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"We are ready to take orders on the test pipes."

Streetconcepts are you calling the 2nd CAt./resonator/mid-pipe a test pipe. If so I want one of those 2nd CAt/resonator/mid-pipe "thing a ma jig!!!"

Talk about an easy job/mod it's literally 4 bolts and 2 gasket, but is there REALLY any gain for the $150?
 

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"We are ready to take orders on the test pipes."

Streetconcepts are you calling the 2nd CAt./resonator/mid-pipe a test pipe. If so I want one of those 2nd CAt/resonator/mid-pipe "thing a ma jig!!!"

Talk about an easy job/mod it's literally 4 bolts and 2 gasket, but is there REALLY any gain for the $150?
[/b]
Exactly. $150 is a bit of cash for a test pipe, but it did take some work (unlike most test pipes) to produce.

Jason
 

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I would think that the only times you would "feel" the gains would be if...

1. you have a new downpipe and a stock midpipe.... now the second cat is acting as the restriction...

If you are doing this and not the downpipe I don't think gains will be that noticeable... but combine a catless downpipe and midpipe and power is definately to be had...
 

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Discussion Starter #25
I would think that the only times you would "feel" the gains would be if...

1. you have a new downpipe and a stock midpipe.... now the second cat is acting as the restriction...

If you are doing this and not the downpipe I don't think gains will be that noticeable... but combine a catless downpipe and midpipe and power is definately to be had...
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I'd be willing to bet that the second cat is much more restrictive than the first. First off, most pre cats (including ours) are VERY short. The grid is probably no more than 3-4" in length. Second, since its so close to the turbo, it must be metal matrix instead of the ceramic type. Metal matrix cats flow very well and cause very little restriction. Thrid, the opening to the precat is huge. This means more flow.

Now, the second cat is 2-3 times as long and probably ceramic. Both of which add greatly to the restriction. I think all the gains from a downpipe will be because of the 2nd cat being gone, not the first. Hopefully Street Concepts will dyno both setups so we can see how much is gained by dropping both cats vs. one.

Hey STREET CONCEPTS: Are the flanges AND piping on your test pipe all stainless steel? Is an O2 bung welded on too? I need a spot for my AFR meter.
 

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if anyone will be buying an aftermarket downpipe, buying this unit at this point would not be worthwhile as the length of the dp is unknown at this point...

Fingers crossed we don't see boost creep issues w/ a bellmouth dp!
 

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I have an apointment tomorrow to get my last cat deleted. I did a custom 3 inch exhaust and took out one cat and tomorrow im going to delete the cat near the downpipe and run a straight pipe to connect it.
 

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I know its a completely different car... but ATP on the SRT4 got 67.4 FT LBS of torque TO THE WHEELS with a downpipe and midpipe....

Clickage
 

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I am going to keep the stock downpipe at this point since this is my daily driver, and need to pass OBDII tests - so no CEL codes can be on. Thus, I need to know if the stock O2 sensors are moved by getting the test pipe. I also would like to know if the test pipe would bolt up to a magnaflow catback. Since the magnaflow bolts up to the stock catpipe, I would think it would be fine, but I dont know if the flanges on each would mate up.

I would think that by combining the magnaflow catback, along with the test pipe would produce a pretty decent gain, probably at least 15whp - at least I hope it would - maybe more but its just speculation now.. I know getting the downpipe would free up alot more power, but that is something I am just not prepared to do on my daily driven brand new car yet.


Anyone know the answers to these questions? I PM'ed street concepts to see if they knew if it would mate up to the magnaflow. I am also one of the people that want the exhaust to go to both sides, thus I am excluding the cp-e exhaust from my questions.
 

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If you're going for sound (like yours truely), just drop the second cat completely. It's loud and I can feel a bit of a difference. It does seem to be causing a VERY SLIGHT boost spike (at least according to the Autometer guage I installed). I'm not getting too much vibration from anything inside the cabin either. Mazda's got a really solid interior. Going this route deffinately turns alot of heads, especially when you're caughing out fire-balls at night. I mostly like drowning out brand new vettes and chargers and mustangs simply by pulling up next to them at a stop light! It does tend to pi$$ those old guys off a bit. :nana:


BTW: No CEL with this!!!!!!!!!!!!
 

