This first post has been updated to list all the information related to this install. To read the orginal post and responses, scroll down.
Flowmaster® 70 Series Big Block II Muffler Install
Plan:
I wanted to give my Titan a little more aggressive sound, but not so much to be annoying. I wanted an exhaust sound that had a signature V8 rumble, but with a civil highway ride in the cabin. I had good experiences with other Flowmaster mufflers in the past and like their signature tone. I also wanted the look of dual straight back tips. After researching on the Internet (including this site), talking to various shops, and getting quotes, I decided to go with the Flowmaster 70 series Dual In/Out.
Design:
All the factory pipes would be removed just aft of the flanges behind the cats. From there 2.25" aluminized steel pipe would be run to a stainless steel X-pipe. Then from the X-Pipe to the dual inlets of the muffler. The dual exits then snake over the rear axle. The left side squeezes around the spare tire, and is a pretty tight fit. The tips are mounted directly next to the sides of the trailor hitch and just past the edge of the bumper.
Below is a simple layout of the exhaust:
Parts:
Flowmaster 70 Series:The 70 Series Big Block® II is designed around a large Flowmaster case for maximum volume and efficiency. The case is two-inches narrower than Flowmasterās original Big Block® muffler, making for easier installation in tight applications. The 70 Series offers a mild mellow exhaust tone and incorporates a Resonant Tuning Chamber for reduced interior sound levels. It is great for tow vehicles and RVs and trucks with dual exhaust.-Taken from Flowmaster's Website
X-Pipe: The X-pipe is an alternative to an H-pipe, both can be called crossover pipes. They are used to help balance the exhaust pulses coming from the left and right banks of the engine and to improve the scavenging effect. Therefore increasing low end torque that may be lost by increasing pipe diameter and/or removing the factory Y-pipe. Flowmaster strongly recommends the use of an H-pipe for dual exhaust set ups. I started a seperate topic on the subject here. I bought my X-pipe online from Husker High Performance. They were out of aluminized at the time, so I went with stainless, which will be better in the long run.
Tips: 3.5"x17" rolled edge slant cut tips were used for the outlets. I think the rolled edge gives it a better look than the plain thin tips you commonly see. The tips were chromed steel, stainless is available but a good deal more expensive.
Pipes: All 2.25" aluminized steel was provided by the install shop. At the time of install, Flowmaster didn't offer a complete system for the Titan, so a custom install was required.
Price:
The original price of the system was $330, including everything except for the X-pipe. I had the X-pipe installed later, which cost $45 for the part and another $45 for install. An H-pipe would be far less expensive, especially if it were installed at the same time as the muffler. The 70 Series muffler goes for about $100 from online vendors, and my installer matched prices.
Results:
Sound: I'm very pleased with the overall results of this exhaust modification. The sound is definately much more aggressive at WOT and has a more recognizable idle rumble. At the same time, it is not overly loud in the cabin at cruise speeds. I can still listen to the radio at low volume settings or carry on a conversation. The exhaust is loudest (other than WOT) when travelling at low speeds (<40) under a load (ie. up steep hills) in the 1600-1900rpm range. The 70 series is by far the most tame of the Flowmasters, but still has the signature sound. After clocking several hundred more miles I feel the system is sounding even better. Performance: Immediately I could tell a slight improvement in the upper RPM range. During full throttle accelerations the power band seems extended upwards. The low end seems to have improved slightly, but nothing to write home about. A future dyno is planned and results will be posted. Mileage: After installing the exhaust I have improved from 16mpg highway to 18mpg. I have gone from 13 to 15mpg in city driving. Better results could probably be had, but I drive an average of 85mph highway.
Sound Clips:(mp3 format)
Sorry, but the mp3's got deleted, I do have the original AVI video files still. You can watch/listen to them here.
This one is accelerating from a right turn to about 40mph. The recorder was placed on the center console storage box.
**Link Removed**
This one is a hard accerleration from about 10mph to 65mph, then cruise at 65 for a few seconds then punch it to 80mph. The recorder was on top of the steering wheel. The engine makes alot more noise then what you are hearing from the exhaust.
