Divorced Down Pipes

[Doat]

Alright ladies and gents, school me on the different variations of down pipes. I have researched and got so many mixed opinions and "facts" etc. I want to blow my brains out. I hear and read I could get an ebay DDP and be better off instead of spending the extra $200+ on a name brand one; HOWEVER, I prefer to go with the name brands like BIC since they would fit perfectly to our cars because they are either tested thoroughly or made by people who actually own an MK3. Another thing is the wastegate pipe being recirculated or vented to the atmosphere, here is what I have gathered. Recirculated eliminates the possibility of boost creep and you can hear the turbo spool better instead of the vacuum or blowing sound of the wastegate. Vented wastegate has a chance of boost creep and may increase hp a little bit and you don't hear the turbo spool as much.

I am considering getting a DDP from BIC performance with the flex but I do want to hear the turbo whistle more than the blowing sound of the wastegate but have no idea how to re-route the wastegate pipe, at least until I look it up in a sec lol.

I just want some straight answers from you guys the Supra Mythbusters. Thanks.

 

[Insidious Surmiser]

BIC sells re-routed ones FYI... great product too, perfect fitment.

 

[Doat]

I just saw that, sheesh $500 for that and the flex section. Would be great if I could find some comparison videos.

 

[Suprajay]

If you are going to get one from BIC you better hurry and order it they are phasing their ddp out of production. They also no longer have the flex sections I tried to get mine and they no longer stock them. And be prepared for like a 2month wait. I ordered mine at the beginning of march and just got an email saying I wont be receiving it until the first week of may.

 

[Insidious Surmiser]

i got one in 2006 (or was it 05?) not re-circulated w/ no flex section. perfect fit.

 

[suprarx7nut]

I'm not sure about the boost creep being any different for reroute vs atmosphere. I'd think the ct26 would be the limiting factor before the divorced section of piping.

Rerouted is classy and quiet. Open atmosphere is LOUD. Either way I'd pay to do it right and support local folks in the community. Raptor racing, bic, etc.

Sent from my Galaxy Nexus using Tapatalk 2

 

[lithium14]

Now imagine divorced down pipe AND open DP harharhar

 

[Doat]

Yea I am going to buy a down pipe from either Raptor or BIC I've seen and held Ebay metals and it feels and sounds like plastic with metal paint and I am all for supporting locals especially if they do great work.

Lithium, you just blew my mind

 

[Grandavi]

I have Raptor.. damn good work and coated inside and out. Not too loud, but it roars on the dyno.. lol.

You must be talking jz though.. fairly certain that BIC doesn't make 7M DP's anymore.

 

[Insidious Surmiser]

was never aware that anyone made divorced dp's for 1j... in any case... open downpipe is just as loud as an open dump DDP... the contrast in noise just makes it seem louder... granted it is loud enough to make old people think that the world is ending

 

[Grandavi]

I know very little about the jz's.. just didn't think that Randy built any DP's for the 7M (CT26) anymore. (BIC)

 

[mcammarn]

So I to am curious about downpipes, buttheres 3 styles I'm looking at, dumped, recirculated, or the integrated elbow to downpipe (Is this the open downpipe?). And do all 3 have the same hp increase? Or are they different. I know from reading that recirculated is quiet, and dump is loud, but the "open downpipe" what's that like? Just normal?lol
This is the open one I'm talking about.
http://store.driftmotion.com/static/i-3inchdpwithelbow7m-gte.php

 

[57trimMKIII]

I'll be going the BIC-divorced-and-recirculated-without-a-flex-section route.

And y the looks of SupraJay's post, I hope I order one before it's too late.

 

[Insidious Surmiser]

guys referring to "open downpipe" have no exhaust on their car, with the exception of the dowpipe

divorced w/ open dump removes a lot of turbulence from the exhaust system, BIC's website quotes 29whp proven difference over standard 3" DP.... not sure if that's referring to a bellmouth or what... also could be due to creep (extra boost over another DP design)

 

[MarkIII4Me]

I must be the only one who doesn't find the open ddp all that loud. I actually like the aggressive sound it produces. It gives sort of a jet engine whistling noise at full boost. The exhaust leak at idle is a bit annoying though. It does tend to go away after the engine warms up though.

This:


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This:


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This:

[video=youtube;VGeuF48W_CI]http://www.youtube.com/watch?v=VGeuF48W_CI[/video]

 

[19supra90]

In my opinion re-routed is the way to go. I bought mine used and couldn't be any happier. I did a lot of researching on it too. Everything I read, a lot of people who got the open waste gate wanted to go with the re-routed option because it would be so loud. I daily drive mine so re-routed was the way to go for me. Mine is a BIC but I've read nothing but great reviews on raptor racing DDP also. They had a group buy when they first came out with it at raptor racing and it seemed every one of them was pleased with the quality and craftsmanship.

 

[DeMoN2318]

I must be the only one who doesn't find the open ddp all that loud. I actually like the aggressive sound it produces. It gives sort of a jet engine whistling noise at full boost. The exhaust leak at idle is a bit annoying though. It does tend to go away after the engine warms up though.

I get the same thing with my DDP. You get the cool turbo spool sound at lower RPM but when you get on it...HOLY COW...it screams!!!! I also have the boost lead sound but like you...it goes away when warm.

My BIC DDP fit perfect!!

 

[DeMoN2318]

So I to am curious about downpipes, buttheres 3 styles I'm looking at, dumped, recirculated, or the integrated elbow to downpipe (Is this the open downpipe?). And do all 3 have the same hp increase? Or are they different. I know from reading that recirculated is quiet, and dump is loud, but the "open downpipe" what's that like? Just normal?lol
This is the open one I'm talking about.
http://store.driftmotion.com/static/i-3inchdpwithelbow7m-gte.php

Integrated elbow causes quite a bit of turbulence in the elbow with reduces flow efficiency...the DDP separates the turbine exit flow from the wastegate flow so you reduce turbulence due to the two flows not mixing. I would say the 29whp BIC claims is probably pretty close...I went from an integrated elbow DP to a vented DDP and there was a noticeable different on the road.

Noise wise...the vented DDP is by far the loudest...stupidly loud at full open (BIC said it would be loud and they were right), next loudest is the recirculated DDP, and the integrated elbow will be the "quietest"...I had ZERO turbo spool sound with my integrated elbow DP but it was still a nice deep roar when you would get on it...kinda made for a sleeper when a turbo civic would pull up and think he was racing an NA...plah hahaha

 

[Rkenshin03]

I bought one of the eBay DDPs and it was too short, flange had to be machined flat, and a dividing tab had to be welded on. Ended up paying almost as much as BIC OR Raptor racing downpipe would of cost.

 

[Grandavi]

I considered the eBay DP, however,you get what you pay for. Any flange gets a lot of welding and needs to be done properly, there will always be some distortion due to the heat. Even with the Raptor DDP I had to cut the seperator off to machine the flange perfectly flat. I want no extra tension on a flange area from bolts trying to mate flanges. I also removed the flex section simply because it made it too tight to the area where the speedo cable comes in. Didn't have to, but it made a cleaner fitment. Removed my cats simply because we don't need them and they are unmonitored in mk3's (except California of course).

Almost Amy after market performance part isn't going to be a simple plug and play, but I'm very happy with my exhaust now (it's mated to a 3" hks catback with the hks twin tip muffler). Sounds great with no highway drone.