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View Full Version : Any photos of exhaust with dual outlet resonator?



OldZofTorC
10-30-2013, 10:14 PM
I have a borla two outlet resonator. I want to have this installed so I can drive the car without fear of blowing a head gasket. I have looked through the archives but not much there.

MadMikeyL
10-31-2013, 11:48 AM
Changing the resonator will not do anything to help your head gaskets. They blow due to time, torque to yield bolts, electrolysis in the coolant, detonation, or overheating. A freer flowing exhaust will help performance, but if you are concerned about the head gaskets blowing on you, you would be better off just replacing them now, getting the heads checked/resurfaced, and using ARP head studs to put it back together.

capri347
10-31-2013, 06:15 PM
on that note (sorry for jacking a thread) but what are the best head gaskets to use?

figulaz
10-31-2013, 06:52 PM
A lot of threads and faqs on this forum also point to our exhaust ...specifically the resonator as a bottle neck causing high psi and hg failure...especially if overdriving. I went with arp studs and was planning exhaust not only for performance but it looked like a hg safety precaution.

archerman0531
10-31-2013, 07:14 PM
A lot of threads and faqs on this forum also point to our exhaust ...specifically the resonator as a bottle neck.

I was thinking its more on the line of the manifolds not being big enough, thats why they are commonly ported. They are smaller than the exhaust opening on the head and restricting air flow there, I haven't read much about the resonator being the problem.

MadMikeyL
10-31-2013, 07:18 PM
That is unfounded speculation. There is no evidence that exhaust either causes or saves head gaskets. If you want to keep them intact as long as possible, make sure your cooling system and ignition system are in good shape, make sure you don't have any vacuum leaks, don't over-rev the motor, and always run premium fuel. If you don't know the history of the car or how it was maintained, and you need it to be dependable, my advice at that point is to do them yourself so you know they were done right. As for what gaskets to use, felpro either way, and mls gaskets are nice, but unless you are going to have the block and heads resurfaced to the right roughness, just order the ones for an SC.

racecougar
10-31-2013, 07:25 PM
Don't judge me on the exhaust; I didn't bend/weld it up. I do plan to weld up a more aesthetically pleasing system, though it will likely be the same configuration. Hopefully these pictures help.

http://i6.photobucket.com/albums/y207/racecougar/90%20XR7/underside/onthelift5.jpg (http://s6.photobucket.com/user/racecougar/media/90%20XR7/underside/onthelift5.jpg.html)
http://i6.photobucket.com/albums/y207/racecougar/90%20XR7/underside/onthelift2.jpg (http://s6.photobucket.com/user/racecougar/media/90%20XR7/underside/onthelift2.jpg.html)
http://i6.photobucket.com/albums/y207/racecougar/90%20XR7/underside/onthelift3.jpg (http://s6.photobucket.com/user/racecougar/media/90%20XR7/underside/onthelift3.jpg.html)

KMT
10-31-2013, 07:33 PM
Looks as nice under as it does above - I hope you sent the 2nd image in for the calendar :)

sc91gt
11-01-2013, 12:44 AM
A freer flowing exhaust yields less heat especially in the heads. So it will help in general. Do not replace headgaskets until needed. You need to open outlet on manifolds. And 2" or 2 1/4" down pipes to resonator. Then....



Changing the resonator will not do anything to help your head gaskets. They blow due to time, torque to yield bolts, electrolysis in the coolant, detonation, or overheating. A freer flowing exhaust will help performance, but if you are concerned about the head gaskets blowing on you, you would be better off just replacing them now, getting the heads checked/resurfaced, and using ARP head studs to put it back together.

figulaz
11-01-2013, 01:50 AM
A freer flowing exhaust yields less heat especially in the heads. So it will help in general. Do not replace headgaskets until needed. You need to open outlet on manifolds. And 2" or 2 1/4" down pipes to resonator. Then....

This article touches on exhaust temps and measured pressure. I don't have a frame of reference but per the author the 15 psi back pressure our stock exhaust creates is way too much. I hogged out the outlets on my car but still need exhaust work.
http://www.sccoa.com/articles/cwexhaust.php

racecougar
11-01-2013, 06:57 AM
Looks as nice under as it does above - I hope you sent the 2nd image in for the calendar :)

Thanks! :)

OldZofTorC
11-01-2013, 01:19 PM
Those pictures are very helpful and the car looks awesome. Those are some monster sway bars. I should have mentioned mine is a 95 but have seen that this year should be even easier. The car has not had a nut turned on it yet besides tranny rebuild with 2k torque converter and the overdrive on the blower. The car has only 45k. I have been very cautious with it because of the HG stories. Should this set-up as it is now be able to break the tires loose from a standing start? I will do a coolant flush and Check the spark plugs.
I have only had the car for a couple of thousand miles.

OldZofTorC
11-01-2013, 01:25 PM
I see you are not running mufflers. What is the sound level inside the car? I was planning to start slow and just have the resonator and separate outlets with stock mufflers. I was hoping to stay pretty stealth.

XR7 Dave
11-01-2013, 01:42 PM
This article touches on exhaust temps and measured pressure. I don't have a frame of reference but per the author the 15 psi back pressure our stock exhaust creates is way too much. I hogged out the outlets on my car but still need exhaust work.
http://www.sccoa.com/articles/cwexhaust.php

If that were really the case, then turbocharged cars wouldn't even run. Think about it.

racecougar
11-01-2013, 08:44 PM
Those pictures are very helpful and the car looks awesome. Those are some monster sway bars.
Thanks! Those are ADDCO 1-1/4" sway bars.


I should have mentioned mine is a 95 but have seen that this year should be even easier.
While the car pictured above is a '90, that is a '92-97 fuel tank, so you'll have the same routing/space to work with on your '95.



