Finally a Performance Board for me to brag in. [Archive] - SaabCentral Forums

: Finally a Performance Board for me to brag in.

3rd March 2002, 09:59 PM
As you all know I have been making various modifications to my classic 900 turbo. In case some one is coming to this forum first and have not read my other posts my car is a 1984 900 turbo, it is in excellent condition inside and out in both mechanical and visual respects (after some considerable time and money).

Upon getting the car back to factory spec I decided to move it a bit further up the performance latter and since have added silicone vacuum hoses, tweaked the APC, a K&N cone filter, dual stage water injection, and a full throttle trigger for the 5th fuel injector.

The vacuum hoses make the biggest improvement though standard rubber would have done just as well, they simply sealed my vacuum system and allowed my APC to give the car full boost.

Tweaking the APC was next (and is curently the next thing I plan to do), this helped some what, allowing my boost to travel up to the red but it was then quickly sent back to the upper yellow due to knock, thus..

Water Injection, the single best thing you can do for your turbo vehicle (in my opinion). I added a dual stage water injeciton system (read all about it in the SAAB Lounge). The water injection allowes my boost to travel all the way to the red, and stay there, solid. I have not yet retweaked my APC to take full advantage of the system, but already I have found a noticable incease in performance, especially under high load situations (4th and 5th gear acceleration).

I just finished rigging my 5th fuel injector so it would fire at WOT, but I am not sure if I plan to keep it, I know it is to help avoid knock at high boost, but my water injection is doing such a great job I may just disconnect it from my switch, and put it back the way it was.

My last thing that I have done for performance enhancement was to remove the factory air intake system and air box. I found a K&N cone filter that would mount straight to the bottom of my AMM, thus, I have air coming from my engine cavity (warm I know, I will fix this when it starts to get warmer out) and straight through the AMM, this appears to work great. On my two hour trip back to my dorm I noticed a great enhancment in my mid to high rev acceleration and an incredable improvement in the spool up and basic level of my turbo, the car just seems to work better, and I have a great deep throated sound coming from under my hood now (which I do not notice insed the car).

Coming soon...
I plan to remove my cat, re-tweak my APC, and construct a ram/cold air induction system. Now on the wishful thinking side are rims, stiffer/lower springs, high performance tires, an uprated pinion bearing, and just any other performance mod you can think of.


1984 900 turbo ( with lightly tweaked APC, SVH kit, K&N filtercharger, Dual-stage Water Injection, and CIS. 5th fuel injector mod will be carried out this weekend with cold air induction

<font size=-1>[ This Message was edited by: eric_b on Mar 4, 2002 3:00am ]</font>

4th March 2002, 01:23 AM
When you did replace your rubber hoses with silicon ones did you replace *all* vacuum hoses or just the ones that were turbo related?

5th March 2002, 02:22 PM
I replaced all hoses that I could get to, with the exception to a few of the tiny ones that move my vents and the ones going to the windshield washer jets. I replaced all the ones from the intake manifold to the APC gauge, as well as the one from my intake maniflod to the vacuum advance unit and the ones to my charcoal canister and vacuum canister. I think that rubber would have done just as well, but the gloss black that I used gives a very classy, understated look to my underhood area.


5th March 2002, 02:37 PM
In replacing the vacuum hoses, are the ones listed on the vacuum diagram,( the yellow sticker on the front driver wheel well) the only hoses that are turbo related. I checked the ones listed on the diagram, and they all seem fine, but are there other hoses that would effect boost as well.

p.s. How much did your water injection cost all together? Summer's coming soon, and I'm already feeling bored.

5th March 2002, 03:40 PM
I'd love to see more pics of your car! Would you be able to post some of the engine and rest?

