Ideas for putting dual exhaust on my car?

[LTDScott]

When I had my custom cam grinded for my car, the cam guy suggested that the single 3" exhaust in my car is actually around the size of dual 2.25" exhausts. That's not sufficient considering I'm hoping my car will be pulling around 275 rwhp.

So I want to convert my car to dual 2.5" exhaust. This is not a hard job (just like on pre-85 Stangs) except for the factory inline pump and filter being in the way of the passenger side muffler. Here's what it looks like:

http://memimage.cardomain.net/member_images/12/web/324000-324999/324557_6_full.jpg

Ideally I'd like to convert my dual pump system to single pump. The problem is my car uses a 20 gallon tank with the fuel pump and sender combined in one hanger unit like so:

http://www.partsamerica.com/product_images/AAP/CTR/P74511S.jpg

So I can't simply swap in a Mustang hanger and pump.

I've already investigated the fuel lines from a Fox Tbird or Mark VII and I could simply use them along with the fuel filter bracket, but that still doesn't solve the problem of the pump itself. I've also heard that the actual tank from the same cars is a direct bolt-in to my car, but all the self serve junkyards here pull out the tanks, senders, and lines before the cars hit the yards, So buying a new tank, pump, sender, and lines is expensive!

So I'm wondering if anyone has any other ideas on how to make this work?

Thanks!

[shok]

couldn't you adapt a higher psi pump onto the stock pickup assembly? I've heard of other cars doing this without much trouble.
Any idea if those 20 gal tanks fit in a capri? :D

[Anonymous]

I was wondering if you could adapt a mustang high-flow pump to your stock sender??...I've never tried it before but I will be in the not to distant future with my 80 fairmont....so whatever you find that works or doesn't work, please let us know!!

[LTDScott]

Yeah I think I'll end up having to adapt some other pump to the stock hanger. Once I've got the cam in the car and it's running I'll probably pull out the fuel pump and get all the dimensions and see if I can find a similarly sized Walbro high flow replacement.

Then there's also the challenge of getting the lines from a Fox Tbird or Mk7, since like I said before the junkyards hack them off with a Sawzall.

[FoxChassis]

Ideally I'd like to convert my dual pump system to single pump. The problem is my car uses a 20 gallon tank with the fuel pump and sender combined in one hanger unit.

So I can't simply swap in a Mustang hanger and pump.
Will a Mustang/Capri tank fit? (Even though official capacity is 5 gallons less.) Can you "sump" your existing tank?

[LTDScott]

I don't think a Mustang tank will fit, but then again I haven't tried, and have no way to do so short of buying one.

I suppose it is possible to sump the tank, but I want to keep full capacity. I do drive this car hundreds of miles sometimes.

[FoxChassis]

Putting a sump in/on the tank doesn't diminish capacity one bit. In fact it adds a small amount (the volume of the external sump).

http://mustang50magazine.com/techarticles/p57651_image_large.jpg

http://www.competitionengineering.com/catalog/CategoryDisplay.asp?CatCode=10070
http://www.aeromotiveinc.com/products/product.phtml?p=27
(18650 - Universal, Baffled Fuel Tank Sump)

http://www.hotrod.com/howto/70438/
http://media.mustangworks.com/showgallery.php/cat/3076
http://moparmusclemagazine.com/projectbuild/155_0401_fuel_flow

[zak]

Scott,

I still think, based on the Vizard article that I PM'ed you, that a 3 inch single will support ~ 300 crank hp, and even then might only cost ~ 5 hp on a 325 hp engine, in this range the muffler flow becomes important (Borla XR1 or Performer RPM would be wise choices based on their design)..

About 10 years ago was the last time I seriously looked into getting duals onto my LTD LX. The plan was to drop the 20 gallon tank and install an LTD 16 gallon fuel tank, as the extra volume is all on the passenger side where one would want to run the other pipe. The aftermarket still has them, expect to pay around $100 for the (new, aftermarket) tank. May still yet have to do this if I try to bolt an IRS on this . . . .

