FRPP Shorty Headers 4.6 4V Cobra Dyno Test

[Glenn]

I have attached a professional dyno test review of the FRPP shorty headers on a Cobra 4V NA 10.5 compression engine. This is the closest engine dyno test to our MM engine I could find. The dyno tests were done by Richard Holdener in his book "Building 4.6/5.4L Ford Horsepower on the Dyno". The largest gains were 16 HP and 11 TQ at 6,500 rpm. (I could not find a 4.6 4V SC dyno test with the shorty headers.)

I will post the LT 1 5/8" header NA dyno test later. It shows 18 HP gains at 6,100 and 19 TQ at 3,600 rpm. I will also post Cobra SC LT Hooker header dynos which shows 14 HP gain at 6,500 and 13 TQ at 5,800.

I believe these test results prove the point that LTs are not the only header option open to MM owners, in fact for cost vs. performance the shorties win hands down at the high end. http://www.fordperformanceclubofatlan ta.com/Forum/images/smilies/signeek.gif

Keep in mind these are not the HP results you may get with your MM on a dyno. These are professional dyno tests in a controlled environment. But, you cannot ignore these results and simply write them off.

OK ------:flamer:

Glenn


http://www.mercurymarauder.net/gallery/data/500/medium/FRPP_Shorty_Dyno_p1.jpg (http://javascript<b></b>:;)http://www.mercurymarauder.net/gallery/data/500/medium/FRPP_Shorty_Dyno_tests_p2.jpg (http://javascript<b></b>:;)

[offroadkarter]

i wouldnt even consider those shorty headers, they look like glorified exhaust manifolds to me...

[LANDY]

thats intersting

[dohc324ci]

So Glenn you going to do this mod?

[ctrlraven]

I have the same book lol. I will still be going with LT headers because I plan on moving a lot of air down the road.

[Glenn]

I have had the the FRPP shorty headers for about 4 years with the Cobra X-pipe and coupled to the OEM mufflers, tail pipes and tips. See my Sig for the results.

Glenn :burnout:

[Glenn]

I have the same book lol. I will still be going with LT headers because I plan on moving a lot of air down the road.

I will post the LT Hooker headers on the Cobra 4.6 SC tomorrow. They show even less HP then the shorty headers with the SC engine.

Glenn :burnout:

[dohc324ci]

I have had the the FRPP shorty headers for about 4 years with the Cobra X-pipe and coupled to the OEM mufflers, tail pipes and tips. See my Sig for the results.

Glenn :burnout:

What did that combo net you....I am going to have to address the exhaust once the the motor is in. What did that combo cost you? You think 2.5" or 3" piping?

[RR|Suki]

<--- gained 8mph in the 1/4 mile with LT headers

[dohc324ci]

<--- gained 8mph in the 1/4 mile with LT headers

What size pipes you running?

[RR|Suki]

What size pipes you running?

1 3/4" primaries, 3" collectors

[SC Cheesehead]

Interesting info, Glenn, thanks for posting.

Do you see any adavantage going to LT with certain mod configurations? If not, then I think your assessment is spot on.

[Glenn]

The NA LTs do show more HP and particularly TQ then the shorties at lower rpm. The greater torque at a lower rpm will get you off the line quicker. Greater HP at the top end will pull you across the finish line quicker. If money is no object then the LTs are a better choice - but very expensive. I am just offering professional dyno tests on these headers - the final choice is the members.

bcastro:

If you are to be only NA and have lots of money I would go with the LTs. Install them on the engine as you are pulling it back in the car. But, LTs show less improvements with SC engines. My dyno tests on SC LTs will explain why. 3" are not cost vs. performance effective and cost a great deal. 2 1/2" are more then sufficient.

Glenn :burnout:

[RR|Suki]

The NA LTs do show more HP and particularly TQ then the shorties at lower rpm. The greater torque at a lower rpm will get you off the line quicker. Greater HP at the top end will pull you across the finish line quicker. If money is no object then the LTs are a better choice - but very expensive. I am just offering professional dyno tests on these headers - the final choice is the members.

bcastro:

If you are to be only NA and have lots of money I would go with the LTs. Install them on the engine as you are pulling it back in the car. But, LTs show less improvements with SC engines. My dyno tests on SC LTs will explain why. 3" are not cost vs. performance effective and cost a great deal. 2 1/2" are more then sufficient.

Glenn :burnout:

you gained 8mph in the 1/4 with shorties? I'd like to see that

[Phrog_gunner]

I have had the the FRPP shorty headers for about 4 years with the Cobra X-pipe and coupled to the OEM mufflers, tail pipes and tips. See my Sig for the results.

Glenn :burnout:


Glenn since you seem to be the duty expert. Will those ST bolt up to factory MM exhaust without modification, or is that why you went with the Cobra Xpipe??

[Glenn]

I am not an expert - just have some experience and knowledge. The FRPP shorties will only bolt up to a Cobra X-pipe. Most members use the Cobra Magnaflow X-pipe with rear hi-flow CATS part #93335. You then need a 4" spacer inserted in the X-pipe due to the extended wheel base of the MM. There are many, many posts on this set-up with pictures - see Search.

Glenn :burnout:

[RoyLPita]

With the FRPP shorty headers, a 1/2 to 3/4" shim is needed under the left side motor mount where it bolts to the crossmember to clear the steering shaft.

[Phrog_gunner]

I am not an expert - just have some experience and knowledge. The FRPP shorties will only bolt up to a Cobra X-pipe. Most members use the Cobra Magnaflow X-pipe with rear hi-flow CATS part #93335. You then need a 4" spacer inserted in the X-pipe due to the extended wheel base of the MM. There are many, many posts on this set-up with pictures - see Search.

Glenn :burnout:

I appreciate the help....:beer:

Duty expert is a Marine term = someone in the general vacinity (on your duty shift) that is knowledgeable on the topic (expert). Thanks for the info...I gave up on the search function a long time ago. We all know there was a thread recently about "FHP Marauders"....yet when I search for "FHP" it finds no matches. And if I search for FRPP headers I get 993 returns, which are most likely every person with "headers" in their signature. I don't have that much extra time and refuse to start a new thread on the subject because that would only add to the problem. Rant Complete!

[Glenn]

Note these additional fabrication points needed with the shorties:

You need to put a 1/4" shim under the driver's side motor mount.
The H (or X) pipe will have to be cut and extended about 4" to clear the crossmember.
There is an adapter fitting that is needed to fit the EGR tube.
Maybe a little adjusting (bending) of the EGR tube.
Short custom pipes needed between mufflers and H (or X) pipe.

Glenn

[dohc324ci]

Note these additional fabrication points needed with the shorties:

You need to put a 1/4" shim under the driver's side motor mount.
The H (or X) pipe will have to be cut and extended about 4" to clear the crossmember.
There is an adapter fitting that is needed to fit the EGR tube.
Maybe a little adjusting (bending) of the EGR tube.
Short custom pipes needed between mufflers and H (or X) pipe.

Glenn

Hey Glenn good to know as I may consider this apposed to LT. Maybe.

[fastblackmerc]

Note these additional fabrication points needed with the shorties:

You need to put a 1/4" shim under the driver's side motor mount.
The H (or X) pipe will have to be cut and extended about 4" to clear the crossmember.
There is an adapter fitting that is needed to fit the EGR tube.
Maybe a little adjusting (bending) of the EGR tube.
Short custom pipes needed between mufflers and H (or X) pipe.

Glenn

I added the 1/4" shim under the right aide also.

[Bradley G]

For the guys that drive daily and to church(example), I would tend to believe they would be less tempramental with the usual annoyances that LTs can have.
If exhaust work is in the future, this is the only option for the Marauder I get to drive.

[babbage]

For the guys that drive daily and to church(example), I would tend to believe they would be less tempramental with the usual annoyances that LTs can have.
If exhaust work is in the future, this is the only option for the Marauder I get to drive.

