Thoughts on exhaust for Explorer engine swap

[drhill]

OK,

After driving my bone stock 90 Town Car for a few months I'm in need of a bit more passing power and grunt for getting on the freeway etc. I guess if I drove like a grandma the 150hp would be fine but I don't have time for that. I'm thinking a relatively low mile 96 explorer engine with the necessary conversion parts (flipped TB linkage, bored out EGR spacer). I am looking to keep the cost down and keep the stock 3.08 gears for hwy mpg. I have a mark VII converter that stalled at about 1800 rpm in my wagon that I could use as well as 1 5/8" mustang shorty's and a stock mustang h pipe. OR I could just stick with the factory lincoln logs and factory cat pipes and upgrade to factory duals as there is a car in my local yard that has a set. I do want to keep this car quiet. Any thoughts?

How much of a HP difference am I looking at between the mustang exhaust stuff and the oem exhaust stuff?

Thanks!

[His Royal Ghostliness]

Don't choke the explorer heads down with those Lincoln logs, use the Mustang parts. What size is the H-pipe anyways? What about the dual exhaust out of the junkyard car, what size is it? Splicing the two will likely give you the lowest cost for a decent system - it won't flow as much as a full 2.5" setup, but at the same rate with 3.08 gears you're in the low RPMs all the time so your engine just doesn't produce enough flow to utilize a big exhaust. I'm thinking something like the shorties, 2.25" H-pipe, and 2" tails will work quite well in your application. Then later on upgrade as needed.

[gadget73]

Stock duals would do it, but you can probably get a bit more out of it if you wanted to. I might consider a decent pair of mufflers and larger tailpipes at a minimum. The stock ones are not very big, and with all the bends it doesn't flow that well. Those huge quiet mufflers also do not do great things for performance. Maybe a pair of Walker QuietFlow mufflers, and tailpipes for a 90s Impala. You used to be able to get a nice 2.5" mandrel bent tail for the 96 Impala SS that fit in there just nicely, but I think its out of production. I believe the stock tails are 2.25", where the Lincoln ones are 2".


Stock head pipes are 2.25", the H pipe necks down to 2" just behind the flanges.

[drhill]

Thanks guys. I'm trying to do a quick and dirty swap with parts on hand...I also have a pair of summit 2.5" turbo mufflers sitting int he garage that droned too much for cross country trips in my wagon so I replaced them with late model mustang GT mufflers. On second thought - i want this car quiet too

Well the jyard wants 33 bucks per side for the duals in the yard. Rockauto still carries the 2.5" mandrel bent over axle tailpipes for the Impala SS for about $35 each plus shipping. coupled with my free mufflers and free headers this would be the best way to go performance wise. I would just need to get someone to weld up hangars for the tails and pipe from the mufflers to the h pipe. This is what I did on my wagon..worked great. I'll still probably do quieter mufflers since I remember how droney these summit turbos were. I may consider taking out the first two cats on the h pipe because the driver side cat interferes with the shift linkage.

I'd love to get about 250hp out of this thing but likely not with the explorer cam in there. maybe with a stock ho cam and then the governor from my HO AOD? Shoot, then it would just be a TFS stage 1 cam and 3.73s away from being a hot rod

[gadget73]

I've wondered what might happen if you used a short glasspack behind the tailpipe as a resonator. The stock Impala exhaust used that. Also, different length mufflers are supposed to help with drone. The stock Mark VII exhaust had different muffler lengths and different tailpipe diameters to stop that. It did work, those things were whisper quiet in stock form.

[drhill]

Yeah, when I had mustangs I looked into drone elimination. The factory did use different mufflers on each side. They didn't use different pipe size on those but I would believe it on the mark viis. I may try the different size muffler trick

[88Vic]

Use what you have and see how you like it. If you have factory Mustang H-pipe, that's 2.25" and I assume that's what you mean when you say taking out the cats, on the Mustang H, not the factory cats. If I were you, I'd just either cut out all 4 cats and weld in 2 cheap highflows, or scrap the H-pipe for cash and buy an offroad H-pipe and weld in highflows if that's easier, and you'll have all new pipe to mess with.

If you go that route, some Mustang guys say eliminating or using highflow cats reduces drone, don't know why but weird tricks work sometimes. In that case, the Summit Turbo's may be quiet enough. The sedans don't drone quite as much as wagons anyways so you might be fine there. If not, weld in a pair of short perforated-core glasspacks so it won't reduce flow but it'll reduce drone.

