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This is something that I agree with john on. While the price of this piece is crazy and something I wouldn't have done(but it was cheap for me). The TBTC on a T5 is restrictive and the larger delivery pipe replaces that piece. It definitely smoothed out things and felt stronger up high.

The T7 is a different animal.

With that said, I probably wouldn't have gotten one if I had had to pay for it as they are many other things I would have spent that kind of money on first.

 

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SPATL said:
This is something that I agree with john on. While the price of this piece is crazy and something I wouldn't have done(but it was cheap for me). The TBTC on a T5 is restrictive and the larger delivery pipe replaces that piece. It definitely smoothed out things and felt stronger up high.
More a less a copy and paste from my to saablink few weeks back.

It cannot be that hard to understand that usally the car "rips" becuase the boost spikes and if boost spikes the boost control tuning for the cars HW is from the rear? Just look around in topics where the level of boost is the topic, how many comments do you see "mine spikes to x psi and then holds y". By this I mean that maybe one should discuss with the SW provider to smooth things out rather than trying to blame the behaviour to the std pipes and bends, since they dont cause it.


But lets take an example

Two cars, later one is mine. Both run with ~1.65bar boost
The boost behaviour from car 1

As we can see the boost cotroller mapping is from the rear and the boost overshoot the target by 0.2bar before it stabilizes to the wanted value.
This causes the car to "rip" hevily when boost is built. So I would imagine this type of behaviour is considered to be normal "boost mapping"? or at least it presenes seem to be common.

Mine

I dont boost "spike" map the car, because I like to retain the traction to as high torque levels as possible (spikes lead to loss of grip and when it happens it hurt performance) and give value to "smooth" power delivery.
By looking at the acceleration curve (yellow) one can see that it raises nice and smooth, no ripping, spiking or anything else what has be claimed to be introduced by the orig delivery pipe. I do have both the T5 delivery pipe and the last "restrictive" bend intanct.

Please note also that all mechanical boost gauges are quit hevily damped and the true height of the boost spike is often not visible to the "eye".

So why is this matter usually brought up only with T5 cars? T7 is much more clever in boost control adaption and it does the work for you which the tuner failed to do :)

We all are of course free to install what ever parts we like to our cars, but I just wanted to point out that the orig pipe is not the cause of the noted symptoms...
 

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Are you running the stock t5 elbow or another type tb? Part of the problem is the stock oe bend and tb connection pipe in my opinion. My car got better with stock sw on my 9k aero and it got better with stage 3 sw as well. My other stock cse also got smoother power transition on stock sw from saab.

Are you saying the stock saab sw is bad and the tuned sw is bad too? I noticed smoother power and less of a torque slam on all 3 of the cars I have changed to larger 2.5" piping and by removing the stock small tb section right before the tb on the ng900.

It does seem strange that the larger pipe had the same effect on all 3 of my cars with stock sw and with tuned sw. Its also strange just about everyone, but you claims to notice the smoother power with the larger piping.

I did dyno mine before and after, but I would love to see you're car with stock t5 tb, bends and delivery pipe and then with 2.5 or the new 3"tb with full on 2.5" piping all the way from the ic. I would bet money you will show a difference on the dyno and that difference would be a trade-off in torque or at least move the torque curve up a few hundred rpm on the rpm band.

I saw 7whp gain up top and a loss in torque by 22, but I am not 100% sure there were no other changes besides the delivery pipe and tb elbow.

John
 

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John Z Williams said:
Are you running the stock t5 elbow or another type tb? Part of the problem is the stock oe bend and tb connection pipe in my opinion. My car got better with stock sw on my 9k aero and it got better with stage 3 sw as well. My other stock cse also got smoother power transition on stock sw from saab.
I do have std T5 delivery pipe, T5 elbow, T5 TB, T5 intake manifold, T5 head (modified), so basically everytying after IC is T5 std parts.
John Z Williams said:
Are you saying the stock saab sw is bad and the tuned sw is bad too? I noticed smoother power and less of a torque slam on all 3 of the cars I have changed to larger 2.5" piping and by removing the stock small tb section right before the tb on the ng900.
All the std T5 cars I have driven work smooth, just like the modded once when you bypass the boost solenoid, i.e run the pressure directly into the WG or map the boost control and other parameters in away that the power delivery is smooth.
John Z Williams said:
It does seem strange that the larger pipe had the same effect on all 3 of my cars with stock sw and with tuned sw. Its also strange just about everyone, but you claims to notice the smoother power with the larger piping.
you know how to read graphs? The acceleration curve is visible in the plot and more or less in all the logs I have posted. How do make it smoother?

