Go Back   Rotary Car Club > Tech Discussion > RX-7 2nd Gen Specific (1986-92)

RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections.


Welcome to Rotary Car Club.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Reply
 
Thread Tools Display Modes
Old 08-03-2010, 07:28 AM   #31
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

I had another thought on my commute this morning (I know it's dangerous). I have functional perforated tube mufflers that are still functional. What if instead of using regular old tubing to go from the y-pipe portion of the muffler I use these rather 'small' mufflers instead. I see the benefit two fold:
1) I save money by not buying additional stainless steel tube
2) I get a quieter note because they have muffeling capability

Basically I'm doing what Ted suggested about ferrari and making a huge muffler .

In addition to this though what if I combined a diffuser and a muffler together? Have a large perferated tube design feed into a rather flat but large muffler filled with stainless steel wool and outputs into two exhaust mufflers on the side in the normal location.

Thoughts? (I want to see if anyone can spot the issue with the latter idea )






vex is offline   Reply With Quote
Old 08-03-2010, 11:09 AM   #32
jtbshaw
ORD - Old Rotary Dude
 
jtbshaw's Avatar
 
Join Date: Feb 2008
Location: Pelham, AL
iTrader: (3)
Posts: 319
Rep Power: 17
jtbshaw is on a distinguished road
Default

T, the RB mufflers are the best for the rotary IMO. I have been using them for years with fair success in accomplishing what you are trying to do......quiet without losing too much performance. I have had to modify a few RB pre-silencers to fit in limited areas and was able to see the internals, which is as Ted mentions...perforated and offset with a bunch of curly stainless noise suppression material.

You may want to also consider a heavier wall thickness if you purchase tubing...this takes out a good bit of the "metallic" sound in the rotary exhaust.

On a different note, I will shoot you a PM soon about seeing if you can help me with a intake plenum design for a sidedraft Weber (DCOE).

Todd B.
(formerly of No Limit Industires in Alabama)
jtbshaw is offline   Reply With Quote
Old 08-03-2010, 12:12 PM   #33
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

Quote:
Originally Posted by jtbshaw View Post
T, the RB mufflers are the best for the rotary IMO. I have been using them for years with fair success in accomplishing what you are trying to do......quiet without losing too much performance. I have had to modify a few RB pre-silencers to fit in limited areas and was able to see the internals, which is as Ted mentions...perforated and offset with a bunch of curly stainless noise suppression material.
Is this their normal/self branded mufflers or their universal mufflers they offer?
Quote:
You may want to also consider a heavier wall thickness if you purchase tubing...this takes out a good bit of the "metallic" sound in the rotary exhaust.

On a different note, I will shoot you a PM soon about seeing if you can help me with a intake plenum design for a sidedraft Weber (DCOE).

Todd B.
(formerly of No Limit Industires in Alabama)
Sounds like a plan.
vex is offline   Reply With Quote
Old 08-03-2010, 01:21 PM   #34
RETed
RCC Addict
 
Join Date: Mar 2008
Location: Honolulu, Hawaii USA
iTrader: (1)
Posts: 1,813
Rep Power: 18
RETed will become famous soon enough
Default

Quote:
Originally Posted by vex View Post
In addition to this though what if I combined a diffuser and a muffler together? Have a large perferated tube design feed into a rather flat but large muffler filled with stainless steel wool and outputs into two exhaust mufflers on the side in the normal location.

Thoughts? (I want to see if anyone can spot the issue with the latter idea )
This is exactly what we're going to do with our 20B project...

Magnaflow center 4" in, dual 3" out
...into...
twin 3" in / 3" out offset mufflers in the back

It should to pretty good noise suppression.


-Ted
__________________
reted_2000@yahoo.com
Technical Advisor
FC3S Pro
http://fc3spro.com/



Quote:
Originally Posted by TitaniumTT View Post
because you're only as good as your backup
RETed is offline   Reply With Quote
Old 08-03-2010, 01:25 PM   #35
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

Quote:
Originally Posted by RETed View Post
This is exactly what we're going to do with our 20B project...

Magnaflow center 4" in, dual 3" out
...into...
twin 3" in / 3" out offset mufflers in the back

It should to pretty good noise suppression.


-Ted
Will you have to worry about the gas tank in the stock location? AKA if you're running hot you'll heat the gas in the stock location and if there's an accident...?
vex is offline   Reply With Quote
Old 08-03-2010, 01:50 PM   #36
RETed
RCC Addict
 
Join Date: Mar 2008
Location: Honolulu, Hawaii USA
iTrader: (1)
Posts: 1,813
Rep Power: 18
RETed will become famous soon enough
Default

Dunno, but good question...

The owner of the car is doing all the fab'ing on that exhaust.
He's the certified weldor.

The layout sorta mimics the Racing Beat / RS*R FC turbo exhaust, with the exception of the center muffler.
We're hoping that center muffler will help quiet things down.

We were running a 4" in / out center muffler, but it was still too loud.
We've gotten warnings here in Hawaii for exhaust noise - kinda rare, so it's pretty loud.


-Ted
__________________
reted_2000@yahoo.com
Technical Advisor
FC3S Pro
http://fc3spro.com/



Quote:
Originally Posted by TitaniumTT View Post
because you're only as good as your backup
RETed is offline   Reply With Quote
Old 08-03-2010, 03:21 PM   #37
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

hmmm.... Interesting thought. Let me know how it turns out. I may potentially do a similar route when I'm in a house.
vex is offline   Reply With Quote
Old 08-03-2010, 03:44 PM   #38
jtbshaw
ORD - Old Rotary Dude
 
jtbshaw's Avatar
 
Join Date: Feb 2008
Location: Pelham, AL
iTrader: (3)
Posts: 319
Rep Power: 17
jtbshaw is on a distinguished road
Default

Quote:
Originally Posted by vex View Post
Is this their normal/self branded mufflers or their universal mufflers they offer?.....