The bone stock duals with pipe in place of mufflers on my Lincoln doesn't drone at all. Might be a tad loud inside to some people, but not loud enough for me, and I'm getting to the point where I like milder exhaust noise inside, most of the time.

[knucklehead0202]

I recently bought a '90 LTD/Vic. The exhaust is deafeningly quiet and I can't stand it. I have procured mustang shorty headers, a mustang off-road h-pipe, moroso spiral-flow mufflers, flow tubes, and impala SS 2.5" over-axle pipes. I plan to finish this off with tucked-up turndowns at the rear, don't want crap hanging down. Not sure how loud it'll be but bear in mind these are LOPO engines, not 11:1 hot rod motors, no matter what heads you put on it. I wouldn't worry too much and going bigger just gives you room to grow for later, without having to re-do things.

[drhill]

Yeah, you guys talked me into it. That's a good idea on scrapping the h pipe w cats - I know I can get between 20-25 per cat from the local scrap yard. A used off road H pipe is about 50-60 bucks. Mustang headers, off road H, weld up some pipes to the summit turbos and the impala tail pipes. Weld in some cats in the best spot once it's all situated. Because of the parts I have on hand, it won't be any more expensive than j yard duals. I guess I'll deal with the noise once it's in. I may have to do the stock mustang muffler trick again or the glasspack resonators. This will flow plenty for the explorer engine. tempting to do a cam and gears but this project isn't really for Max HP, I need a quiet ride that has a nice boost in HP over LOPO.

[gadget73]

personally I like converters. Keeps the car from stinking so much. Also, it keeps it legal.

[DerekTheGreat]

personally I like converters. Keeps the car from stinking so much. Also, it keeps it legal.

I second this. Five minute spent tinkering with my cat-less '69 Plymouth and I smell like hydrocarbons.

[88Vic]

You need to go 2.5" offroad H-pipe, since you'll have the choice because you're buying a new one. If I were you, I'd look for 2.5" Impala SS tailpipes just in case you decide that's what you want, you can always store them and use them in the future. Personally I'd say just use them now but it's up to you.

And if the Turbo's are too loud, just say f*ck it and throw on Dynomax Race Bullets, make it sound half as cool as this:

[drhill]

agreed on the converters - I'm so over having no cats on cars...my wife and kids hate the smell too. Yeah I would buy a used 2.5" off road h pipe, didn't know they even made them in 2.25. They pop up on C/L all the time here.

The muscle truck is awesome! But no, I wouldn't want my slow Lincoln to sound that loud...that's what this car is for:

[gadget73]

umm, not to point out the obvious but offroad pipes have no converters. Not useful if you aren't into the smell.

The stock downpipes with the converters are actually 2.25". The tubular manifolds aren't amazing, but they probably aren't as terrible as you might imagine. They are a fair bit better than stock Explorer exhaust is at any rate. I half suspect that the difference in performance with shorty headers and a 2.25" offroad pipe vs the manifolds and the stock converter pipes is not enough to notice in a non-racecar situation. The Explorer camshaft will run out of steam before the exhaust limits you in a meaningful way.

[drhill]

umm, not to point out the obvious but offroad pipes have no converters. Not useful if you aren't into the smell.

The stock downpipes with the converters are actually 2.25". The tubular manifolds aren't amazing, but they probably aren't as terrible as you might imagine. They are a fair bit better than stock Explorer exhaust is at any rate. I half suspect that the difference in performance with shorty headers and a 2.25" offroad pipe vs the manifolds and the stock converter pipes is not enough to notice in a non-racecar situation. The Explorer camshaft will run out of steam before the exhaust limits you in a meaningful way.

Ha ha - yes I know - that's why a few posts up I mentioned welding in cats in the best location once it's on the car

See that's what I was originally thinking - since I was planning on using the explorer cam - will the 1 5/8" mustang shortys and 2.5 offroad pipe w 2 cats welded in be overkill? Seems like to me. It wasn't ideal, but I had a mustang that made 500 rwhp through 2.5" offroad pipe and stock mustang mufflers. by tubular manifold are you referring to the lincoln logs or the oem mustang shortys?

I see you have an explorer cam with all the bolt ons...almost exactly what I would be doing except no 3.55's. 'd be curious to know the difference between your set up with logs and oem duals vs your headers and 2.5" exhaust...