Single Turbo RX-7's Questions about all aspects of single turbo setups.

Tuned Length Exhaust Manifold

Thread Tools
 
Search this Thread
 
Old Sep 29, 2004 | 12:40 PM
  #1  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
Tuned Length Exhaust Manifold

I was wondering where I could purchase one or have one made?


This is for my FC and I will be running a TO4R P-trim 1.32 A/R divided.

Any links, help, info would be greatly appreciated!!
Reply
Old Sep 29, 2004 | 05:12 PM
  #2  
rotarygod's Avatar
Rotors still spinning
Tenured Member 20 Years
iTrader: (1)
 
Joined: Jul 2002
Posts: 4,181
Likes: 23
From: Houston
If you are running a divided exhaust, there isn't much tuning that can be done. The length will have little effect on your setup. Just make sure the tubes are equal length if you are concerned. Typically people who want a tuned length will use a nondivided inlet and then basically build a set of headers that collect at a certain length before the turbo. The good thing about foced induction is that there are many ways you can do things and still get good results. Your exhaust runner lengths aren't nearly as critical as they are on a non turbocharged car.
Reply
Old Sep 29, 2004 | 10:08 PM
  #3  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
Cool thanks...

So can someone please direct me in the right direction about how to choose a length on the runners?

I know that the WG comes into play about how its positioned and what not. I have seen a few designs, but mostly pictures without any type of descriptions or reasons for being made a certain way.

Im assuming that a shop could fab up one if they know specs of somesort, which is prolly the way i'll go.
Reply
Old Sep 30, 2004 | 11:50 AM
  #4  
SnowmanSteiner's Avatar
Ga-nome liberator
Tenured Member: 20 Years
 
Joined: Jul 2002
Posts: 1,990
Likes: 0
From: Hell
I have a somewhat different opinion on this. From what I've read exhaust runner length can play a somewhat significant role. With longer manifolds you can get a quicker spooling turbo. Obviously this is to a degree. But many pro drag turbo cars are running 15inch plus exhaust manifolds. But as far as tuning for sound resonance, and the sound wave, that most n/a people look for specifically, it is not as much of an issue as stated above, because you have a greater force of air being pushed out. I hope this helps, and anyone correct me if any of the above information is not accurate. As far as someplace to get it done, the best I can say is look for a good machine/exhaust shop around town. Look at some of their work, and see what the quality of their welds, what type of exhaust tubing they're using etc.

- Steiner
Reply
Old Sep 30, 2004 | 12:24 PM
  #5  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
I thought I had read that it played a significant role in "large turbo" spooling as well, which is why I figured I would ask. I can definitely understand the impact that collected headers will have on an NA motor.

the thing is, I don't think there are any decent exhaust shops around here. The only ones that I know of are Muffler Bros, Muffler King and the like. I don't know if I could trust those types of shops with such a significant part on my car.
Reply
Old Sep 30, 2004 | 12:38 PM
  #6  
SnowmanSteiner's Avatar
Ga-nome liberator
Tenured Member: 20 Years
 
Joined: Jul 2002
Posts: 1,990
Likes: 0
From: Hell
Although I am not a fan of their service Jason at Rx7store might be able to do it, I haven't ever heard of them doing manifolds though so I don't know.

- Steiner
Reply
Old Sep 30, 2004 | 01:28 PM
  #7  
TechTrix's Avatar
Senior Member
Tenured Member 05 Years
iTrader: (2)
 
Joined: Jan 2003
Posts: 409
Likes: 0
From: Los Angeles
I can build you a manifold, ive done quite a few, not just for rotarys, but i also make porsche headers, intercoolers, well i fab pretty much anything. I use 1/8 wall 304 stainless cast elbows and stainless turbo flanges. let me know if your interested. I have an FC and an FD, and a coupple turbos, so if you let me know what you want, i can make it and ship it to you.

Michael
www.techtrixmotorsports.com
Porsche & Ferrari Performance
Reply
Old Sep 30, 2004 | 04:13 PM
  #8  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
Originally Posted by SnowmanSteiner
Although I am not a fan of their service Jason at Rx7store might be able to do it, I haven't ever heard of them doing manifolds though so I don't know.

- Steiner
Yeah, I have heard a few things here and there about their shop up in Cbus. I bought my flywheel from them, and things when smoothly...but who knows when it comes to fabrication
Reply
Old Sep 30, 2004 | 04:15 PM
  #9  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
Originally Posted by TechTrix
I can build you a manifold, ive done quite a few, not just for rotarys, but i also make porsche headers, intercoolers, well i fab pretty much anything. I use 1/8 wall 304 stainless cast elbows and stainless turbo flanges. let me know if your interested. I have an FC and an FD, and a coupple turbos, so if you let me know what you want, i can make it and ship it to you.

