I know virtually nothing about the exhaust of the Mustangs so please bear with me and correct me if I am at all wrong. right now I have a stock exhaust with a Flowmaster (Which I bleieve means it's just a catback) Eventually, now this is where I'll need the help, I would like to put on a set of Mac-1 5/8" coated headers (simply because those are the only headers I've found for the 98 GT on this site) also I'll put on an SLP X-Pipe (My question for this is catted or off-road?) and then to finish it off an SLP Loudmouth Catback exhaust. Is this a good plan or am I missing something? Will that setup even work on my 98 GT? And the other thing was, in replacing the cats with the X-pipe, what are the MIL Eliminators and will I need them?
I appreciate any feedback. Thanks for all your help,
Cody

 

Well Im pretty sure that the MAC Headers wont work with an SLP X pipe. Maybe im wrong. You need to either go ALL SLP Or Put on a nice mix of things. If you want the SLP sound then you need theyre headers, xpipe and catback.

Otherwise I would go with MAC Longtube headers. MAC Prochamber midpipe. and a Borla Catback. That would sound really nice. If you want the more common mustang sound you can swap the Borla for Flowmaster 2 Chambers.

MIL Eliminaters will only be needed if you plan on removing the cats. They trick the computer into thinking that cats are still there. If you dont hav MILs you will always have a "Check engine soon" light on. You can also use a chip or programmer to turn the light off.

 

I think as long as the headers and midpipe are matching, you can run whatever catback you want. All catbacks bolt up at the same place at the end of the midpipe.

 

This is true. The only LT headers that SLP xpipe works with are SLP headers I'm pretty sure. MY advice, stick to one company. They design they're products around each other, not other products. I have full SLP and would do it again if I needed too.

 

i would go with bassani equal leanth headers and bassani x pipe catted or o/r and borla stinger catback/ borla race catback

 

Hey thanks for all the information guys. I was wondering if I was going to have to stick with the same brand or not. I think I will go with all SLP just to make it easy and I've become somewhat familiar with that brand. Although on this site I could not find any headers made by SLP that will fit my 98 GT. I'll look again but I didn't see any before. Also if I want to go with the X-Pipe offroads then what Type of headers will I need? (Long or short tube?) And if I do go with the offroads I will for sure have to get the MIL eliminator right? Well that's all for now, I appreciate the responses you've all been so helpful.
thanks,
Cody

 

The xpipe you'll need is the SHORTY xpipe to fit the longtubes. They with both cats or non cats. The off-road just means they're are no cats.

With my experience. If you do NOT get cats, this WILL BE LOUD! One of the loudest combos you can get on your car actually. Also, it will not be emissions legal if you have that in your state. I choice to get cats for the reason on "smooting" out the sound and making it not so loud. With out cats it'll have a more raspy, crackling, pooping like sound. I still have this with cats, just not near as much.

 

For the most part you NEED to match up the headers with the X-pipe. It has to be the same company in almost every case, otherwise the X-pipe will not fit the header. Any catback will work, but don't mix and match headers and x-pipes.

I want the SLP Exhaust, but my cars a vert, so the SLP Headers won't fit and if Im going with BBK LT's, I can't us ethe SLP X-pipe because it won't match up. It sucks, but its true.

 

I know you had a thread on this, but I'm sure you can make those SLP headers work with a good shop.

 

Yea but I would have to get an aftermarket K-member. Or... they would have to really mess with the K-member, which ties down the hood... so If they **** up or its not stable enough, Im screwed.

Plus my car is based on show... I don't need to spend $1700 on installs + exhaust. I just want a really nice, LOUD sounding exhaust, so for $400 less, which I can contribute to my "showiness" of my car, I will go BBK. 1, because I know they fit Verts, and 2, because for what I want, its not worth the money to go SLP.

Plus seriously, all of you... The gains between SLP and BBK especially are minimal, so minimal. The only reason people go SLP is because they are slightly better quality. And in general the gains between Headers + Exhaust are no different between brands. Hell their was an article about MAC Headers putting up serious dyno numbers =) aka - SAVE THE MONEY! =)

 

As far as the x pipe you'll have to make the choice if you want it off road or catted.....like others have said, off road will be loud. Regardless of which you choose keep your original mid pipe cause your in Cali (me to) and putting an aftermarket x or h with or without cats will more than likely cause you to fail emissions based on a visual inspection.....given, I think each county might be a little different, but just be safe and keep your original mid pipe.

