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Discussion Starter · #1 ·
ok, i have finially gotten around to being willing to do this and was looking on 900aero.com at how to do it. there are a couple things i am slightly woried about...

Method 1 - 13.05-20.3 psi (if my calcs are correct)
Method 2 - 7.25-20.3psi

is it just me or does 20.3 psi sound a bit high for a C900? i am afraid of ripping my gearbox to shit if you know what i mean...

also when it says

"3. Locate the R42 resistor
4. Exchange the resistor for a wire."

it dosent say where to put the other end of the wire...

any help or pics would be appreciated

thanks
-wyeth
 

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i can help, i did just about the same mod i think, when it says to replace teh resistor with a wire, they mean just that, you disconnect the resisitor wich is connected to the circuit board in 2 places, and put a regular wire there, its a direct swap.

as for 20psi being too much, yes it is. the tranny probably wont blow up right away, but it will soon. i have mine set at a peak of 16-17psi and holding around 15. i'd say that that is possibly just beyond the limit of what the trans will handle, but its really fun :twisted: . but honestly as long as you shift carefully and smoothly, no grinding and no powershifting and no burnouts, the trans should last a fair amount of time.

on a related note, you should upgrade your fuel pressure regulator to a 3.0 bar unit. that will help the fuel system cope with the extra boost. they arent hard to find, any na 16v has one and you shouldnt pay more than $10 at a junkyard for one. its also possible that someone on here has one that they are willing to sell to you cheap.

any more questions, dont hesitate to ask.

Paul
 

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Discussion Starter · #4 ·
thanks paul and burn i will proally take the apc out on tuesday (as i dont have work) and have a gander at it. then i will decide what im going to do from there...also i dont have a true boost gauge (only the dash shit) and i realize it would proally be a good idea to get one before i do any modding of the apc...

thanks for the help guys
-wyeth
 

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If you want to keep things mild, you can just tweek the pots (except for the one that controls knock sensitivity - is that the P pot? it's been a few years.) If you've never soldered, the APC would be a tricky place to learn.

Another source for 3.0 bar FPR's that will fit your car is Volkswagens. They were used on several digifant models (early 90's).
 

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I have a few 3.0FPR if ya want one cheap - I can also get you a cheap boost gauge like I have in my Car.

It has a backlight - works very well and includes decent instructions.
 

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Discussion Starter · #7 ·
how much are ya thinking for the injectors and the boost gauge? it would be appreciated 8)

in fact u are only like an hour from me so i could just grab them from u some time heh
 

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20 psi is too high. I know it says on 900aero that it goes from 0.9 bar to 1.4 bar (20.3 psi) with that tweak but it is generally acknowledged that 1.15 - 1.2 bar (around 15 psi) is as high as you should go without extra fuelling, water injection or chargecooling. Even then I have seen plenty of people get knock at below 1.2 bar. I don't have an APC in mine, but I run 1.15 bar with no problem with an MBC. I only have a 2.5 bar FPR, and the stock Lucas injectors (LPT issue, with a higher flow rate, apparently). Mine was dynoed at 183 bhp (bit low due to a knackered wastegate spring) and fuelling was fine, no knock at all, so I've left the setup alone and not put on a higher FPR.

the one that controls knock sensitivity - is that the P pot?
IIRC the knock one is the K pot, which shouldn't be touched.
 
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