3.8 Exhaust System

Topic: 3.8 Exhaust System (Read 2075 times) previous topic - next topic

3.8 Exhaust System

November 17, 2016, 06:35:03 PM

I've been considering upgrading my Cougar's exhaust system. I'm not dead set on anything other than wanting to use the SN95 headers due to cost and apparently decent performance. Being that I have an 88', I'm aware that I won't run into obstructions if I want to go with a dual exhaust setup but I'm also open to doing a single 3" setup. My limitations are that I have a column shifter (which I don't plan on changing anytime soon) and I need to car to pass emissions so the cats must stay.

Any recommendations?

3.8 Exhaust System

Reply #1 – November 17, 2016, 09:13:00 PM

The SN95 manifolds will fit a Fox 5.0 H-pipe, but don't go bigger than 2 1/4. You'll have to cap the EGR tube on the manifolds IIRC. If you go dual and H-pipe as I've said, I'd go with Mark VII mid pipes and tails as well. Whatever lers you want, but the Mark VII stock cat back is 2" which should be more than enough for a good increase on a 3.8/4.2 without being too much and costing you precious low end torque. When I built my 3.8 car back in the day, I used a Windstar cam with Dynomax Super Turbo lers and it sounded pretty nice. Mine was 2 1/4 all the way back, and it seemed like it might have been too big. That said, mine was CFI and it was the CFI that was the performance bottleneck. If yours is an 88, it's SFI and with that being the case you can go a lot further power wise.

3.8 Exhaust System

Reply #2 – November 18, 2016, 01:38:36 AM

X2.

I actually attempted a h-pipe and header swap on my old 87 v-6, the biggest problem was the shifter linkage. Being young and dumb, I just gave up on in. There is actually a few different places to adjust and move the stock linkage, with a bit of work you should be able to make it work.

The 87-88 exhaust hangers are completely different on the 87-88 cars. I swapped my car back from my 86 and they are too wide to fit. The 87-88 have the mini spare bump and it gets in the way of the older hanger setup.

Im sure generic aftermarket hangers or even bent up steel with holes drilled in it from the hardware store would work fine, but just something to keep in mind.

3.8 Exhaust System

Reply #3 – November 18, 2016, 11:42:28 PM

Good to know, Haystack. I wasn't aware that adjustments could be made to the linkage. I'll look into how to make the adjustments tomorrow.

TheFoeYouKnow, how did your engine perform with the windstar cam and dual exhaust? Was there anything else you did to optimize your 3.8? Just curious because I'd like to squeeze as much as I can out of mine. I'm really not planning on doing a V8 swap, which I know most people would suggest.

Also, since this is an even firing engine is there any advantage of using an H/X pipe as opposed to running a divorced dual exhaust?

3.8 Exhaust System

Reply #4 – November 19, 2016, 07:59:24 AM

Even fire or not, having a balance tube is important for cylinder scavenging. You can use an x if you want, but an H is easier and cheaper to get. I'd look for a used stock 5.0 Mustang h-pipe, you could probably get it cheap and you'd have all the flow you'd probably ever need.

As for my engine, it had a cfi on top and couldn't breathe as well as it needed to. It probably ran 175 or 180 horse. With your setup, I'd mess around with different stock heads and intakes. I saw a guy who used a Windstar cam, split port heads, Mustang split port lower, early 4.2L truck vacuum split port actuators and a Freestar 4.2L upper. He was crazy, but he said it ran hard. Most importantly, there's aftermarket support for your setup.

3.8 Exhaust System

Reply #5 – November 19, 2016, 10:18:36 AM

I've read a little about doing the split port swap but am anxious about how long the change over would take.

Would it reasonable to expect around 200hp if I were to do the following?

- Bigger Throttle body
- Ported Intakes
- Ported Heads
- Roller Rockers
- Underdrive Pulleys
- SN95 Headers + Foxbody Dual Exhaust

Id probably want to go with a bigger cam later on as well.

