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Old 07-16-2002, 08:36 PM   #1
'99 RS Drifter
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Default New exhaust system for my RS

Just finished installing my new exhaust system for my '99 RS, first I'll detail my mods:
Rebuilt engine with high compression pistons, new camshafts, fully ported head, multi-angle valve job. This was just recently installed complete with an ACT clutch, I followed the instructions on break-in and ran the car with the stock exhaust system. I was warned that it would seriously choke off the power at high rpm's as the engine would breath much better then the exhaust would allow. But finances were not ready for the whole exhaust until now. Initial impression of the new engine is wow, does it have grunt, throttle response is amazing. Little lump to the idle, very minor but just enough for someone with knowledge to know its not stock. Very impressed.
Then I got the exhaust installed, holy crap. This car is in serious need of its rev limiter bumped up, way up. Pulls so hard so fast it hits the limiter before you know it, major improvement everywhere. And the best part is the sound, man does it sound good, deep and mean.
Its easily WRX fast, no lag just pulls everywhere, I am so pumped Im going out looking for some WRX's to spank.
Here's the real cool part, the exhaust is warrentied for life, I've never seen much talk about it but I think most those that have the system don't want other to find out lol, I don't care I just blown away, best money I spent yet on this car.
Check them out at their website, TWE
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Old 07-16-2002, 09:04 PM   #2
Poppa smurf
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interesting but how much does that intrest cost?
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Old 07-16-2002, 09:21 PM   #3
Reciprocity
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Very interesting cam specs there too...hmmm.

NC
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Old 07-16-2002, 09:33 PM   #4
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oohhh! new parts would you be able to post any sound clips. I'm sure everyone would like to hear them.


dcrawford: explain interesting as i know nothing
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Old 07-16-2002, 09:42 PM   #5
Reciprocity
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Interesting because the duration was only SLIGHTLY more but lift was increased quite a bit over stock vs Cobb with a lot more duration.

I only know enough to say it's interesting...but that's all I know! I'll contact my expert.

NC
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Old 07-16-2002, 11:11 PM   #6
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Wow, those headers and that intake really have me interested. Do you know if the headers bolt up to the stock cat? And are you running their air intake system? Looks interesting, no price for the intake though.
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Old 07-16-2002, 11:47 PM   #7
'99 RS Drifter
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No but I think that will be my next step, that carbonfibre intake sure looks awesome. No idea on price, odd it isnt listed.
The exhaust is a 3 part bolt on. They told me it would fit all pieces to the stock units, so you could have just the cat back, or just the cat or just the header(why though?
I think you need to let them know so it will have the correct flange, not totally sure, I got the whole system.
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Old 07-17-2002, 01:04 AM   #8
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That's a pretty slick header- it's the first one I've seen that mentions the use of a merge collector (which isn't cheap or easy.) It's funny that their header theory info is lifted directly from the Burns Stainless website. Definitely looks like they know what they're doing. Thanks for the heads up.
Jerome
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Old 07-17-2002, 01:22 AM   #9
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That's a pretty slick header- it's the first one I've seen that mentions the use of a merge collector (which isn't cheap or easy.) It's funny that their header theory info is lifted directly from the Burns Stainless website. Definitely looks like they know what they're doing. Thanks for the heads up.
Jerome
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Old 07-17-2002, 01:22 PM   #10
RawCode
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Man that is the best header design I have seen yet, that uses that stock location. Very interesting,

So who here is going to be the first to buy it?

RawCode
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Old 07-17-2002, 01:24 PM   #11
cRayZee
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would be nice to see a dyno chart of your car and see what kind of power the higher compression pistons and all the other work you've done

-vic
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Old 07-17-2002, 01:25 PM   #12
Reciprocity
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I wonder how that intake hooks up...I can see the replacement scoop, but what about that other bit? Hmmm...

NC
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Old 07-17-2002, 04:35 PM   #13
'99 RS Drifter
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Well small problem just cropped up, driving it today I am amazed at how the ECU adapts, took a bit but it seemed to have relearned what it needed to for this exhaust.(after I reset the ECU) Anyhow here is my problem, the transmission was rebuilt under warrently over a year ago(warrently is over now, typical) I was driving today and shifted to second, not hard or anything just casual then I floored it, it pulled hard and went bang, clunk clunk clunk. Tow truck is taking it to the dealer, I hope its just the shift fork...
I am going to get it done right, this car has some serious balls, had a run with an Audi S4 biturbo, dead even to over 100mph yesterday. I can't wait till the transmission is fixed, hoot.
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Old 07-17-2002, 05:09 PM   #14
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hrm...interesting company..and theyre Canadian based!
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Old 07-17-2002, 07:00 PM   #15
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Any clue what their "ram air" intake costs? Not really an intake, but rather a replacement for one of the hood vents

Scott
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Old 07-18-2002, 01:25 AM   #16
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Thumbs up

wow, that twe site is sweet!

also, 99rsdrifter, you have a sweet setup.
I have one request, can you post a pic of the exhaust from the back of the car? I just want to see what the muffler looks like when it is installed.

thanks
-aaron
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Old 07-18-2002, 08:59 AM   #17
MY99 2.5GT
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Wow great link!



