Was bored today, so in went a screamer!
07-29-2005, 06:05 PM
#46
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he he he well, I am on the track next Saturday with a Porsche driver training thing, so I will try get some video of that, otherwise it will be August 13 when I go back on the dyno 
07-30-2005, 01:30 AM
#47
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Originally Posted by gman1868
So, after reading three pages of comments, I still don't see a pic of where you welded it into the exhaust. We wanna see where it's attached 
07-30-2005, 01:42 AM
#48
Three Wheelin'
For you guys with strait dump tubes, do you just let it exit right under the car? Do you muffle it at all? Route it out just behind the pass side front wheel? 
Is anyone running the LR dump tube?
http://www.lindseyracing.com/Merchan...951EXHAUSTMISC
For only $17.95, its totally cheap enough to try out. Although you still have to figure out how to plug the hole back to the main exhaust. I guess I could just have a shop make a blockoff plate for that.
Is anyone running the LR dump tube?
http://www.lindseyracing.com/Merchan...951EXHAUSTMISC
For only $17.95, its totally cheap enough to try out. Although you still have to figure out how to plug the hole back to the main exhaust. I guess I could just have a shop make a blockoff plate for that.
07-30-2005, 01:53 AM
#49
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Thread Starter
You obvioulsy have to get the exhaust shop to weld in a section where the old tie in was, you had might as well just keep a certain length of the stock WG pipe on there! No need to pay $17.95 for a section of pipe you already have on the car!
07-30-2005, 02:33 AM
#50
Three Wheelin'
Yeah, makes sense NZ. If I'm already paying an exhaust shop to work on the main pipe, it'd probably be less than $17 for them to just adjust the stock WG dump tube to point at the ground. Maybe add a bit of an extension to it to get it down into the under car airflow.
07-30-2005, 02:39 AM
#51
Race Director
Thread Starter
Yeah if I was you, I would cut it off as far back as possible if you dont want to run it out the end like I did. I say this because a pipe that small posted above will likely be prone to putting exhaust gasses into the cabin.
07-30-2005, 07:01 AM
#53
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Is anyone running the LR dump tube?
http://www.lindseyracing.com/Merchan...951EXHAUSTMISC
Looks neat. Given it blows off at speed unlikely to get fumes in the cabin unless there are some large rusty holes in the floor. Probably get more fumes just from being in traffic. Also may be possible to connect the now unused pipe section into the larger exhaust upstream of the main cat for less restriction.
http://www.lindseyracing.com/Merchan...951EXHAUSTMISC
Looks neat. Given it blows off at speed unlikely to get fumes in the cabin unless there are some large rusty holes in the floor. Probably get more fumes just from being in traffic. Also may be possible to connect the now unused pipe section into the larger exhaust upstream of the main cat for less restriction.
07-30-2005, 08:08 AM
#54
Burning Brakes
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When I bought my 86 951 the RPO (retarded previous owner) had the wastegate dumping to atmosphere only 18 inches from the rear of the wastegate. It sounded pretty cool, but every time you got on boost with the windows open you got plenty of exhaust in the cabin. To make matters worse he was running wayyy rich in the midrange and so it was like huffing gasoline. 
-John
-John
07-30-2005, 09:20 PM
#55
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how much performance gain do you think venting to atmosphere would be, if you already run a 3" test pipe as I do? (Trying to figure whether too consider this with the engine rebuild) Is it only obnoxiously loud when on boost, or all the time?
07-30-2005, 09:25 PM
#56
Race Director
Thread Starter
Well, I am on the dyno in 2 weeks, so I can tell you exactly how much the gains will be. I am expecting around 20HP, I know it sounds absurd, but that 6 psi of pressure in the exhaust is a killer. The car is noticable quicker, thats how I figure 20HP, as it would need to be that much to feel it. Its ONLY loud when the WG starts venting... as far as idle, cruising, low boost runs etc, its as quiest as stock. The loudness will depend on how you vent it, you could put in a muffler or resonator and have it very quiet, dumping it immediately, it will be very loud I suspect.
07-30-2005, 09:33 PM
#57
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I guess the other issue is weight. If i put a muffler on it, and run it a reasonable length aft of cabin area, I'm adding weight. hmm. I think a muffler is out, as mine is LOUD as it is. My exhaust is ceramic coated alminum so it's VERY light. I'll be interested too see your dyno. Cheers.
07-30-2005, 09:48 PM
#58
Race Director
Thread Starter
Well, the weight of 1 3/4 pipe is not very much! But if the full boost noise is not an issue, then go for it! I would suggust cutting ot at around the same length as the tie though, just to lesson the risk of cabin fumes. The added HP outweighs the weight
07-31-2005, 08:06 AM
#59
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Originally Posted by johne
When I bought my 86 951 the RPO (retarded previous owner) had the wastegate dumping to atmosphere only 18 inches from the rear of the wastegate. It sounded pretty cool, but every time you got on boost with the windows open you got plenty of exhaust in the cabin. To make matters worse he was running wayyy rich in the midrange and so it was like huffing gasoline.
-John
-John