Take a look at this setup.

http://www.mustangandfords.com/techarticles/mdmp_0904_2003_mercury_maraude r_exhaust_install/duel_angled_pipes.html

I'd like the LT's but the noise is a big game killer for me. I realize that LT's are quiet until you get on it (re: church) - I've seen the clips on youtube of the SW sounds and holy crap - I'm worried that's too much.

Glen thanks for posting that data - what about MID length kits anyone ever tried one on an MM?

[ImpalaSlayer]

why not buy what fits our cars and be done? if your worried about noise get a quieter muffler.

[ddogg626]

I'm building my exhaust now and was wondering rather I should run the X pipe or just run each side back from the headers with out any H or X pipe ????? HELP

[Glenn]

Never run divorce pipes - always use an X or H pipe. The X pipe is by far the perferred alternative.

Glenn :burnout:

[ddogg626]

k, thanks Glenn

[Hooptie]

Take a look at this setup.

http://www.mustangandfords.com/techarticles/mdmp_0904_2003_mercury_maraude r_exhaust_install/duel_angled_pipes.html

I'd like the LT's but the noise is a big game killer for me. I realize that LT's are quiet until you get on it (re: church) - I've seen the clips on youtube of the SW sounds and holy crap - I'm worried that's too much.

Glen thanks for posting that data - what about MID length kits anyone ever tried one on an MM?
Wondered bout that mself.

[FordNut]

The Kooks are usually referred to as long tube, but they're really closer to mid-length. The StainlessWorks are actually long tubes.

[Spectragod]

I'm sold on my SW LT's, the numbers speak for themselves, with 9 lb's of boost....

You get what you pay for...

http://www.mercurymarauder.net/forums/picture.php?albumid=59&pictureid=478

[Spectragod]

And....... no shims.

[juno]

Please note the numbers in Holdner's books are Fly Wheel HP. But it is an excellent book for comparisons of a million different combo's. His book and Hyland's 4.6 book are really must haves for these motors.

[Bradley G]

Are you saying that the SW headers do not require shims, or you just got lucky?
And....... no shims.

[Spectragod]

Are you saying that the SW headers do not require shims, or you just got lucky?

Mine, like most, required no shimming.

[jdenning002]

What is the correct part number for the FRPP shorty headers??

And just to confirm, the cobra X-pipe bolts right onto the FRPP shortys without modification except for extending the pipes to the rear??

THANKS!

[Glenn]

SS: M-9430-E464
CC: M-9430-E465

I would recommend the ceramic coated headers. I have had mine for 4 years and they look like new. Yes, the Magnaflow X-pipe connects directly to the Cobra shorties. But, I would take the time to use Search and read all of the many, many posts on this exhaust mod. There is a wealth of knowledge in these posts including pictures.

Remember LTs are measurably better for NA, but more expensive. This is just an option which I choose for my SC engine which I found cost effective and performed well.

Glenn :burnout:

[Bradley G]

Those Ford engineers know their stuff!
SS: M-9430-E464
CC: M-9430-E465

I would recommend the ceramic coated headers. I have had mine for 4 years and they look like new. Yes, the Magnaflow X-pipe connects directly to the Cobra shorties. But, I would take the time to use Search and read all of the many, many posts on this exhaust mod. There is a wealth of knowledge in these posts including pictures.

Remember LTs are measurably better for NA, but more expensive. This is just an option which I choose for my SC engine which I found cost effective and performed well.

Glenn :burnout:

[jdenning002]

SS: M-9430-E464
CC: M-9430-E465

I would recommend the ceramic coated headers. I have had mine for 4 years and they look like new. Yes, the Magnaflow X-pipe connects directly to the Cobra shorties. But, I would take the time to use Search and read all of the many, many posts on this exhaust mod. There is a wealth of knowledge in these posts including pictures.

Remember LTs are measurably better for NA, but more expensive. This is just an option which I choose for my SC engine which I found cost effective and performed well.

Glenn :burnout:

Thanks for the info.

I have had the kooks LTs for 3 years now, I have the complete kooks kit w/ their x pipe. I removed the cats, and I have magnaflow mufflers...

