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How will car run with exhaust removed after downpipe?

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Old Jan 21, 2004 | 10:49 PM
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From: Stillwater, Ok
How will car run with exhaust removed after downpipe?

I have an 87' turboII and i was wondering if it would be workable to remove my exhaust from after the downpipe back. Ive been told that it will be (very loud) but im wonderin if there is a danger to the turbine blades by having cold air get to them so quickly after the car is turned off and possible warping them. That an any other possible dangers. This isnt an permanent setup just a temporary fix before i go to straight pipes. input would be appreciated.
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Old Jan 21, 2004 | 11:02 PM
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My friend had his AE like that, Kinda loud, and he was running pig rich......just let your car cool down after you boost.....I am not sure about the backpressure though....
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Old Jan 21, 2004 | 11:04 PM
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biggest concern would be melting / catching fire to the bottom of your car....
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Old Jan 21, 2004 | 11:07 PM
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i took my exhaust off after my bonez high flow cat on my 87 TII... it was loud as hell(tho not as loud as my 3" straight pipe), and noxious gases entered my car all the time... if u do u'll be driving with ur windows down a lot... i wouldn't recommend it... if u want to run with no exhaust just get a straight pipe made for it
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Old Jan 21, 2004 | 11:10 PM
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Please do not do this. Read about back pressure first, and you will know where I am coming from. You will burn up your valves after a while, so it isnt worth it.
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Old Jan 21, 2004 | 11:37 PM
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Originally posted by The AntiRice
Please do not do this. Read about back pressure first, and you will know where I am coming from. You will burn up your valves after a while, so it isnt worth it.
valves???
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Old Jan 21, 2004 | 11:38 PM
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Originally posted by The AntiRice
Please do not do this. Read about back pressure first, and you will know where I am coming from. You will burn up your valves after a while, so it isnt worth it.

umm I hope this is a joke.....
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Old Jan 21, 2004 | 11:41 PM
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Originally posted by The AntiRice
Please do not do this. Read about back pressure first, and you will know where I am coming from. You will burn up your valves after a while, so it isnt worth it.

Dude, I think you should read a bit before making comments like that...
Backpressure after the tuned section of the exhaust should be close to zero and the tuned section of the exhaust of a two rotor single turbo will always be right at the exit of the turbine section. It is also beneficial to have a higher temp(pressue) drop across the turbo blades... Which means less 'restriction' behind it. However this doesn't always mean venting the pipe to atmosphere as soon as possible, this might not be the best for flow.
This has however been covered much more in depth in another thread... I think everyone interested should search for it and have a read.

The only really "bad" thing that could come of doing this is the noise.. if you call that a bad thing.
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Old Jan 21, 2004 | 11:42 PM
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I read that and was like...ummmmmmm i think u got the wrong forum buddy.......he will either explain or never show his face ever again......*prepares flame gun, and gloves* I'm ready to
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Old Jan 21, 2004 | 11:46 PM
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god i'd love to see the surprised look on his face if he ever tried to rebuild his own motor, only to find the closest thing to a valve he has is his throttlebody lol
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Old Jan 25, 2004 | 09:43 PM
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Yeah, and you will blow a cylinder, give me some credit, i was seeing who would bite.
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Old Jan 25, 2004 | 09:45 PM
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this is fun
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Old Jan 25, 2004 | 10:12 PM
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running it off the DP is STUPID loud, especially if have an aftermarket dp wit no cats. I had to drive 5 miles all the way to the muffler shop. (now i have a stright pipe) It backfired once, it was so loud i couldnt hear for 2 min after that. Oh and running your car like this isnt good for your exhaust bearings, if they seize, you might have to get some blinker fluid to replace the loss of momentum for your flux capacitation diodes. -alex
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Old Jan 25, 2004 | 10:18 PM
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My friend started up his car with just the downpipe and at idle, it was LOOOOOOUUUD. I thought I would have gone deaf. I can't imagine driving it around.
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Old Jan 25, 2004 | 10:27 PM
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i heard you'd blow your piston return spring
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Old Jan 25, 2004 | 10:44 PM
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From: jefferson Or
A long time ago befor must of you where born I was into Corvairs, Had me a 60s and collected all the good parts from the other modles. Ended up with a 110 turbo 4 speed. You need to know what a 110 is befor just saying something, but not now. So I woudl run it with just a stright pipe, you could hear the terbin spool up just like a small jet engine with more boost and faster. Never lost any valves. In later years at the dealer ship I cought one of them rotarys on fire with just open ports, loud is where you cant hear your self think and so fare that was the only I couldn't hear my thinking
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Old Jan 25, 2004 | 10:47 PM
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npen exhaust

I had to run mine with basicaly open exhaust like your talking about. Its loud as hell and your turbo will spool insanely quick. I liked having the turbo spool quick but it was too loud and you would get light headed at stop lights. Also I almost got a ticket for noise pollution and all the tracks around here require you to have mufflers.
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Old Jan 25, 2004 | 10:49 PM
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you would also warp your ganooder sprockets to hell and back
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Old Jan 25, 2004 | 11:24 PM
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dont do it man youll be replacing the whole engine..it has something to do with backpressure i cant really remeber what it does but i was told that it would ruin a turbo charged car
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Old Jan 25, 2004 | 11:29 PM
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Originally posted by Baka_Gaijin v2.0
dont do it man youll be replacing the whole engine..it has something to do with backpressure i cant really remeber what it does but i was told that it would ruin a turbo charged car
I think you're talking about boost creep... and thats from lowering the restrictions in the exaust... if he has a ported wastegate it shouldnt matter...
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Old Jan 25, 2004 | 11:31 PM
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Originally posted by Corbit
i heard you'd blow your piston return spring
no no no I heard you fry piston rings, so you gotta "rip apart the block and replace the piston rings you fried!" (ok ok yea i know making fun of F&F is old ) AntiRice I seriously hope you aren't that stupid and aren't trying to cover up.... You really really really had me worried man! Back to the question though, don't run open downpipe, its not worth the smell in your car and the extreme loudness. If anything run a straight pipe back, to at least keep the smell out of your car!
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Old Jan 26, 2004 | 09:33 AM
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yea its really loud, espesially at WOT, it will scar the **** outta anyone you drive by. Its funny to see the look on there faces though. one thing, i thing i might of vibrated the **** outta my O2 sensor doing this and now its either the strieght pipe i put on after 4 miles of driving like this is making the car run UBER rich or the o2 sensor is indeed fucked up i do not know, but i can tell you this, the piston return spring, when broken, can damage your valve sensors and your apex seal motors, lol if that happens you gonna have to re calibrate every single exhaust caliper on your car, all 29 of them <- taken a little too far
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Old Jan 26, 2004 | 10:03 PM
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valves-rotary, dont worry speedfreak, im not that stupid.
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