**Link Removed**
And of course, some more high revs from outside the truck. The recorder was placed on the ground about 5 feet behind the rear. Turn up the speakers for this one!
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Pictures:
::::::::::::::ORIGINAL POST BELOW:::::::::::::::::
I got a few questions for those of you who have installed dual outlet exhaust systems, specifically those who have used flowmaster mufflers. My plan is a single muffler (probably 70 series) with dual outlets.
Flowmaster offers a muffler with dual 2.25" inlets and outlets as well as one with a single 3" inlet and dual 2.5" outlets. Would it be better to remove the Y-pipe and run pipe directly from the cats to a dual inlet muffler or to leave the Y-pipe and run it into a 3" single inlet?
I noticed the factory Y-pipe looks kind of restrictive and might have too much back pressure, if need be an aftermarket Y-pipe could be welded in and still run a single inlet muffler. Any suggestions?
The two mufflers in question can be found on the data sheet (part #'s 524704 and 530712) So far I've been given one quote of around $200 for install and $100 for the muffler.
Well I got the truck looked at by a few different shops and here's what I've settled on. A Flowmaster 70 dual-in/dual-out with straight back 3.5" rolled tips. The Y-pipe and everything just back from the cats will be removed and straight pipe ran into the muffler. The total came to $330, all aluminized pipe. I'll try and get some picts/sound bytes after I get it installed tomorrow. Should sound pretty sweet.
Should be great, i have the 40 series which is really loud but i like it loud.
Man, I bet it's loud. The 50 series seems to be the more popular of the truck mufflers, the 70 is suppose to be just a tad more rumble than stock. I've had good experience with Flowmaster in the past, and this install should turn out pretty good. I've never had a dual-in/dual-out, but without the Y-pipe it should flow better. I talked with a guy at the local speed shop who said the 70 series would preserve the low end torque better than the 50, so hopefully that's true.
You live in San Diego? I always thought flowmasters on trucks was only something us Southern boys did.
Got the Flowmaster 70 installed today. Sounds great. It's got that signature Flowmaster rumble, but quieter than you'd expect. It's actually quieter at idle from the inside than the stocker, but has a good deal more rumble in the 2,000-3,000 range. At the higher RPMs I hear the engine more than the exhaust. When cruising at highway speeds it's actually quieter than stock, probably because of the straight rear exits instead of the turn down. The dual tips come out on either side of the hitch and look awesome. I got 3.5" chrome rolled edge angle cut tips. The installer did a pretty good job, it did take him longer than expected (3 hours.) Not bad considering it was his first Titan. The hardest part was getting the left pipe over the axle and around the spare, but you can't see the pipe, only the tips.
He ran new pipe (2.25 I believe) from the factory flanges behind the cats straight into the mufflers dual inlets, so no Y-pipe anymore. The low end performance actually seems improved. I spun tires accidentally twice as I was driving it home. I'll try and get some picts, maybe a sound clip, and MPG figures later. All this for $300, and a 20 year warranty on the muffler.
Window tint goes on tomorrow.
Last edited by sammy sandbag : 04-13-2004 at 05:31 PM.
Ahh... that's awesome! I can't wait to do the same thing with mine. How hard do you think the job would've been to do a self install? Have you done an intake yet to go along with the exhaust? I can't wait to see pics!
Ahh... that's awesome! I can't wait to do the same thing with mine. How hard do you think the job would've been to do a self install? Have you done an intake yet to go along with the exhaust? I can't wait to see pics!
-Jay
I suppose it wouldn't be too difficult if you had a hydraulic pipe bender and a mig welder and lots of knowledge. Obviously most of us don't have the tools/skills to do something like this. However, if you just want a replacement muffler you could buy a 70 series with the single offset inlet and single outlet, but chances are that it'll still be a different length and you'd have to still fab new pipe for the outlet side. I don't recommend clamps, weld it.
No intake as of yet, I'll probably just do the K&N drop in or do a home made conical like BigHawaii is working on.
Sandbag, did you use a regular muffler shop? Or did you go to a performance shop? Thanks.