3.8 Exhaust System

Reply #6 – November 19, 2016, 12:47:08 PM

Skip the underdrive pulleys, the charging and cooling losses (with a 60A alternator you can't really afford any losses) aren't worth it. I think to get over 200, you're going to also need a tune. I'd say if you're going to go that far in the first place, go big or go home and start with a 4.2L and a cam. The 4.2 already had over 200 in the F truck, so it's a solid starting point.

3.8 Exhaust System

Reply #7 – November 20, 2016, 05:08:46 AM

And to be honest, the amount of labor alone isn't worth the power. I did a few things to my 3.8L back in the day. To be honest, the best thing to do with a 3.8L is drive it, or pull it out.

Doing a heads/cam/intake to maybe make the same power as a 5.0 is disappointing.

But, in the spirit of helping you gain some power and speed, keep in mind that there are plenty of things other than the engine that will liven the car up. A set of 3.73 gears and a stall converter will wake it up. Get rid of the clutch fan and get an electric fan.

3.8 Exhaust System

Reply #8 – November 20, 2016, 11:02:10 AM

I have a TC 7.5 traction lock rear with 3.45 gear that I will swap in hopefully soon. I'm going to attempt to make this car my daily driver at some point soon so engine swaps right now are out of the questions, otherwise I'd definitely go with a 302 being that there is so much support for it. I'm just thinking about fairly inexpensive things I can do right now to give it a little more pep.

Tbird232ci, can you tell me more about the electric fan setup and what the benefits are?

TheFoeYouKnow, if I did a 3G alternator conversion would the underdrive pulleys be worth it? So you know on the cooling side of things, I just dropped in a new 3 row aluminum radiator and thermostat.

3.8 Exhaust System

Reply #9 – November 20, 2016, 12:24:36 PM

You don't want to sacrifice coolant flow. At every engine speed, the water pump is turning more slowly, which means less heat is being carried to the radiator. Upgrading the radiator will not help to offset the loss of flow. Will it be a problem? I don't know, but the idea makes me uneasy. Typically, you want to increase flow and thereby carry more heat away from the engine, especially if said engine is upgraded to produce more power (power is heat). With more heat and more flow, you then need more surface area with which to dissipate heat to the air and out of the coolant before it's carried back to the engine. Nobody should ever install under drive pulleys, they don't increase power, they reduce parasitic drag, and by so little that they're almost irrelevant. Example: many cars are quicker and faster that police cars, but police cars aren't meant to outrun, they're meant to outlast. 5% lower parasitic drag gains you almost nothing, but costs you somewhere like 33% of your idle coolant flow and charging current depending on the ratio of underdrive. So would you rather be 5% faster, or run flat out 33% longer?

3.8 Exhaust System

Reply #10 – November 20, 2016, 02:46:27 PM

Good point. Especially if the gains are marginal it won't be worth it for the potential risk and money. I'd like this car to be reliable more than anything.

3.8 Exhaust System

Reply #11 – November 21, 2016, 12:59:05 AM

I've used under drive pulleys on a TC and my LT1. The LT1 only has the A/C and power steering on the belt, so it really make a difference. I got the pulley for 25 bucks so it was worth a shot. The TC showed no real difference. No measurable difference in performance or cooling. Once again, it was inexpensive so I figured it wouldn't hurt.

The electric fan reduces the load off of the crankshaft. It actually did make a noticable differnece on my 3.8L, which was a CFI car. I used a bunch of aftermarket back then, but I found an article that gives a basic idea on how to do it.

http://www.fordmuscle.com/archives/2003/02/electricfan/index.php

Upgrade to a 3G alternator (which should be done on every fox body) and toss the fan on.

3.8 Exhaust System

Reply #12 – November 21, 2016, 04:30:30 AM

Agree, the 3G is absolutely required for an electric fan. I like the 207 degree fan switch (low speed) from an Escort GT. I've got the diagram for the electric fan setup I built in one of these threads somewhere.