John Z Williams said:
I did dyno mine before and after, but I would love to see you're car with stock t5 tb, bends and delivery pipe and then with 2.5 or the new 3"tb with full on 2.5" piping all the way from the ic. I would bet money you will show a difference on the dyno and that difference would be a trade-off in torque or at least move the torque curve up a few hundred rpm on the rpm band.
but why would I want to delay the torque to higher rpms? and by 200rpms, IMHO that would be nghtmare if you ask me. Bhp at higher rpms already exceeds the gols which I had set for this HW and the bhp curve raises almost to the rev limiter I have in use.

John Z Williams said:
I saw 7whp gain up top and a loss in torque by 22, but I am not 100% sure there were no other changes besides the delivery pipe and tb elbow.

John
be careful when you make analysis especially if the conditions vary.
With this in mind whos interested in bying "specail snake oil" spark plugs from me. In real life I did measure a 200rpm lower spool, just like the below graphg indicates

disclaimer the verification run was made in lower ambient temp.
 

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One thing that I thought of is I had the same effect when I installed my larger ic and you're ic is so large, it may be big enough to smooth the power out enough where you do not notice the change in torque very much with the piping.

The only way to know for sure is put a better 2.5" with a 3" tb on it and test it against the stock oe pipe.

I bet if you put the stock ic on it you would notice a huge difference in torque between the stock piping and the larger 2.5" piping as that is when I noticed the big change...

More volume to fill with a larger ic and larger piping means it takes a little longer to fill the ic an piping and this has the effect of moving the torque band up the rpm band a little.

You would want the torque to hit later if its hitting too low and causing traction and tranny issues. That is what I am saying. Moving the toque curve over a little in the rpm band is easier on the tranny, but since you have a huge ic and a larger .86ar turbine housing, you have already done that in a different way. With the smaller turbos, the larger piping and ic's show themselves in the way of a change in power transition and when the torque actually hits,

John

John
 

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John Z Williams said:
One thing that I thought of is I had the same effect when I installed my larger ic and you're ic is so large, it may be big enough to smooth the power out enough where you do not notice the change in torque very much with the piping.

The only way to know for sure is put a better 2.5" with a 3" tb on it and test it against the stock oe pipe.

I bet if you put the stock ic on it you would notice a huge difference in torque between the stock piping and the larger 2.5" piping as that is when I noticed the big change...

More volume to fill with a larger ic and larger piping means it takes a little longer to fill the ic an piping and this has the effect of moving the torque band up the rpm band a little.

You would want the torque to hit later if its hitting too low and causing traction and tranny issues. That is what I am saying. Moving the toque curve over a little in the rpm band is easier on the tranny, but since you have a huge ic and a larger .86ar turbine housing, you have already done that in a different way. With the smaller turbos, the larger piping and ic's show themselves in the way of a change in power transition and when the torque actually hits,

John

John
But again all the items above can be taken care of with mapping... if you dont want the torque "down low" dont boost down low, just that simple.
For instance run your car with a 0.5bar boost all the way from bottom to top and and I dont think you wont disagree that it hurts the tranny, hits too fast, isnt smooth or looses traction? From this point up the shape of the torque curve is cotrolled by mapping and all the unpleasent stuff that appear are do to the settings you run. As stated in the previous post the main reason why the car rips is caused by a spiking boost, so focus on having it eliminated by mapping.

I have had a smaller turbo a smaller a/r housing on the current, smaller IC etc. etc. on my car and nope the smoothes is not a charactar of the current HW, it has always been like that when the mapping has not done anything "odd".

Ps, the car from which the first graph is of utilizes a 60mm delivery pipe ;)
 

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I don't know about you, vigge, but most of us don't build cars to have them run 70%, 90% of the time.

I wholeheartedly understand what you're saying, and I get why you do it.
For me, I want full-power all the time, and I have a feeling you're going to see this in ANYONE that is serious about racing in a straight-line.

The whole tuning-power-out thing... is more for street and road-course.
 

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Vigge said:
Ps, the car from which the first graph is of utilizes a 60mm delivery pipe ;)
Isn't the stock pipe 60mm?
 

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wait..... am i understanding this correctly? stock t5 delivery pipe is 2 inches. genuine saabs delivery pipe is 2.5 inches? is that right?
 