I have always wanted a bit quiter sound, and I have had the drivers side header pulled and welded twice for a small leak, it is back and I am about ready to change them out.

I heard that for s/c cars that LTs actually reduce max HP. (I have a novi 1200 s/c) I don't care about a few HP + or -... I want driveability for the car, as it is my DD...

Shortys are also a bit quieter, I suppose...

I will probably have the Kooks repaired and coated and sell them w/ the x pipe.

Any additional thoughts??

[Glenn]

Sounds like your are a good candidate for this option. The shorties are quite, but the hi-flow X-pipe with the rear CATs deleted does open up the exhaust sound and makes it more throaty. But, you have the complete Kooks kit so you may want to consider going back to OEM mufflers and tail pipes like I have. The sound is louder then stock, but no drone.

Good Luck,

Glenn :burnout:

[Spectragod]

I heard that for s/c cars that LTs actually reduce max HP.


Uhhhh, are you serious? Did you see my dyno chart? I will beg to differ.

[RR|Suki]

Thanks for the info.

I have had the kooks LTs for 3 years now, I have the complete kooks kit w/ their x pipe. I removed the cats, and I have magnaflow mufflers...

I have always wanted a bit quiter sound, and I have had the drivers side header pulled and welded twice for a small leak, it is back and I am about ready to change them out.

I heard that for s/c cars that LTs actually reduce max HP. (I have a novi 1200 s/c) I don't care about a few HP + or -... I want driveability for the car, as it is my DD...

Shortys are also a bit quieter, I suppose...

I will probably have the Kooks repaired and coated and sell them w/ the x pipe.

Any additional thoughts??

again, I gained 8mph in the 1/4 just changing to LT headers

[ImpalaSlayer]

this is so funny! :laugh:

[jdenning002]

Sounds like your are a good candidate for this option. The shorties are quite, but the hi-flow X-pipe with the rear CATs deleted does open up the exhaust sound and makes it more throaty. But, you have the complete Kooks kit so you may want to consider going back to OEM mufflers and tail pipes like I have. The sound is louder then stock, but no drone.

Good Luck,

Glenn :burnout:

Glenn,

How much better than stock are the shortys and cobra x pipe???

I am just comparing cost vs. performance.

#1 right now to me is quiet...

I am considering buying stock manifolds, mid pipe and muffllers.

[ImpalaSlayer]

what the hell do the headers have to do with how loud the car is? change the damn mufflers!

[Glenn]

Glenn,

How much better than stock are the shortys and cobra x pipe???

I am just comparing cost vs. performance.

#1 right now to me is quiet...

I am considering buying stock manifolds, mid pipe and muffllers.

I do not know of any MM dyno test before and after. But, the dyno book says the shorties were worth 16 HP at the top end. The book used 2 1/2" straight pipes after the headers. So 16 HP may be it in a dyno test. Keep in mind the Hooker LT dyno test showed 18 HP with the same 2 1/2" straight pipe exhaust, but with the HP at a lower rpm.

You will notice a drop in performance on a NA engine at the low end with the Shorties if you already have the Kooks. It's all an individual choice and what you want and how much money you have to spend. If you're big at the drags and street racing keep the Kooks.


Glenn :burnout:

[jdenning002]

I do not know of any MM dyno test before and after. But, the dyno book says the shorties were worth 16 HP at the top end. The book used 2 1/2" straight pipes after the headers. So 16 HP may be it in a dyno test. Keep in mind the Hooker LT dyno test showed 18 HP with the same 2 1/2" straight pipe exhaust, but with the HP at a lower rpm.

You will notice a drop in performance on a NA engine at the low end with the Shorties if you already have the Kooks. It's all an individual choice and what you want and how much money you have to spend. If you're big at the drags and street racing keep the Kooks.


Glenn :burnout:


The only place I drive is the freeway and lots of it and open road, and I like to be seen and not heard...

It seems like the shortys are the way to go...

