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Old 06-11-2006, 05:00 PM   #1
chrisarella
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Default Bosal DP installed and feels like less power. :huh: ??

I just installed my Bosal downpipe with the divorced wastegate tube yesterday. Everything is torqued pretty good. I used OEM gaskets and the Helix DP resistor mod. I didn't have time to install my gutted UP so I left it all bolted up and didn't touch the uppipe/turbo bolts at all. No CELs yet and I've gone 200 miles since. The only hitch was that I broke one of the spring bolts that attached the cat to the midpipe and left it off (the part store was closed). How bad could that possibly effect it. I'd assume it would just sound slightly louder. No big deal right?

Anyway, as soon as I started the car and stepped on the throttle I could hear the turbo spooling noticeably louder. Bonus. What I didn't expect was that my butt dyno told me there wasn't any improvement. So I chalked it up to not reseting the ECU. Fine. I woke up this morning and did just that. I did the Vishnu reset and took her out for a spin. No better. I checked everything and it's all tight. Pulled the battery cable for (15+) 17 minutes to reset the ECU again incase it didn't take and went out for another spin. Still no change. I thought maybe the ECU had to relearn tne new mod but I figured I'd atleast notice some better throttle response or something.

Hmmmm.

Current mods:
K&M Panel filter
Standard Turbo XS axleback
No engine management.

Any help is appreciated, especially from someone who has or knows someone who has experienced this and fixed it.
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Old 06-11-2006, 05:12 PM   #2
JRSCCivic98
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Are you absolutely sure there's no interfearence between the downpipe devider and the wastegate flapper?
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Old 06-11-2006, 05:41 PM   #3
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you dont need the CEL fix for the bosal DP since the cat the O2 sensor is in stays...maybe that could be it?
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Old 06-11-2006, 05:53 PM   #4
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Quote:
Originally Posted by o2sys
you dont need the CEL fix for the bosal DP since the cat the O2 sensor is in stays...maybe that could be it?
I'm not familiar with the bosal DP, but many downpipes have a 02 bung and still require a CEL fix after awhile.

My MRT catted, single tip turbo back exhaust didn't throw a CEL for a few thousand miles until it got hot out and then it finally through a CEL when I was doing 80mph over steaming asphault.

The answer, use a 18mm Help! brand spark plug antifouler and screw the 02 sensor into it and then screw that into the downpipe. It pushes the sensor further out so it doesn't read that so much air is flowing nor does it read how hot the air actually is. It costs ~$5 for 2 antifoulers, one should be drilled to 1/2inch with a drill press, and it takes 10 minutes to install and have no worries.

I had a thread that went into details pretty extensively, do a search if interested.


Original poster;
Maybe as someone mentioned something is blocked by the turbo exhaust side/wastegate - or your butt dyno is just broken.

You already saw a large part of your gains with the catback/axleback. Do you still have the stock midpipe or...? If thats the case then the midpipe will be robbing a lot of your gains because the air gets to be free flowing and then gets pushed and constricted in a tiny stock pipe. Otherwise your butt dyno is just broken and you made most of your gains already with the catback. I did catless helix flex uppipe, 3inch high flow catted mrt turboback exhaust - replacing my blitz nur spec exhaust - and I still saw big gains and it felt like an entirely new car.
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Old 06-11-2006, 10:53 PM   #5
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y did u go divorced and not get the helix or ebay dp for a lot cheaper?? the bosal is only 1 cat delete correct?

that divorce part aint gunna do jack man... just sell it and get a full 2 cat delete downpipe for $100 (ebay) or spend a lil extra and get a helix

bellmouth > any dp design unless your external
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Old 06-11-2006, 11:46 PM   #6
totalburnout
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Quote:
Originally Posted by kcook
y did u go divorced and not get the helix or ebay dp for a lot cheaper?? the bosal is only 1 cat delete correct?

that divorce part aint gunna do jack man... just sell it and get a full 2 cat delete downpipe for $100 (ebay) or spend a lil extra and get a helix

bellmouth > any dp design unless your external
uh...

