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Discussion Starter #1
Alright, I have heard that running with an wastegate open to atmosphere allows more power because a car with a wastegate routed into the exhaust is trying to shove more air through the exhuast. I'm buying my T-78 kit next month and am debating which way to go? I know the external wasegate is loud, but what are some other pros/cons performance and otherwise? Thanks fellas!
 
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Discussion Starter #5
1. Sounds cool, but only at full boost (ie hard for a cop to prove you have a over loud exhaust)

2. More power. I have heard enough accounts of power increase on the same car of open vs closed into exhaust to convince me.

3. Cost. Since you are getting a T78 kit, it will vent to atmosphere as shipped. It will cost you money to route it back into exhaust.

I say leave it. Drive it for ahwile. If for some reason you hate it, by all means spend the money and have it re-routed into the downpipe.
 

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Somebody post what it sounds like please:rolleyes:

Jeff
 
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Discussion Starter #8
Ya inside the car it sounds kinda cool - outside it sounds scary as shit! :) I'd say run it open - power gains have been up near 20 RWHP on my friend's T88.
 

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Shawn Davis
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Definite power gain. I think the ideal solution is to route a seperate exhaust line from the waste gate to vent to atmosphere under the car. Keeps the noise and dirt down while preserving power.
 
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Ubermensch said:
Definite power gain. I think the ideal solution is to route a seperate exhaust line from the waste gate to vent to atmosphere under the car. Keeps the noise and dirt down while preserving power.
That's exactly the way a T78 kit comes. Exits pointing straight down after it has made it totally under the car. None of the exhaust roasts anything under the hood.
 

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...For Me to SUP On!!
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in addition to more power, a big benefit is increased accuracy in boost control... any amount of back pressure after the wastegate hinders its ability to regulate boost... the wastegate needs to be able to quickly bleed off pressure (possibly LOTS of pressure)... so having a restriction at this point is much more likely to cause boost creep...
 

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Imagine what kind of power the SP kits could make if they vented to the atmosphere. :eek: Right now they are routed back into the exhaust. Them seem to be working pretty well with this setup. I am sure there is probably a gain to be had, but it's probably only at super high boost and hp.

As far as controlling boost. I have no problems with boost control on my SP kit. I feel it's more important to have a high flowing wategate than whether or not it's vented to the atmosphere.

I have been in a PHR car that vented to the atmosphere and my SP car that doesn't and the sound isn't that much louder when venting to the atmosphere. It's not at all like my friends T78 on his RX7. When that thing vents to the atmosphere, hide the women and children. It really sucks. I didn't mind it on a Supra.

Later, Steve
 
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