Does a Catless up pipe shorten turbo life

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06-17-2004, 08:12 AM

#16

crash n burn

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Quote:

Originally Posted by RCFerrara

I've read several places, most recently on MRTPerformance's site (http://www.mrtrally.com.au/performance/howbov.htm), that "turbo RPM is based on a "thermal load" NOT rpm as some people think". I guess I always thought that engine RPM and Turbo RPM are directly related. From what this website is saying, it sounds like heat is necessary. What am I missing here? Thanks.

It isn't the heat directly that you want, it is the 'transfer' of this heat from one point to another. This thermal variance, from what I understand along with the exhaust gases leaving the cylinder, get the turbine spinning really fast. The engine rpm thing is correct. That is why if you are at, say, 6K rpm's, but off the gas, you aren't running any boost. Things change when the car is under load (throttle) that change what the turbo is doing.

06-17-2004, 12:00 PM

#17

Littleboyblue

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The precat is used to pass smog. They use it to warm the car during the begining of the smog test. At least that is what I've heard.

06-17-2004, 02:02 PM

#18

mexicanpizza

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Car Info: MMVI AW WRX STI

JDM-SAL...the Uppipe "fix" is basically a resistor so you can eliminate the stock EGT sensor. The stock sensor can be reinserted into your catless uppipe, but the community has found that the sensors are very prone to failure in a catless uppipe.

When they fail, you either get just a CEL (for failure of the EGT sensor) or you get a CEL accompanied by "limp mode" (when the sensor fails on the high side, telling the car there is a fire in the exhaust). I got limp mode 5k miles after installing my catless uppipe. It's just easier to plug the hole, and plug in the resistor. The resistor is a 2.2k ohm, 0.5Watt one that you just plug into the ecu side EGT harness. It's a no brainer. Search on clubwrx.net for "EGT resistor mod" for more info.

Littleboyblue: I think you've proven in most of your posts that you know NOTHING about this car, and you just regurgitate what "you're heard" with the hopes of getting an avatar/higher postcount. I'm on to you!

06-17-2004, 03:07 PM

#19

bassplayrr

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Car Info: CRZ EX-Navi/6MT & Vue Redline

Quote:

Originally Posted by Littleboyblue

The precat is used to pass smog. They use it to warm the car during the begining of the smog test. At least that is what I've heard.

The pre-cat is used for cold starts. That is true as it is extreamly close to the manifold and therefore "lights" very quickly. However in most states the cars are not required to cool down before the smog test. Since your car should be at operating temp. by the time you make it to the smog shop, the heat that has been created in DP cats will be enough to pass smog w/o a catted UP.

-Chris