3" Exhaust... for NA modified engine. Muffler options?

[inline6]

I've spent a rediculous amount of time researching choices of mufflers for a new 3" exhaust I will be making. I've listened to tons of videos, but it seems there are practically no 3" systems on normally aspirated L-28s out there, or next to no video's of them anyway. Basically, I don't want to spend a bunch of money and time building a custom system that ends up sounding "ok". I have heard some great sounding z cars and some not so great sounding ones. I'd sure like this one to fall into the first category.

 

I've found a couple on YouTube that I like:

 

 

Since the car is mainly a track toy at this point, I can take it being loud, but not so loud that I can't drive it without my ears bleeding when I am keeping my foot out of the throttle. I've already got some hearing loss, most certainly from a Datsun 510 that I had a 2.5 inch system on it years ago... I used to drive 1.5 hours each way every weekend to see my girlfriend. Anyway, I plan to drive this car to and from the track and on the road every now and then. Has anyone here run just a single Borla XR-1 like this:

 

Borla 40944

 

on a three inch system? Can it be driven without ears bleeding?

 

With both of the video's above, the owners are running a combo of mufflers/reasonators. Since the 2.5" system in video #2 is "too loud" for the owner (he added a dynomax bullet), then I'm thinking my 3" with the 40944 will more likely be too loud for me (unless at the track). His motor, by the way, is quite similar to mine.

 

Video 1 has a three inch pipe, and an interesting configuration - a Magnaflow muffler "near the diff" and a two foot glass pack mounted at an angle after that. Definitely like that the "rasp" is not present with this setup. I wonder if that is the configuration though or maybe 3" pipes reduce that in general.

 

Here is what I am thinking about right now:

 

Tunnel Options:

Borla 5" round

Magnaflow 4" round

Section of pipe that can be substituted in with band clamps.

 

Rear Muffler:

Borla Oval 40944

 

 

Anyone have a 3" system on a NA Z? If so, can you post a video so I can hear it?

Edited September 23, 2012 by inline6

[tecreatta]

3.0 inch on a NA system seems a bit much mate. You want a bit of back pressure on a NA engine. I'm running a 2.5 inch system with a magnaflow muffler. It has a decent sound.

[78zstyle]

It's going to be freaking LOUD.

[stony]

I know that 3 inch is big on a NA motor BUT for me a 3 inch exhaust with a decent pre silencer... the sound cant be beat!!!!

 

this header

 

and this exhaust has the best sound EVER!!!

 

 

 

 

Good luck getting it in the states. If you can your looking at 1500+ for the header and exhaust.

Edited September 23, 2012 by stony

[akeboshi]

Exhaust 1 sound too raspy and wimpy. Exhaust 2 is right on the money though! sounds beast. If you are worried about hearing loss there is a miraculous product made specifically for loud environments, its call foam earplug inserts and they block up to 25 decibels!!! Try it!!!

 

 

http://www.amazon.com/dp/B0030HUE9C/ref=asc_df_B0030HUE9C2194055?smid=A13TITLYH5KSUI&tag=hyprod-20&linkCode=asn&creative=395105&creativeASIN=B0030HUE9C&hvpos=1o3&hvexid=&hvnetw=g&hvrand=11594359181245474061&hvpone=&hvptwo=&hvqmt=

[Leon]

3.0 inch on a NA system seems a bit much mate. You want a bit of back pressure on a NA engine. I'm running a 2.5 inch system with a magnaflow muffler. It has a decent sound.

I swear to god, I'm gonna pistol whip the next person that says "back pressure"! Read the exhaust sticky.

 

FWIW, I like the first video after he added the resonator. Nice, crisp sound. My next exhaust is going to be a 3" single, have 2" duals now (L24).

Edited September 23, 2012 by Leon

[Leon]

If you are worried about hearing loss there is a miraculous product made specifically for loud environments, its call foam earplug inserts and they block up to 25 decibels!!! Try it!!!

I always have a pair in the car, can't go more than 30min without them.

[Tony D]

I've said it as long as the Internet has been commercial that a larger glass pack makes what normally a raspy popping eardrum buster into something that can be quieter than stock.

A 3" is fine if you can package it the way you want. Most loud exhausts are single can set ups.. Most will be tamed with a glass pack added in the proper place with minimal flow impact, if any.

[Pyro]

FYI, Do not use glass packs with bumps inside the tube. Use the glass packs with perforated holes inside the tube.

 

Glass packs with bumps are very restrictive.

 

I recommend Dynomax Bullet Glasspacks, as these are made with the new perforated hole design.

 

For up to 200 to 250hp, I recommended a 6 into 1 header, single 2-1/2 inch exhaust system with mandrel bends to get around the rear end. And one dynomax bullet in the tunnel and a turbo muffler out back.

[madkaw]

You definitely want a good size pre-muffler. Another thought is a chambered type muffler instead of a turbo-type. I like the sound of my duals, but wonder what impact a baffled muffler would have had on the sound. I have pre-resonators( glass packs) and wish I could have fit bigger cans in there.

My magnaflows do a much better job of mellowing the tone over the previous glasspacks.

I vote for good flowing chambered muffler with a large resonator on your 3" system.

 

Or duals.......

[EF Ian]

3" is a good size on a tuned NA engine, I'm using a 3" system on my high comp B20 motor and get very good results.

 

 

 

You don't want any backpressure idealy, what you want is good flow velocity.