How do the 86+ cars route the fuel lines w/r/t the H-pipe/exhaust?

zak

[Dean_T]

Hi Scott,

AS you know, I'm facing a similar dilema with the Friggin' Futura. Is there a way to adapt the EFI Fox Mustang Fuel pump onto your sending unit? I'm sure those Mustangs only have the one in tank fuel pump. I plan on buying an EFI Mustang fuel tank and forcing it to fit the '78 rear trunk pan - some welding will be necessary.

Doesn't Ecology wrecking yard out near browns field still leave the tanks in but drill a half in hole to drain the gas? I know the Pick-Your-Part yards remove them and trash everything in the way. I'll have to check to see if my favorite yard in Sun Valley leaves their tanks in. I seem to recall they just tear a gash in the tank to drain them.


Regards,

Dean T

[LTDScott]

Zak, I know you think that 3" single is adequate, but think about this: A single 3" pipe has a volume of 28.27". Dual 2.25" pipes have a volume of 31.81". Dual 2.5" pipes have a volume of 39.27". So my single 3" is smaller than a stock 86+ Stang exhaust! A lot of folks say the first mod that a Stang owner should make is to uncork the exhaust. So I definitely want to go bigger.

The issue is not the room for the tailpipe next to the tank. There's just enough room there for a pipe to fit, so swapping to a 16 gal tank won't accomplish anything. The issue is the pump on the frame rail. There was no 86 LTD LX, but the V6 cars still had the same pump setup.

Dean, the Stang in-tank pump (just the pump) is a different size than on the LTD. Doesn't look like it'll fit the LTD hanger. The Ecology yards down here completely remove the tanks and use Sawzalls to do it! So the tank, lines, and wiring are unusable from there.

So you see my problem!

[Dean_T]

Hi Scott,

Bummer regarding Ecology - I thought they used to just cut a small hole.

I vaguely recall the Vintage Mustang folks that convert to the EFI roller 5.0L sometimes use an external fuel pump from an EFI F-150. Could that be done in your case? Retain the stock LX in tank fuel pump, install the second fuel pump near the fuel tank and relocate the fuel filter to the same general area?

Yeah, I know, how to plumb everything without having leaks everywhere. I hope Phil and his parents bring their 5.0L LTD wagon to Knotts. I'd be very curious how they dealt with this.

Regards,

Dean T

[boway]

Hey Scott, Are you still looking for fuel lines? I think I can help! I also have info on pumps and tanks. E-mail me if you are interested boway@webtv.net, Binnie

[LTDScott]

Hey Scott, Are you still looking for fuel lines? I think I can help! I also have info on pumps and tanks. E-mail me if you are interested boway@webtv.net, Binnie

Absolutely! Once my car is up and running, the fuel system/exhaust is the next thing I want to tackle. I'll shoot you an email when I get home or you can always post info here. I'm sure any info you have wouldn't be wasted here on other people.

[frink84]

Yeah, I know, how to plumb everything without having leaks everywhere. I hope Phil and his parents bring their 5.0L LTD wagon to Knotts. I'd be very curious how they dealt with this.


yea we are planning on coming this year

[LugNutz]

I'm bringing this back to the top, good info here that I need to get rid of my in-line pump on my 84 CFI. I'm trying to install a catback but need to move my pump...

[boway]

Hey Scott,

I saw a reply to a post of your's on The Corral were 84' LTD LX was telling you to use a 87-88 TurboCoupe fuel tank so you could run dual exhaust. I did some research and the problem with that is the 85 up T-Bird, Cougar, Continental and Mark VII uses a high resistance fuel sender that will cause the LTD dash gauge to read backwards. I see no benefit to use a different model fuel tank as the LTD has plenty of room for a right tail pipe, and we can do like the SVO and XR4ti guys and upgrade our in-tank pump to a high pressure one.