From the looks of it this header set would work best with a raised redline and cams specced to make power up high. This looks to be as close to a 4 to 1 Header that a Subaru engine will ever see. In the Honda and V8 world a 4 to 1 header can't be beat for making top end power. They do however give up a little bit of low end power gain when compared to a normal 4-2-1 header design. Personally I think our engines make plenty of good low end power to get you off the line but they really need better ability to use those higher revs.

Everything looks really good except for that muffler. It looks to be a dual chamber and like the restrictive one that comes with the MRT setup. If I were buying this setup I would probably buy everything but the muffler section of the cat back. Buy a straight through design that doesn't inhibit flow at all.

This looks like the ultimate exhaust for making top end power. That is if the bends don't cause too much restriction.

By the way a 2840lb RS needs only 200hp to be at the same power to weight ratio as a 3593lb 250hp audi S4. Technically you should have blown the S4 away because with all of the work you have done to your engine you should be well above the 200hp mark. I bet if you creaped the rev limiter up to 7800-8000 you would pull away from an S4 fairly easily. Did you get stiffer valve springs and stonger valves when you rebuilt the top end?

Brad
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Old 07-18-2002, 09:29 AM   #18
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jerome02rs - Merge Collectors are common to most Subaru exhaust and most exhaust systems in general.

MRT has Merge Collectors where the primaries collect and where the secondaries collect into the cat section.
Attached Images
File Type: jpg mrtequal length.jpg (38.9 KB, 1109 views)
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Old 07-18-2002, 09:31 AM   #19
MY99 2.5GT
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Borlas have a similar Merge Collector design
Attached Images
File Type: jpg borla real.jpg (42.3 KB, 1104 views)
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Old 07-18-2002, 09:39 AM   #20
MY99 2.5GT
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Infact Brullen is the only header design that doesn't really take advantage of the smooth flowing merge collector design for both primary collections and the secondary collection. As you can see the driver side primaries don't even collect before abruptly meeting the secondaries of the properly collected passenger side piping at a very strange angle. There haven't been any back to back dyno runs comparing the Brullen's to any other exhaust so my critisizm must be postponed. However I have shown this design to a few experienced exhaust techs and they just kind of shook their heads and began explaining why this header design just isn't good.

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Old 07-18-2002, 11:37 AM   #21
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MY99 2.5GT - well, here are some pics of the iON/Brullen equal-length header set-up. If you note, the way the primaries are brought together, there is a very shallow angle of attack, and hence flow is still kept smooth. It'll definately be interesting to see the dyno run when you and Ken get together to do them. Both of you will probably need to unbolt the muffler sections as IIRC your section is 2.5" which will definately help up the top end. Then at least both mid-pipes will be similar to the original set-up.



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Old 07-18-2002, 11:56 AM   #22
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zoiks!

why do i have a sudden urge to drop a built 2.5L into my car, instead of going the JDM route? all i'd have to do then is figure out how to get the power to the ground in an efficient manner, and i'd have a DAMN fast n/a impreza...hmmm...
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Old 07-18-2002, 01:00 PM   #23
'99 RS Drifter
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When I raced the S4 it was 33 degrees C out and I'm at 3700 ft altitude(about 12% less hp then sea level) The turboed S4 doesnt get the same hp loss at altitude so I think that's pretty damn good. Another thing to remember is the hp rating on that S4 is on the low side.
I am told that this engine will safely rev to 9000 rpm's, a chip is being worked on that will allow the car to rev higher to take advantage of the engine design and the exhaust system.
The car has ti retainers and aftermarket springs.
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Old 07-18-2002, 01:57 PM   #24
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dude, contact JoeT, or go to www.toronto-subaru-club.com to find out about the guy that re-programs stock Subaru ECU's to your engine's specs (ie: higher rev limiter, etc...)

I assume youre from Canada? Might be a good way to go
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Old 07-18-2002, 02:01 PM   #25
techworkseng
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Default merge collectors what they are and aren't

There seems to be some misconceptions about what defines a collector as a merge collector. Borla and MRT are definitely not merge collector designs. These header collectors (and 90% of the headers mass produced) terminate the header primaries abruptly. The transition of primaries into collector outlet is achieved by forming or welding a preformed stamped piece of sheet metal over the four ( in the case of a 4-1) straight primary tubes and the outlet pipe. This creates a very sudden area transition which in turn creates a sudden scavenge pulse with short duration. This also creates a higher probability of inducing a shock wave (exceeding local acoustic velocity) which will destroy the scavenging pulse as it will be converted to heat energy instead.
A merge collector use four pipes (4-1) that are sliced and "merged" together to form the collector instead of formed sheet metal. When the pipes are joined in this manner the primaries area ratio makes a much more gradual transition which results in a stronger, longer duration wave inversion (scavenging pulse). This means the scavenging occurs over a greater rpm range. Merge collectors are easily identified by the pyramid shaped projection visible when looking into the collector end of the header.
I hope this has been helpful.

Tom Penner
Head of R&D\
Tech Works Engineering
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