5th March 2002, 04:50 PM
As far as the hoses: I simply went out to the car with a tape measure and got a rough estimate of what would be neccessary to replace all vacuum hoses I could see. For my '84 900 turbo this was (if I remember correctly) 24 feet of 4mm and 10 feet of 6mm (though 3 feet would have done it for the 6mm, but the minimum order was 10 feet, and I was able to use the leftovers to create a heat shield for my water injection lines). I then went out to the car and removed the hoses one at a time, cutting length as I went and then replacing that hose with a silicone one. When the hose went into the car I attatched the silicone hose to the existing (very brittle) rubber hose and pulled it through bringing the silicone in with it, I then proceded to replace all the vacuum hoses under my dash while I was there. The whole thing was very easy and took me less than an hour.

So in short, no, I never refered to the diagram under the hood.

As far as pictures, I would very much like to get them up, I have several in my cheap digital camera, but I upgraded to Windows XP and the camera's driver was not compatable. I attempted to download the upgrade, but the new system will still not recognize the USB connection, so, none yet, though I may be able to get the pictures onto disc when I go home, then I can get them into the computer and up for you all to see.

In short, pictures are on the way.

The water injection ran me about $250 for the parts I ordered (pump, selonoids, injectors, high pressure hose, and the splitter for high pressure hose), and I spent about $22 on fittings and adaptors for the pressure resivour. I did not have to buy wire or low pressure hose because I had that laying around, so I figure the complete system will cost about $300. The cost could be cut down by about $100 if a single stage system were opted for, but I sure like the way my dual stage system works.

With the pump that I used (diaphram type with intenal pressre switch) the pressure chamber is absolutly neccessary. Without the pressure chamber the pressure inside the 4mm outside diameter aquamist line would quickly reach 100psi and turn off my pump. But with the pressure chamber, when the 100psi is reached and the pump turns off there is still pressure present to push the water through the injectors. When enough pressure is released the pump turns back on for a few seconds and repressurizes the system.

I don't know if the short runs will wear out the pump prematurly, but they are long enough for it to reach speed, and it does not recieve a hard cut off, so I don't think its life should be considerably shortened. I also recently checked my system after 3 days of non-use and found it to still be under pressure, so I guess the 11 or so fittings on the pressure chamber are holding strong.

I do highly reccomend a high pressure two stage water injection system, use the aqamist injectors, they seem to work great.

Another thing I have recently learned is do not use methanol in your system when you have aluminium parts in your engine, it is a basic chemical reaction that will eat away the aluminum. Instead use ethanol, or more commonly, 180 proof drink such as Everclear. It posseses the same feeze protection and will not harm your engine.


P.S. my goodness that was a long one.

5th March 2002, 07:31 PM
What about some of that XXX keg Moonshine?
I think i got some in the basement as a means of pest control. LOL

5th March 2002, 08:18 PM
I have heard that works in a most excellent manner, though I would make sure to fit an inline filter to keep all the little critter parts gathered in the distilling process from jamming your injector heads.


5th March 2002, 09:08 PM
you guys make me jealous with your turbo 5spds!!

I want a turbocharged model but the car I got is very good, it only has 60k miles and I've had it for a year and it hasn't broken (though I did have to fix the AC). so I'm not going to get rid of the one I've got. maybe when it comes time to get a new car after college I'll just take less than half what I would spend on a new car and swap out my tranny for a 5spd :smile:
and spend the other money on a t16s convertible for the florida weather
as for now, my 3spd auto will take anyone over the age of 65 right off the line
(high senior citizen population in FL - they clog up the roads something awful!)

PS eric_b my computer has windows ME and I can't get my USB to work either :sad:

1992 900 60k miles

<font size=-1>[ This Message was edited by: conradFL on Mar 6, 2002 2:09am ]</font>

5th March 2002, 09:52 PM
I feel sorry for you man, heard people complaining that 3 spd autos take forever to get going... beside manual is always more fun :razz:

I don't have a turbo engine yet but I'm looking into doing an engine swap this summer, shouldn't run me up too high of a bill, hopefully under $1k.

5th March 2002, 11:01 PM
they never get going, so I guess they do take forever

I want a brand new 5spd...someday :smile:

7th March 2002, 04:19 PM
I'm sorry you guys, it must really suck to have a saab sans turbo. Especially without turbo or manual, my goodness, you may as well own an Escort.