Sounds like a plan.
Their normal mufflers/pre-silencers that are included with their systems. I have never used one of their universal mufflers.

I am trying something a little different on the current system. I will be using a Vibrant stainless pre silencer to see if it holds up like the RB units. It costs about $100 less than the RB and stated that it was for higher temps than standard mufflers. I have a feeling that within the first few thousand miles, the sound deadening material (even though it is stainless similar to the RB) will be burned out and I will have a hollow resonator.
jtbshaw is offline   Reply With Quote
Old 08-03-2010, 06:41 PM   #39
TitaniumTT
Test Whore - Admin
 
TitaniumTT's Avatar
 
Join Date: Mar 2008
Location: Right Behind you son
iTrader: (4)
Posts: 4,581
Rep Power: 10
TitaniumTT will become famous soon enough
Default

Quote:
Originally Posted by RETed View Post
This is exactly what we're going to do with our 20B project...

Magnaflow center 4" in, dual 3" out
...into...
twin 3" in / 3" out offset mufflers in the back

It should to pretty good noise suppression.


-Ted
Nice, that's my exact setup with a different sizes

Quote:
Originally Posted by jtbshaw View Post
Their normal mufflers/pre-silencers that are included with their systems. I have never used one of their universal mufflers.

I am trying something a little different on the current system. I will be using a Vibrant stainless pre silencer to see if it holds up like the RB units. It costs about $100 less than the RB and stated that it was for higher temps than standard mufflers. I have a feeling that within the first few thousand miles, the sound deadening material (even though it is stainless similar to the RB) will be burned out and I will have a hollow resonator.
I've used the vibrant tubing in my exhausts. Holds up quite well. Can't speak about their muffles though.
__________________
-The Angry Stig-
DGRR 2009, 2011, 2012 & 2013 - Best FC

DEALS GAP!! WOOHOOOO!!!!!

2015 Audi S4 - Samantha - Zero Brap S4
2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter
2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins
1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle
1988 'Vert - In progress
1988 FC Coupe - Gretchen -The attention whore BEAST!


I'm a sick individual, what's wrong with you?
I'm pure Evil
I'm still insane, in the best possible way.
I think Brian's idea of romance is using lube.
Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion.
You win with your thread. Most everything
It's a truck with a steel gate on the back. Just a statement of fact

Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff....
No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon.
-Angry Motherf*cker Mode ENGAGED-
TitaniumTT is offline   Reply With Quote
Old 08-03-2010, 08:07 PM   #40
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

Just out of curiosity where is everyone finding these offset mufflers they're talking about? Everyone I've looked at doesn't seem like it would hold up. I'm half tempted to lay down some real coin and buy the RB y-pipe and mufflers.
vex is offline   Reply With Quote
Old 08-03-2010, 11:44 PM   #41
RETed
RCC Addict
 
Join Date: Mar 2008
Location: Honolulu, Hawaii USA
iTrader: (1)
Posts: 1,813
Rep Power: 18
RETed will become famous soon enough
Default

Magnaflow
Walker Dynomax UltraFLO
Borla

That's the ones that come to mind right now.


-Ted
__________________
reted_2000@yahoo.com
Technical Advisor
FC3S Pro
http://fc3spro.com/



Quote:
Originally Posted by TitaniumTT View Post
because you're only as good as your backup
RETed is offline   Reply With Quote
Old 08-04-2010, 07:43 AM   #42
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

welp the fine state officers of VA have decided to give me a birthday present in the form of another exhaust ticket.
vex is offline   Reply With Quote
Old 08-04-2010, 12:19 PM   #43
vex
RCC Loves Me Not You
 
vex's Avatar
 
Join Date: Jul 2008
Location: Influx.
iTrader: (6)
Posts: 2,113
Rep Power: 19
vex will become famous soon enough
Default

alright, so I looked a tad bit closer at the 'oem equivalent' system that racing beat provides and have noticed that what I thought were cylindrical mufflers are actually oval. With that in mind I've got a fair few selections to which I can purchase (since i'm no longer limiting myself to the round style mufflers). This is what I have thus far:
From Magna Flow:
Mufflers: 12256 $81.82
Y-pipe: 12198 $90.88

From Flowmaster:
Y-pipe chambered: 80430402 $79.95

From Borla
Mufflers: 40665 $168.95

From those choices (or any others you could recommend) which would provide me with the most performance? (If it's still too loud I'll just get the augor/butt plug and through it in the resonator)
vex is offline   Reply With Quote
Old 08-04-2010, 02:27 PM   #44
sen2two
KTEC
 
sen2two's Avatar
 
Join Date: Jan 2009
iTrader: (2)
Posts: 642
Rep Power: 0
sen2two is on a distinguished road
Default

Also, I wrapped my entire system from the turbo all the way back to the muffler with heat wrap which helped big time. Soaked up a lot of the metal sound and deepened the tone some.

Using a thicker wall tubing will also have a similar effect. Stainless is better also in noise suppression than regular mild steel. But this will add to cost... But as usual, you get what you pay for.
__________________
what I have:
1985 Gs:12a All motor Drag car - 1973 Rx2: Play car
What I had:
93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2
sen2two is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 09:30 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Hosted by www.GotPlacement.com
Ad Management by RedTyger