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The 2nd o2 sensor is before the mid pipe so that will not be an issue. $150 seems a bit high for a pipe that is maybe 12" long. Although lookng at the pictures by Street Concepts it looks to be good quality with Mandrel bends. The good thing is that there is literally only 4 bolts holding it in so if it is too loud just bolt the stock one back in.
 

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I seriously hope your car isn't coughing fireballs...that usually indicates you are running a BOV with VTA settings...and the fireball is caused by a massive rich spike, followed by a lean spike...which is bad for the engine, and especially bad for the precat sitting behind the turbo.

Btw though there isn't any O2 sensor monitoring the test pipe, its usually a good idea to wait 5k-10k before claiming a product doesn't throw a check engine light.

If you need evidence of no cel claims, please go back to 2002 and start reading all the AEM RnD and Injen threads about how their products don't throw check engine lights, and how they've been properly engineered.

You can easily be driving around with a pending code and never see it if you don't have a scanner.
 

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Is it spiking higher or is it boost creep?
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It spikes to anywhere from 19-21 psi (depending on what gear I'm in), then settles at a little under 17.

Crossbow,

I'm still using the stock blow off valve. The fireballs are actually typical of running an open downpipe stock OR catless, especially when your running with higher octane fuel as I am (~98). As far as the precat is concerned, I'm planning on moving to a catless setting shortly, again with no test pipe or mufflers.
 

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I'd be willing to bet that the second cat is much more restrictive than the first. First off, most pre cats (including ours) are VERY short. The grid is probably no more than 3-4" in length. Second, since its so close to the turbo, it must be metal matrix instead of the ceramic type. Metal matrix cats flow very well and cause very little restriction. Thrid, the opening to the precat is huge. This means more flow.

Now, the second cat is 2-3 times as long and probably ceramic. Both of which add greatly to the restriction. I think all the gains from a downpipe will be because of the 2nd cat being gone, not the first. Hopefully Street Concepts will dyno both setups so we can see how much is gained by dropping both cats vs. one.

Hey STREET CONCEPTS: Are the flanges AND piping on your test pipe all stainless steel? Is an O2 bung welded on too? I need a spot for my AFR meter.
[/b]

Yes the Flanges and piping is all polished stainless steel. Also the flanges that are used for this test pipe had to be custom made by a local cnc shop because there was no stainless flange that would work. Also there are bends in the test pipe which is where the extra cost comes from. Most cat pipe for the evo sell for around $130.00 and there just a straight peace pipe with two flanges.

Tommy
 

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It spikes to anywhere from 19-21 psi (depending on what gear I'm in), then settles at a little under 17.

Crossbow,

I'm still using the stock blow off valve. The fireballs are actually typical of running an open downpipe stock OR catless, especially when your running with higher octane fuel as I am (~98). As far as the precat is concerned, I'm planning on moving to a catless setting shortly, again with no test pipe or mufflers.
[/b]
Is it me or did you pick up some boost from this??? I haven't read of anyone seeing 21PSI yet....
 

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Is it me or did you pick up some boost from this??? I haven't read of anyone seeing 21PSI yet....
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Yes I did gain a few across the table it seems. Kinda leads me to beleive that the second cat is the major restrictor in the set up, because before I took it out it would spike close to 18 and settle at a little under 16. Same gauge, same car, same everything else; just no second cat or anything behind it. I left the mid pipe and mufflers hangin there to avoid issues with the local authorities seeing two hollow tips. I've done the air-box mod and a K&N filter, but that was before I got the gauge. I don't think that would effect the psi anyway.
 

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hmm, that doesn't make any sense to me...Unless boost creep is causing it. Generally the more flow (less restrictions) you have the less boost there is.
 

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Reducing restriction after the turbine allows more boost since there is a higher pressure differential across the turbine.
 
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