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11 sec club
04 Cayenne TT
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1,486 Posts
Discussion Starter #1
I'm installing a Maddad header this weekend and it's the one that comes with the 3-bolt flange at the header-to-uppipe. I'm currently running a Borla and stock uppipe (catless 06). I plan on taking some pics of the two "systems" but was going to see if there is anything else you all wanted me to measure. I'll be measuring the primary tube dia at the head, dia at the flanges, and length of the tubing for each cyl. Anything else?

I did go with Polydyn coating since they are local to Houston. I don't think it's quite as good as say, Jet Hot 2000, but it'll help some and was cheaper (get what you pay for). I only did the outside of the header and uppipe. The borla is heat wrapped. So when you see the pics of the Maddad, it won't be as they actually come if you buy them new (they are nice and shiny).
 

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11 sec club
04 Cayenne TT
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1,486 Posts
Discussion Starter #2
A couple of quick notes:
Maddad uppipe: inlet ~56mm dia, outlet ~51mm dia, 14" length
Stock uppipe: in ~43mm dia, out ~42mm dia, 14" length

Maddad header tubing size: inlets ~38.5mm, collector outlet: ~55.5mm dia
Borla header: in ~44mm, col out: ~54mm
Thing to note: the stock lower uppipe gasket is 51mm dia. Since the Maddad is a 3-bolt flange there it came with its own gasket. I took pics of the stock gasket where it interfaced in between the Borla and the stock uppipe and it's in sad shape. So are the stock Suby gaskets where the header bolts to the heads. Pics coming.

Also notice that the outlet of the Borla is 54mm, Stock gasket is 51mm, and the stock uppipe inlet is 43mm. Just a slight mismatch... I knew this all along when I put the header on it but after the nice smooth transition with the Maddad product I'm sure it will make a difference.

Notes on install: The studs Maddad sends are all the same length. After looking it over, I put two shorter stock ones off the stock uppipe on the rear where the DP side is. I just didn't think the bellmouth would clear the londer studs. I also had to loosen the slip-on joints that connect the driver's side primary pipes to each other as the head studs didn't line up right. It was barely noticeable but needed it. I also had to use the handle of a hammer to give the turbo flange a couple of taps to get the studs started to mount it (FP Green). But there are no chassis or oil filter interference issues.
 

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Premium Member
2004 FXTi
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764 Posts
I worry about decreased spool with headers, particularly headers used with a larger diameter up-pipe. I've been thinking about getting a header that uses the stock up-pipe.

I'll look forward to hearing how your spool changes. Do you datalog?

Regards,
Justin Wade
2004 FXTi
 

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513 Posts
I installed a Mad Dad last week (with a VF39). Spool is about 300-400 later than with a Stage 2 FXT. But it comes on SO much harder.

As for the studs on the upipe interfering with the downpipe, I had a ***** trying to figure out what to do with those. I just ended up using stock bolts in those areas.
 

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11 sec club
04 Cayenne TT
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1,486 Posts
Discussion Starter #5
I worry about decreased spool with headers, particularly headers used with a larger diameter up-pipe. I've been thinking about getting a header that uses the stock up-pipe.

I'll look forward to hearing how your spool changes. Do you datalog?

Regards,
Justin Wade
2004 FXTi
Well with the FP Green, it's not the quickest spooling turbo out there to begin with but I'll be sure to share that. From what I understand, the previous Maddad uppipe was bigger. But there is a venturi of sorts welded inside the uppipe. I have no way of accurately measuring it, but it does neck down through that section.
I don't data log - the tuner does on the dyno when it's getting Protuned. I just look at the wideband at the track.
 

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I think they said for version two, the uppipe was 45 mm (down from 48), so that much be the next down section. They advertised a velocity stack IIRC, but there is none.
 

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11 sec club
04 Cayenne TT
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1,486 Posts
Discussion Starter #7
Well I had one problem with fitment and that is the plastic undertray. The small square door that is on the front passenger side will not close. In fact, it melted part of what it snaps to off. I went ahead and trimmed a little off of that area and it seems fine now. Initial driving impressions: spools about 200 rpm faster than with the Borla & stock uppipe I had before. From a 2nd gear punch it pulls hard at 3800 rpm and from a 4th gear punch it's around 3400 now. Tone is a bit deeper in the exhaust and it seems to idle a bit smoother. My a/f is still around 11.3 on the wideband so th current tune is still OK but I plan on a dyno visit to make sure it's OK everywhere. So far so good.
 

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11 sec club
04 Cayenne TT
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1,486 Posts
Discussion Starter #8
Some pics:
You can see the leaks from the Borla setup. Some I could really only hear when it was cold. I'm thinking they either sealed or got smaller with the metal expanding when hot. The header to uppipe gasket was about to go out (mostly was) again. The O2 sensor at the bottom is only on one primary tube rather than the collector on the Borla. Oil filer clearance is tighter than the Borla as well. EGT bung came with the header. Uppipe bung was welded shut prior to coating.
 

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