I have no idea how difficult an engine or tranny swap would be, but it should be easily carried out by a competient mechanic.

By the way, there is little that is more fun than executing a perfect double-clutch into a tight corner and feeling the instant acceleration out of it. I highly reccomend that all with manuals learn how to double clutch, not only do you get better road skills and performance, but your tranny will last longer.


7th March 2002, 07:22 PM
I double clutch all the time :smile:

I can let out a little too fast though before I slam on the gas, I can onyl imagine the amount of strain that puts on my thrust bearing

7th March 2002, 08:20 PM
I'm interested in this double de-clutch thang. But where (how) is there any benefit over a smooth normal change?

7th March 2002, 11:08 PM
Since when does double clutching improve performance?

8th March 2002, 12:21 AM
Double clutching saves the synchros on the gears and that's about it, and it doesn't improve performance but you can shift harder when you do it (ie you slam your foot to the floor twice quickly while changing gears and either be skilled at it or pray you don't grind your gears at 50mph or whatever)

8th March 2002, 01:05 AM
I read an article somewhere that very clearly explained the skill. From the article I gather that double-clutching is only really neccessary when downshifting. What you do is push the clutch in put the car in neutral, rev the engine to where it will be when you put it into your desired gear, then push the clutch back in and put the car into the desired gear which the revs are matching.

Double-clutching, if you are really good, makes your syncros obsolite, thus they are not used and last longer. In fact, if you get really good you do not even need your clutch, all you have to do is pop the car into neutral, rev the engine perfectly, then place it into its new gear (some racers can do this while braking with their left foot and gassing on the right). There is no engine performance increase, but a clean double clutch will allow the engine to skip the stage where it is being drug down by the transmission, thus allowing it to go straight into power production and not have to switch from decelerating to accelerating, thus you can exit the corner faster, or speed up quicker after a down shift on the free-way.


8th March 2002, 01:48 AM
Makes sense... however I don't race around corners, only in parking lots and long roads which run parallel to the freeway which the police don't know about. :razz:

8th March 2002, 01:50 AM
For those who don't know, "double clutch" and "Double Shuffle" (Aussie i think???) are the same things.

I am only 17 and due to aussie legislation i only got my liscence 6 months ago (on the day of my 17th birthday). I actually got marked down on my liscence test for double shuffling (my only markdown). However in my car i always double shuffle, it will save me for one day making a quick "granny Shift" into third and hearing a big crunch...

Back to what was being said before. I don't mean to brag (actually this is a brag topic isn't it??) but i have a spare fully reconditioned '92 5 speed box sitting under the workbench in my garage. I had it built to the shortest stock ratios possible and can't wait to put it in, But i have my last year of school coming up (HSC) so it must wait to september, But then

8th March 2002, 02:08 AM
Swoit mate :smile:

Let us know how it turns out, have any other mods on your car or will it just be a stock engine with short ratios?

8th March 2002, 12:45 PM
On 2002-03-07 21:19, eric_b wrote:
I'm sorry you guys, it must really suck to have a saab sans turbo. Especially without turbo or manual, my goodness, you may as well own an Escort.

I really don't know what you mean...

Are you saying that the only good thing about saabs is that some of them have turbochargers?

Or is a saab identical to a Ford escort? If a non turbo saab is an escort, then a turbo saab can only be an escort with a turbocharger fitted.

So then it is YOU who drives an escort!!!

No no no thats all rubbish....non turbo saabs = same car but slower

nothing more nothing less

8th March 2002, 03:50 PM
To reply to razor...

At the moment it is a stock engine, stock turbo, stock IC but it has exhaust mods, 18psi boost, 5th injector, Fuel chip.
The brand new turbo clutch is slipping like a *** after 4000rpm.

When the new G-box goes in i am adding a '92 flywheel and clutch (larger) and lightening that flywheel, also adding a ball bearing turbocharger (stock turbo with ball bearing internals and upsized exhaust and compressor covers).
Unfortunately my budget wont reach a new IC at that stage, but it will follow.

To answer all your questions, I am not full of ***. My father is a motor mechanic that just can't help himself playing with all this *** (Advice: get to know a mechanic, never pay retail again).

