900/9000 APC

[royboy]

Could anybody tell me if the apc box on the 900 turbo 16v are the same as the ones fitted to the early 9000 turbos. Are they interchangable at all?

[Matthew]

There was a red box 9000 APC for sale at the recent National event. I remember being told that this could be used with a 900, and would give 205BHP. I don't know which years are compatible with the 900 though.

[Alex]

Providing the 9000 APC is the standalone unit (looks like the 900 one) it will fit a 900, ie it isn't part of the DI/APC system fitted from '89 onwards (or thereabouts).

A friend tried to buy a 9000 red box from the local Saab dealership, and they refused to sell it once they found out that it was intended for a 900. Apparantly they were worried about any possible warranty claims if he had broken parts of his transmission.

[Matthew]

Really wish I had bought that 9000 Red APC box now :evil:

[royboy]

Thanks for the responses. Now I know that they are compatable,ive seen one for sale, but it says that it will give the 16v turbo engine 175bhp. I have a uk T16s, which already has that much power. Am a right in thinking that an redbox would bring a US spec (160bhp) 16v Turbo up to 175bhp, and a uk car upto 185-190bhp?

[tandino]

Your correct here,
Some Uk cat equiped T16's came with 'only' 160bhp though,
If yours is a 175bhp non-cat cat then ther red box should conservatively give you 185bhp+.
Alternatively why not tweak your own box to red box spec?? - cost about 20p :D
Plenty of info here on the site if you do a search.

Pete.

[Johann F]

You can save yourself the cost of a Red Box purchase by replacing a few resistors and adjusting a couple of pots on your existing APC - there is a link on the tech help section - there is no other difference between the boxes except the colour!The late red box APC's were designed to give the late UK CAT equiped cars 185bhp from either 160bhp (T16) or 175bhp( T16S). Only if used with 98ron fuel and when fitted (or DIY) with a modified retard capsule to give more retard.

[Matthew]

So what mods do Trent Saab make to their APC boxes?

[royboy]

I did a search on the forum for redbox info and am now pretty confused. From what ive read, if the serial number on the redbox begins with 137...then it will only give you 175bhp.

"You can verify the claimed output by the serialnumber on the APC. Number for a 185 hp APC box is 4393971, but there can also be a number of Saab "perfromance kit" starting with 137***.
But according Saab sales brochures it should have 175hp"

Might just be best to tweak mine myself!

[Deanosabby]

Hi there,
My 1993 TurboS 16v has the red apc box 4393971 and it has 185bhp as confirmed by Saab GB. Some people when they ordered their Saab new got this as a cost option so I guess im lucky, You are best using Shell optimax as this has a higher RON rating then super unleaded. Optimax is closer to 5 star rating.
Cheers,
Deano.

[Alex]

Matt, its very remiss of me but I've never really looked inside the Trent APC.

From what I understood when the work was done, its a set of resistor changes and the pressure transducer is bridged to reduce its signal (ie signal sent is low so the APC tries to increase the boost).

[john-w]

I had a "red box" on my 93 T16s I think they did it to overcome the losses caused by the fitting of the CAT

I also have a tuning kit (red box) and the number is 137007100

[royboy]

ok; so is this how it works?

Pre cat T16 black APC 175bhp
Catalyst T16 160bhp standard and 175bhp with saab tuning kit redbox APC (170-100...)
Catalyst T16 with proper redbox APC (eg ruby and carlsson) 185bhp

so what about pre catalyst T16 with either tuning-kit APC or the one as fitted to ruby etc?

[Alex]

Carlsson was 185bhp without catalyst dropping to 175 in the catalysed versions.

The Ruby was the only 185bhp catalysed c900.

[Johann F]

As I understand it with UK cars;
All T16's pre cat had 175bhp (except very early 1984's with alternative cams)
With the introduction of the CAT - non S T16's had 160 bhp and S variants had 175bhp.(engines are identical- power governed by APC) Both of these models when fitted with the Red box and distributor (the Kit) and run on 98ron have exactly the same 185bhp potential. The APC for these cars took special account of the fueling characteristics of a Cat equiped car - the boost cut after knock was more aggressive as the fueling is less rich on boost. When you look at the specs the R42 resistor is significantly different in value ( higher) than any other APC box (according to sources I remember) The redbox alows slightly higher boost (but not significanty) but it's main effect is to allow the boost to hold more in the higher revs. Torque increases slightly but HP increses significantly. I can only assume that the earlier red boxes gave a similar 185bhp limit as further increases would be unsustainable in terms of stock fueling, ignition timing and intercooling - as well as increased warranty claims for broken gearboxes! The Red box for the Saab 9000 may well have been 205 bhp as it has the advantage of better intercooling. I can just see no sensible case for buying a red box - you have to adjust the retard to use it (either DIY or fitting a new capsule). If you can do this yourself you have the ability to do the red box mod to your existing box.

[Alex]

To make matters more confusing the first catalysed T16s were only available with an auto gearbox!

[Matthew]

Have you been digging through your reference manuals again Alex? :nono;

:wink: :cheesy: