unequal length headers

9

95cobra svt

New Member

Oct 26, 2009

18

0

0

Nov 26, 2009

#1

• Nov 26, 2009

• #1

whats up was wonderin what differences there would be if i put unequal length shorty headers on my 95 cobra? Or if anyone has an idea of how the sound torque and horsepowwer would change with them installed

 

COBRA90GT

Mustang Master

Sep 22, 2001

6,654

0

87

HOCKEYTOWN ® , MI

Nov 28, 2009

#2

• Nov 28, 2009

• #2

Bump - Gonna piggyback on your thread 95cobra svt...

I would also like to know about shorty headers for 94-95 snakes.

Are equal length shorties significantly "better" than unequal length shorties from a performance standpoint? Anybody have dyno comparisons between equal length shorties and unequal shorties? What does the area gains under the curve look like?

How much hp/tq do shorty headers typically add on the 94-95 engines?

I know longtubes are "preferred," but I just added a new midpipe (and catback) so I am going to avoid longtubes.

 

final5-0

Mustang Master

Apr 6, 2003

6,817

12

79

DFW Texas

Nov 28, 2009

#3

• Nov 28, 2009

• #3

There is not gonna be much, if any, difference between the two types
of shorty headers.

LT will promote better low to mid range due to their true collector
shortys just don't have.

If you are talking about a stock Cobra, the shorty header will not
give you much of a gain.

I'd say 10 rwhp at the most

Grady

 

COBRA90GT

Mustang Master

Sep 22, 2001

6,654

0

87

HOCKEYTOWN ® , MI

Nov 28, 2009

#4

• Nov 28, 2009

• #4

Alright, thanks for the info about "unequal Vs equal" length shorty headers final5-0.

 

skunk21

Active Member

May 22, 2007

1,203

3

36

Taxachusetts

Nov 28, 2009

#5

• Nov 28, 2009

• #5

another down side to unequal length headers they come very close to the frame section by the struts towers and burn off the paint and rust out that area. I have seen it many times and my buddy is repairing his from this very same problem. I have the JBA shorties but in most cases shorties don't offer much of any gain even over stock.They do clean up the flow restriction but like stated it's a small hp gain..LT's for best gain and low/mid power torque improvement!

 

99FiveOh

15 Year Member

May 20, 2006

2,051

20

99

J-Ville, FL

Nov 28, 2009

#6

• Nov 28, 2009

• #6

I'd be willing to bet 100 bucks that if you built a 350 HP N/A motor, there would be a huge difference between stock header manifolds and aftermarket shorties.

Yes, it's true...they don't give you much on a stock or near stock engine, but if you put them on now and upgrade heads/cam/intake and/or a do a stroker...the shorties will most definately improve power quite a bit. It's just that the stock ones don't offer enough of a restriction for a stock motor.

 

revhead347

Apparently my ex-husband made that mistake.

20+ Year Stangneter

Jun 14, 2004

9,288

1,631

214

Acworth, GA

Nov 28, 2009

#7

• Nov 28, 2009

• #7

Quick correction there. LTs improve high end power more than low end torque. Theoretically, a shorty header should give you more low end torque than a long tube. In my experience, the LT offers better performance overall though.

Equal length shorties are worth this much power (----), and this much pain in the ass (--------------------------------).

Kurt

 

skunk21

Active Member

May 22, 2007

1,203

3

36

Taxachusetts

Nov 29, 2009

#8

• Nov 29, 2009

• #8

revhead347 said:

Quick correction there. LTs improve high end power more than low end torque. Theoretically, a shorty header should give you more low end torque than a long tube. In my experience, the LT offers better performance overall though.

Equal length shorties are worth this much power (----), and this much pain in the ass (--------------------------------).

Kurt

Click to expand...

correction to you correction ..The longer the individual tubes the more scavenging occurs at lower speeds, this gives the long tubes a longer broader torque curve that starts at a lower rpm vs a shorty header which has less of a scavenging effect, this can actually be tuned in a set of headers for race car, etc( it can get more technical). shorties lend themselves to upper mid- higher rpms and less low end torque than the long tubes.

one of the sources for info: "exhaust header theory and design" by Jack Burns.

 

99FiveOh

15 Year Member

May 20, 2006

2,051

20

99

J-Ville, FL

Nov 29, 2009

#9

• Nov 29, 2009

• #9

Correction to your correction correction.... uh.. there is no correction, I just wanted to be the first to say that!

 

9

95cobra svt

New Member

Oct 26, 2009

18

0

0

Dec 6, 2009

#10

• Dec 6, 2009

• #10

thanks for the help everybody. so it the longrun the longtubes are gonna be better off?

 

revhead347

Apparently my ex-husband made that mistake.

20+ Year Stangneter

Jun 14, 2004

9,288

1,631

214

Acworth, GA

Dec 6, 2009

#11

• Dec 6, 2009

• #11

Yeah, longtubes are a lot better. They aren't too bad to install, but you do have to jack up the motor and stuff.

Kurt

 

S

sl03gt

20+ Year Stangneter

Sep 29, 2003

182

1

18

Dec 9, 2009

#12

• Dec 9, 2009

• #12

I read an article along time ago in MM&FF that compared equal length shorties and just plain shorties on a s/c car some where in the upper 300 rwhp range. If I remember correctly I think there was a 4 or 5 hp favoring the equals but the article also said that there would have been an even smaller difference on a na motor. Again long time ago, numbers might be off. They also tested stock ones I think and there was a good difference between stock and aftermarket.

 

9

95cobra svt

New Member

Oct 26, 2009

18

0

0

Dec 10, 2009

#13

• Dec 10, 2009

• #13

what do u know about the pypes polished 304 stainless steel shorty headers