8th March 2002, 04:22 PM
Sorry Conrad, I can see how that was taken poorly. The saab is a special vehicle in any form, turbo or non, auto or 5 speed. And kinda yes, my mom has an escort 5 speed wagon, and it is the deadest car to drive. My sister's YUGO seems to have more pep.

Sounds great, make sure to have (if you don't already) the pinion bearing reinforced or upgraded while the new tranny is out. If not you may experience the faliure that so many others have.


8th March 2002, 05:39 PM
Saab strengthened that bearign after 87 right?

8th March 2002, 07:21 PM
I thought it was 89.

8th March 2002, 09:40 PM
Oh well either way I'm set :smile:

1990 900S

<font size=-1>[ This Message was edited by: Smackrazor on Mar 9, 2002 2:41am ]</font>

9th March 2002, 04:25 AM
Na thats taken caare of, the new box is a '92 box...

I made sure of that b4 having it built...

The only problem i think will be with all those mods at once i won't be able to evaluate them separately....

But it is labor saving so i am in...

9th March 2002, 05:11 PM
Never to miss an opportunity to bore you here's my input. :smile:

&lt;snip eric_b>
In fact, if you get really good you do not even need your clutch, all you have to do is pop the car into neutral, rev the engine perfectly, then place it into its new gear (some racers can do this while braking with their left foot and gassing on the right).

I was taught a similar theory which works well and will prolong the life of the gearbox. It'll also enable you to exit a corner quicker and better balanced and reduce considerably the wear to all transmission components. PAssengers will also find a smoother qieter ride without any revving.

As you approach the corner, depress the clutch whilst you hold the accelerator in the same place. The revs will rise to a level which matches the engine speed of your new gear. then after engaging, lift off and trail throttle into the corner to the apex, where you can firm up on acceleration, in the correct gear for exit. Exit speed will be increased (some call it the sling-shot effect) and the car will be better balanced since the weight is transferred to the more rigid, rear of the car.

Itll take a bit of practice but if you like, start on level road at a constant speed and simply depress the clutch. When the revs rise select the next lower gear and release clutch, gearchange should be smoother too, and will impress passengers (when perfected) especially with added progress.

later on, youll find that on deceleration, you can go from gear into neutral with no clutch depression and as the revs rise, engage the new gear again without clutch and no grinding either. Saved me a long walk one day when a clutch cable snapped. Stop lines werent much fun then as I had get down to first and then switch off. The when clear, start the car in 1st and keep going as before.

The only word of caution is that the 900 gearchange may prove tricky at first but if you can do it in one of these, you can do it in anything.

personally, i'm not fused on double de-clutching since for a few seconds, I'm in no gear so one of my accident avoidance options is removed just where I'm about to potentially meet the more sudden surprise of something in my way - just on a bend.

Janne Selinummi
10th March 2002, 03:15 PM
IMHO a double declutched gear change shouldn't take much longer than a regular, cautious one. But it does take some practice - I find myself unable to do it correctly when I'm really pressing on - and that's when the advantage should be used.

But, I have to say that the Saab 900 gearbox is not nearly the worst around to operate - try changing gears without clutch in an Alfa Romeo Alfetta and you know what I mean! I never ever managed to do a clean change w/o clutch in my Alfa, while in the Saab it isn't difficult at all.

12th March 2002, 09:15 AM
DO NOT RAM AIR A TURBO! you will destroy the blades!

What power figures you getting?

12th March 2002, 06:01 PM
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>DO NOT RAM AIR A TURBO! </BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>

That's what the bypass valve is for...

As for shifting without using clutch you can just pop it into neutral as long as you're not pressing the accelerator without damage to the gears, right? Then to engage it you just need to bring the revs to the amount that a particular gear likes or is it more complex than that?

(Just asking coz I don't want to learn the heard way)

14th March 2002, 12:39 AM
That is basically the jist, i mastered the technique in my old turbo volvo(even down shifting into first which is pointless but possible) It is not that hard to do but it is still hard on a normal tranny even if it doesnt grind!!

