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-   -   Decat Pipes on the Way (https://www.6speedonline.com/forums/991-turbo/396874-decat-pipes-way.html)

wrs Sep 20, 2016 08:30 AM

Decat Pipes on the Way
 
Scheduled to be at my house on Thursday afternoon. So I am going to replace my headers with the original manifolds because one header is cracked as discovered by my most recent service at Porsche. That may offset the additional noise introduced by the cat removal and not bother my neighbors as much and finally, we will see if OEM manifolds and no cats make my car faster or not. I am scheduled to drive at COTA on Oct. 1 and I may be able to get out to the dragstrip a week from Friday. I can have a car weekend as I did back in February. My wife already bought a new purse in retaliation.........

Visceral Sep 20, 2016 10:26 AM

If its only a purse (assuming its not a Birkin bag, though those are good investments), you got away pretty well.

The decat pipes make the car sound really good. If the headers were equal length, the car will get a louder rumble back with the stock manifolds, but it wont be as loud WOT. (thats my experience... though the measurements were within 2dB)

SamboTT@ByDesign Sep 20, 2016 01:36 PM

LOL! Doh, every time with the purse! But happy wife ...happy life.

Davie will take care of you at Porsche and we ca n log as soon as you are ready bud.

kodiakz Sep 20, 2016 08:48 PM

Im interested to see if you notice any unburned gas odor. I used to smell like a gas pump after I did the cat delete on my gtr. Granted, the exhaust on the p car is all in the ass end so may not notice it

SamboTT@ByDesign Sep 20, 2016 09:38 PM

It's def less on Porsche especially DI. We can also tweak it a little if it bugs you. Most people don't have an issue.

nabizzy Sep 20, 2016 09:52 PM

I had a cat delete done last week. Car sounds amazing, pops are louder, you hear a lot of turbo noise, and even a bit more engine noise. Startup is not affected much. There is a lot of gasoline smell, but not inside the car while driving if thats what you are referencing. If you drive with windows down you will get some if you are idling somewhere. If you turn off car after driving and walk around back you will smell some. Car will also shoot fire. I will make a video soon showing the differences so everyone can have an idea.

Nanook Sep 21, 2016 07:16 AM

No odor..nada. Maybe if you stood behind the car you would notice it but it's certainly not evident nor a nuisance. (Kline inconel catless)

Visceral Sep 21, 2016 12:36 PM

I only notice it a lot because I have to walk behind the car each morning after cold start to open the gate. It never smells inside the car. But it does smell pretty "VOC" out back after start up :)

manolis991 Sep 22, 2016 01:06 PM

wrs did your manifolds crack from a tune? I was looking at changing factory manifolds to make a little more power.

wrs Sep 22, 2016 02:02 PM

3 Attachment(s)

Originally Posted by manolis991 (Post 4563318)
wrs did your manifolds crack from a tune? I was looking at changing factory manifolds to make a little more power.

Don't know why they cracked. FVD won't warranty them because they claim there are scrapes on them and there are but they aren't the reason for the crack. I backed up over a parking stop and scraped it. That's fine if they want to pretend that is why they won't replace it but that's not the reason. More likely because they didn't have a good weld and it failed under stress. I have had the car out at the track three times with those headers and it's gone to the drag strip several times on them as well.

Anyway, there is another thread about how FVD headers or maybe it's unequal length headers cause power loss. They sound good but the question on the power is based on one guy's car, not mine. I have no comparison of before and after. I am putting the factory manifolds back on because I don't want an exhaust leak and I want to see how they do with the cat bypass pipes. If it runs good and sounds good I will likely just leave it alone. Headers do have ground clearance issues.

Here are the pictures the Porsche dealership took for me.

manolis991 Sep 22, 2016 02:26 PM


Originally Posted by wrs (Post 4563335)
Don't know why they cracked. FVD won't warranty them because they claim there are scrapes on them and there are but they aren't the reason for the crack. I backed up over a parking stop and scraped it. That's fine if they want to pretend that is why they won't replace it but that's not the reason. More likely because they didn't have a good weld and it failed under stress. I have had the car out at the track three times with those headers and it's gone to the drag strip several times on them as well.

