I just picked up my f-150 SC 4x4 yesterday after having a custom exhaust installed. It sounds great. But I have 2 issues, can anyone help!!

1. I have lost noticiable low end. The man who did the work said that maybe we could reduce the pipe just before the muffler to 1 1/2" or so to possibly increase back pressure or put resonators(?) in the cat back pipes? Does anyone know if this will work or what else can I do?
2. The cab noise is more than I expected. I drove about 200 miles today an it started to get to me. I noticed that in the rear wall of the cab when you remove the seat that there was only sheet metal. Would some type of insulation work? Also what is the deal with the 2 vents?

Thanks for the help.

 

UCRed,

You've run into what others have reported here in the past - open up the exhaust too much and you lose backpressure and low-end torque.

From your description it sounds like you had duals installed? I'm not sure if this is the correct way to figure this but let's use it for the sake of argument:
- the stock exhaust pipe is 2.5"(id). If I remember - that 7.85 sq. in. of area
- if you went with dual 1.5" pipes that would be 9.42 sq. in. of area
- if you now have dual 2.5" pipes (my assumption from your description) you are running a whopping 15.7 sq. in. of area pipe.

Sounds like the dual 1.5" would provide more flow area than the factory single pipe. Or you could go with a single 3" exhaust pipe and get the same flow.

Regarding the drone - there are several things you can do. To keep the inside of my truck quiet I installed a Flowmaster 50 series Delta Flow muffler that keeps the sound going out the end of the pipe instead of allowing it into the cab. Another thing I did was to remove the back seat (mine is a supercab) and the side panels and all trim from the back area. I sprayed adhesive on all the bare metal areas and installed one continuous sheet of 3/4" dense foam rubber that runs from the left 'B' pillar, around the back to the 3rd door opening. The foam runs from the bottom of the rear window down below the carpeting. It made a very big difference in the noise level - almost as quiet as my mother's Buick Park Avenue. You can buy sheet foam at any upholstery shop, or even from the J.C. Whitney catalog.

The two vents are big contributors of road noise in the cab. They are nothing more than rubberized flaps that allow air to escape from the cab when you close the doors or have the vent blower running. The drawback is that they also allow road noise, tire hum and exhaust sound into the cabin. I laid the foam rubber right over the vents. The foam is porous enough to allow air to pass thru.

I hope this helps some.

Tom in Tacoma



------------------
1998 F150 XLT S/C 4.6L Auto, 3.55LS, 4X2, Moonlight Blue, all the factory bells & whistles except for leather seats.

• Lund Deflector
• Lund Premier Tonneau Cover
• K&N Filter
• Body-color painted Throttle Cover
• Blue wire-looms
• Pentaliner S/R
• Window tint
• Ford side-steps
• Infiniti component speakers - front
• Polk Audio speakers - back
• Superchip (OH YEAH!!)
• Flowmaster 50 Series 'Delta-Flow' w/ 3" pipe
• Clear turn signal lenses
• Ultra Type 50 16x8" Rims
• Wild Country APT 255/70-16's

Tom in Tacoma

(Washington not Toyota)
Go check out http://communities.msn.com/SS97FordsPics for the second best website for F150's

 

hey guys,

tom, i gotta hand it to ya, the foam thing is a great idea, i will be doing this soon....ok, ucred, i have not seen the 1.5" pipes in a long time...when i first had my straight duals installed i had the guy ( a buddy of mine) use 2.5" pipe...big mistake....lost lots of low-end...took it back and had him redo with 2.25" pipe ( still a buddy of mine, lol)...my torque was restored.....the smaller pipes are the key, just don't go too small....i have the 4.6 and have the factory grunt with a better top-end, now...good luck, Rich

------------------
-1999 F-150 4X4 SC
-4.6, auto
-3.55 gears
-Westin chrome nerf bars
-dual straight pipes
-hikerdadrich@aol.com

 

UCRed,

What exhaust setup did you use? I keep debating on the whole exhaust issue. I was planning on going with Flowmaster 40 Delta Flow single in-dual out.

