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I was just curious if you saying that to me or in general. I agree with what you wrote.
The Sentra SE-R (Not the SE/XE etc) is an *extremely* over built car. The engine has rods fatter than my wrist, the aluminum block has lived past 800hp with no problems, the crank has a main bearing girdle etc etc.
The car is turbocharged in the rest of the world and has fat axles, and other parts to take the power. The Chassis (91-94) was designed for the World Rally Championship (Those on the board from other parts of the world will recognize the Sentra as the AWD Sunny/Pulsar GTiR)
The weak part is the transmission, we don't get the big case trans in the USA. While not as fragile as the Saab they do blow, oddly enough it's third gear.
But I digress as this is the Saab board. I just wanted to answer some of your questions about the car.
In regards to the turbo...Straight from the mouth of a Garrett engineer that designs these things for a living. The turbo is out of it's range after 12psi. Now we are talking the Saab T3 and not the T3 turbo in say the Mustang SVO.
The Saab unit uses a 58mm wheel on the turbine side and it is WAY too
small for any kind of power production, and when you stick a T4 compressor
on the stock turbine section it actually makes matters worse in regards to turbine backpressure. That's where people are getting more of the detonation from, the exhaust side. Reversion and over the top EGT temps due to a constipated turbine section combined with pushing the compressor way out of it's range past 15psi and making a lot of heat.
The Saab is out of cross-over (More pressure in the intake than in the exhaust manifold) pretty quickly and that leads to higher combustion temps etc.
The proper thing to do is have a Stage-III 65mm wheel put in the stock
turbine housing, and then go to a light 40 trim T4 compressor in a T04E
housing and keep the .48 A/R turbine even though it's a bit small. That
will make full boost at 3000rpm and support about 275whp. More than enough
for a daily driver Saab. If you want better transient response, and higher
efficiency with full boost at 2600rpm, go for a BB center section.
Keep in mind Rob specs turbo for OEM applications so in regards to reliability, he has this in mind. He actually said 12psi on the Saab T3 but from my calcs it seems okay to 14psi as I'm not as conservative as him but after that it goes down hill fast.
posted by 24.18.134...
, Thu, 3 Jan 2002 14:09:00, Thu, 3 Jan 2002 16:36:46
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