Newest APC-mod!

[Saab-Daniel]

Hi Tadek...
This mod alters the 40-ohm resistor, instead, the 50-ohm potentiometer will help you out. I think mine is adjusted to around 45 ohms or so, giving me 0.350 volts over the pot. The old 40-ohm mod was made to a few box's here in Denmark aswell, and I have yet to see your results. I will look into it, and ask people to try out what you did on the motor-way. Hope we can figure this out, but if it's the mod that causes it, we will have to look into that aswell, of course...
Daniel.

[martin.nicoll]

Originally Posted by trackside

"The car did a 15.01 1/4 mile run on a semi-wet track" -I do find this a little hard to believe from only an APC adjustment. 15 sec 1/4 mile times from FWD cars need some serious power and expert launching.

I can believe that, my T8 ran 16.2 with just a de-restricted exhaust and MBC.

[Basre]

Wellllll... Mate.. A Lot of us HAVE been wasting our time with Fuel Mods and Ic Upgrades :-)
Extra Fuel is not really needed up to 18 Psi.. and then water injection is the prefferable route.
OEM Ic's are lindeed limiting.. at 20 psi .. but much less so at 16psi.
There is a LOT of hearsay and anecdotal evidence in the Saab worlld about what is needed and what does what.. But this IS the internet and all manner of Sillyness gets passed off as Gospel :-)
Do yr own experiments and you may get different ideas than the generally posted ones :-)

[Jezzadee]

As stated earlier by Alex, there seems to be quite a difference when it comes to fuelling between Lucas and Bosch systems. Stock Lucas cars seem to cope far better with higher levels of boost. Not very scientific I know, but I peak at 1.25 bar using an MBC with a stock Lucas system, except for the FPR which is only 2.5 bar instead of 3 bar. No knock detected on several rolling roads, and it has surprised a few people when they see the lower rated FPR. I think it just shows the potential of the other components in the system. My boost drops off after 4000 rpm though, so at 5500 rpm I'm at about 0.7 bar. I would have thought 1 bar up to 6000 rpm is certainly possible on stock Lucas fuelling, but not recommended.

(Not that I suggest anyone else tries my setup at home - it just happens to work for me.)

[-Frank-]

I have just got my K&N cone filter and battery cables to move the battery to put the exhaust on. I think i might do this mod at the same time.

UNLEASHED

[nick900]

If you look at the picture, he has removed the headlamp for better airflow to the intercooler. I am sure that this would help quite a bit. If you think of full boost for most of those 15 sec then the standard intercooler would benefit greatly from headlamp removal, so it might not be just the APC tweak.

[Saab-Daniel]

I agree nick, that probably will help. I removed mine too And the weather was misty/wet with around 13 degrees celcsius, so pretty cold too. The car did idle every time the line moved, so must have heated some then... I think the head-lamp removal help though, nice airflow to the IC!
Daniel.

[Tadek]

Hi guys!

Just to keep you informed: I removed the "new mod" and now run the "old mod" from 900aero.com. Boost ist nice and stable with the old setup again.
The new mod is no good for me, as stable boost without spiking and overboosting is more important to me than the boost taper "problem" at high rpm.
Enjoy the boost,

Tadek

[trackside]

"Extra Fuel is not really needed up to 18 Psi.. and then water injection is the prefferable route." - at high rpm and 18psi - stock fueling is inadequate.
"OEM Ic's are lindeed limiting.. at 20 psi .. but much less so at 16psi." - even at 16psi there is a large pressure drop and their small size and poor position means that they soon become heatsoaked and ineffective.

[Alex]

Originally Posted by Basre

Extra Fuel is not really needed up to 18 Psi.. and then water injection is the prefferable route.

Is this 18psi from a T3, TE-05 or hybrid turbo? Running Bosch or Lucas injection?

Water injection shouldn't be used as an alternative to inadequate fuelling either.

Originally Posted by Basre

OEM Ic's are lindeed limiting.. at 20 psi .. but much less so at 16psi.