Anyway, there is another thread about how FVD headers or maybe it's unequal length headers cause power loss. They sound good but the question on the power is based on one guy's car, not mine. I have no comparison of before and after. I am putting the factory manifolds back on because I don't want an exhaust leak and I want to see how they do with the cat bypass pipes. If it runs good and sounds good I will likely just leave it alone. Headers do have ground clearance issues.

Here are the pictures the Porsche dealership took for me.

Interesting. I know with stainless headers the life span is not great.. welds crack, material weakens over time from heat and breaks up, pretty common just didn't know how they behaved this car and if they make any extra power. I can see why they won't warrant them. How long did these ones last? Actually looking at the heat discolorations on the material they have been operating at temp...so life span is not going to be as good as cast. What did you dealer say?

wrs Sep 22, 2016 03:13 PM


Originally Posted by manolis991 (Post 4563338)
Interesting. I know with stainless headers the life span is not great.. welds crack, material weakens over time from heat and breaks up, pretty common just didn't know how they behaved this car and if they make any extra power. I can see why they won't warrant them. How long did these ones last? Actually looking at the heat discolorations on the material they have been operating at temp...so life span is not going to be as good as cast. What did you dealer say?

Those have been on the car since Feb 2015. Not all that long but like I said, I do have three track sessions on them and numerous runs at the dragstrip. Funny though, FVD claims they are better than the factory ones but I guess not.

sdg1871 Sep 22, 2016 08:06 PM


Originally Posted by wrs
Don't know why they cracked. FVD won't warranty them because they claim there are scrapes on them and there are but they aren't the reason for the crack. I backed up over a parking stop and scraped it. That's fine if they want to pretend that is why they won't replace it but that's not the reason. More likely because they didn't have a good weld and it failed under stress. I have had the car out at the track three times with those headers and it's gone to the drag strip several times on them as well.

Anyway, there is another thread about how FVD headers or maybe it's unequal length headers cause power loss. They sound good but the question on the power is based on one guy's car, not mine. I have no comparison of before and after. I am putting the factory manifolds back on because I don't want an exhaust leak and I want to see how they do with the cat bypass pipes. If it runs good and sounds good I will likely just leave it alone. Headers do have ground clearance issues.

Here are the pictures the Porsche dealership took for me.

So sorry. Yes on my car the dyno showed power loss from the FVD headers at least when running the GIAC tune. It was a shame as I had bought them and was hoping for gains. I ended up putting the stock headers back on

Your car has not gone as fast as I would've expected it to go in the quarter-mile. Maybe getting rid of these FVD headers will help your times. I believe they will.

wrs Sep 23, 2016 05:44 AM


Originally Posted by sdg1871 (Post 4563453)

Your car has not gone as fast as I would've expected it to go in the quarter-mile. Maybe getting rid of these FVD headers will help your times. I believe they will.

I think the bigger issue is taking the cats off. Right now there isn't much of a leak but it will get worse with time so I am getting ahead of the problem. I can also have the broken header re-welded and put them back on to see how it goes. I am hoping for .2s improvement due to de-catting, i.e. 10.3-10.4.

sdg1871 Sep 23, 2016 06:53 AM


Originally Posted by wrs
I think the bigger issue is taking the cats off. Right now there isn't much of a leak but it will get worse with time so I am getting ahead of the problem. I can also have the broken header re-welded and put them back on to see how it goes. I am hoping for .2s improvement due to de-catting, i.e. 10.3-10.4.

John Morgan has turned high 10.3s with a Cobb custom race tune, stock headers and high flow cats (Europipe). There is no reason why On a prepped dragstrip you shouldn't be turning 10.3 with the cats off and stock headers. I've always thought that something was slowing down your car from its potential. I do think going back to stock headers and using a catless exhaust will get you there


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