WTB AFtermarket Midpipe - Page 2 - Subaru Enthusiasts Car Club of the Sierras

02STI · 2009-03-25, 08:05 AM

Quote:

Originally Posted by 100_Percent_Juice

might need to go ...gulp... custom.

custom,,what is that

naw jk. idk. i guess i might have to.. or maybe i should keep the stock catback..

cody · 2009-03-25, 08:25 AM

Does your DP have a 3" flange or the OEM style donut gasket?

If it's the donut style, http://www.daddysscp.com/dcart4/prod...&cat=17&page=1

3" flat flange: http://www.daddysscp.com/dcart4/prod...&cat=17&page=1

cody · 2009-03-25, 08:34 AM

Quote:

Originally Posted by Kevin M

If you're keeping a 2.5" axleback, you don't need a 3" midpipe.

I was thinking the same thing. But at some powerlevel there's theoretically a benefit but the only evidence I have to support that is the fact that the TurboXS Stealth Back is a TBE that replaces everything except the stock muffler. For a stage two 2.0L, for example, the muffler doesn't seem to be a big restriciton (although it does hold back probably 5HP)...but you'd think that the muffler would be a bigger restriciton than a straight pipe given that the muffler isn't straight through like the pipe. Dunno.

The gasses cool and contract as they travel down the TBE. Larger pipes offer less performance benefit toward the exit end of the exhaust tract (the muffler) than they do toward the hot side.

02STI · 2009-03-25, 10:05 AM

cool. thanks for the links, yea, i just wantet to have the 3" midpipe so it could be alittle bit more flow, i have the sti catback, if thats on the sti its good for me, but i just wanna keep the axle back not the stock midpipe, idk if it will add any power, im sure it wont but still..

cody · 2009-03-25, 10:30 AM

My CBE is really overkill since I'm essentially just stage II on a 2L. I have a ceramic coated DWG shorty DP to 3" ID all the way, straight through with one high-flow cat in the midpipe. All I'd need to go to a bigger turbo is injectors, TMIC, the snail, a tune and a tranny fund.

02STI · 2009-03-25, 10:39 AM

yea lol.. you need to get new exhaust, i have 4" DP on top and goes to 3" and sti catback, catless

i recently changed my turbo, injectors, ecu, TM

cody · 2009-03-25, 10:43 AM

I don't need a new exhaust, but it sounds like that STi CBE might be a serious restriction if you've got a significant turbo upgrade.

Kevin M · 2009-03-25, 12:26 PM

Quote:

Originally Posted by cody

I was thinking the same thing. But at some powerlevel there's theoretically a benefit but the only evidence I have to support that is the fact that the TurboXS Stealth Back is a TBE that replaces everything except the stock muffler. For a stage two 2.0L, for example, the muffler doesn't seem to be a big restriciton (although it does hold back probably 5HP)...but you'd think that the muffler would be a bigger restriciton than a straight pipe given that the muffler isn't straight through like the pipe. Dunno.

The gasses cool and contract as they travel down the TBE. Larger pipes offer less performance benefit toward the exit end of the exhaust tract (the muffler) than they do toward the hot side.

That whole thing is a myth. It's based the Ideal Gas Law, PV=nRT, except for one slight flaw- IGL deals with closed systems. If you keep your axleback, there is no benefit to replacing your midpipe.

Kevin M · 2009-03-25, 12:27 PM

Quote:

Originally Posted by 100_Percent_Juice

might need to go ...gulp... custom.

Why?

100_Percent_Juice · 2009-03-25, 12:41 PM

If he is going from a 3" DP to a 2.5" axle back then he would need a mid pipe like the one in Cody's link.

cody · 2009-03-25, 01:17 PM

Quote:

Originally Posted by Kevin M

That whole thing is a myth. It's based the Ideal Gas Law, PV=nRT, except for one slight flaw- IGL deals with closed systems. If you keep your axleback, there is no benefit to replacing your midpipe.

So you're saying that a bottleneck midpipe isn't any different than a bottleneck before/in the muffler, for example? Interesting. Do you have a source you could link me to?

Kevin M · 2009-03-25, 01:46 PM

Quote:

Originally Posted by 100_Percent_Juice

If he is going from a 3" DP to a 2.5" axle back then he would need a mid pipe like the one in Cody's link.

NT RLY. Unless it's flat flange and just plain won't seal to his stock mid.

Kevin M · 2009-03-25, 01:49 PM

Quote:

Originally Posted by cody

So you're saying that a bottleneck midpipe isn't any different than a bottleneck before/in the muffler, for example? Interesting. Do you have a source you could link me to?

