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Discussion Starter · #1 ·
Can someone explain the differnce to me between the new B235R motor in the new 9-5 Aero with 250 hp and the B235R motor in the Viggen 230hp. Is the 250 only achieved with 'overboost function'? Or does the new B235 have an addition 'overboost' on top of the 250? Does the viggen have overboost funtion?

I know the origional '99 Viggen B235R had only 225hp and the difference with that motor and the '00 230 hp version was the intake pipe from the MAF to the turbo was greatly improved on the '00's, thereby giving it the additional 5hp.

So basically what changed in the B235R motors from the '00-'02 where the newer B235R's now have 250hp?

Thanks!!
Jason
 

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Originally posted by perkj:
[qb]Can someone explain the differnce to me between the new B235R motor in the new 9-5 Aero with 250 hp and the B235R motor in the Viggen 230hp.  Is the 250 only achieved with 'overboost function'? Or does the new B235 have an addition 'overboost' on top of the 250? Does the viggen have overboost funtion?

I know the origional '99 Viggen B235R had only 225hp and the difference with that motor and the '00 230 hp version was the intake pipe from the MAF to the turbo was greatly improved on the '00's, thereby giving it the additional 5hp.  

So basically what changed in the B235R motors from the '00-'02 where the newer B235R's now have 250hp?

Thanks!!
Jason [/qb][/b]
Hi you with the new cobra also the SW was changed from MY00 on. The original viggen SW was "made" by TWR and there where some downsides to it. Many swedish MY99 viggen got the new SW later in regular maintanance.

To my knowledge the 9-5 aero is the on T7 that has the "real" owerboost funktion.
It's not recommeded to put the aero SW to viggen.
Given reaon is that the SW will run the engine too hot in a 9-3 since the engine bay is much smaller than in a 9-5. Even though the SW delivers about the same numbers there are plenty of difference, due to different HW (like IC) parts and purpose of use.
 

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A while back I was invited to a Saab GB Track Day and given a 9.5 Hot Aero to try. Talking to the technical chap he explained the car puts out 250bhp standard, but with overboost (which will last for 20 seconds and is intended for overtaking) this increase the power by 20% to 300bhp which and I quote 'makes it faster mid range than a Porsche 911 Turbo'.

Hope this helps.
 

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Originally posted by Naranto:
[qb]A while back I was invited to a Saab GB Track Day and given a 9.5 Hot Aero to try. Talking to the technical chap he explained the car puts out 250bhp standard, but with overboost (which will last for 20 seconds and is intended for overtaking) this increase the power by 20% to 300bhp which and I quote 'makes it faster mid range than a Porsche 911 Turbo'.

Hope this helps. [/qb][/b]
Maybe little marketing extra there

Manual
M/00 has 230hk/350Nm (240hk/370Nm with OB)
M/01 has 230hk/350Nm (about:250hk/370Nm with OB)
M/02 has 250hk/350Nm (250hk/370Nm with OB)

Automatic
M/00 has 230hk/330Nm
M/01 has 230hk/330Nm
M/02 has 250hk/350Nm

Overboost, it odoes not give you +20 Nm in whole rpm span, so the affect to 250bhp aero peak power wise is rather small. Max torque goes up 20Nm though.
 

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Agreed. The EGT would get out of control with any additional boost at high RPM.

On the 05 cm housing and the 2.3L engine the velocity of the exhaust-gas reaches the local speed of sound (1,500 mph @ 900*C) at about 4,500 RPM. The throttle position and mass flow is somewhat important to this equation, but not as much as one would think. This is due to the fact that the exhaust gas in the cyllinders and exhaust ports is well under the local speed of sound, and thus the gas is considered an incompressible fluid.

The formula I used for calculating exhaust velocity is straight out of "The Scientific Design of Exhaust and Intake Systems" by Philip H. Smith. It should be fairly valid.

Once choke flow is reached, no amount of upgraded post-turbo exhaust parts will increase horsepower significantly. Choke flow is a speed, and thus, volume/second limit for an orifice. The only ways to increase the mass flow are to increase the local speed of sound with higher gas temperature, raise the absolute pressure (pressure drop across turbine is insignificant, only absolute pressure matters), or increase the size of the orifice.

At near the local speed of sound the compressability effects of the gas are significant and small obstacles on the walls of the housing will small shock waves. Smooth walls are good.

An 06 cm housing raises the choke RPM to above 5,000 even for the 2.3L. Not a bad idea to make the swap, though the transition from manifold to housing will be akward, and at the local velocity it's an important transition. A good set of headers would be awesome.

Adrian W~
 

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I quote 'makes it faster mid range than a Porsche 911 Turbo'.  [/b]
I love that quote! ;-)

I really would like to see a 9-5 Aero stand up to a basic 911 Turbo, which IIRC has, well 2 turbos and produces 420HP and 560NM between 2.700 rpm and 4.600 rpm has 4 wheel drive for superior traction and weighs less than the 9-5.

This has to be the most stupid of all the marketing stuff they spew...

grrr...
 

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Originally posted by Mark_A:
[qb] QUOTE
I quote 'makes it faster mid range than a Porsche 911 Turbo'.  [/b]
I love that quote! ;-)

I really would like to see a 9-5 Aero stand up to a basic 911 Turbo, which IIRC has, well 2 turbos and produces 420HP and 560NM between 2.700 rpm and 4.600 rpm has 4 wheel drive for superior traction and weighs less than the 9-5.

This has to be the most stupid of all the marketing stuff they spew...

grrr... [/qb][/b][/quote]You remember saabs ferrari quote from way back with the 9000 aero? I'll dig it up for you but it was in some magazine.
 

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Discussion Starter · #9 ·
Originally posted by Naranto:
[qb]A while back I was invited to a Saab GB Track Day and given a 9.5 Hot Aero to try. Talking to the technical chap he explained the car puts out 250bhp standard, but with overboost (which will last for 20 seconds and is intended for overtaking) this increase the power by 20% to 300bhp which and I quote 'makes it faster mid range than a Porsche 911 Turbo'.

Hope this helps. [/qb][/b]
So what specifically changed to get the new B235Rs to 250HP (from 230)? Is this purely a software update?
 

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Well it really dosnt matter to me if an Aero can beat a turbo porsche, as I dont see many of those around here in Denmark. But I do whant to kick som a... on all those big diesels!!!!!!!!
 
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