This is an e-mail I sent Ron Gregory at APE:

I have a 1985 Ford LTD LX 5.0 HO with CFI. It has a low pressure in-tank pump and a high pressure external pump. What I am looking to do is replace the low pressure in-tank pump with a high pressure pump and replace the external high pressure pump with a filter. I got the idea from this Merkur site:

http://www.merkurencyclopedia.com/Fuel/Fuel_pump_upgrade.html

Also here is a pic of what my pick-up and sender looks like:

http://www.partsamerica.com/product_images/AAP/CTR/P74511S.jpg

Do you have a pump kit that will work? What is the part# and price? I know of a few others that are interested too.

And here is his reply:

"I don't have any catalog info from Walbro about your LTD. But, from looking at the photo you sent a link to, I don't see why a FPF003 wouldn't fit in your tank assembly. Without measurements, I'd be guessing, though.

The pump in the photo looks shorter than the Walbro pump, but it appears there is plenty of room above the pump to trim a piece of hose to fit. The pickup filter in the FPF003 looks similar to the one in the photo, too.

From looking at the photo you pointed me to, I don't think there is a better choice for a performance upgrade.

Ron Gregory
Auto Performance Engineering
http://APEusa.com"


Scott for relocating the fuel filter your idea of using the 85 up T-Bird fuel lines would be no problem. There is a self-serve junk yard near me that Does Not pull the tanks or puts a stand under the tanks. Let me know if you need the lines just to the filter or all the way to the front.

The only other thing I can think of is the wiring issue that is in the Merkur site above. I have other links that address that issue also.

Binnie

e-Mailed and Posted to Four Eyed Pride

[LTDScott]

You and I have the same idea. I already emailed APE about this and he
said that this could be done. He said that Mustang SVO guys have been
doing this. Well I asked the SVO guys and it turns out that most of
them have just been using the tank hangers from later 5.0 Mustangs and
putting them in their original tank. Not an option I have.

I then did the exact same thing as you and pulled up a pic of our pump
from Kragen and sent it to APE but never got a response. Glad to see
you got a response from him. I think this is the way I'm going to go.

The only question I have is regarding the wiring. The SVO and XR4Ti
guys say on their cars they have to run a new ground wire because
there is a resistor in the factory wire. I checked the factory EVTM
for my car and there is no mention of a resistor. I suppose it's easy
enough to just run a new ground wire just in case.

Regarding the fuel lines, I would love to get the Tbird/Mark lines if
you could get them. I think I'd just need the pressure line from the
tank to the frame pump. I think the line from the frame pump to the
engine is okay. I'll have to look a little closer. My torque box
already has the holes in it for the Tbird's sideways mounted fuel
filter. Gotta love Fox body interchangeability! So all I'd need is the
filter bracket and the body nuts (I can get them locally).

I won't be able to do any of this stuff until I get my damn car back
up and running and smogged.

Thanks,
Scott

[boway]

Hey Scott,

I will hit the yard later in the week, I will let you know how I make out on the line.

Binnie

[boway]

Hey Scott,

I got your fuel line. E-mail me your address and I will get it sent out tomorrow.

boway@webtv.net

Binnie

E-mailed and posted to Four Eyed Pride

[LTDScott]

emailed. Thanks again!

[LTDScott]

Binnie, I got the line. Thanks so much! Won't be able to use it for a little while but I want to at least see if it'll work properly.

[boway]

Hey Scott,

Good Luck, and keep me posted.

TTYL, Binnie

[FoxChassis]

Yes, keep us all posted on all the parts and modifications required to accomplish dual exhaust on your LTD LX. In other words, let me know so I can copy you. :D

['84 LTD LX]

WOW...Just poking around and it seems I get mentioned on boards I don't visit. Well I'm registered now and will be posting often.:D


My current LTD LX is still a roller right now, but I've had 4 of them with several different combos over the last 15-16 years, yeah I'm old. I do plan on using a built 347 shortblock, Brodix heads and a 3500 stalled AOD. 8O

