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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

Exhaust Size W Forced Induction?

  • Thread starter Thread starter 90lxwhite
  • Start date Start date Jun 22, 2014
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90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
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Jun 22, 2014
#1
  • Jun 22, 2014
  • #1
Alright fellas here's the deal: I recently installed a Vortech si and I'm wondering much things on the exhaust end are holding me back if any? My setup is as follows. 302 w slightly "worked" e7's w beehive springs, .512 lift on in and ex, stock ho upper intake with ported lower, stock headers, stock h pipe w pre cats removed, the other's were replaced with high flows, and Forzaflow mufflers. Before the blower I was making 223 rwhp and I think like 280 some odd ft lbs. (waiting for tune appt) Since I'm forcing more air in do I need to step up to 2.5 or with my modest combo will the 2.25" suffice? I'm guessing that there would be no real gain if I went catback only. If I indeed should go 2.5" what's the best way going about doing it? Get a 2.5" mid pipe(I want cats due to smell) and a 2.5" catback system? Or is it more cost effective to purchase a 2.5" header back weld-up system? Or how a about having a shop fab up something custom? Labor costs is a factor if that will help narrow down the decision. Oh and no "long tubes ftw" please, ain't happenin'. One more question if I go w larger piping are the chances fairly great that I'll have to get new mufflers?
 

Shoomakan

Member
Jun 7, 2014
74
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18
Beirut, Lebanon
Jun 22, 2014
#2
  • Jun 22, 2014
  • #2
I think you'll need new mufflers if you increase exhaust pipe diameter.

I feel since you're still on E7's and mostly stock everything, 2.25" will suffice for what you want from it. Each 2.25" is dealing with a ~170hp 2.5 liter 4 cylinder, in essence, (assuming you make 300rwhp with the blower). Less restriction is more power, don't get me wrong.. I just don't feel that with your combo you're aiming for maximizing power anyway.
 

25thmustang

Mustang Master
Sep 5, 2003
2,021
85
99
Montgomery, NY
Jun 22, 2014
#3
  • Jun 22, 2014
  • #3
Mandrel bent 2.5" would be plenty.
 

bentley429isBAC

10 Year Member
Jul 23, 2009
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Jun 22, 2014
#4
  • Jun 22, 2014
  • #4
Longtubes 2.5" x pipe and a decent catback will be fine
 

90lxwhite

I'm kind of a She-Man
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Jun 22, 2014
#5
  • Jun 22, 2014
  • #5
bentley429isBAC said:
Longtubes 2.5" x pipe and a decent catback will be fine
Click to expand...
Long tubes...
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
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Between the Red and Rio
Jun 22, 2014
#6
  • Jun 22, 2014
  • #6
Shoomakan said:
I think you'll need new mufflers if you increase exhaust pipe diameter.

I feel since you're still on E7's and mostly stock everything, 2.25" will suffice for what you want from it. Each 2.25" is dealing with a ~170hp 2.5 liter 4 cylinder, in essence, (assuming you make 300rwhp with the blower). Less restriction is more power, don't get me wrong.. I just don't feel that with your combo you're aiming for maximizing power anyway.
Click to expand...
honestly if I'm looking at an arm and a leg for 5 or 6 extra horsepower I'd leave it as is but for say I dunno 20 or so horse it'd be worth considering.
 

stykthyn

I want to measure mine. It doesn't look that tall.
15 Year Member
Jul 6, 2006
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gainesville
Jun 22, 2014
#7
  • Jun 22, 2014
  • #7
I think that if you picked even 5 or 6 hp over your current set up it would be a miracle.
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
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Jun 22, 2014
#8
  • Jun 22, 2014
  • #8
stykthyn said:
I think that if you picked even 5 or 6 hp over your current set up it would be a miracle.
Click to expand...
Point taken. Forza flow's it is.
 

Onefine88

Previously 89SSC18
10 Year Member
Aug 3, 2006
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Jun 22, 2014
#9
  • Jun 22, 2014
  • #9
2.5" and never look back.

Trust me
 

Gearbanger 101

Straight Outta Locash
20+ Year Stangneter
Aug 10, 2002
9,457
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Ontario, Canada
Jun 22, 2014
#10
  • Jun 22, 2014
  • #10
Pick yourself up a set of used 1 5/8" shorty headers, and a 2 1/2" off road mid pipe and call it a day. You could probably get it done for a couple hundred bux.

The stock 2 1/4" diameter exhaust will support over 375fwhp. No need to go bigger...especially if you've already got a set of hose knock off Flowmasters on there.

Since you're running that blower, I'm betting with the stock headers on there and bastardized H-pipe you're probably leaving a good 10-12hp on the table....maybe more?

