[daddysscp]

Originally Posted by GraphicSTI

Ordered...Thanks.

M. Scott Stenner

Scott,

Got it - will be out the door Monday. I was in slow mo mode today and missed it with today's pick

Rich

[torqueflight]

I'm in the market for a DP. Hoping to go stage 2. I just had a few questions that I cant seem to find the answer to.

If there a difference between the divorced and the bell mouth? Torque?

My goals are, high torque, peak torque at lower rpms and fastest boost response possible (stock turbo MY07).

The Metal V2 one piece catted really has my attention, but I want to make sure it will fit my goals.

BTW I gotta ask even know you already said it (I just want to be sure). The V2 one piece catted only has one cat at the top right? The bottom shield is just a shield, and no cat?

Thanks,
Matt

[Digitalfiend]

Originally Posted by torqueflight

I'm in the market for a DP. Hoping to go stage 2. I just had a few questions that I cant seem to find the answer to.

If there a difference between the divorced and the bell mouth? Torque?

With a divorced wastegate setup, the wastegate gasses have their own immediate path to exit the turbo and don't rejoin the main exhaust for about a foot or so. This allows the wastegate to work exceptionally well because there is less backpressure; i.e. a divorced wastegate can really help with boost creep.

A bellmouth setup allows the wastegate gasses to exit more freely than the stock unit, but the exhaust gasses join much sooner, about an inch or two after the turbo. This can lead to more backpressure/turbulence.

Both methods are MUCH better than the stock DP setup. As for which one is better overall, I prefer the divorced wastegate setup and haven't had any boost creep. I'm not sure there is a big difference, power-gain wise, between the two...at least not on a VF39. Technically a divorced wastegate downpipe should flow better in general.

Originally Posted by torqueflight

My goals are, high torque, peak torque at lower rpms and fastest boost response possible (stock turbo MY07).

The Metal V2 one piece catted really has my attention, but I want to make sure it will fit my goals.

BTW I gotta ask even know you already said it (I just want to be sure). The V2 one piece catted only has one cat at the top right? The bottom shield is just a shield, and no cat?

A downpipe will help you spool faster but, if you are looking for throttle response, you will likely also want to consider picking up a GM/Prodrive boost control solenoid and a more responsive BPV. I recently got a ride in a prepped WRX race car that had some JDM BPV (looked like a stock STi unit but wasn't...it was rated for 25psi). Apparently, that thing, between shifts, opens and shuts VERY quickly, so there isn't a large pressure drop between shifts, resulting in better response. TGV deletes might also help give you more airflow. With the VF43 you might even be able to run a stiffer wastegate spring which would improve spool up too. As long as the wastegate hole can get rid of the excess exhaust fast enough.

You will probably also want to consider a lighter flywheel and possibly a light carbonfibre driveshaft. This should help to improve throttle response quite noticeably.

[torqueflight]

Thanks ^^^^^^. I just cant stand how un responsive my car is (stock 07). Going from my SRT4 to this is night and day. Before I even got my foot to the floor in the SRT in was pretty much full boost, and in the STI, it doesn't matter if I'm a 5k and I punch it, it still takes a few seconds to go to full boost, which is just insane. It just enhances how bad the DBW feels.

Thanks,
Matt

[ReleaseDaKraken]

daddysscp, you got pm.

[seattleswimboy]

Hello,<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
<o></o>
I am pretty much sold on the Stromung / MadDad™ Secondary Cat(F3) system and I plan on ordering it some time next week. I just had one question about the cat that is used.<o></o>
Can you please tell me what the “Cell” ratting is on the The MadDad secondary hi-flow cat pipe is?
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Thank you,
<o> </o>
Evan

[seattleswimboy]

I forgot to ask!
Do you have anymore coated Stromung DP's in stock?

Thanks

[daddysscp]

Sorry for the late replies. It's funny, I'm not subscribed to my own thread

Various questions answered...

Our metal substrate cat is a 300 cell. Keep in mind it's metal substrate and they flow better than ceramics. If I was comparing I'd compare it with a 200 cell ceramic....only it will last a hell of a lot longer. I've heard many many stories of guys that have bought downpipes that had a ceramic based generic hi-flow cat and the cat falls apart after 12,000 miles or so. Our latest 300 cell metal substrate is warrantied for 50,000. Our existing 300 cell in every V2 one-piece has never had an issue and we've never had to replace a cat under warranty(that's a small lie, we replaced one brand new one that had a loose cat inside the shell...one in 3 years).