The LTD should be running by now, but I spent the last of my budget on my newly purchased '85 GT. BTW...Black, loaded with options, T-Tops, very little rust, T5Z, 5 lugs and lots of suspension mods.
---
Way back in '91 on my '85 SSP LTD (I had a 308 in it), I used stock '86-93 headers, stock '86-93 four cat h-pipe, and a 2 1/2" Dynomax SuperTurbo exhaust kit for an '87-93 GT ( IMO...cheapest one out there with good mufflers). I added the '86-93 Mustang H-pipe hanger when I swap the single hump crossmemebr for a double hump crossmember out of an '84 5.0L AOD cougar and the '86-93 Mustang tailpipe hanger on the passenger side. The stock LTD LX hanger will work on the driverside. I also used the stock gas tank. I added 2 1/2" pipes on the other 3 LTD,'s that I've owned in the past and never swapped the gas tank in any of them.

The '86-93 Mustnag GT Dynomax kit comes in 3 sections, flowtubes, mufflers and tailpipes.

Go ahead and yank the old exhaust.


Now go ahead and install the crossmember, and the two hangers. Next install the headers and h-pipe.

Go out back, install the tailpipes and just hang the mufflers on. Next , bolt on the flowtubes and measure the gap in between the flowtube and muffle. Use some generic 2 1/2" exhaust pipes to lengthen the pipes about 5 inches. Get some pipe about 12" long that will slip over the flowtube and slip into the muffler. These 2 1/2" extensions are common and should be about $5 each.

Once you get everything hung, go back and make sure everything is even and has clearance. Then tight/clamp/weld your new duals together.

The '87-93 GTs have a turndown at the end of the exhaust. Even though they are a little short, they still look OK.

[LTDScott]

WOW...Just poking around and it seems I get mentioned on boards I don't visit. Well I'm registered now and will be posting often.:D


My current LTD LX is still a roller right now, but I've had 4 of them with several different combos over the last 15-16 years, yeah I'm old. I do plan on using a built 347 shortblock, Brodix heads and a 3500 stalled AOD. 8O

The LTD should be running by now, but I spent the last of my budget on my newly purchased '85 GT. BTW...Black, loaded with options, T-Tops, very little rust, T5Z, 5 lugs and lots of suspension mods.
---
Way back in '91 on my '85 SSP LTD (I had a 308 in it), I used stock '86-93 headers, stock '86-93 four cat h-pipe, and a 2 1/2" Dynomax SuperTurbo exhaust kit for an '87-93 GT ( IMO...cheapest one out there with good mufflers). I added the '86-93 Mustang H-pipe hanger when I swap the single hump crossmemebr for a double hump crossmember out of an '84 5.0L AOD cougar and the '86-93 Mustang tailpipe hanger on the passenger side. The stock LTD LX hanger will work on the driverside. I also used the stock gas tank. I added 2 1/2" pipes on the other 3 LTD,'s that I've owned in the past and never swapped the gas tank in any of them.

The '86-93 Mustnag GT Dynomax kit comes in 3 sections, flowtubes, mufflers and tailpipes.

Go ahead and yank the old exhaust.


Now go ahead and install the crossmember, and the two hangers. Next install the headers and h-pipe.

Go out back, install the tailpipes and just hang the mufflers on. Next , bolt on the flowtubes and measure the gap in between the flowtube and muffle. Use some generic 2 1/2" exhaust pipes to lengthen the pipes about 5 inches. Get some pipe about 12" long that will slip over the flowtube and slip into the muffler. These 2 1/2" extensions are common and should be about $5 each.

Once you get everything hung, go back and make sure everything is even and has clearance. Then tight/clamp/weld your new duals together.

The '87-93 GTs have a turndown at the end of the exhaust. Even though they are a little short, they still look OK.

THREAD RESURRECTED FROM THE DEAD!

You never mentioned anywhere here about the fuel pump being right in the spot where the pass. side muffler is supposed to be. If you read the whole thread, you'd see that this is the main problem I had.

But it's solved now. Bought a Walbro high flow pump and converted the in tank pump to high pressure, and I now have most of a Mustang exhaust system in my garage ready to be installed on the car when I have a few more bucks.

