sweet99

I would just get a pair of your favorite mufflers( I prefer Dynomax) and cut out the originals and have the mufflers you get put in their place. The stock system has an H-pipe and the HP return on a complete system, especially a catted one, is not worth the expense. In retrospect I would sell my PYPES catted X-pipe and catback with their Race pro muflers and replace my stock system which I saved and just replace the mufflers. Save $500.+ and gain just about the same. Just my .02. mark

red2k1gt

On the down side of that...you gain zero HP and very little sound. An aftermarket exhaust system greater in diameter and allows for the real sound of the muffler to actually be heard. Most anyone you ask who has just welded in mufflers will tell you that they shouldve gone with a real catback. If your going to mod a car why not just do it right...IMO

Matts00GT

You won't gain hp from mufflers. Buy a catback. It's worth the money. Who's letting these new people do write-ups? Code, make some rule or something...

red2k1gt

Everyone's entitled to express their personal preference about this, I wouldnt call it a write up. Let's just say this: with a catback and aftermarket midpipe your going to make approximately 5-7 more rwhp more than a person with just weld-ins. On the other hand...the person with the aftermarket catback/midpipe is going to have a MUCH better sounding car. It all depends on what you want to do with your car and how much money you really want to spend.

bigedog8

damnit sweet first u talk about not being able to get a gt in the 12's then u tell us uve never actually been to a strip and ur using some g tech **** to do ur quarter mile..... now u say buy weld in mufflers..... have u ever had a car with a weld in muffler... they suck compared to a catback. sound quality is crappy. volume is low. and there is still all the restriction of the smaller pipe as red2k1 already stated. and an o/r pipe makes your car sound like sex... it also doesnt help you bought one of the cheapest catbacks out there for your car.... please dont be giving people retarded advice. u can buy a good catback for about 370ish i got mine on sale for cheaper... by the time u buy 2 mufflers at around 100 bucks get em welded in why not just pay 200 bucks more for more hp AND much better sound quality

sweet99

Sorry but most of that is incorrect. I said it is difficult to get a 2v 4.6 into the 13's not the 12's. 12's would be almost impossible if not impractical needing NOS. I said 13's with bolt ons. Street tires. I am not interested in having a 3000 stall copnverter and slicks to get 13's when most of my activity is on the street so I want engine POWER. Needing some kind of measuring stick I use a passport timer. It may not be the most accurate method but I cannot think of a better way to test mods or tuning changes immediatly. Somebody talking junk said 12's with a 2v. Dan with the supercharged cobra I think who has 130HP more than a 2V and runs a 12.5x! He should be in the 11's. My last car did 11's and 120+MPH. Turbo Talon with a lot of money invested which I don't want to do with my automatic convertible. Not many Mustangs running 11's and capable of 122MPH traps here are there? Don't get me wrong I love this Mustang. My mods are listed and thay gained .4 and 4 mph over stock and cost around $2000. Not a good return is it? Then in the thread about 2v's and getting into the 13's guys say "I know lots of guys who have done 13's". Show me who. Show me what mods they have. Tell me what is missing from my mod list for the POWER to get into the 13's, not by hooking and getting a 1.8 60'. Is it possible without a SC?
I have been to the track, just haven't been since '79 I believe. Again for the timer we compared it to the track time with a 440 GTX and found that the timer was off by .2 on the fast side and I am only using it as a measuring stick, not interested in total accuracy.
If you think another exhaust system besides the PYPES will produce a significant amount of more HP you are incorrect. The ONLY difference is I chose the quietest mufflers PYPES sells which are still a straight thru design! I'm 53 and do not want a loud car. I've been through that stage 30 years ago!
Then nobody came up with guys running a 2v in the 13's on street tires and what mods they used to do it in a car weighing 3350lbs. plus the driver. My testing takes place with a friend watching the timer bringing the weight of my car to 3750lbs.with an automatic that can't be launched with any kind of power launch or it would fry the 315's I have for traction.
I know with slicks and a hard launch I would get into the 13's as I have done 14.02 with the weight and launch and street tires mentioned above. My full PYPES exhaust with catted X-pipe that keeps the car legal probably gave the car 10-15whp tops! Given the opportunity to go back I would have added mufflers and been done with it and maybe given up 5whp. 5WHP for $600. when a pair of mufflers would have been $150. and have cost no more than $50. to have installed. I would take the 5WHP loss and pocket the $400. By the way what is YOUR best track time and trap?
All I'm trying to do is save some 18-20 year old kid who wants an exhaust system but doesn't have $600.-$800. for the 15WHP return and sound. I don't need sound. Mine sounded fine when it had the stock exhaust but as you know I am trying for the power to get 13's. mark

72MachOne99GT

launching/hooking up is 90% of the battle... maybe i missed something, but you could have a car with 600 hp, and if you cant drive/launch it at all, you could still be in the 12's for all you know

if you really think its that difficult to get 13's then look at what im thinking

stock, lets say a 14.2@98 with a 2.1 60'
Here is what i think you need.

DR's-300$
4.10's-600$ ish...including parts and install and recall, maybe a bit more

good driver mod.

thast all you need, if youve spent 2K, and only gained a little bit, its because you cant drive, or you spent the wrong 2K

EDIT: that 13.98 in my signature is with 4.10's, midpipe, catbback, and DR's,, if i could drive (aka my **** poor 60') then i'd be 13.5 all night long.. which i will be a week from friday

damdanger

or you can do what im doing, befriend a mechanic at muffler man and get a custom 2 1/2" flowmaster catback and o/r hpipe for 300$

JJ03MustangGT

dude i got my catback done at my local muffler shop for like 250. most people should be able to put a mid pipe on. i have flowmasters and all i ever get is compliments. so tell me how u would spend 6 - 800 bucks on an exhaust, besides goin and buyin the most expensive thing on the market.

Hyper00

In Sweet's defense, swapping the cat-back part of the exhaust doesn't grant much hp at all. Most of our "hp hang-up" is through the mid pipes where all those damn cats are. I would get weld in mufflers...but I would take it a step further and get some mandrel bent custom piping also( just to up the diameter a little). HP gained should be about the same and it would probably cut the price of an aftermarket system in half. Although I think I would rather buy a newer midpipe with a little research and development put into it.