 

its not the manufacture that it has to match but the connction type. SLP is a slip fit like hookers and flowtech so you can use a hooker shorty xpipe on either one along with teh slp xpipe on the other one.

Mac and others use a ball and socket type so any other brands that use that aka BBK can be used with there long tubes and vis versa.

and any catback will bolt to any mid pipe thats universal for the catback doesnt matter whos x,h, striaght pipes your running.

 

Yea I mentioned the fit, you would have to make sure they use either flanges or clamps and match the Headers with the X-pipe, but thats not all.

For instance BBK Headers have a different style/design than the SLP, therefore when they are put in, they may not reach out as far to the X-pipe causing a length issue.. Therefore you would need modifications like cupplings or pipping to account for the length issue... So you have to be careful of designs too.

Im not saying it can't be done, but its much much more difficult than many expect... Its much more practical to just say the time and money and go with the same front end exhaust manufacturer, because they are obviously guaranteed to match up.

 

thats because BBK used the ball and flange kind so its different then the slip fit which are longer so the pipe and slide into the headers a bit.

 

The only thing that wont work is a Prochamber with a set of BBK longtubes, UNLESS you heat up the prochamber and bend the pipes. The flanges will fit though.

 

While we're on the topic, I have a question.

I want a full exhaust with an H pipe, but since SLP doesn't make one, my only other option is Mac (BBK LT's don't fit autos). My question is would SLP LT's give me more HP than Mac LT's? Is there anyway I could go SLP LT's -> Mac Catted H -> LM II? Or do I have to go Mac LT's -> Mac H -> LM II?

OR should I just suck it up and get SLP LT's -> SLP Catted X -> LM II?

 

#1 - SLP will NOT give you any better gains over MAC, this is a myth between header brands. MAC did a recent study in a mustang magazine, which proved their dyno numbers. I refuse to pay SLP's price for gains you can get with cheaper good products.

#2 - 99% of exhaust system components use flanges. SLP is unique because they use clamps. MAC h-pipes use flanges, therefore SLP Headers won't line up. It can be done, but with a lot of modifications. Its really the whole SLP setup, or just their catback with a different front end. You can't really mix and match SLP besides their catbacks.

I personally like the X pipe over the H pipe, so if you want I would go full SLP. They do make Great products. However if you want H pipe, MAC Headers are very good. You may have to drill the flanges to get a perfect alignment with MAC headers though, thats the only downside. But a hell of a lot better than mixing and matching headers + mid-pipe.

Hope this helps.

 

Yea, you won't gain anything or lose anything between products really. It's just about quality and fitment. With SLP I've always heard that they fit perfectly and I can vouch with that with my full SLP setup, great fitment also outstanding quality.

No experience with anything else but have heard BBK sometimes has trouble fitting. I've heard bad things with Mac, my personal tuner has ordered MAC headers before and when took them out of the packaging, all the ceramic coating just started peeling and pooring out of the inside of the headers. YIKES!!

 

Your going to hear good and bad things about every company.

Ive never heard anything bad about BBK until I started posting on this forum, and Ive heard a LOT of good things about BBK.

A guy I know, whos know A LOT, about mustangs and has over $20,000 into his stang has MAC LT's and he LOVES them. Never had a problem, except drilling the flanges a little on the install, but other than that he loves them.

So you will hear good and bad about every company.. They are all great products though, BBK, MAC, SLP... Do what you want, you will be happy.

 

Thanks, I guess I'll probably go with Mac, although despite cost, SLP gets more and more appealing because of it's ease of install and modularness. Guess I'll just have to think about it some more.

 

Honestly, EVERY header is going to be a bitch and a half to install. While some headers have better quality and fitment, it isnt easier by ANY means. Get something that fits your budget, and that others have had luck with, ie mac. Youll be fine, just make sure to get ceramic coated ones.

 

+1

Exactly ^^.