[fliptopbin]

Here : http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=264507

Talkiing about adding NOS, but worried about the transmission - what sort of limit will the NG900 'box put up with?

 

[mark e]

Well, as has been said before, it's not the power but the torque that is liable to lunch the gearbox.

I know of at least one 2 litre NG900 that's been successfully tuned to over 250hp. I don't know what torque it was putting out, but on the track it was about matched with my (then) 300lbft 9000. The NG900 is lower geared, but I reckon it still must have been making over 250lbft.

Something like the Maptun Stage 3 kit might give the sort of results required (270lbft). Stripping the interior out could loose quite a bit of weight too.

Oh, and of course, there's no point adding all that power without doing some serious work on the suspension

 

[ERP]

My NG900 is putting down 230 wheel hp. On the high boost setting it spikes 27-30 psi and putts down a torque spike of 280-300 ftlbs. Last time I dynode my Saab I only did one pull with the high boost setting but the dyno didn’t record the values of the spike. It is more than 280 and I am estimating about 300 ftlbs.

Eric's Saab Site - Dyno

 

[frankem3]

Just finished my stage 3 upgrade in my NG 900 Turbo....oooh my, oooooh my, no I mean ooooooh my.

Listed below, are some of the changes...:
1. Air filter to K&N drop in filter; 5 minutes
2. The bypass to Hyperboost valve; 10 minutes
3. Installed tornado spinner down from air filter, creates a vortex of the intake air; 15 minutes
4. The dual pass intercooler to a one pass alluminum one; 1.5 hours
5. Replaced the downpipe with a 3 inch downpipe
and race cat; 40 minutes
6. Replaced damaged O2 sensor; 15 minutes (tinkering again)
7. Changed plugs; 25 minutes
8. Retorqed heads; 30 minutes
9. Changed oil, and filter; 20 minutes
10. Installed rear sway bar; 20 minutes
11. Installed Stage 3 Maptune ECU; 10 minutes

Car kicks in incredibly...pulls like a bat out of hell. I'm trying to find reasons to drive the car for everything now. Let's see ...I can go to the store, to visit work on the weekend, cruising..., maybe I can find a way to drive it to the bathroom.

Fun car to drive, and a true sleeper. Feels like the car doubled in power almost. I can peg the needle....(the boost needle) now. I use to only get a little less than a quarter of the way into the red zone. I use to wonder what it would be like on the far right of the red zone...., and now I think I understand.

I'm off to find a dyno now.

DC

 

[NickturboSE]

DC_SAAB,

What do you think about the Vortex Spinner? It would seem to me that one is creating a vortex in the very air that is immediately sucked through your turbo's compressor. I don't see how this could benefit a turbo car.

Thoughts?

Nicholas

 

[KevinY]

My current project car, a 1997 NG900 Talladega, is planned for 450hp and I will post the dyno runs once the build is completed. The bottom end will be stock (refreshed of course) and a ported head with stock cams. Like you said, its a trade off between hp and torque. My previous build, '94 Aero, was a torque monster with 425 lb/ft and 330 hp and the transmission is still holding to this day. Now, with this new project, we are actually putting in a 5 speed transmission from a 9-3SS with the newer shifter and lsd. Seeing how this tranmission is off a race car before being rebuilt with similar output, I am sure it will hold. Stay tuned, the proof will be in the pudding. Yankton Tuned

 

[CO-Saab]

Along those lines I have a '99 9-3 T-5 I am hoping to get ~280-300 WHP (330-350 Crank). Torque will be in the neighborhood of 360 Ft-Lbs. All hardware is installed and I am waiting on a custom software tune. Kevin and I will have this done at the same time as both are trying to coordinate a time with SQR. Link to my homepage is above.

 

[maartenvandorst]

Originally posted by Mark E:
[qb]Oh, and of course, there's no point adding all that power without doing some serious work on the suspension      [/qb][/b]

Mark's right. To be fast at a trackday, the 900 needs decent shocks, lowering springs and a stiffer rear antirollbar. These items made a big difference in handling on my NG900.
I've driven my car at the Nürburgring without the proper shocks and upgraded rear antirollbar when it was 250hp (at the moment it's 270hp). Accelerating out of a corner, it was very hard to get enough grip.