The stock IC will heatsoak very quickly even on a car running standard boost and will take up to 4miles of gentle(ish) driving to cool down again, and this effect on performance is very noticeable even in the UK climate. Changing to a FMIC, which can be done cheaply if using a 2nd hand Volvo unit, is one of the best initial modifications that can be carried out and will allow the car to perform consistently on every throttle application. This is before the boost is even increased.

[Si]

.......nearly finished my modded intercooler, I've welded together 2 standard coolers and made 2 single outlet endcaps for it, just got to seal up the ends properly now and then fit it. I'll post some pic's when it's done(also got to sort out a lame website to host pics), will be interesting to see how it copes, I'm also trying to reduce the intercooler pipes down as much as poss as they seem quite long on the volvo mod.

Anyway , I concur, when i've been a bit heavy footed you can tell the standard intercooler gets saturated very quickly and you loose performance, fingers crossed the modded one with double the flow rate/volume should help.

[Tadek]

@ Alex: Water injection shouldn't be used as an alternative to inadequate fuelling either.

Okay, but what is inadequate? It depends on your setup! Most turbocharged cars run a very rich mixture at full load to prevent detonation. Therefore slight increases of boost / performance are possible without heavy changes to the injection system. On the other hand, if you still want more power and boost, the fueling has to be adjusted accordingly. You would probably want to run an even richer mixture with higher boost to be on the safe side.
But if you use water injection, the additional fuel won't do any good, because the water will do the job of cooling and knock prevention. As a matter of fact the additional fuel will cost you some power, because the engine will produce max. power at an air/ fuel ratio of approx. 12,5.
I aggree that water injection should not be used as an alternative to adequate fueling, but water injection changes your need for fuel.
I used a rising rate FPR, which was nice untill I installed WI. With WI I had to reduce the fuel pressure by installation of an 3.0 bar FPR (LH2.2) and the car runs noticably better with lower fuel pressure.
Cheers,

Tadek

[Alex]

I to use water injection as part of the overall engine tuning. As with your car it enables me to lean the mixture out slightly (and this is just as applicable if running lower boost pressures as well) and run increased timing.

[SteveS]

Dan

Would it be possile for you to post a few pics of the mod? I have a spare Red APC which i would like to try out your mod on but this will be my first APC mod so don't want to get it wrong. it certainly sounds easy enough but better safe than a blown engine

Cheers

[Saab-Daniel]

Hi Steve. I only have a camera-phone, so can't take proper photos of it... But if I can borrow a digi-cam, I could deffo post pictures. It's not hard to do the mod...

Daniel.

[dr_zero]

at the risk of sounding like an idiot i have a couple questions.

when you say "mount" in the instructions do you mean that the existing resistor is left in place and that the new item is soldered to the same point on the board (or soldered to that side of the resistor, as if in parallel or 1/2 in parallel) ??

(i.e., a side of the resistor isn't taken from it's location and soldered to something else)

the only things "removed" from the board being R138 and the right side of R36 ??


also, is this mod is for any of the 16V turbos ?? i have an 89 900T and i am debating this with an extra APC box for the fun of it. are there different APC boxes out there for 16V turbos ?? also does this require changing the FPR to a 3.0 bar ??

thanks a lot.

sorry for my ignorance

[Kaas]

Originally Posted by SteveS

Dan

Would it be possile for you to post a few pics of the mod? I have a spare Red APC which i would like to try out your mod on but this will be my first APC mod so don't want to get it wrong. it certainly sounds easy enough but better safe than a blown engine

Cheers

Hi Steve!
I think I have some pics at home on my puter somewhere! If I remember it I will look when I get home from work!

Cant you find a black box insted! And keep the red one! They are a bit rare! A black one dont cost much from the scrappy!

[Kaas]

Here is some pics of the new mod!

[Bennie]

Hi! here some pics of my mod.

But the mod does not work properly.

What did i do wrong??

[Kaas]

Is your R36 "right side" On the same leg where the R102 is conneced to the pot? You see the yello wire!