------------------
2000 F-150SC 5.4L 4X4ORP
DEEP WEDGEWOOD BLUE
AUTO, 3.55LS, TOW PKG.
CAPTAIN'S CHAIRS,
REMOTE KEYLESS ENTRY
REAR SLIDER
PREMIUM SOUND w/ CD
RHINO LINER
STATE ISSUED UNIV.OF GA. PLATE.
UGA RECEIVER COVER
UGA LICENSE PLATE(FRONT)

WISH LIST:
FLOWMASTER DELTA 40
AIRAID FIPK
SUPERCHIP
TINTED WINDOWS
HOOD DEFLECTOR(PAINTED)
RAIN GUARDS(PAINTED)

A NATIONAL TITLE FOR UGA(FOOTBALL)

 

I'm sorry to say that unfortunately you were not forewarned about the loss of back pressure dual exhausts create. I too originaly wanted a dual exhaust system on my Supercrew but JBA Headers urged me not to go for it. They suggested a single 3" and I'm happy they did.
Also, I got a chance to ride in a 40 Delta Flowmaster equipped F150, before deciding between a 40 or 50 series, and I found the 40 to be way to loud for me. I really dont want to hear my exhaust when the windows are rolled up and have resonance on long trips.
Using the JBA shorty Headers,3" single 50 Delta, and an FIPK really does the trick. I highly recommend it. Still loud enough to excite me every time I start it(turns heads too!)and make car alarms chirp as I motor by. Not to mention much better performance.
Quick note:Your muffler will quiet down a bit after you put about 2,000 miles on it.

 

What is a FIPK?

 

ptfii, why would you go with headers if running a single exhaust? What did that do for you?

 

Fuel Injection Performance Kit (K&N).

------------------
2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification, Superchip,
Dynomax ultra-flow welded 3" cat-back,
3" exit Y-pipe, Hellwig rear anti-sway bar.

 

What it did for me was about 30 more horsepower according to the dyno. The JBA headers w/a flowmaster single 3" exhaust system is what that company recomends using.I did not loose any low end torque or enough that's noticable.Can't stress enough how sweet it is!Get compliments on the sound and even from the Master Tech's at Ford service dept.

 

Wow I went away for a couple of days and came back to a great response. thanks.

Tom, I appriciate the info on the amount of volume. I feel like an idiot, that I did not think about that before I did this! The good news is that I have called the shop and they have agreed to make any changes to make me happy. I have dual SS from the cat back. I love the sound and am not sure if I want to give that up or not.

Ptfii, Bad news I already have the PIFK. I can't even think how poor the perormance would be if I didn't have that already on.

Do you guys think installing a chip would bring it back leaving the duals?

 

Wemjr,

I had a Custom shop make me Stainless duals from the cat back. They used 2 mufflers that look like glass packs to me. They are not very big. I told them that I wanted it to sound like I had an engine! And it sounds great!! I went with these guys because Gibson and the like were telling me that I would have to move the spare tire. Also It turns out that it was a good move because these folks are willing to work with me through my power issue.

 

Max,

I noticed in your write up you appear to have duals out of the muffler and a superchip did this help the low end?

 

UCRed- I do not have duals out of the muffler. I have a 3" single system. It is similar to the factory 2.5" system. I had the Y-pipe cut out and replaced with one that exits 3" instead of 2.5". That way my 3" cat-back system is fed by 3" pipe. Most of the cat-back systems that are 3" still use the 2.5" Y and some 2.5" intermediate pipe. This is the most forward restriction. I believe to fully utilize a 3" cat-back system, it needs a 3" pipe leading to it. On my application, my experience is as follows: no loss or gain in low end torque or towing, substantial gain in top end WOT performance. As for the Superchip, I believe that this is the best mod for the money/HP/effort. For the chip, my experience is as follows: shift lag removed, increased performance at all speeds and conditions, 2nd gear rubber when manually shifted while floored. I hope this helps some. Do you have true, completely separate duals or duals from the muffler back with a single forward section? What year truck and engine do you have? What size pipe did they use?

------------------
2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification, Superchip,
Dynomax ultra-flow welded 3" cat-back,
3" exit Y-pipe, Hellwig rear anti-sway bar.

 

You'll not find anyone that will sing the glory of a Superchip more than I will (you really should get one). It's a rare occurance that someone installs one and does not think it worth the money. However, to install one thinking that it will 'make right' an otherwise detrimental modification will surely result in a thumbs-down opinion of the Superchip.

Fix the exhaust first - then install a Superchip. That will give you two excuses for the grin on your face.

Oh yeah, if/when you contact Mike Troyer for your Superchip - tell him Tom in Tacoma says "Hey". Ask him about the VW bug we used to run around in - great story.

Tom in Tacoma

 

Well I have an appointment this thursday to see what can be done. At least with the info you folks have provided, I will be able to give direction. I will let you know what happens. Thanks again for all the info.

By the way Tom, I used the idea of the foam behind the seat. I worked out great. I couldn't find the foam so I used carpet padding. I had to cut holes in the pad for the vents because the truck was too tight.