[fastblackmerc]

Here is my install.

http://www.motorcitymarauders.com/forums/showthread.php?t=2138&highlight=rack

[jdenning002]

Here is my install.

http://www.motorcitymarauders.com/forums/showthread.php?t=2138&highlight=rack

Wish that shop was near me!

[dohc324ci]

OK Glenn I am getting close to a set of these bad boys!

[musclemerc]

Not you too! ;) This all a part of Glenn's evil plan to take over the world!

[dohc324ci]

Glennatized>? Shorty's rule!

[Kennyrauder]

All this sweating going on...... bite the bullet & go with Kooks ... at least 35 HP with the Magna Flow exhaust .

[dohc324ci]

One word "Kalifornia"!

[musclemerc]

All this sweating going on...... bite the bullet & go with Kooks ... at least 35 HP with the Magna Flow exhaust .

Theirs another set for sale on MCM... Go for it!

[bigmerc'03]

my shorties are great! with my set up 2 1/2 inch pipes high flow convertor and flow master mufflers this this thing is bad azz i turn heads everyday and every where i go

[dohc324ci]

Thats good to know they sound great. what were your gains?

[FordNut]

Thats good to know they sound great. what were your gains?

So are you going to do before & after dyno testing and let us know the numbers? I was searching in some old posts yesterday and found where I posted my numbers way back in '03, the Kooks gave me a 22 rwhp gain on the dyno.

[ImpalaSlayer]

So are you going to do before & after dyno testing and let us know the numbers? I was searching in some old posts yesterday and found where I posted my numbers way back in '03, the Kooks gave me a 22 rwhp gain on the dyno.

shorties would have yielded over 40 ;)

[dohc324ci]

You just cant help it huh Davey....Yes I have been Glennatized and shortys rule!

FordNut, I am going to see if I can do a before (fix tune and run base line) and after so we could have some data on the shorties.

[Smokie]

I also have the shorty headers along with other changes to the stock exhaust, The advantages that I found with my decision were cosmetic (they look better than rusted cast iron), performance improvement over stock manifolds, they cost less than mid length or long tube headers and a primary concern for me is that I want my car to be quiet at cruising speeds and I have been in mm's with "real headers" and the sound level is not acceptable to me.

If you want maximum power gains and cost and decibel level are NOT a concern, the shorties are not for you. Below are a couple of links to some mods I did a long time ago that were modest in cost and produced results that made me very happy. Today I have a 100% daily driver that I can drive to the track and run high 12's and drive home as is, no modifications at the track.

DYNO (http://www.mercurymarauder.net/forums/showthread.php?t=13390)

PICTURES (http://www.mercurymarauder.net/forums/showthread.php?t=13501)

[dohc324ci]

Awesome man Thanks! Shorty's are my only OPTION in California.

[ImpalaSlayer]

You just cant help it huh Davey....Yes I have been Glennatized and shortys rule!

FordNut, I am going to see if I can do a before (fix tune and run base line) and after so we could have some data on the shorties.

lol its just for fun. if i were to do it over id prolly go that route

[musclemerc]

[quote=Smokie;875958]I also have the shorty headers along with other changes to the stock exhaust, The advantages that I found with my decision were cosmetic (they look better than rusted cast iron), performance improvement over stock manifolds, they cost less than mid length or long tube headers and a primary concern for me is that I want my car to be quiet at cruising speeds and I have been in mm's with "real headers" and the sound level is not acceptable to me.

If you want maximum power gains and cost and decibel level are NOT a concern, the shorties are not for you. Below are a couple of links to some mods I did a long time ago that were modest in cost and produced results that made me very happy. Today I have a 100% daily driver that I can drive to the track and run high 12's and drive home as is, no modifications at the track.




These are the EXACT reasons I also went with shorty's. Along with the cost factor, I just cannot justy the expense for LT's. Either way the main restriction on a stock MM exhaust is the mid pipe. No one can argue that shorty's with a 2.5" H, X, or Prochamber are'nt far better than the stock design that goes down to 1 7/8" in some areas.

I will get with you Brian as soon as I hear from the seller! OOPS! Did I say that... ;)