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Maptun in Poland sells delivery pipes like these. I haven't seen anywhere else such design, it's all one part no need for silicon hoses.


 

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Nice workmanship - that transition into the throttle looks perfect. It would seem a shame to hide such a thing under the bonnet! Any idea of the cost?
 

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Shirozina said:
We blow on our hot cups of coffee or tea to cool them - the air is the same temperature but as it moves it transfers heat. Thus the faster it moves the more the cooling effect even though the air is the same temperature. The outside air temperature sensor in the front bumper is not in the direct airflow for this very reason - it would give you ambient air temperature when stationary but on the move it would give this plus the cooling effect or 'wind chill' as it's commonly known. I'm sure Saab will have factored this into the ECU as they will have some idea of air velocity at certain RPM/load but if it changes it may well throw this off. Again I may well be way off on this one but I'm pretty sure moving air has a bigger cooling effect than still air of equal tempreature. They got it right with T7 in this respect as this has an air mass measuring system (rather than a speed - density system on the T5) which incidentaly works of the same principal - moving air cooling a heated wire.
IMHO the wind chill does not "cool" the air below the media temperature , if that is what you mean, i.e for instance if you put a can of soda in a cup holder which hangs from your cars mirror the temp of the soda will be ambient no matter if you drive 10km/h or 100km/h, assuming of course that sun is not shining. You can try this out also, by sticking a temp sensor out of the window while you drive.

The T7 viggen/SE ambient temp sensor is right in the flow, i.e. connect to the mesh screen in front of the IC.

However if you expose you for instance expose your body in mid winter to chilly temps you will feel alot colder if the wind is present due to wind chill, since due to it the temp escapes you body faster.
 

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OK - so if there are no big and sudden swings in the temperature of the intake the sensor stays around the same actual temperature as the intake air then the readings should be good. That makes sense also with regard to the hotwire in an AMM as it's kept at a certain temperature ABOVE the air temperature and the energy/voltage needed to do this is what the ECU reads.
 

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Shirozina said:
OK - so if there are no big and sudden swings in the temperature of the intake the sensor stays around the same actual temperature as the intake air then the readings should be good. That makes sense also with regard to the hotwire in an AMM as it's kept at a certain temperature ABOVE the air temperature and the energy/voltage needed to do this is what the ECU reads.
The hotwire is as you say a differnet story since its heated/kept above the media temp, i.e. to faster the flow rate the faster the temperature would decrese if no extra energy was brought into the element to keep it "hot".
 

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Vigge said:
Actually those logs are from road, not dyno and the car with the spike has GT3071 ar 0.86. All turbos will basically boost quick when ever you're in the rpm range where the turbo works, so the problem with boost mapping cannot be forgotten even when the std size mandarin is replaced. Also componets like stiff wg's increase the tendency for spike, since the "window" between target boost and baseboost decrases.
Gear in use plays also a big role, since the rpm ramp-up is much different for instance in 3rd compared to 5th.
I just got my car running again and with the gt3071 .86ar turbine housing, the boost and power comes on much less abruprt. The power seems to be much smoother and I think this will also aid in tranny issues and boost spikes. Much more consistant boost up top. It comes on about 300rpm later, but comes on smooth and hard and holds that strong boost for days.

After saying all that, I guess my bad luck is continuing. I broke in the new motor in with new forged pistons and new .86ar housing at about 18psi of boost and within 50 miles I did a light pull in 4th gear and spun all the teeth off that gear. I have no more 4th gear and it made all kinds of horrible noises as the pieces banged around inside the case. All the fluid drained out on the 9 mile trek home. I made it into the garage luckily.... Gt3071 .86ar 1, tranny 0.

John
 

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John Z Williams said:
I just got my car running again and with the gt3071 .86ar turbine housing, the boost and power comes on much less abruprt. The power seems to be much smoother and I think this will also aid in tranny issues and boost spikes. Much more consistant boost up top. It comes on about 300rpm later, but comes on smooth and hard and holds that strong boost for days.

After saying all that, I guess my bad luck is continuing. I broke in the new motor in with new forged pistons and new .86ar housing at about 18psi of boost and within 50 miles I did a light pull in 4th gear and spun all the teeth off that gear. I have no more 4th gear and it made all kinds of horrible noises as the pieces banged around inside the case. All the fluid drained out on the 9 mile trek home. I made it into the garage luckily.... Gt3071 .86ar 1, tranny 0.

John
How did you mange to brake the box with 18psi? or was it completely toast already.

Once you get it back running test the boost build-up from lets say 4500-5000rpm and you'll note that there ins't much difference to the smaller housing.
 

