|
Author
|
Topic: 393w exhaust 2.5 or 3"?
|
4MY8TERS
¯
Member # 7840
|
posted
 
 
I know 3" would be best since I'm going blown, but how about the clearance issues over the rear end?
--------------------
1985 Notchback-393w Vortech
1991 Convert Lx-H/C/I-Vortech
1984 T-Top 306-H/C/I
Posts: 2337 | From: THE GOLDEN CITY AKA SFC | Registered: Aug 2007
| :
|
|
racsirx
CAFords OG
Member # 1710
|
posted
Yes 3" would the best, I got my 3" catback from Flowmaster
--------------------
88 Saleen #564
88 GT 331 NOVI2000
88 Coupe TURBO 9.75@142
95 Cobra R #75-SOLD
06 F250
13 BMW AH3
17 GT350 #5556
GOD'S NOT DEAD
Posts: 20750 | From: Concord & Pittsburg, CA | Registered: Aug 2002
| :
|
|
Secnd2nun64
¯
Member # 1431
|
posted
2.5 will be fine if that's what you already got. I wouldn't go out and buy new exhaust to just to go to 3", not worth the investment.
Posts: 1460 | From: CA | Registered: Jun 2002
| :
|
|
racsirx
CAFords OG
Member # 1710
|
posted
quote:
Originally posted by Secnd2nun64:
2.5 will be fine if that's what you already got. I wouldn't go out and buy new exhaust to just to go to 3", not worth the investment.
A blown 393 needs to breathe, 2.5" will hold it back.
--------------------
88 Saleen #564
88 GT 331 NOVI2000
88 Coupe TURBO 9.75@142
95 Cobra R #75-SOLD
06 F250
13 BMW AH3
17 GT350 #5556
GOD'S NOT DEAD
Posts: 20750 | From: Concord & Pittsburg, CA | Registered: Aug 2002
| :
|
|
Secnd2nun64
¯
Member # 1431
|
posted
quote:
Originally posted by racsirx:
quote:
Originally posted by Secnd2nun64:
2.5 will be fine if that's what you already got. I wouldn't go out and buy new exhaust to just to go to 3", not worth the investment.
A blown 393 needs to breathe, 2.5" will hold it back.
Not saying that it wouldn't. I'm saying the gain is not worth the investment if you already have 2.5 pipes. The 2.5 can handle 500hp. Going to 3" may pick up 15-20 hp. It really depends on if the builder is looking to get every little bit out of the combo, but if so why not do a 427w?
Posts: 1460 | From: CA | Registered: Jun 2002
| :
|
|
racsirx
CAFords OG
Member # 1710
|
posted
I have seen bigger gains with a 302 HCI with a S-trim when switching over to 3"
--------------------
88 Saleen #564
88 GT 331 NOVI2000
88 Coupe TURBO 9.75@142
95 Cobra R #75-SOLD
06 F250
13 BMW AH3
17 GT350 #5556
GOD'S NOT DEAD
Posts: 20750 | From: Concord & Pittsburg, CA | Registered: Aug 2002
| :
|
|
turbo50
¯
Member # 6700
|
posted
We seen gains on the naturally aspirated 393 when going back to smaller header 1 5/8 and 3 inch exhaust versus larger 1 3/4 header and 3 inch exhaust. Never got to test it with 2.5 but maybe the new owner will.
--------------------
.........when was the last time YOU built something with YOUR own hands?
I offer quality sidework at reasonable prices. PM ME
Posts: 7606 | From: Discovery Bay, California | Registered: Apr 2006
| :
|
|
Boss 327
¯
Member # 9143
|
posted
quote:
Originally posted by turbo50:
We seen gains on the naturally aspirated 393 when going back to smaller header 1 5/8 and 3 inch exhaust versus larger 1 3/4 header and 3 inch exhaust. Never got to test it with 2.5 but maybe the new owner will.
Why do you think that is?
--------------------
"You'll never truly understand building engines until you can make power N/A. FI overshadows an engines defficiency." Al Papito
Posts: 1789 | From: East Bay | Registered: May 2009
| :
|
|
Notch1320
Man Pedal
Member # 2647
|
posted
The header is key on a max effort deal. There is a reason good headers cost so much! Finding the right stepped header/ collector combo for my car made some good gains. I would go 3" on your car though for the exhaust.
Posts: 2349 | From: Yuba City, CA | Registered: Mar 2003
| :
|
|
warhorse58gt
¯
Member # 7702
|
posted
Go 3" I have went 9.76 on shorties and 2 1/2 exhaust. I added 135lbs, when I added the long tubes & 3" exhaust. Car still picked up a full .10 and 2 mph. So it was worth at least .2 & 2mph with the extra weight. To me that is worth the money to do.
--------------------
WOLFPACK RACING
With guns, we are 'citizens'. Without them, we are 'subjects'.
83gt 354ci sbf 9.40 @ 143
77 cobra 2 171ci 97hp of pure fury!
Posts: 4200 | From: 209 | Registered: Jun 2007
| :
|
|
Secnd2nun64
¯
Member # 1431
|
posted
quote:
Originally posted by warhorse58gt:
Go 3" I have went 9.76 on shorties and 2 1/2 exhaust. I added 135lbs, when I added the long tubes & 3" exhaust. Car still picked up a full .10 and 2 mph. So it was worth at least .2 & 2mph with the extra weight. To me that is worth the money to do.
Did you change mufflers too? I asked a lot of people and researched when I had my exhaust redone for my 393w and was told to keep the 2.5. Got me wondering if I should change mine out now. lol
Posts: 1460 | From: CA | Registered: Jun 2002
| :
|
|
|
|
warhorse58gt
¯
Member # 7702
|
posted
quote:
Originally posted by Secnd2nun64:
quote:
Originally posted by warhorse58gt:
Go 3" I have went 9.76 on shorties and 2 1/2 exhaust. I added 135lbs, when I added the long tubes & 3" exhaust. Car still picked up a full .10 and 2 mph. So it was worth at least .2 & 2mph with the extra weight. To me that is worth the money to do.
Did you change mufflers too? I asked a lot of people and researched when I had my exhaust redone for my 393w and was told to keep the 2.5. Got me wondering if I should change mine out now. lol
I had the shorties then a x-pipe, with 12" race bullets. With the long tubes I have 1 7/8 kooks header with a 3" collector to x-pipe, Then in to borla xs 2 mufflers. I got them dumped after the mufflers. I would like to have it all the way out to the back of the car. But I ave a weld in sway bar, that keeps me for being able to do that. ![[Frown]](frown.gif)
[ 2013-07-18, 09:34 PM: Message edited by: warhorse58gt ]
--------------------
WOLFPACK RACING
With guns, we are 'citizens'. Without them, we are 'subjects'.
83gt 354ci sbf 9.40 @ 143
77 cobra 2 171ci 97hp of pure fury!
Posts: 4200 | From: 209 | Registered: Jun 2007
| :
|
|
Email this post to someone!
Printer friendly view of this Ford topic
