|
|
|
|
| Author |
|
|
Registered
Join Date: May 2008
Posts: 35
|
Quote:
Mike (Danglerb) is correct, moving the "Y" forward would be better with that system. Adding in a 3" Hi-Flow Cat behind the "Y" will also not effect the power in anyway that you could ever feel and may even add a little more lower end torque. Also that 3" cat-back(from the 4 bolt flange rearward) is one of the best flowing systems ever made for your 79. You can spend some money on some "prettier" systems, but I doubt you can find one even now that flows better. I also made a single 3.5" version that was really good for the higher powered S2 and S3. It is kind of neat to see one of my old Cat-back systems still on the road, the last time we made those was over 10 years ago. BTW, I can't say how yours sounds with the "Y" that far back, but I still have the 3.5" version on my S2 and trust me, it sounds nothing like a tractor :-) Everyone that hears it has commented on how good it sounds.
__________________
David Roberts 85 928S Euro 5-Speed "Supercharged by 928 Specialists" 16V Prototype 928 Owners Club Member/Co-Founder |
||
06-25-2009, 04:49 PM
|
|
|
NO substitute
|
Quote:
Thx Doc, appreciate the feedback. So, this is one of "your" cat back systems on my car? It does sound ridiculously insane, a little too insane for my liking. I have to say the car runs like a raped bear and has smoked many a std 928 and S's, not the S4, for sure... Everyone else seems to love it but I need it a little more friendly and not so raspy, but I think that has something to do with the spin tech race free flow muffler on there, too open. Now, the only problem I am having is that with this system I am very limited to the mufflers I have to choose from, beings I need a 3 inch in and 3 inch out, same side inline/offset, etc. I have seen the typical Flowmaster Super 44(not interested) and a few others. None from magnaflow will fit this specific topology, again kinda limited. Any ideas on a nice 3 inch muffler that will fit(3 inch same side inline offset) and give me a nice euro v8 sound, not so race trackish?!?!?  Thx again Doc, nice to hear some good feedback, look forward to some more... Last edited by SharkTech; 06-25-2009 at 06:45 PM.. |
||
|
06-25-2009, 06:43 PM
|
|
|
Registered
Join Date: May 2008
Posts: 35
|
Hi Tech,
Who is "Doc"?? :-) the "DR" is my initials. Yes that is my system and yes it was(is) loud. Back in the day we offered an additional add-on inexpensive round resonator/tip for those that needed it to be quieter. If you look at the rear bracket on yours it was made specifically for you to be able to cut off the rear section and add the resonator without having to change the rear bracket. Bet you wondered why it was made like that :-) I can't remember the brand or part number, but look for a 3" rear Tip/Resonator about a foot long?? and see if that gets it to where you want it.
__________________
David Roberts 85 928S Euro 5-Speed "Supercharged by 928 Specialists" 16V Prototype 928 Owners Club Member/Co-Founder |
||
|
06-25-2009, 06:55 PM
|
|
|
NO substitute
|
Quote:
I figured that much, Dave Roberts, Doc just sounded cooler.  And after a peek at that euro of yours I figured you were some sort of Porsche Doctor anyway, Jeeesis Chrise. I would rather not mess with the rear resonator crap, and just find a nicer, more mellow(slightly chambered) 3 inch muffler that will work with this setup. Love it too much to change it. Was hoping you had something in mind... |
||
|
06-25-2009, 07:13 PM
|
|
|
Network Native
Join Date: Jan 2007
Location: SoCal
Posts: 10,349
|
I would leave the spintech and add something small to replace a short section in the rear, just to take the rasp out.
Years ago I got talked in to a big pipe Hooker system for my 240z, and it was pure John Deere.
