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saab intercooler question


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I just installed a saab 900 intercooler into my 88rx. I noticed that the wastegate hoses run to the turbo housing. The wastegate will still open at 7psi, but wouldn't the engine get less boost since the intercooler takes some of it away? Would I be better off to route the wastegate hose after my intercooler? it would seem to me that if this was done the turbo might have to work a little harder but the engine would still end up with 7 psi of boost after the intercooler. Is this correct, or is the pressure equal throughout the whole system?

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I have no idea what you are asking, but I'll tell you how to hook it up. There are 3(basically) tubes coming off the recirc valve(which is what I think you are taking about). Theres an input, an out put and a vac line which is the "control". The input should be somewhere after the turbo and before the throttle body, usually best between the IC and the throttle body. The vac line goes to the vac system on the intake manny... I used a T on the area right on the right side of the intake where it has a few existing vac lines. Now the output of the recirc valve needs to go between the MAF and the turbo.. I put mine in the end of the round cylinder thing on the side of the intake... The waste gate is the thing in the exhaust side of the turbo that bypasses the exhaust impeller. There is a big vac actuator on the side of the turbo thats hooked from the act, to thhe fender solenoid and then back to the intake side of the turbo.

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I know what you are saying, but I'll rephrase my question. between the turbo and the intercooler the car should have 7psi. after the intercooler the pressure drops, meaning the throttle body actually sees around 5psi. . If the hose that sends signal to the wastegate, which you would call the input line, was connected between the intercooler and the throttle body instead of between the turbo and the intercooler, the car would have 7psi after the intercooler instead of before it. Would moving this hoes to get its signal between the intercooler and throttle body make me go faster, or would my car run exactly the same?

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If you are getting a 2psi pressure drop, you have a leak. Even a big 9000 IC shouldn't see more than 1/2 psi drop.

 

To run stock 7psi/wastegate boost, simply run the wastegate signal line from the compressor housing of the turbo to the wastegate.

 

If that doesn't net what you need, it is time to invest in a boost controller.

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I actually see the logic in his statement.

And i cant see why it wont work or why it will cause any problems

 

A boost controler only creates a pressure drop to make the wastegate come on later.

 

I dont see how it could do any bad,... these motors can run 10psi anyway

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So what youre saying is: you want the wastegate to be actuated by the pressure closer to the throttle body, so the turbo will compensate for the drop due to an intercooler?

 

Well first i'd agree with calebz, 2psi is a rather large drop. It doesnt sound much but its over 10% of your turbo's work being wasted. Also id agree with everyone else, invest in a boost controller. Its simple equipment and when combined with a boost gauge - gives good results.

 

If i misunderstood your question, sorry. If ive given a stupid answer i apologise as im used to working with a volvo turbo.

 

KELTIK

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I don't think he actually has a 2 PSI drop. He is just worried about where to route that hose INCASE there is a pressure drop caused by the intercooler. And from what I can gather most of you are saying there isn't and if there is it isn't more than .5 psi. Would there be any negative effects of him routing the pressure sensor in post-intercooler to prevent ANY drop in boost?

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