot tell which
cylinder is in the compression stroke and which is in the exhaust
stroke. The ECM has the ability to remember which was the last
cylinder to fire as the engine was shut off and can use this
information to determine which cylinders to fire when cranking. If
this information is not available due to loss of battery power and
memory, the DI will determine which cylinder to fire by using the
spark plugs as combustion sensors. During the first few cranking
revolutions of the engine the ignition will supply spark to both
partner cylinders at Top Dead Center (TDC) until it can
synchronize the spark to the proper cylinder. In addition to sending
the actual spark, DI constantly applies a 70-volt reference signal
across each spark gap. This 70-volt reference would not normally
cause any current to bridge the resistance of the 1.1 mm spark plug
gap. However, during the heat, pressure, and turbulence of
combustion, the gases within the chamber become highly ionized.
The ionized gases create a more conductive path across the spark
plug gap allowing the sensing current of the synchronization circuit
to flow. This current flow signal informs the ECM that combustion
has occurred in this cylinder while its partner cylinder, on the
exhaust stroke, does not transmit such a signal. The ECM will
discontinue sparking both partner cylinders after the first 25
successful cylinder firings. The system eliminates the extra spark to
prevent unnecessary spark plug erosion.

The innovation isn't over yet. As the engine cranks below 850 rpm,
the DI will fire double sparks to the spark plug at 10° BTDC to
enhance starting. If the cranking speed drops below 150 rpm, such
as on a very cold day, the DI will fire multiple sparks from 60°
BTDC through 10° ATDC! Once the engine is idling at 850 rpm
the single spark returns ... unless the rpm drops below 420 rpm,
which engages the multi-sparking again. The "burn-off function"
described in Part One will clean and heat the spark plug electrodes
if the engine fails to start on the first try.

When the engine is running, the spark plugs continue to send
valuable information to the ECM. The circuit now determines the
timing and frequency of combustion chamber events such as
pre-ignition and detonation. As DI monitors the cylinder, it looks
for combustion occurring outside the programmed parameters. If
the cylinder initiates combustion BEFORE the spark is sent, DI
senses this unprogrammed early combustion as pre-ignition.
Pre-ignition is often caused by overheating of the air-fuel mixture by
hot spots within the combustion chamber and can lead to melted
pistons and spark plugs. Detonation is more commonly known as
"knock" or "pinging."

The ECM will inject additional fuel into the pre-igniting cylinder to
cool the affected chamber and stop the pre-ignition without
decreasing power output.

Detonation occurs when a second flame front may spontaneously
ignite AFTER the programmed ignition has occurred creating a
hammering effect in the cylinder, which lowers performance and
can damage the engine. The ECM will retard ignition timing only on
the detonating cylinder while keeping the other cylinders at peak
output. Turbo boost, which affects all cylinders, will only be
decreased if individual cylinder management fails to limit the
detonation.

The innovative Multi-Spark Firepower and Spark of Intelligence
possessed by the SAAB Direct Ignition combine to give each
engine cylinder the precise management needed to generate
maximum performance and economy even in less- than-optimum
conditions.

-Written by Daniel Winterhalter, IDENTIFIX European
Team Leader. Daniel is certified Saab Master, ASE
Master and L1, with 25 years of diagnostic experience.

wrighar, when was this published?

you're right...it is long! interesting in a glib marketing way though.

The article was published in an american online (and paper?) magazine about a year ago.

One of those DIY mechanics mags.

found it,

part 1 here
http://www.autotruck.net/ms/archives/2000/...1200/1200pf.asp (http://www.autotruck.net/ms/archives/2000/1200/1200pf.asp)

part 2 here
http://www.autotruck.net/ms/archives/2001/...01/0101patf.asp (http://www.autotruck.net/ms/archives/2001/0101/0101patf.asp)

Auto gerabox and idling?
http://www.autotruck.net/ms/archives/2001/...701/0701med.asp (http://www.autotruck.net/ms/archives/2001/0701/0701med.asp)

EMS/cat bits here
http://www.autotruck.net/ati/archives/1998...198/0198mc.html (http://www.autotruck.net/ati/archives/1998/0198/0198mc.html)
http://www.autotruck.net/ati/archives/2000...800/0800mch.asp (http://www.autotruck.net/ati/archives/2000/0800/0800mch.asp)
http://www.autotruck.net/ms/archives/2001/...201/0201sen.asp (http://www.autotruck.net/ms/archives/2001/0201/0201sen.asp)

ECM's?
http://www.autotruck.net/ms/archives/1999/...99/199cntrl.asp (http://www.autotruck.net/ms/archives/1999/0199/199cntrl.asp)

Saab published a shorter description in the 1993-94 Owners Saab Book (Not Owners Manual, but a supplimentary freeby which came with the car and told you all about Saab inovations, etc).

The official saab speel on the DI pack doesn't mention the multiple sparking when crank revs drop when turning engine over, though.

Stewart,
Regarding your query on plugs..
'BCPR7ES' are for Turbo Engines.

BCPR6ES are specified for some Saab Engines, and I believe that these are for non-turbo versions.

Neo Bros only sell BCPR6ES for all Saabs, but these are incorrect for the Turbo versions.

9000 Spark Plugs here:
http://www.elkparts.com/acatalog/Elkparts_..._Plugs_236.html (http://www.elkparts.com/acatalog/Elkparts_Catalogue_Spark_Plugs_236.html)

Stewart

Regarding Plugs

9000T (85-87) (Non DI) NGK BCP7EV
9000T (88-98) (DI) NGK BCPR7ES
9000i 2.0 (86-91) NGK BCP5ES
9000i 2.0 (92-93) NGK BCP5EV
9000i 2.0 (94-98) NGK BCPR6ES
9000i 2.3 (90-98) NGK BCPR6ES

the letter R means resisted and ONLY use these with a DI

AYM

Hi I'm new in this forum. Can anyone tell me if I can use NGK BCP7EV spark plugs for my 1996 9000 CD turbo B204 engine and whats the gap I can use?