Divorced wastegate > bellmouth.

Divorced wastegate has less turbulence since it keeps wastegate gas and exhaust gas seperate - rathing than causing turbulence and having them smack right into one another.

I have a bellmouth pipe and I understand why the divorced wastegate pipe is generally considered superior.

Also, $100 ebay pipe may not be of the quality that he wants - also he might want to maintain cats. In which case, he should go 3inches all the way back with high flow cats. Getting rid of the highly restrictive cat in the midpipe is a must if he hasn't already.
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Old 06-12-2006, 12:12 AM   #7
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w/e .. lol i had an ebay dp (my first mod) and the gains were just as much as any. i dont have to worry about turbulence anyway so i dont really care , i was just tryin to help the fella out
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Old 06-12-2006, 12:14 AM   #8
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get a tune and you'll tell the difference
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Old 06-12-2006, 12:25 AM   #9
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I would say, that not very much could be wrong other than perhaps the car needs more than 200 miles... It shouldn't, but I mean you in theory could run with no turbo back exhaust at all and that shouldn't cause a problem other than maybe a rough idle and some terrible spiking. In otherwords, having a leak after the turbo shouldnt do much of anything other than be louder. What does your boost gauge tell you? What boost are you running at and do you have a boost controller? If you are running at stock boost than power should come on sooner but running X psi on a given turbo of Y volume gives you Z hp even if its easier for it to have X psi. A tune would certainly give you some more power and allow you to get the most of the mod but you do have a pre-04 ecu.
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Old 06-12-2006, 12:57 AM   #10
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....smoother power delivery can 'feel' slower.

and the Bosal dp is a proven, quality, part
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Old 06-12-2006, 01:16 AM   #11
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Quote:
Originally Posted by theicewall
I would say, that not very much could be wrong other than perhaps the car needs more than 200 miles... It shouldn't, but I mean you in theory could run with no turbo back exhaust at all and that shouldn't cause a problem other than maybe a rough idle and some terrible spiking. In otherwords, having a leak after the turbo shouldnt do much of anything other than be louder. What does your boost gauge tell you? What boost are you running at and do you have a boost controller? If you are running at stock boost than power should come on sooner but running X psi on a given turbo of Y volume gives you Z hp even if its easier for it to have X psi. A tune would certainly give you some more power and allow you to get the most of the mod but you do have a pre-04 ecu.
The real problem would be if the wastegate was blocked. We know that its a divorced wastegate bosal pipe - so its not like the exhaust just has a metal plate block the wastegate side off that would hurt performance but if there's a problem at the turbo to downpipe...thats where major problems would occur.

I'm going to go with so long as they torque the bolts properly and used oem gaskets, that his butt dyno is broken or that he retained the stock 3 cat and thats acting highly restrictive and now accentuating the gains of the aftermarket downpipe.
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Old 06-12-2006, 01:17 AM   #12
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Quote:
Originally Posted by anthonyrb98
get a tune and you'll tell the difference
***get engine management, then get a tune.
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Old 06-12-2006, 04:28 PM   #13
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UPDATE: I have noticed what feels like a loss of power in the bottom end, but might have picked up a little in the top (above 5000 RPM). Who knows, my butt dyno might be broken, but I'm definately not getting the same bottom end power that I was. Yes, the power is smoother, but it seams to struggle getting above 4000 rpm. Once I hit 4k, it starts to come on better. This is obviously not ideal for a daily driver. So far I have about 50 more miles since the last reset. Maybe I'll feel the HP love this week when I've gone another 400 miles or so. Hopefully the ECU will work it out soon before I have to spend the money on engine management, but I planned on doing this anyway.
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Old 06-12-2006, 04:56 PM   #14
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Question

Did you buy the full bosal downpipe, or just 1/2 of it?

Chris
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Old 06-12-2006, 05:07 PM   #15
totalburnout
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Quote:
Originally Posted by GNV Motorsports
Did you buy the full bosal downpipe, or just 1/2 of it?