[paul78zephyr]

Scott,
Im sorry I did not reply here before. I cant remember if you and I discussed dual exhaust stuff somewhere before. But if we did not here is what I did on the Zephyr:

My Zephyr has a stock 87-93 type 5.0L Mustang exhaust system consisting of the stock headers, stock 4 cat H-pipe, stock tubes from H-pipe to mufflers, stock mufflers, and stock stainless steel LX type tailpipes. Obviously I used a double hump crossmember - modified to fit the early F/Z mounting brackets. I used short lengths of 2-1/4 exhaust tubing to 'stretch' the exhaust system between the stock tubes and the mufflers due to the F/Zs 5" greater wheelbase. The mufflers mount using the stock Mustang forward mounts/rubber. The necessary holes are already in the unibody (near the forward rear upper control are mounting brackets) for the U-nuts that the brackets mount with. The only 'problem' (not really) that I had was there is no threaded holes in the rear frame rails that the late Mustang has for mounting the tailpipe hanger brackets. So I got everything bolted in (bolts hand tight) and supported each tailpipe by putting the rubber isolator and mount on the tailpipe and used C-clamps to clamp the stock brackets in place on the rear frame rails - repositioning them until I had the pipes in the right location and even/level. I had the fuel tank out at the time to replace it so I had room to work. I then marked the frame rail thru the holes in the mounting brackets. I then removed the clamps and using a right angle head on my drill and shortened bits I drilled pilot holes in the frame rails. I then used stainless steel self threading screws to permanently mount the tailpipe hanger brackets. Im using a stock (although new) 78 Zephyr fuel tank (carb type) and have NO clearance issues with it and either tailpipe. Its a bit close on the passenger side but no closer than on stock Mustangs.

It sounds like you already know most of how to do your exhaust but I just thought I'd add my info.

Paul

[LTDScott]

Paul, the more info, the better! As I said before, my biggest challenge was the fuel pump relocation. But now I have that sorted out.

As you said, the actual exhaust is fairly easy. Just take Stang stuff and lengthen it. I already bought the mufflers, flow tubes, and tailpipes. I just need to decide which H or X pipe I want and take it to my friend's shop. I'll probably have the passenger side muffler hanger welded on to the rear "frame" like the quad shock brackets were.

['84 LTD LX]

You never mentioned anywhere here about the fuel pump being right in the spot where the pass. side muffler is supposed to be. If you read the whole thread, you'd see that this is the main problem I had.

But it's solved now. Bought a Walbro high flow pump and converted the in tank pump to high pressure, and I now have most of a Mustang exhaust system in my garage ready to be installed on the car when I have a few more bucks.

You still had the low pressure-high pressure system feeding the EFI conversion ?

I just ASSumed it was already upgraded to a single pump. along with the other mods. Mine have been carb. conversions and I just yanked the stock stuff out and tossed it. I the use a mechanical fuel pump for a '69 351W Mustang, carb. timing cover and run a 5/16 hard line for the supply.

The last LTD LX I bought, had a single in tank pump feeding the CFI. This was a 'reconstructed' vehicle and it may have been swapped by a previous owner during the rebuild. This car is long gone...


Hey, you find me a passenger side tailight yet ??? :P

[FoxChassis]

Whomever is finding parts, find me a whole front end!. :D

I need to fix this:

http://www.foureyedpride.com/phpBB2/album_pic.php?pic_id=4232

[LTDScott]

I just ASSumed it was already upgraded to a single pump. along with the other mods.

Hey, you find me a passenger side tailight yet ??? :P

Yup, it ran just fine on the dual pump setup. Converting to single pump was the biggest obstacle I had, and it took some creativity on my part to solve it. Nobody else seemed to know how to convert it over, short of using a Tbird tank, which isn't cheap.

No taillights. I haven't been to the junkyards in a while, and it's been ages since I've last seen an LTD LX in there.

Foxchassis, just use a normal LTD front end and paint the grille and headlight bezels the proper colors. There's nothing specific about the LX nose except the grey rub strips on the bumper. Everything else can be painted.