What about the NGK plugs that end with -11 eg. NGK BCPR6ES-11 are they the same as the NGK BCPR6ES? Is the -11 the gap size?

Foosurat, the accepted wisdom is to use ONLY the BCPR6-ES, gapped to 1.1 mm. Hang on! Or do I mean BCPR-7ES? Somebody will tell us soon; I can't recall which I used..... But no, you should not use BCP7-EVs in your car.

That said, I had Champion platinum plugs in my '98 Annie 225 bhp, and I only found out when I changed them after I'd done 12000 miles. The previous owner had the bill for the service done just before he sold me the car, and he'd been billed for new NGK BCPR- plugs. The previous service had been 12000 miles earlier, so the Champions must have done at least 24,000 miles, and I never had any indications of any ignition problems at all.

BOF

[ QUOTE ]
Hi I'm new in this forum. Can anyone tell me if I can use NGK BCP7EV spark plugs for my 1996 9000 CD turbo B204 engine and whats the gap I can use?

[/ QUOTE ]

Welcome

No, those plugs will not work properly with the DI cartridge, and will probably damage it too.

The correct plugs for all turbo models are NGK BCPR7ES-11. The "-11 denotes that they have been pre-gapped to 1.1mm. You can get them not pre-gapped and set them yourself.

The BCPR6ES are for non-turbo models.

[ QUOTE ]
Neo Bros only sell BCPR6ES for all Saabs, but these are incorrect for the Turbo versions.

[/ QUOTE ]

On page 21 of the Neo Brothers Catalogue BCPR7ES-11 are listed at £2.50+vat.

[ QUOTE ]
[ QUOTE ]
Neo Bros only sell BCPR6ES for all Saabs, but these are incorrect for the Turbo versions.

[/ QUOTE ]

On page 21 of the Neo Brothers Catalogue BCPR7ES-11 are listed at £2.50+vat.

[/ QUOTE ]
Yes, but perhaps the original post was referring to the 2001 Neo Brothers catalogue, since that was current when that post was made

Yes, BCPR6ES for non-turbo DI applications and BCPR7ES for turbo DI applications.
The reason the BCP7EV are very definitely not suitable is that they are not resistive (denoted by the "R" in "BCPR..."). They will damage the DI cassette, which usually has a sticker underneath saying to "Use ONLY resistive spark plugs".

Other than that, DI's use of the spark plug gap as a combustion sensor means it is only really guaranteed to work with the plugs it was designed to use - BCPR6ES and BCPR7ES. Other "equivalents" may or may not work since the properties spark plug manufacturers measure and match for equivalence (often more mechanical than electrical) are not necessarily the properties that matter to the operation of the DI.

Symptoms can range from misfires to subtle lowering of boost and in some cases (as it seems with Dennis's), they seem to run fine.

Have tried looking for BCPR7ES-11 but did not seem to find it at my local spart parts shop. However I saw NGK BKR7EVX-11 spark plugs. These are platinum plugs. Anyone knows if these are ok for my 1996 9000CD turbo? Thanks.

> I usually went for the bosch super 4's.
> I found them to actually be better than normal plugs

Not for the Saab - Assuming you have a DI cassette? I don't know much about the 91 model but my 92 2.3 Turbo did.

For a 2.3 Turbo 9000 you want NGK BCPR7-ES11

> (or was I simply trying to convince myself that £20 for 4 plugs was ok?)

£20 for 4 plugs!

£1.89 each (so £7.56 for 4) from Elkparts.

No point fitting any other model. They can more than cope as my 9000 is running 285bhp and they have no problem.

Take a look here (http://www.elkparts.com/index.php/cPath/23_476_477)

[/ QUOTE ]Yes, but perhaps the original post was referring to the 2001 Neo Brothers catalogue, since that was current when that post was made


Well spotted Bill. I didn't notice the post was 5 years old!

Having ben experiencing varing problems with starting and running on my MY93' Aero I decided that my plugs needed changing. I've now had the car 3 yrs and done 24,000 miles, the plugs were part of the service when I bought it. I bought the new set of BCPR7ES-11 from my local motor factors for £7.80, who says SAABs are expensive to keep?

When I removed the old plugs I noticed that they were BCPR6ES plugs from a non-turbo model. Having read through the above posts the questions i am left with is

What effect does using the 6 model have on my Aero?
and
Can I expect to see any improvement by changing back to the 7s?

Sorry to hi-jack but I hate to spawn new threads when there's no need.

Thanks
Lee

The 6s are designed to work with lower performance engines and are not as effective at conducting heat away from the cylinder as 7s. In practical terms this may have mean that detonation (pre-ignition) would have tended to occur earlier. Trionic will have adpated for this, and it may be semi-permanent. Your best bet is to perform an adaptation run to get things back to normal.

Will do. One of the problems I noticed was lower performance recently, that coupled with lower fuel economy made me decide that 24K was enough for the old ones.

Thanks
Lee

Just to let you know the car now starts on the first rotation and runs so much smoother than it was. Economy seems to be slightly up too although that remains to be seen in time between fill-ups.

Thanks for all the info.

Lee

Not wanting to confuse, but I have been running the BCPR8ES plugs - These run even cooler than the 7's and are happy in higher tune cars. I found the engine to be a little bit rougher at lower rpm though so have gone back the original 7's and gapped to about 0.9mm to help keep an easy spark under higher boost.