Chris
GNV Motorsports
w3rd.

We need this answered for the third time its been asked...

...and 50 miles isn't sufficient.

Your butt dyno is the sux.
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Old 06-12-2006, 05:59 PM   #16
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I'll try to answer as many of these as I can so everone knows.

Why did I go with a shorty divorced DP and not a full bellmouth DP? Because I read good reviews about it smoothing out the RPM range because of the decreased turbulence... and care a little about the environment I leave behind for my kids. I'm not running out and buying into the hydrogen lie, but I won't go totally catless on a car I drive 23k miles a year either.

^^^ Sorry totalburnout, but I thought the shorty was the only one Bosal made. I did a search and still couldn't find any other versions sold for the WRX or STI. And I thought the other piece was the Third Cat Eliminator or a Race Pipe. It isn't sold with the DP. And you are right, I bought the Bosal because it was a quality piece, unlike the eBay DPs. Sure they work, but I wanted to keep the 3rd cat.

I may be getting a custom hi-flo 300 cell cat installed in August.

Bosal only makes a divorced wastegate version and no bellmouth.

There isn't an o2 bung, only the one in the the cat after the DP.

I can't change this setup and go 3" from the turbo back because I am already committed to what I have spent my money on unless someone wants to trade me for a quiet(ish) catback with a divorced wastegate and 1 cat still in the system.

I doubt the resistor is the problem, and incase some of you haven't heard, the mechanical fix will throw a CEL after a few thousand miles when the ECU has had time to figure out that the DP cat is missing. I was told by the dealer that the ECU uses readings from the manifold sensor and compares them to the 3rd cat sensor. Eventually it will detect a cat inefficiency and throw a code. The resistor should send consistent good signals so no CEL. That's why I got it. I'm not making any of this up.

I don't think the wategate was blocked but I didn't actually check it either. Maybe. But this was a used DP that someone else had successful gains with. Wouldn't he have had the same problem with his td04? Just for aguements sake, wouldn't a blocked wastegate as the underlying issue be negated since the HKS DP has a plate there anyway.

Again, there is definately less low-end power and not my imagination. I've driven my car for almost 70k miles and I know how it drives. My butt dyno can feel when it needs 1/2 a qt of oil. Right now 0-60 is much slower and it struggles on hills below 3500 RPMs. I live on Long Island so I'm not talking about Rocky Mountain hills either.

Discuss.
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Old 06-12-2006, 06:03 PM   #17
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Ah, so you bought the first half, correct? Check here for which you bought.

EDIT: Let me rephrase that. Your 1st half of the bosal downpipe should definitely help, as you have eliminated a restrictive catalytic converter and increased piping size. It may seem like less power due to the increased smoothness of spool-up, but, your power should not have decreased. Try resetting your ECU (disconnect battery and hold brake down for 10 seconds). However, you still have bottle necks in the rest of your DP and your midpipe. To get full use of your exhaust setup, you need to address those issues.

Chris
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Last edited by GNV Motorsports; 06-12-2006 at 06:14 PM.
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Old 06-12-2006, 06:34 PM   #18
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^^^ Thanks Chris. Yes, I have the divorced 1st pipe with the 2nd factory catalytic converter and not the "Bosal catless secondary pipe" as stated on that page.
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Old 06-12-2006, 07:06 PM   #19
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...and that price is WAY-WAY outa line fer a Bosal dp
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Old 06-12-2006, 07:15 PM   #20
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Quote:
Originally Posted by Uncle Scotty
...and that price is WAY-WAY outa line fer a Bosal dp
Ours? $345 shipped for the full downpipe, $235 shipped for first half, and $140 shipped for the second half? That seems right about where everyone else charges

Chris
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Old 06-12-2006, 08:10 PM   #21
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Quote:
Originally Posted by GNV Motorsports
Ours? $345 shipped for the full downpipe, $235 shipped for first half, and $140 shipped for the second half? That seems right about where everyone else charges

Chris
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My appologies, Chris.....that price is confusing....that is a great price for the whole thing....BOTH pieces......I saw that and thought it was for JUST the dp.