I see you are not running mufflers. What is the sound level inside the car? I was planning to start slow and just have the resonator and separate outlets with stock mufflers. I was hoping to stay pretty stealth.
The "resonator" is in fact a muffler. It's a straight-through crossover design, but it does reduce the sound level. Between the cats and the mid-mounted muffler/resonator, it's aggressive, but not overly loud. Here are a couple of videos. Keep in mind, this car isn't a V6 anymore.

In-car video of a pass at the '12 SC/XR7 Shootout:
http://s6.photobucket.com/user/racecougar/media/90%20XR7/Shootout%202012/Shootout2012run2incar.mp4.html

Exterior video of two pulls at a local dyno in '10:
http://s6.photobucket.com/user/racecougar/media/90%20XR7/DynoRuns5-20-10.mp4.html

OldZofTorC
11-01-2013, 10:17 PM
Should this car be able to break the tires loose with the stock set up?
I have tried with a rolling start and they will start to break loose at around 4k.
My girlfriend had an SC years ago. I thought it was stock and I think it would break em loose with no problem.

racecougar
11-01-2013, 11:06 PM
I'm not sure. I've never ridden in a stock SC.

archerman0531
11-02-2013, 12:49 AM
Mine is completely stock and it breaks the tires loose with ease. Even before 2500rpm.

820
11-02-2013, 05:05 AM
As far as i can tell my 94-5speed is stock with a tiny resonator that almost fits in the palm of your hand and it will break loose and go sideways from a 10-15 mph roll.

OldZofTorC
11-02-2013, 01:53 PM
I have always suspected something was amiss. Must be the stall converter. Softer from a stop but comes on real good after about 3k although I haven't really been watching the tach. I am in a small town but we have townies, counties, and staties, so I have to keep it down and an eye out for these guys. I don't want them to mark me, the car does stand out.

I have an appointment Tuesday to have the Borla installed. I am pretty sure I will go straight out from there with the option of adding mufflers if it is too loud for me.

OldZofTorC
11-02-2013, 01:57 PM
Thanks again for sharing the photos of your exhaust set up. I will show this to the guys at the exhaust shop Tuesday and tell them that's how I want it.
:cool:

OldZofTorC
11-04-2013, 10:35 PM
Should this car be able to break the tires loose with the stock set up?
I have tried with a rolling start and they will start to break loose at around 4k.
My girlfriend had an SC years ago. I thought it was stock and I think it would break em loose with no problem.

I decided to quit babying the car. Sunday I took it out through a twenty mile run of nice twisties and long straights. Ran it pretty good and had a great time. And today at the stop light i shifted it down into first, turned of the traction control and let 'er rip when the light changed. Spun the tires until I let off to shift and then chirped them with light throttle going into second. So now I have my base to see what the difference is after I get done at the muffler shop tomorrow.

Scott Long
11-05-2013, 12:41 AM
As far as i can tell my 94-5speed is stock with a tiny resonator that almost fits in the palm of your hand and it will break loose and go sideways from a 10-15 mph roll.

Stock resonator is large 2>1 setup.

820
11-05-2013, 08:08 AM
Any body have a pic of a stock resonator for the late modle sc. i will posy one of the one yhst is on my car tonight if i dont forget).

S_Mazza
11-05-2013, 01:40 PM
I think I would say the stock SC resonator is more of a muffler as well. It doesn't seem to have any purely resonant chambers, but is almost all perforated tubes inside. I would say it works more on impedance mismatching than anything. Still, it makes a big difference in drone. I think the resonant chambers in the stock twin mufflers at the tailpipes do most of the drone reduction, but they can't eliminate it on their own.

Here is a link to a cutaway picture. (Which, apparently, was the only one ever posted - or at least the only one I have ever found!)

http://www.sccoa.com/forums/showthread.php?t=38869

OldZofTorC
11-05-2013, 06:01 PM
Had the car at Alert Exhaust in Las Cruces,NM today.
The guy did a great job for me. Borla 2x2 with 2'' back to each stock muffler.
Everything is right where it is supposed to be.
Definately can feel the improved breathing. A little bit of sound driving next to a wall with the windows down. I was not looking to raise the sound level so I think I will be quite happy with the results.
Thanks to all with suggestions and info.

820
11-05-2013, 07:22 PM
this is what is on my car. it has a ford logo and part number. even if the small muffler looking part is not original it was never a large muffler looking 2 int 1 part. remember this is a california car.

racecougar
11-05-2013, 08:03 PM
That's a third catalytic converter and a muffler/resonator. I know a '94 4.6L would have received that setup, so it's very likely (to me at least) that it's factory.

820
11-05-2013, 09:10 PM
Thats kinda what i thought about the third cat. That goes to show that cali cars are different. Its a wonder that it runs as hard as it does. I had it on the strip at muncie once and only was able to get one pass in. i got over enthusiastic and went from second to overdrive. i was pissed and left it to the mat in od and still chugged to a high 15. a very high.15 that was the fall of 04. my oldest son was behind me looking up the track and said it jumped sideways when i hit second then he thought i broke. ripper shifters are better than the factory shifter, but nothing beats a hurst. anyway i plan on dynoing it if mcgunnigle can ever get his dyno installed.

S_Mazza
11-05-2013, 10:46 PM
The 5-speed cars got a third converter in some years, while the autos were able to keep just 2. My car is a 1990 auto and the resonator matches the cutaway pic I posted above.

820
11-06-2013, 06:53 AM
I remember gutting the resonator on my sons 90 automatic. it was as you pictured,and plugged as bad as the one you pictured. man that was eons ago lol!