<font size=-1>[ This Message was edited by: ianlax55 on Mar 15, 2002 5:23am ]</font>

14th March 2002, 02:51 AM
Hmm, ok well you can easily pull the car out of gear when it gets down to around 1,000 rpms but how on earth do you put it back in gear? I tried going from 4th to 3rd and ground 3rd a little...

Janne Selinummi
14th March 2002, 06:03 AM
You'll just have to feel it out, when the revs are correct for the chosen gear, the lever should find home easily enough and without a noticeable clunk. So you have to find the correct accelerator/gearlever movement combo, and there you go!

14th March 2002, 09:40 AM
hehe -- Smack, it looks like you ARE learning the hard way! :wink:

1990 Saab 900S 4-door
1990 BMW 735i (I know, blasphemy)
Luigi DiLioni

<font size=-1>[ This Message was edited by: Lui on Mar 14, 2002 2:40pm ]</font>

14th March 2002, 06:21 PM
Lol, true Lui, true :smile:

ep gio
14th March 2002, 06:39 PM
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>hehe -- Smack, it looks like you ARE learning the hard way! </BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>

Perhaps the car IS learning the hard way :smile:

17th March 2002, 09:07 PM
Wow, gone for a week and the string takes on a life of its own.

Very interesting on the shifting techniques, I will experament a little, but safly.

I just got done with my spring break and am now back at my desk in my dorm room, bored as usual.

Over the course of spring break I removed my catylitic coverter and finally got to wash my car.

The cat removal was too easy, I just put the driver's side up on jack stands and hit the pipe with a very large recripricating saw, the 2.5 inch pipe cut like butter, I then had a new piece welded in. The car runs great, I have already noticed a slight incease in fuel economy, as well as more power throughout the range, my turbo also spools up quicker, and the car has aquired a wonderful exaust note. I am most pleased.

Everything that I have done so far is working great, I am happy (though it does feel as if my clutch engagement point has changed slightly, but it does not slip so I am not going to worry).


17th March 2002, 10:48 PM

I live in CA so I can't remove it... can however add a sports cat of sorts...

But then again my car is NA so theres no point in me upgrading the exhaust 'till I get a turbo (probably will run at 6psi or something until I can swap in some turbo pistons, rods, and cams).

Now all I need is some money...

17th March 2002, 11:38 PM
Eric! have you wound the wick up on your APC yet?

18th March 2002, 12:59 AM
Did you wire up the 5th injector as I suggested, via a relay using the earth side??
Do you notice any difference with the injector working?

18th March 2002, 02:00 PM
Keith, "wick"? I am sorry, I'm just a yank. I have tweaked the APC a bit though, it helped a lot, now I run boost which sits on the yellow/red border as long as I keep the car under load (i.e. accelerating).

I did a quick job on the 5th fuel injector just to see if the improvement was noticiable. I simply put a 5 amp roller switch on the selonoid, the switch gets its juice from the second stage of my water injection, thus the car only uses the 5th fuel injector when I am at wide open throttle and under more than 12 psi of boost. And for all my trouble, I noticed no improvement. The 5th fuel injector works (i miss it on cold starts, and if triggered at idle the car almost stalls), but I don't think I am running high enough boost to make it neccessary, my water injection does all the work in keeping the engine cool and free of lean out.

I will tweak on the car some more, and probibly get a bit more boost from the APC, but I don't plan to shorten my wastegate actuator arm. I do, though, plan to put the restrictor in the APC selonoid, though I guess that really isn't neccessary, especially since I never get any knock.

My boost does drop down a bit though some times, I think that it is rising to the point that the APC feels it needs of be lower, thus the APC blows off a little. Is this a possibility? The drop very slight, unnoticable without the gauge, not like the knock caused drop in pressure.


18th March 2002, 02:11 PM
Come on Eric i've seen all them westerns where they turn up/lengthen the wick of their oil lamps to make them glow brighter!!!!
You got it now??

18th March 2002, 04:34 PM
I get it now, thanks for the clarification.