Michael
www.techtrixmotorsports.com
Porsche & Ferrari Performance
Thanks man...

I definitely appreciate it. I will be doing some research to figure out the best lengths and designs and what not. I will definitely be in contact with you soon, just waiting on some knowledge and of course, the funds. If you have any pics of your work or anything, shoot it to me at ttvert@yahoo.com
Reply
Old Sep 30, 2004 | 04:59 PM
  #10  
Zero R's Avatar
Just in time to die
Tenured Member 10 Years
iTrader: (1)
 
Joined: Nov 2001
Posts: 4,143
Likes: 2
From: look behind you
Have you searched in this forum for manifolds made and what not? I'm pretty sure I can get you one made if your interested.


-Sean
Reply
Old Sep 30, 2004 | 05:01 PM
  #11  
modrx7's Avatar
Rotary Enthusiast
Tenured Member 05 Years
iTrader: (1)
 
Joined: Sep 2002
Posts: 1,462
Likes: 0
From: Chicago, IL
Sean, I have tried emailing you and calling you at the shop. I even left a message with Niko for you. Can you get back to me, Thanks Edan

847 627 0789
Theres my cell in case you don't have it
Reply
Old Sep 30, 2004 | 05:57 PM
  #12  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
Originally Posted by Zero R
Have you searched in this forum for manifolds made and what not? I'm pretty sure I can get you one made if your interested.


-Sean

Yeah, I have done some searching and have found some posts that include some manifold designs. However, most of those posts go into how nice it looks, etc...and not much into the making or the reasoning behind it.

I will definitely be interested in having one made. If you have any suggestions as far as specs or anything, or if you want to direct me to some threads that i have missed. I would definitely like to do some research to know the fuctionality of the desing process...

Thanks Sean. Let me know.
Reply
Old Sep 30, 2004 | 09:14 PM
  #13  
SnowmanSteiner's Avatar
Ga-nome liberator
Tenured Member: 20 Years
 
Joined: Jul 2002
Posts: 1,990
Likes: 0
From: Hell
Sean is definately one of the best in this industry. His work is incredible. Sorry I didn't mention your name Sean, but I thought that you weren't selling individual parts from kits anymore, and I didn't want to send someone your way if they were just going to be turned down, I know how much work you do, and how precious time is for you guys right now.

- Steiner
Reply
Old Oct 1, 2004 | 10:28 AM
  #14  
TechTrix's Avatar
Senior Member
Tenured Member 05 Years
iTrader: (2)
 
Joined: Jan 2003
Posts: 409
Likes: 0
From: Los Angeles
the length of the runners dont make a difference in a turbo rotary... I used to work for rotary power in LA, when we did abel ibarras r-100 we made 916 hp to the wheels (with a 75 shot of nos) and the runners were different lengths. Ive also made headers for turbo porsches, we tired equal length and un-equal length on the same motor with the same turbo, and dident make any difference, except it cost twice as much to build an equal length set of headers. On an NA car however, length is very important. I make stepped equal length headers that took a lot of dyno hours to get right, and inch here or there makes the difference of 5-10 hp, and so does the length of the pipe after the collecter.

Michael
www.techtrixmotorsports.com
Porsche & Ferrari Performance
Reply
Old Oct 1, 2004 | 12:03 PM
  #15  
Zero R's Avatar
Just in time to die
Tenured Member 10 Years
iTrader: (1)
 
Joined: Nov 2001
Posts: 4,143
Likes: 2
From: look behind you
If you would like you can contact the shop I will go into more with you there, I have no problem making manifolds as one offs. I just do not sell the manifolds from the kits separately, I would have to agree with TechTrix on some of his comments anything over a certain length is pointless and you you wont see much difference if any, but I have notice keeping it equal length and over a certain length will help with turbine response. Truth be said for street use you guys always seem to want more than really is needed.
Reply
Old Oct 4, 2004 | 10:26 AM
  #16  
Comitatus's Avatar
Thread Starter
Down for the count...
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jan 2002
Posts: 806
Likes: 0
From: Cincinnati, OH
Ok...sounds good.

Thanks again fellas...I'll be in contact soon
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Kyo
2nd Generation Specific (1986-1992)
6
Apr 13, 2019 09:24 AM
C. Ludwig
Single Turbo RX-7's
49
Jan 30, 2019 06:31 AM
Engine stand ready
New Member RX-7 Technical
3
Aug 14, 2015 10:26 PM




All times are GMT -5. The time now is 01:54 PM.