Link? No. Just think about it. How is moving the obstruction 30" downstream affecting anything? The gains in that old TXS setup come entirely from the downpipe, because the stock downpipe flange is a much bigger restriction than the piping size of stock exhaust. But once that's gone, if you don't upgrade all the pipe sizing you don't get much compared to replacing all of it.

100_Percent_Juice · 2009-03-25, 04:35 PM

Quote:

Originally Posted by Kevin M

NT RLY. Unless it's flat flange and just plain won't seal to his stock mid.

I don't understand your post.

02STI · 2009-03-25, 04:52 PM

I don't understand anything anymore

sedonabugeye · 2009-03-25, 10:57 PM

adolfo.. sack up and go custom!!!!! haha!

02STI · 2009-03-26, 08:41 AM

Quote:

Originally Posted by sedonabugeye

adolfo.. sack up and go custom!!!!! haha!

hahaha.. i think im just gonna try to get an Apex catback, they sound nice.

dayofpain · 2009-03-26, 03:10 PM

tanabe midpipe. no cats no resonators.

100 bucks avail right now!!!

2009-03-25, 08:25 AM	#27
cody Candy Mountain Real Name: Cody Join Date: May 2005 Location: Californication Posts: 7,751 Car: 03 Pussy Wagon, now with more pink! Class: TESP OMG Internet!	Does your DP have a 3" flange or the OEM style donut gasket? If it's the donut style, http://www.daddysscp.com/dcart4/prod...&cat=17&page=1 3" flat flange: http://www.daddysscp.com/dcart4/prod...&cat=17&page=1 __________________ Slow and low, that is the tempo.

2009-03-25, 10:30 AM	#30
cody Candy Mountain Real Name: Cody Join Date: May 2005 Location: Californication Posts: 7,751 Car: 03 Pussy Wagon, now with more pink! Class: TESP OMG Internet!	My CBE is really overkill since I'm essentially just stage II on a 2L. I have a ceramic coated DWG shorty DP to 3" ID all the way, straight through with one high-flow cat in the midpipe. All I'd need to go to a bigger turbo is injectors, TMIC, the snail, a tune and a tranny fund. __________________ Slow and low, that is the tempo.

2009-03-25, 10:43 AM	#32
cody Candy Mountain Real Name: Cody Join Date: May 2005 Location: Californication Posts: 7,751 Car: 03 Pussy Wagon, now with more pink! Class: TESP OMG Internet!	I don't need a new exhaust, but it sounds like that STi CBE might be a serious restriction if you've got a significant turbo upgrade. __________________ Slow and low, that is the tempo.

2009-03-25, 12:41 PM	#35
100_Percent_Juice (40 percent vodka) Real Name: Joel Join Date: Oct 2006 Location: Reno, NV Posts: 4,446 Car: 2004WRX Class: Baby-Hauler/GroceryGetter	If he is going from a 3" DP to a 2.5" axle back then he would need a mid pipe like the one in Cody's link. __________________ "A power nap is when you sleep on someone who is weaker than you." - Dimitri Martin

2009-03-26, 03:10 PM	#43
dayofpain R.I.P. Join Date: Apr 2003 Location: reno, nv Posts: 599 Car: 09 335xi silva	tanabe midpipe. no cats no resonators. 100 bucks avail right now!!! __________________ DayOfPain "In order for me to get busy at maximum efficiency, i need a girl with a big 400 ton booty."

2009-03-25, 10:05 AM	#29
02STI EJ18 Join Date: Mar 2009 Posts: 42 Car: 02 Wrx	cool. thanks for the links, yea, i just wantet to have the 3" midpipe so it could be alittle bit more flow, i have the sti catback, if thats on the sti its good for me, but i just wanna keep the axle back not the stock midpipe, idk if it will add any power, im sure it wont but still..

2009-03-25, 10:39 AM	#31
02STI EJ18 Join Date: Mar 2009 Posts: 42 Car: 02 Wrx	yea lol.. you need to get new exhaust, i have 4" DP on top and goes to 3" and sti catback, catless i recently changed my turbo, injectors, ecu, TM

2009-03-25, 04:52 PM	#40
02STI EJ18 Join Date: Mar 2009 Posts: 42 Car: 02 Wrx	I don't understand anything anymore

2009-03-25, 10:57 PM	#41
sedonabugeye EJ251 Real Name: Andy Join Date: Feb 2009 Location: Sparks Posts: 566 Car: Leggy wagon/Bugeye/megacab	adolfo.. sack up and go custom!!!!! haha!

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