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Discussion Starter #1
I will be going to the 1/4 mile track here in April. Would I be better to go with no exhuast or leave the Blitz nur spec on there, as you know im looking for the best et.
 

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leave the exhaust. w/ and open dp your car will run like crap, boost will keep climbing when you dont want it to. it will sound like @ss. and it most likely wont be any faster.
 

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mr2perfection said:
I will be going to the 1/4 mile track here in April. Would I be better to go with no exhuast or leave the Blitz nur spec on there, as you know im looking for the best et.
Turbo cars benifit from the least amount of backpressure possible. The shorter the exhaust has to travel, the better. You will most likely get more power with no exhaust at all, which could result in a slightly better time depending on how restrictive the exhaust you had on previously was.
 

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Check your track, many of them will require your car to be quieter than 90dB. You wont run a very fast E.T. if you are kicked out.
 

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GoTime242 said:
Turbo cars benifit from the least amount of backpressure possible. The shorter the exhaust has to travel, the better. You will most likely get more power with no exhaust at all, which could result in a slightly better time depending on how restrictive the exhaust you had on previously was.
i know this is theoretically true, but i drove my car w/ just a downpipe ..... and it felt crappy and much slower than it did once i installed my ko. plus it sounds like the car is gonna blow up too. and i hate anything that sounds like that.
 

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Discussion Starter #6
93smgturbo said:
Check your track, many of them will require your car to be quieter than 90dB. You wont run a very fast E.T. if you are kicked out.
Im sure I wont be as loud as some of drag cars thatll be there.


BTW, I dont think no exhuast sounds that bad.....you can really hear the turbo...and it sounds kinda mean.....but would like to leave the exhuast on.....I could try a couple times with it and without it....

My fastest 1/8 mile time came with no exhuast.
 

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A lof tracks require a muffler, come tracks require a muffler at certain times (noise ordinances).

As for the performance benefit, you are all bouncing around pretty darn close to the truth as far as I know it :)

Turbos love to breathe, the more open the exhaust the more flow through the turbo and the potential for more power.
As sexy pointed out, the more open your exhaust is the harder it is to control boost.
You are more likely to overboost with a 100% open exhaust.

I ran an open exhaust for the best part of the last 3 years, but I have an external wastegate to help control boost. Trying to run 15 psi or less on an internally gated turbo with completely open exhaust is asking for big boost spikes.

If I had to guess about sexy's observation, it was more than likely "smoother and more pleasant" with his exhaust on than without. It is aset of the pants thing. Unless you have back to back ETs to compare or dyno pulls, no one can say with certainty which was better for performance.

Theoretically, with an open exhaust "tuned properly" it should be faster.
I'd say leave the muffler on unless you have an external wastegate.
 

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smoother and MUCH more pleasant. if your willing to deal w/ an extremely choppy powerband, big annoying noise, and uncontrollable boost for MAYBE a tenth or two, go for it and tell me all about it. :)


oh and jeff, i love it when you call me sexy!!!! :p
 

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uhm ... Hyde has always been smooth, was never "annoyingly" loud to me and has boost pretty much undercontrol.

Sxy, I think you missed the part where I said if your car is "tuned" for an open exhaust :p
 

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jeff, when you said "open exhaust", im not sure if you were referring to the same "open exhaust" as i was. i'm referring to an open downpipe, which was indeed (given stock tuning) very choppy and annoyingly loud. to the point where i could hear each individual cylinder fire and "POP" out the dp. but yes, im sure yours ran much better (with straight pipe exhaust?) than mine, given the tuning and external wastegate.
 
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