As far as V2 One-Piece Divorced vs. the upcomging Catted Bellmouth that's a tough call really. I'd base it on your model year. The V2 was a purpose built piece to help minimize boost creep that was quite apparent when the 04 STi hit the market. The V2 as the name applies evolved so it could flow better but still keep creep in check which is why it has a catless wastegate tube - no back pressure on the wastegate gases so they can blow off fast and complete plus a tinge of back pressure with the cat up high = minimized boost creep piece of mind while still delivering the goods in hp/torque.

07 STis from what I've seen are less prone(doesn't mean it doesn't exist) to the creep than the 04-05s. Different turbo and slight change to the wastegate make it better in this respect. The only MadDad catted bellmouth on a car right now is actually on an 07 STi. Dyno #'s look very nice(they are posted here in the Dyno Plots forum here on iwsti) and no creeping. Now keep in mind even our new bellmouth is a different beast from all the others. The overall diameter of the bellmouth is slightly smaller and the wastegate merge is much longer than any other bellmouth the market and we believe this makes for a better bellmouth(better torque). So far the dyno results are backing that up pretty well. We have a plot from an 05 STi catless that is very strong, one of the flatest torque curves I've see from OTS cobb STG II. If you have an 07 and can wait the better "value" is going to be the catted bellmouth. The V2 One-Piece is a bit more intricate to assemble and its a 100% US built piece so it's price it a bit higher. The new bellmouth is a east meets west product with the catless downpipe coming from one of our oversees partners, then shipped to our US fabricator where our US built cat is fitted to the catless pipe ensuring we have the quality we want in the cat. The downpipe itself is a very nice piece with a unique cast bellmouth, TIG welded with care, and the quality shows.

I'm out of the Stromung coated pipes right now. Waiting for Stromung to build us another batch to send to the coater. Probably about 3 weeks before I have any back in stock already coated.

R.

[valleySTI]

pm sent on v2 divorced catted downpipe shipped to 78574 07 sti

[daddysscp]

Originally Posted by valleySTI

pm sent on v2 divorced catted downpipe shipped to 78574 07 sti

Got them. Was out of the office since tuesday. PM'd you back. We've got V2's on the shelf ready to ship(for once). Even Whisper catbacks..woohoo.

Rich

[nonissan]

i emailed you yesterday.

t

[wi77iam]

Rich, you got pm.

[SCE-CHRIS]

May have read too much and confused myself, so I'll ask:

I'd like a DP without a cat in either section since I have 6 years till smog. I would like the 02 protector(fake cat)in the lower section though.

So now my questions; without cats won't I throw codes? Also, will these pieces be bolt on? And how hard to install since most muffler shops get scared around the CAT's...

Please let me know ASAP as I think I am ready to order.

TIA

[DCH]

Originally Posted by SCE-CHRIS

May have read too much and confused myself, so I'll ask:

I'd like a DP without a cat in either section since I have 6 years till smog. I would like the 02 protector(fake cat)in the lower section though.

So now my questions; without cats won't I throw codes? Also, will these pieces be bolt on? And how hard to install since most muffler shops get scared around the CAT's...

Please let me know ASAP as I think I am ready to order.

TIA

I just did the install less than a week ago, so I can tell you right now that it's a complete bolt-on installation. No bending, no custom fabricating of anything. I ordered the Metal V2 One-Piece with a single cat.

I don't know much about cats throwing codes, so I'll leave that to Rich.

It's a simple piece to install. Glad I did it myself and saved all the labor fees.

[daddysscp]

Originally Posted by SCE-CHRIS

May have read too much and confused myself, so I'll ask:

I'd like a DP without a cat in either section since I have 6 years till smog. I would like the 02 protector(fake cat)in the lower section though.

So now my questions; without cats won't I throw codes? Also, will these pieces be bolt on? And how hard to install since most muffler shops get scared around the CAT's...

Please let me know ASAP as I think I am ready to order.

TIA

If you run any of the popular engine management they will eliminate any codes(meaning you won't get the codes). If your not planning on any engine management then you can do a couple of things. Get a Stromung DP mated to a MadDad secondary cat pipe which has a repositioned 02 sensor after the metal substrate cat so it won't throw any cels and it doesn't need any fancy tricks because basically the 02 sensor is sniffing a clean exhaust stream. If your running any engine management though it's all moot. Go catless, single cat - you won't throw a cel either way.

R.