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That is what I was wondering. I was only at maybe 15psi when the rpm's went through the roof... I was quite surprised and was not really sure what had happened until I tried to put it back in 4th gear at 70mph and there was nothing there... I found 5th gear and all my other gears where still there, but there were lots of crunching noises going on and then I smelled tranny fluid and then I could see smoke coming into the cabin...

My thoughts were the season of drag racing took its toll as I was not beating on it hard at all when it took all the teeth off 4th gear... That was my favorite gear, besides third of course...

That sux, all that back breaking work to get it all back together and then bam, no tranny.... I did hear Maptun will have their 6 speed tranny out in about a week, but I don't have that kind of cash right now. Now I have to pull the sub-frame back off and drop the tranny out and put in another used one. Dang-nabit...! Thats two in 25k.....

John
 

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John Z Williams said:
That is what I was wondering. I was only at maybe 15psi when the rpm's went through the roof... I was quite surprised and was not really sure what had happened until I tried to put it back in 4th gear at 70mph and there was nothing there... I found 5th gear and all my other gears where still there, but there were lots of crunching noises going on and then I smelled tranny fluid and then I could see smoke coming into the cabin...

My thoughts were the season of drag racing took its toll as I was not beating on it hard at all when it took all the teeth off 4th gear... That was my favorite gear, besides third of course...

That sux, all that back breaking work to get it all back together and then bam, no tranny.... I did hear Maptun will have their 6 speed tranny out in about a week, but I don't have that kind of cash right now. Now I have to pull the sub-frame back off and drop the tranny out and put in another used one. Dang-nabit...! Thats two in 25k.....

John
Did the failure happen as the boost came up or later in the rpm range, when boost was already steady?

just re-build the broken tranny with 9-5 internals and it will hold "plenty". I drive with viggen std gearbox and have beaten it good for the last 120t km ;)
 

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Yes, it broke just as it was building good boost, just as I was passing 15psi it snapped.

What do I need to rebuild this tranny. I have two used ones, so I think I would have a good 4th gear in the other case. Do I need all the bearings only or do I need some of the gears too? I have access to liquid nitrogen, I should treat the gears and input shaft in liquid nitrogen.

Maybe you mean put the entire gears and bearings from a 9-5 in the ng900 housing?

John
 

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John Z Williams said:
Yes, it broke just as it was building good boost, just as I was passing 15psi it snapped.

What do I need to rebuild this tranny. I have two used ones, so I think I would have a good 4th gear in the other case. Do I need all the bearings only or do I need some of the gears too? I have access to liquid nitrogen, I should treat the gears and input shaft in liquid nitrogen.

Maybe you mean put the entire gears and bearings from a 9-5 in the ng900 housing?

John
So you're sure it did not "spike" when boost was building up? Remember the mechanical boost gauge dampens the signal quit heavy and you wont see the whole trueth from it?

I can check up the gearbox part list, but I do mean the complete 9-5 rebuild kit which is available from saab.
 

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Yea, it broke while building boost and I was not even full throttle... Just a light pull and it broke on the bottom end of the pull. I was just starting to go and I was not getting any boost spikes at the settings I had the boost controller set up at, which was peak 23psi, made at about 4000rpm in 4th gear.

When racing, I was hitting 29-31psi and spiking about 3psi over what it would hold, but I was breaking in the pistons at a lower boost level.

John
 

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Welcome to the NG900 exploding gearbox club JZW! I thought I'd run over a railroad sleeper until I went for second gear..... Then it all came horribly into focus what had really happened :x

It's funny 12 months later. Honest :cheesy:

Second gear synch ring had blued and spat the three locating tabs.I think you've done a more thorough job if all the oil came out too. Full marks :lol: :lol: :lol:
 

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Yea, that is two for me in two years... I kind of want to tear it down and see what happened. I bet between the two boxes, I could get enough good gears and then replace all the bearings and syncros and what not. My first one would no longer stay in third gear on decel...

I found a good used one from a 1996 model with 105k and 3 month warranty for 450.00 shipped. Just 4th gear cost 476.00:eek:

John
 

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If you still have the other (less destroyed) box, maybe worth rebuilding that with some new bearings and an amount of lurve :D
 

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I'm back on smooth boost now with a working BPC - the MBC was fun for a while but in the end the boost was all wrong - loads of low down pull/spike but rapid fall off above 3.5k. Now I get less dramatic but smoother power right up through the rev range which feels both kinder to the gearbox and a more sensible and usable power delivery. I have to drop down a gear if I want to go realy fast as I don't have that low RPM / high boost anymore but isn't this how engines are supposed to be?
 
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