areXseven

iTrader: (1)

I was thinking of taking my FD to a muffler shop tomorrow to buy a "stock" type muffler with dual tip exhaust for my 93 FD. It currently has an HKS Super Drager muff, but it's loud and it's as big as a small BBQ pit.

QUESTION: Will replacing it with a stock/dual tip muff have a "major" effect on accelleration.....AND will the stock muff be considerably quite. FYI...my FD has a DP and MP. Thanks.

adam c

iTrader: (2)

The stock muffler will help a lot with the noise. It will also cost you a few HP. With a mid pipe, the added restriction from a stock muffler could cost you 15 HP.

ludeowner

When you say you are getting a stock-type muffler made are you talking "stock" as in stock diameter? or "stock" as in stock looking?

Stock diameter you will definately lose a few HP. But if you are talking just "stock" looking, then you could possibly get a catback made up from your local muffler shop which will not be as restrictive. Have them put together a catback with 3" ID mandrel-bent piping and an oval (stock-looking) muffler with a 3" inlet and 2.5 or 3" twin outlets. Magnaflow makes several different types of mufflers if you wanna see what they look like.

...or you could just buy a Racing Beat or M2 exhaust with twin tailpipes, cause they look pretty stockish.

areXseven

iTrader: (1)

adam c and ludeowner: Thanks for your advise. I'll see if the shop sells an oval shaped Muffler with 3" inlet and large dual tips.

What is the price for the Magnaflow I need??. Thanks

voodooracing

why do that? why not just get a racing beat dual tip... or M2 dual tip... they look stock enough and not much power loss...

ludeowner

Well, if you wanna get a custom exhaust you can go to www.magnaflow.com and do a search for a dealer in your zip code. I think average cost for just the muffler is $80-$100, then you have to get the tips which are about $5-$10 each. Then there will be the rest of your piping and exhaust, etc etc.

First you would have to take some measurements. There are two types of oval mufflers that may work. You can either go with a 5" x 8" or a 5" x 11". Have somebody measure the dimensions on their OEM muffler so you can get an idea of the size muffler you will need.

14221 is a 3" inlet, dual 2.5" outlets
14588 is a 3" inlet, dual 2.5" outlets
14590 is a 3" inlet, dual 3" outlets
14592 is a 3" inlet, dual 2.75" outlets

ludeowner

Cost would be a good reason. He may be able to get a custom job done for about $200-$275 (all stainless steel). The only problem would be workmanship and performance would be questionable.

If it was me, I would get a used RB or M2 for the same amount. Or just splurge and get a new RB exhaust.

skunks

why not jsut get a silencer?

areXseven

iTrader: (1)

Okay guys, here's the 4-1-1 on my quest for a stock type and quiter muffler.; One shop will sell me a Magnaflow Oval with dual 2.5 outlets and a 3" inlet for 160.00 installed. Another shop will sell me a FlowMaster Oval with 2.25 outlets and 3' inlet for 135.00 installed. Will the .25" outlet reduction on the FlowMAster make a difference in performance compared to the Magnaflow?? I think my HKS Super Drager has a 4"outlet, so even the FlowMaster has a combined half inch larger outlet than the HKS (single 4'). What do you think??. Thanks.

ludeowner

Well for comparison, the RB dual tip says it has 3 inch outlets. But it looks like that is the muffler tips diameter, not sure what the inner diameter is on the tip.

You could do a search or ask somebody with a RB exhaust to measure the inner diameter on their tips. One thing that you should also be looking for is muffler design. IMO you'd want a muffler that has a straight through design.

areXseven

iTrader: (1)

ludeowner: Thanks for the info. I think I'm gonna put the Magnaflow on in the morning. I won't mind losing a little HP as long as I gain a little "peace and quite" at highway speeds. Thanks once again to ALL that participated and took the time to give me advise. !!

WaLieN

You might also want to consider Dynomax's Ultra Flo Welded Muffler -- they're around the same price as the Magnaflows. They also flow ~1100cfm and are relatively quiet.

http://www.dynomax.com/ultrafloweld.stm

areXseven

iTrader: (1)

Does the Dynomax have dual 2.5" outlets?

WaLieN

Yep! http://www.dynomax.com/documents/ultrafloweld_specs.pdf

areXseven

iTrader: (1)

Thanks WaLieN. The "17228" is what I'm looking for, but I don't think I can find it here in Corpus. Think I'll have to settle for the Magnaflow. ..........Just curious,....what's the price on the Dynomax??

WaLieN

I'd order it from Summit Racing (They ship *REALLY* fast) -- look on their website. IIRC, it was ~$85. I've always been a fan of Dynomax as their mufflers are usually much more quiet than the Magnaflows of compareable designs without obstructing flow.

GarageBoy

Racing Beat, PFS and RS*R makes quiet muffs/cat backs. Flowmasters flow worse than the glasspacks

WaLieN

Though RB, PFS, etc. are really quiet (Yeah, they are! I own a PFS exhaust, and it's damn quiet, kinda.), they are also relatively expensive. Dynomax is relatively cheap.

Yeah, Flowmasters 30,40,50, etc. series muufflers DO flow like crap, but their race series of mufflers flow quiet well.

GarageBoy

Dynomax racebullets and Borla are also good choices for performance on the cheap

WaLieN

Have you ever *heard* those in person? They're not exactally "quiet," hehe. He's looking more for quiet, so I don't think it would be a good idea to get bullet-style mufflers.

GarageBoy

I've heard them on V8s (not exactly as loud as rotaries) SpinTechs are nice (so I've heard) http://www.spintechmufflers.com/

striker

The RB duals inner tip is 2.5"

maxcooper

Rotaries tend to eat mufflers (hot exhaust), so be sure to choose something that is beefy in its construction and has durable packing material. I think Magnaflow mufflers have been used on a lot of rotary race cars, and I would expect Borla's all-stainless (including the packing) to hold up well, also.

On the sound front, I am not sure a Flowmaster would be a good match for the rotary. I think they tend to be among the louder V8 mufflers.

There was a muffler test in 5.0 Mustang and Super Fords a while back (on a Mustang, obviously) and the results were that all the mufflers seemed to make pretty similar power, but there was a wide range of sound levels. It seems like seeking quiet sound levels should be a major factor in choosing a muffler for a rotary, especially since the power levels are likely to be similar with any decent muffler. I remember that the Borla Pro XS line seemed to be pretty quiet, though there were others. I think the article was in May 2003 or something like that (not exactly sure of the issue date).

-Max

areXseven

iTrader: (1)

I think i'm going with a Magnaflow pro series (S/S) dual tip. It looks just like a RB S/S, at a fraction of it's cost.

WaLieN

Good choice.