I hope others don't make the same mistake
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Old 06-12-2006, 08:21 PM   #22
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Quote:
Originally Posted by Uncle Scotty
My appologies, Chris.....that price is confusing....that is a great price for the whole thing....BOTH pieces......I saw that and thought it was for JUST the dp.

I hope others don't make the same mistake
Hmm, I may have to look at that then. I figured I'd make the whole thing the first price you see, and then you can split it up from there. But, if it is confusing, and may draw customers away, I may have to change it. Thanks for your input

Chris
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Old 06-12-2006, 10:21 PM   #23
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Quote:
Originally Posted by GNV Motorsports
Hmm, I may have to look at that then. I figured I'd make the whole thing the first price you see, and then you can split it up from there. But, if it is confusing, and may draw customers away, I may have to change it. Thanks for your input

Chris
GNV Motorsports

My pleasure.....and it is always a good thing to have a vendor that come to the tech forums and give advice and info on products.

The Bosal is a good piece and having a seperate 'last cat' delete pipe is a great option for some.
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Old 06-12-2006, 11:24 PM   #24
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Hey Chris,

Sorry to hear you're having problems with your Bosal. I think I met you a couple of time at Stop and Shop an Exxon, I'm the guy with the silver wagon with the Bosal DP and Bosal dual tip cat back.
Did you do the install yourself? Metric did mine and they needed to trim the divider a tiny bit to make sure it didn't interfere with my wastegate. Maybe that is the problem with yours?
Let me know if I can be of any help in any way!

Happy driving,

Eric
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Old 06-12-2006, 11:47 PM   #25
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Your 02 bung that you say you don't have, is the spot where the 02 sensor is plugged into.

A mechanical cel fix will not cause your car to throw a CEL after a few thousand miles - your dealer fed you a line of crap because they didn't know what they were talking about. Thats understandable, they're a factory shop and do factory replacement and factory aftermarket parts not custom modification. Don't go to them for info on custom modifications because more than likely, unless they're into modding themselves and into the community, then they won't know the ins and outs.

Mechanical CEL fix will push the 02 sensor further away so the exhaust gas volume isn't read as so great and the temperature isn't read as high either. It puts it back within the threshold its supposed to be within, so as a result no cel. Thats why mechanical fix = cel fix.

The 3rd cat is highly, highly restrictive. Get a high flow cat if you're worried about the environment or go catless for the shorty pipe/midpipe/whatever other name its going to be called on here because you already have a single cat in the downpipe.

Personally I'm on a very quiet MRT racing turboback exhaust that has 2 high flow cats and its 3 inches all the way back. About the quietest aftermarket exhaust you can buy, if not THE quietest.

As the last person suggested, make sure that the divorced part of the pipe is not in the way of the turbo. The turbo may just be millimeters off from the previous owners and/or may have been torqued on slightly off center - tightening one side all the way down rather than tightening both sides evenly and repeating. You never know.

Basically if everything went correctly then your BUTT DYNO IS BROKEN because you certainly didn't lose power. If something is malfunctioning then perhaps thats the cause of little gains.

No higher flowing pipe after the turboback, is going to cause a decrease in performance, a huge uppipe or headers that are before the turbo would create an issue with spool up but not a downpipe since its post turbo.

Fyi, I was talking about bellmouth versus divorced wastegate because someone provided some shoddy information. Divorced wastegate is generally viewed as the most superior design out there for a turbo because it creates less turbulence. A bellmouth has the wastegate and exhaust side of the turbo just run into each other and create a sort of turbulence, but thats better than blocking the wastegate off like the HKS p.o.s.

Basically if you want to take advantage of that downpipe you need to make sure that its not messing with the wastegate (because this is fairly common and shaving the divorced wastegate section of the pipe is the remedy) and that you have a midpipe and catback that are equally as high flowing or else your exhaust gases are just going to hit a restriction further down the line, which kind of defeats the purpose - now doesn't it?
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