 

[xassh]

DC_SAAB,

What do you think about the Vortex Spinner? It would seem to me that one is creating a vortex in the very air that is immediately sucked through your turbo's compressor. I don't see how this could benefit a turbo car.[/b]

i would have thought the same thing, though the vortext may be (for lack of better wording) flattened out in its travels through the bends of the piping to the intercooler and then again from there to the throttle body.

going by memory of the setup on my 92 900T, the air passes through the turbo, then takes about a 30-45 degree bend coming back across the front of the engine bay to the I/C where it then must turn 90 degrees down the I/C, 180 back up, 90 again towards the center of the engine bay, then once again nearly 90 degrees to the throttle body.

i would imagine that this would negate some of the rotation of the air (vortex?, please excuse my lack of knowledge in the area) and that adding the 'tornado spinner' after the I/C and just before the throttle body may be the most advantageous.

this is a topic i have pondered, anyone have any more insight to add?

 

[sgould]

I know i'm more familiar with water turbines, measuring devices and things, but most generic plant in that field is optimised for receiving laminar flow with no turbulence or vortex. Most bits specify a straight length of pipe before and after the device to reduce turbulence.

If this theory transfers to air lines and turbos, you might try a "flow straightener" in the line - a length of pipe with a honeycomb in the centre - just before the turbo or whatever.

The turbos used in Saabs are generic and used in all sorts of applications, so the manufacturer is unlikely to have designed it to work with a 90 deg bend, 45 deg bend, taper, or whatever just in front of it.

 

[chips]

If you can get the vortex flowing the correct way; that is in the same direction as the turbine wheel under load then a 'static regain' can be achieved. In good vent design this can account for 5-10% increase in performance of a fan. This is for a vent system but the principles are the same.

 

[burre]

As a hydraulic system technician on aircraft, I can tell you, just as sgould does, that laminar air flow is much better than turbulent flow. High flow is what we are after with our engines and making the stream turbulent will only slow it down. Also, adding a restriction in the air stream will also slow it down. I do not see how the tornado things can be of any benefit.

 

[xassh]

www.tornadoair.com states that...

Tornado is a non-moving turbine shaped device, which creates a vortex or swirling effect to the engine. The result is improved airflow into the engine's combustion chamber, causing a more efficient mixture between air and fuel. TORNADO fits most cars and will work in either a carbureted or electronic fuel injected engine.  [/b]

also this...

 The Tornado's unique airflow dynamics creates a swirling, fast-burn effect in the combustion chamber. This creates finer particles (atomized fuel), allowing better flame propagation and more complete combustion.[/b]

so i guess the claims are that swirling air will help to atomize fuel for a cleaner burn... i would have no experience in this area to explain that...

 

[mark e]

So, you get all this nice swirling air moving down the intake pipe towards the mainfold. Let's assume that it doesn't get more turbulence from trying to go round corners, over the lips of joins etc, it then gets to the throttle butterfly. Oh dear! A plate in the way, which the air has to get round... that's going to completely wreck the spiral flow. Even at lowest resistance (WOT) the butterfly is then going to act as a straightener...

 

[California Saab Tuner]

But wasn't that device placed BEFORE the turbocharger? If anything is going to swirl the air, methink the turbo will do it best.

The only "tricks" to my knowledge regarding airflow are:

1. Slightly rough boundary walls. Those stabilize the boundary (non-moving) layer of air against the walls of any flow field. In the exhaust the boundary layer is also responsible for keeping the thermal shock, and subsequent convection from affecting the flow field.

2. Increased inner-radius bends (they look flattened) ... like in the intake pipe to a T7 engine. There are two reasons for such shapes. One is because you do not want the sharp inner radii to outer radii ratio that most mandrel bent right angle pieces present. Two is that you still need to have the same cross-sectional area in order to avoid the associated turbulence with velocity transitions. The easiest way to accomplish both is the make the tube flat, but wider. This keeps the outer/inner radii closer to the same, but still has the same cross-sectional area.

Fortunately both of those "tricks" are already in most engines from the factory.

Some more examples are "D shaped" exhaust ports in which the lower Radii is brought up and despite slightly smaller cross sectional area, the turbulence is reduced enough by doing that to increase flow.

Anyhoo ... the only benefits I can see from one of those are on naturally aspirated cars.

1. Carburreted cars may actually mix the air/fuel better.

2. Cars with long and poorly designed plenums may find that by making the gas more turbulent each of the runners gets a more equal share of the air, and therefor a better a/f ratio between cyllinders.

Can't see any other reasons for it.

Dubbya~