Sorry, missed your post. I'm not sure you'd call it a regular muffler shop or a performance shop. It isn't like Meineke or something like that. They do custom set ups, especially dual exit truck setups. The only performance shop in town is only a parts store. I talked with them before hand to check prices and get advice. I had already had my mind set on the 70 series after listening to the sound bytes on flowmasters website, and the shop worker also agreed that the larger 70 series would preserve the 5.6's low end. If you know what to look for and know what you want, most custom exhaust shops can do it for you. The only thing that the exhaust shop recommended was to run 2 pipes into a dual inlet instead of a single 3" from a Y-pipe.
Got the Flowmaster 70 installed today. Sounds great. It's got that signature Flowmaster rumble, but quieter than you'd expect. It's actually quieter at idle from the inside than the stocker, but has a good deal more rumble in the 2,000-3,000 range. At the higher RPMs I hear the engine more than the exhaust. When cruising at highway speeds it's actually quieter than stock, probably because of the straight rear exits instead of the turn down. The dual tips come out on either side of the hitch and look awesome. I got 3.5" chrome rolled edge angle cut tips. The installer did a pretty good job, it did take him longer than expected (3 hours.) Not bad considering it was his first Titan. The hardest part was getting the left pipe over the axle and around the spare, but you can't see the pipe, only the tips.
He ran new pipe (2.25 I believe) from the factory flanges behind the cats straight into the mufflers dual inlets, so no Y-pipe anymore. The low end performance actually seems improved. I spun tires accidentally twice as I was driving it home. I'll try and get some picts, maybe a sound clip, and MPG figures later. All this for $300, and a 20 year warranty on the muffler.
Window tint goes on tomorrow.
wow! it has that sig sound and is quiter at idle, to tell you the truth ive never heard of a flowmaster quiter at idle on a big ol v-8 lol. i just looked at their site and its actually longer then the stocker, sweet! thanks fer your input.
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Let me clarify my statement by saying it is quieter in the cab at idle than the stocker. Standing out back it's definately got the rumble of a flowmaster, but doesn't sound like a dragster waiting to take off. It's loudest when under a load (up hill) at low speeds (<40mph) in the 1,800 to 2,200 rpm range, still not too loud for my tastes though. I haven't heard the Banks in person, but judging from the sound clips posted, I'd definately say I like the Flowmaster's sound better. Signature Flowmaster sound in my mind is automatically associated with big V-8s. Performance wise, the butt dyno says little improvement perhaps. It still leaps from the line like it did with the stocker, but this time the truck in the next lane is not only suprised but also scared!
I'll be honest and say that for me the dual pipes were done mainly for sound/looks with performance and MPG improvements being a side benefit. If you like the Flowmaster sound and dual pipes then do it. If you are trying to squeeze 1 mpg or a couple more ponies out of the 5.6 but still have a civilized truck, then keep your stock exahaust and be happy. There's my warning.
That looks good. I too am a southern boy and put a flowmaster with dual exhaust (h pipe) on my 1999 F-150 and my 1996 Chevy 1500. I love the sound of a flowmaster on a V-8, but I am trying to just be happy with the stock exhaust. I know that as soon as I hear a Titan with a flowmaster though I will be at the muffler shop the next day.
Had a Flowmaster 50 on my last truck (Dodge) with straight out the back
duel pipes and after 4 years, I'd had enought of the "rumble." On my Titan
LE I liked the sound of the stock muffler but wanted the same duel look as
on the Dodge. Therefore, I had a "Y" pipe installed on the back side of the
stock muffler, ran the two 2.25" pipes out either side of the hitch and added
2.75" extensions like Sammy's. Maybe down the line I may go with a 70 series
but for now it looks good, and sounds good, when I get on it - and all for $150.
04-11-2004, 06:12 PM
Flowmaster Dual Pipes (picts and sound)
Obviously most of us don't have the tools/skills to do something like this. However, if you just want a replacement muffler you could buy a 70 series with the single offset inlet and single outlet, but chances are that it'll still be a different length and you'd have to still fab new pipe for the outlet side. I don't recommend clamps, weld it.
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