__________________
US 83 zinc metallic 5 spd, aka the nice car. Euro 85 black, 5 spd, the fast rough track car maybe car. SOLD Euro 84 red, AT, only car in garage in years, my parts car, soon to go last 7 years. |
||
|
06-25-2009, 07:18 PM
|
|
|
NO substitute
|
Quote:
Haha, there you go with that tractor crap talk again!!!  Dunno, I am gonna look around to see what I can find... When you say something small(also 3 inch compatible) have anything in mind???? |
||
|
06-25-2009, 07:31 PM
|
|
|
|
Registered
Join Date: May 2008
Posts: 35
|
Quote:
3" Inlet 12" long Stainless Steel resonator... $56 http://www.sfxperformance.com/parts/VIB1794.htm
__________________
David Roberts 85 928S Euro 5-Speed "Supercharged by 928 Specialists" 16V Prototype 928 Owners Club Member/Co-Founder |
||
|
06-25-2009, 07:41 PM
|
|
|
NO substitute
|
Quote:
Hmmm, that does not sound like a bad idea?!?!?! Looks nice, only a foot long and you think will take some of the OH MY GOD outta the noise? So, this would get "cut in" in the existing 28 inches or so of pipe after the muffler, but leaving the original exit dump out the rear??? How bout hangers, etc? Hmmmmm.... Might work. I guess i do not quite understand the comment about the rear bracket being the way it is, to remove if needed, etc. I like the exit pipe how it is and again was wondering if it would be worth it to cut the resonator in a little after the muffler and leave some of the exit run? Last edited by SharkTech; 06-25-2009 at 08:11 PM.. |
||
|
06-25-2009, 07:51 PM
|
|
|
Registered
Join Date: May 2008
Posts: 35
|
Quote:
__________________
David Roberts 85 928S Euro 5-Speed "Supercharged by 928 Specialists" 16V Prototype 928 Owners Club Member/Co-Founder Last edited by DR928; 06-26-2009 at 05:36 AM.. |
||
|
06-26-2009, 04:46 AM
|
|
|
NO substitute
|
Quote:
BUT, again my question is do I have to lose the nice exit dump pipe to put this resonator right at the end/with a small tip or can I cut it in earlier/closer to the muffler to leave the nice rear piping??? As I said I am a big fan of the nice stainless exit run, big fan... 
|
||
|
06-26-2009, 04:56 AM
|
|
|
Heavy Metal Relocator
|
Quote:
there are high flow CATS available from many muff manufacturers now that do not affect power outputs, but do pass any smog test issues----even racing CATS. detractors included increased undercar heat and added cost. as to the dual into single issue...loose the single pipe. Yes, your car may not need the extra flow capability of a true dual exhaust setup...but----you have twin 3 inch going into a single 3 inch muff with a single 3 inch tailpipe----there will be some drop off in flow. I suggest a 3 inch x-pipe after the header collectors, and then twin 3 inch muffs and twin 3 inch tailpipes (be careful building this as the passenger side tailpipe will route next to the gas lines and gas tank---be sure to install some sort of heat shield/prevention in these areas). a total headers/dual 3 inch system will handle anything any modded 928 engine has to offer---even a blown and stroked 928. OR...... you could just put a set of sidepipes on it like I did mine----but everyone would give you a bunch of crap about it.  --Russ
__________________
Absence of Evidence, is not Evidence of Absence. Bill Maher 8/4/09--- "I'll show you Obama's birth certificate, when you show me Sarah Palin's high school diploma." |
||
|
06-26-2009, 04:51 PM
|
|
|
NO substitute
|
Quote:
Thx Russ, appreciate the feedback... I am throwing all kinds of ideas around, sure I will come up with something soon, or go crazy, one or the other... 
|
||
|
06-26-2009, 04:59 PM
|
|
|
|
Network Native
Join Date: Jan 2007
Location: SoCal
Posts: 10,349
|
Just put the final muffler where a muffler is supposed to go, 8" or so from the tip.
|
||
|
06-26-2009, 05:54 PM
|
|
|
Moderator
|
There you go with that damn pic again. Measure that exhaust tip for me so I can stop pestering you about it.
__________________
1981 Porsche 928 "Euro" Auto Gunsmoke Metallic Flat - Black Interior 1983 Porsche 928S "US" Auto Light Bronze (Copper) Metallic - Brown Interior **SOLD** 
Last edited by MPDano; 06-26-2009 at 09:33 PM.. |
||
|
06-26-2009, 07:04 PM
|
|
|
NO substitute
|
Quote:
Magnaflow? 3 inch in or 2.5? Dual 3 or 2.5 out? Where did you get the tips/custom fab? Finally, how long, overall including tips is that muffler? Thx, in advance... |
||
|
06-26-2009, 08:14 PM
|
|
|
Network Native
Join Date: Jan 2007
Location: SoCal
Posts: 10,349
|
Its a Magnaflow, I'm thinking the whole thing is 2.5" most likely. I dropped the car with my muffler guys and instead of a lot of measuring, I told them do what you think works best. They picked the muffler and tips, and never gave details.
I can't complain about the results, but I am going to do it over again with a few more specifics. I spec'ed the head pipes to the 86 exhaust manifolds as 2.25", and that is the ID of the manifolds, but pipe goes by OD, so I want 2.5". Same size issue on the Y pipe, plus I want to go to a fully tuned X (not a generic Y) with dual cats. The single chamber Magnaflow (5x8x14 maybe) is right on the line of legal muffler, but get you pulled over to prove it, loud. Cat is from the calif cat catalog, nothing special or high flow. Pictures of the rest are in one of the other exhaust threads here. I plan on working on that car next week, and should be able to measure some of it then. |
||
|
06-27-2009, 12:56 AM
|
|
Big REDD