 

 

Unfortunatly 3" systems can tend to be more reaspy than smaller ones.

[Leon]

You don't want any backpressure idealy, what you want is good flow velocity.

You're right on the former bit, but not the latter. Higher velocity generates more "backpressure" (pumping losses).

[Boog]

I am currently running a custom straight pipe back to an ebay fart can muffler. I don't have any bending or welding skills so i had some buddies at a muffler shop hook me up. They were all laughing at the muffler when I left, but when i came back to pick it up they were mouth-wide eyes-open. They were thoroughly impressed by it. I have a full 2 1/2 inch pipe, no resonator, and a ebay $30 glass pack can muffler on the end and it has no rasp at all. Sounds awesome. If you want I can post a video, been looking for an excuse to rev it up.

 

Also, as for the 3 inch exhaust, it really isn't necessary unless you plan on swapping turbo, but I know a lot of people like the sound. If I were you, I would go 2 1/2, but that's my opinion.

Edited September 25, 2012 by Boog

[inline6]

I know that 3 inch is big on a NA motor BUT for me a 3 inch exhaust with a decent pre silencer... the sound cant be beat!!!!

 

this header

 

and this exhaust has the best sound EVER!!!

 

 

 

 

Good luck getting it in the states. If you can your looking at 1500+ for the header and exhaust.

 

 

Well, I checked out Kakimoto... I'd love to hear it. I just bought a whole bunch of stuff from Amazon - about $570 worth... I ended up picking Magnaflow over Borla. Just haven't historically cared for Borla sound much on the cars I've heard it on and am convinced it would be louder than the "equivalent" Magnaflow unit. So, a bunch of stainless steel is on the way...

 

It's going to be quite the project, starting with mods to the 1.75" primary Nissan Comp header. One of the collectors hits the floor (driver side). Been thinking and thinking about how best to resolve. I've finally decided. I'm going to weld a plate onto the collector end (shutting it) and fill primaries 4, 5, and 6 with sand - packed really tight. Close off the primaries with another plate (can bolt that one on)... and then take the header to an exhaust shop and have them heat the primaries just before the collector to red hot, so it can be bent a bit away from the floor. I did this with my roll bar when I made it as it needed a bit of tweaking after being bent by the shop I used. The sand packed tight keeps the tubes from kinking or distorting. Yeah... what a pain!

 

Garrett

Edited September 25, 2012 by inline6

[johnc]

I've run a 3" exhaust with the Borla XR1 Raceline you list above. Its not very loud but I've always raced with either ear plugs or a radio ear buds. Get into that habit right now. A good friend is a professional racer and he's lost all hearing in a very specific frequency range.

 

And I'm with Leon regarding posts about "backpressure" and 3" being too big on a NA engine. Do some research guys before posting Internet myths...

[johnc]

Also, be careful about adding glass packs, etc. You need to purchase a high quality, all stainless unit. Here's a pic of one I took off a customer car after he built his own exhaust and ran it for 6 months behind a 225 HP L6:

 

 

[Tony D]

Things get hot, and saturated wet...and glassfibre holds that in there. Mild steel has no place in the internals of a baffle with glassfibre. Then again, they sound good, rot out, and are cheap, so some MBA figured out 'steady stream of aftermarket follow-on sales" --- the trick was determining how crappy to make it so it fails early enough to insure consistent flow of cash back to the maker, but not so quickly that it gets branded a POS and they loose the hook on the fleshy-mouthed suckers they reeled in initially!

 

I've gone so far as to buy the stainless and make a replica of the can I liked (Trust/Greddy from 1978!)

[inline6]

I looked at many glasspacks because I really like the sound of that one video linked to above. I was going to copy the setup as best as I could based on the owner's descripton, but I couldn't find any glasspacks that I thought would be suitable/durable. I have run them before (a four pack) on a true system, and I liked the sound of it until the fiberglass burned out of them. And they were at the back of the car... Most are not stainless (one from Magnaflow was but it had a 2.5" core - so wasn't 3" all the way through) and I came across your post, John, about the Dynomax during my research. I wasn't sure if that one was stainless, but even so, they use fiberglass in theirs...

 

So, I'm going to try putting the Magnaflow 14867 (5" Dia.) in the tunnel just after the SPD merge collector that John helped me with. At the back, I'm going to try the Magnaflow 12619 (6" Dia.). Both are 100% stainless with no fiberglass to burn out and have 3" cores with straight through perforations. Got a couple of of 3" stainless mandrel J bends, some stainless straight pipe, stainless rod hangers, and stainless band clamps etc. also. The header and the SPD merge collector are both mild steel and are going to be sent off for ceramic coating after I complete the the fitment of the whole system to the car.

 

I'll snap pictures of the construction and put up a video when it is complete. Have no idea what it is going to sound like... just have to wait and see.

 

G

Edited September 26, 2012 by inline6

[johnc]

If you want something really nice and can spend some money, there's always the Coast Fab muffler:

 

http://www.coastfab.com/mufflers.html

 

The can be disassembled and the packing material replaced. They offer fiberglass or stainless packing and it looks like they ahve them on sale. These are by far the best mufflers you can buy.

[BLOZ UP]

3.0 inch on a NA system seems a bit much mate. You want a bit of back pressure on a NA engine. I'm running a 2.5 inch system with a magnaflow muffler. It has a decent sound.

 

No, you don't. You want a vacuum on the exhaust valves, if anything.