Wastegate Outlet Muffler
12-02-2010 | 04:15 PM
#31
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cars sucks the exhaust up to the hatch anyway. If you have a bad hatch seal, you have smelled it. If you have a car that's running very rich, or blowing oil, you see it all over the rear body panel between the headlights. So whats coming out from under the car (wg dump) and what's coming out the tail pipe are both going to end up with the same fate it seems.
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Mike or Dave Lindsey
www.lindseyracing.com
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Other 1-405-947-0137
Mike or Dave Lindsey
www.lindseyracing.com
U.S. 1-877-943-3565
Other 1-405-947-0137
12-02-2010 | 04:56 PM
#32
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From: In the garage trying to keep boost down
Let's try this from a common sense approach.
We don't know exactly how much of your exhaust (percentage wise) is flowing though the
wastegate versus the primary tube. 10, 15, 20% maybe more? We believe most cars when at WOT (and under boost), your wastegate is probably wide open. If you're running a dump to atmosphere set-up now, you can simply verify that with your own ears. There is no questions that it's open and seems to be the case on any level of build so far we have listened to. We find typically if using a DP WG, that your WG is starting to open once you reach 1/2 the total boost setting with the throttle WOT.
So based on that knowledge, if you're tied back in, you're adding that percentage of exhaust back into
your primary tube. That means you're putting more through the same pipe which is going to increase the
back pressure. So dumping to atmosphere has the same net effect as putting a larger primary tube exhaust system on the car without actually putting a larger primary tube exhaust system on the car.
So a stock exhaust may act like a 3", and a 3" may act like a 3.5", and a 4" might act like a 4.5" etc...
Even a 5" exhaust is going to have back pressure. The more HP (air to move), the more back pressure. And if you dump to atmosphere on the WG with whatever size you have, you improve the flow and reduce back pressure even more.
This product is all about doing something with the sound you get when you do dump to atmosphere which some might not find to their liking.
We don't know exactly how much of your exhaust (percentage wise) is flowing though the
wastegate versus the primary tube. 10, 15, 20% maybe more? We believe most cars when at WOT (and under boost), your wastegate is probably wide open. If you're running a dump to atmosphere set-up now, you can simply verify that with your own ears. There is no questions that it's open and seems to be the case on any level of build so far we have listened to. We find typically if using a DP WG, that your WG is starting to open once you reach 1/2 the total boost setting with the throttle WOT.
So based on that knowledge, if you're tied back in, you're adding that percentage of exhaust back into
your primary tube. That means you're putting more through the same pipe which is going to increase the
back pressure. So dumping to atmosphere has the same net effect as putting a larger primary tube exhaust system on the car without actually putting a larger primary tube exhaust system on the car.
So a stock exhaust may act like a 3", and a 3" may act like a 3.5", and a 4" might act like a 4.5" etc...
Even a 5" exhaust is going to have back pressure. The more HP (air to move), the more back pressure. And if you dump to atmosphere on the WG with whatever size you have, you improve the flow and reduce back pressure even more.
This product is all about doing something with the sound you get when you do dump to atmosphere which some might not find to their liking.
Thanks
12-02-2010 | 09:14 PM
#34
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From: Orlando, FL
12-02-2010 | 09:16 PM
#35
Drifting
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From: England UK
I,ve never understood why aftermarket exhausts have the wastegate tie-in close to the downpipe where it is likely to cause some back pressure, the original Porsche setup introduces the wastegate flow where the exhaust gases have cooled and contracted.
12-03-2010 | 10:06 AM
#38
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The factory ties the WG in after the CAT. It's the same size pipe, just 2' further down it. We don't think they cared about that (your theory). We think they did that to run "around" the cat with the exhasut from the WG to make the CAT in effect less restrictive. We do that with our 4 and 5" Big Flow Systems. Around the CAT and also back it where the pipe is 4", not 3" like every other sytem including our stanard 3 and 4's.
12-03-2010 | 11:08 AM
#39
Drifting
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From: England UK
The factory ties the WG in after the CAT. It's the same size pipe, just 2' further down it. We don't think they cared about that (your theory). We think they did that to run "around" the cat with the exhasut from the WG to make the CAT in effect less restrictive. We do that with our 4 and 5" Big Flow Systems. Around the CAT and also back it where the pipe is 4", not 3" like every other sytem including our stanard 3 and 4's.
I do like a lot of your products.
12-03-2010 | 11:14 AM
#40
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12-03-2010 | 11:40 AM
#42
Drifting
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From: England UK
Here's one of mine, I think people spends 1000's on old 944's because they aren't wired up quite right and the logical choice would have a late Corvette or M3 flavour.
12-03-2010 | 12:15 PM
#44
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12-03-2010 | 12:24 PM
#45
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Years ago, on 2.5L car, we had a Super 75/Stage5/#8 and 3" LR exhaust tied WG. We noticed the exhaust pressure was quite high. About 35 psi at 18 psi of boost.
We changed to a P trim. Dropped 5 psi of exhaust pressure.
We then changed to a #10 Hot Housing. Dropped 5 more psi of exh. pres.
We then changed to a 4" Exhaust. Dropped 5 more psi of exh. pres.
We then dumped the WG to atmosphere and dropped 3 more psi.
We did that all in that order. Could we of dropped more then 3 psi on the WG dump had we done the WG dump first, or second, or third? Don't know. Perhaps, but even if not, it still dropped 3 more psi of exhaust pressure in
the end.
That car is now an exact 1 to 1 on pressure. 21 psi, 21 psi, 18/18 and so on.
The engine revs very very fast because it's not backed up or plugged up by
the exhaust not being able to get out of it's own way.
We see people post videos on cars making good power, but are amazed at how slow the engine revs. Even in 1st or 2nd gear. Sometimes not even able to break the tires loose. It's not all about how fast it boosts. It's not all about how early the torque curve is on the dyno chart. It's not all about perfect a/f ratios. If your motor can't breath, those can all still look good, but one that breaths is going to leave you far behind with less power, worse a/f, and a later torque curve.
Once you have tried some of the things and tests we have tried for ****s and gigles, you realize that is all true.