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Just a thought - seeing as T5 cars use a MAP sensor and a temp sensor to govern fueling out of closed loop wouldn't changing the volume and flow of the intake upset this critical measurement and account for the changes in power when these items are changed? Wider pipes will mean slower velocity for any given airflow and the cooling effect on the temp sensor will be less. If this is not linear and cannot be accuratley factored in when the system is in closed loop you will have an unpredictable fueling at WOT?
 

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Not necessarily. It's the air that heats the temp sensor.
So, if it's 10* air moving @ 40m/s or 10* air moving @ 400m/s, it's still 10* air.

If the largest restriction is post MAP sensor (TB and butterfly), it doesn't really matter what the Pipe's VE is. (assuming you've not changed the turbo)
 

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"So, if it's 10* air moving @ 40m/s or 10* air moving @ 400m/s, it's still 10* air" - yes but the sensor will not read 10deg because of the increased heat transfer/cooling with velocity.
 

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The argument seems to revolve around either spending £4-500 on getting a descent software upgrade to smooth out your power curve vs spending between £100-£300 for doing the same thing with a HW upgrade.

If through HW upgrades i had increased power but was getting issues with spiking, being as i can weld together the tubing myself, i think that would be the preferred option. Although ulitmately getting your SW modified to suit every time you upgrade HW i don't think there are that many people who can afford to do it. For me doing the SW upgrades in stages after several HW uprgades is more likley.

I will no doubt be replacing my intake tubing with 2.25", which will only be slightly larger than the stock pipe, but then there is'nt much point me going larger when the exit on my intercooler is only 2.25". I'll sort that out along with a 3" -2.5"-2.25" exhaust and will no doubt get a power run done so will be interesting to see the results, if i can afford it i may even go for 2 runs so that i can measure the difference between the stock pipe and a 2.25" one.
On the last point, obv. water has different thermal properties but when i was looking at electric water pumps the technical info said that there is'nt a huge difference in heat transfere at different velocities (too a point, not too fast or too slow), if the water moves slowly through the head the water has more time to disipate the heat, if it is moving quickly the water has less time but there is more so it evens out.
 

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if i am understanding this correctly, stock is 2 inches, gensaabs is 2.5 with 3 inch tb. why not do an in between pipe tb elbow as i think they would sell a lot more since a lot of people dont make the power to make the 2.5 pipe really useful where as an in between pipe might be just right. so how bout a 2.25 pipe with 2.5 tb elbow?
 

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I doubt that changing the intake delivery pipe will eliminate the kind of boost spikes that Vigge has displayed one of those dyno graphs - I expect the shift in torque from delivery pipe and throttle intake will be much more subtle. The boost spike is an inevitable result of using a small turbo and trying to get it to spool as fast as possible. The faster it spools the longer it takes to regulate and the sooner in the spoolup you have to start to regulate it to stop this the slower the spoolup - a vicious circle that needs very precise control to get good spoolup and no overshoots. I would compare this with trying to pull a trailer with an elastic rope - think about it. I'm not familiar with fluid cooling but I'm very familiar with wind chill which I think is the same concept I was trying to apply to the T5 intake temp sensor. I may well be off the mark here though - it was just a thought. In the end I would probably think these are worthwhile mods if you can fabricate them yourself - the T5 delivery pipe and intake look designed for best fit round the engine rather than optimal flow - but the prices for off the shelf items don't look particularly good value
 

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Shirozina said:
"So, if it's 10* air moving @ 40m/s or 10* air moving @ 400m/s, it's still 10* air" - yes but the sensor will not read 10deg because of the increased heat transfer/cooling with velocity.
I dont really see a problem why the sensor would read off since it measures temp directly, i.e. stick it into the owen and it will give you the values thus no flow, but the time it takes to reach the owen temp takes a longish time.
Air is a touch media to measure since the heat tranfer is small through it, and if the air is more ore less stationary the response time will be lower. However these temp sensor are ment to measure air and the react quit fast even if flow rate is small. In other words the faster the flow rate is the faster the temp sensor will read correct temp and wice versa.
 

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Shirozina said:
I doubt that changing the intake delivery pipe will eliminate the kind of boost spikes that Vigge has displayed one of those dyno graphs - I expect the shift in torque from delivery pipe and throttle intake will be much more subtle. The boost spike is an inevitable result of using a small turbo and trying to get it to spool as fast as possible. The faster it spools the longer it takes to regulate and the sooner in the spoolup you have to start to regulate it to stop this the slower the spoolup -
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.
 

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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.
 
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