Stepping up to a 2.5" cat back at this point without addressing the other issues is likely just going to make your car louder. The cat back isn't the cork....the headers and mid pipe are.
 
Reactions: 7upstang91

7upstang91

10 Year Member
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#11
  • Jun 22, 2014
  • #11
Gearbanger 101 said:
Pick yourself up a set of used 1 5/8" shorty headers, and a 2 1/2" off road mid pipe and call it a day. You could probably get it done for a couple hundred bux.

The stock 2 1/4" diameter exhaust will support over 375fwhp. No need to go bigger...especially if you've already got a set of hose knock off Flowmasters on there.

Since you're running that blower, I'm betting with the stock headers on there and bastardized H-pipe you're probably leaving a good 10-12hp on the table....maybe more?

Stepping up to a 2.5" cat back at this point without addressing the other issues is likely just going to make your car louder. The cat back isn't the cork....the headers and mid pipe are.
Click to expand...
Could not agree more with this post. Didn't feel that "liking" the post was good enough. Headers and h pipe are your problem. Used parts could easily fix the problem for you for under $300. (Depending on the area you live and market). You could do it for under $200 provided you are willing to go off road h pipe.
 

25thmustang

Mustang Master
Sep 5, 2003
2,021
85
99
Montgomery, NY
Jun 22, 2014
#12
  • Jun 22, 2014
  • #12
I agree with 1-5/8 shorties, off road mid pipe and a 2.5" catback of your choice would be a good upgrade, in sound and some power. Craigslist the parts and spend 300-400 total and have a good set up.
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
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Jun 22, 2014
#13
  • Jun 22, 2014
  • #13
7upstang91 said:
Could not agree more with this post. Didn't feel that "liking" the post was good enough. Headers and h pipe are your problem. Used parts could easily fix the problem for you for under $300. (Depending on the area you live and market). You could do it for under $200 provided you are willing to go off road h pipe.
Click to expand...
I haven't looked yet but I bet the biggest obstacle w going used is finding '95 specific headers to where I wouldn't have to do sum riggin w the egr n crap. Y'all know the thread post pics of how y'all's fox sits, well there are like 2k replies. I tried to post a lets see sum sn's and got 13 replies.
 

bentley429isBAC

10 Year Member
Jul 23, 2009
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Jun 22, 2014
#14
  • Jun 22, 2014
  • #14
90lxwhite said:
Long tubes...
Click to expand...

Yes.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
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Jun 23, 2014
#15
  • Jun 23, 2014
  • #15
If you get or make a good 2.5" exhaust set up, you will be ready when you get better heads too.
 

FoxMustangLvr

I love my Pimp
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Oct 14, 2012
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Jun 24, 2014
#16
  • Jun 24, 2014
  • #16
Yesterday (on craigslist) I just sold a used set of 1 5/8" MAC equal length headers for $50, a 2.5" offroad Bassani X pipe w/ flowmaster 40's for $100 and not too long ago a 2.5" BBK h-pipe with cats for $200. This weekend i'm basically giving a stock long block away with a set of 1 5/8" JBA unequal shorties for free (the guy has to yank motor himself and hand me the trans, clutch and flex plate). He will do this in my garage.

The good deals are out there and I'm one to give them. My advice is upgrade to 1 5/8 unequal length shorty headers, 2.5" h/x pipe. Don't cut yourself short on this and search for the good deals.
 

VibrantRedGT

"STANGNET'S PENGUIN SMACKER"
15 Year Member
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Jun 24, 2014
#17
  • Jun 24, 2014
  • #17
I put 6 exhaust systems on my car and 5 of them went on the dyno. Long tubes made noticeable HP numbers over shorties and made double digit TQ numbers in every RPM over them. They are worth it. I should have went this route from day 1.
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
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Jun 24, 2014
#18
  • Jun 24, 2014
  • #18
Agreed with 100%
 

madspeed

Colonel Mustard
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Nov 29, 1999
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Jun 24, 2014
#19
  • Jun 24, 2014
  • #19
Until you go turbo
 

FoxMustangLvr

I love my Pimp
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Oct 14, 2012
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Spokane, Wa
Jun 24, 2014
#20
  • Jun 24, 2014
  • #20
VibrantRedGT said:
I put 6 exhaust systems on my car and 5 of them went on the dyno. Long tubes made noticeable HP numbers over shorties and made double digit TQ numbers in every RPM over them. They are worth it. I should have went this route from day 1.
Click to expand...

Nobody can really argue the HP difference between long and short headers it's just that the OP made it clear he doesn't want to go that route so it's really a non-point.

I just got my 1 5/8" ceramic coated BBK longtubes and h-pipe from LMR and can't wait for the day I get to install them.
 
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