TCCoA Forums banner

New Exhaust

1K views 9 replies 7 participants last post by  dDUBb 
#1 ·
I have a 1989 Cougar XR7 3.8 Supercharged. Everything I’ve read about the choked down exhaust on these engines and blowing head gaskets, seems like I should replace the exhaust before possibilities of that happening. I found headers and new exhaust system on Super Coupe Performance’s website. Does anyone know how difficult it will be to remove the stock exhaust manifolds?? Can this be done easily from underneath or will it have to be done topside which means removing a bunch of stuff!! Thx.
 
#3 ·
I'm not sure how restrictive the manifolds are, but the system is only 2 inch pipe. If you buy something be sure to get it for the correct year, the exhaust routing changed on the later models.

Like Trunk Monkey posted, a lot of info at SCCoA.

Joe
 
  • Like
Reactions: MistaK7
#5 ·
From your other post .. Your car has only 32k miles. With that, I would say your car is hardly ever driven .. Never driven hard, and had regular maintenance / fluid changes up to date.

I would leave it alone as is. As long as you keep fresh coolant and oil in the engine. Like Matt said .. The MLS head gaskets are the way to go but usually not until after a failure has made it a necessity. The OEM harmonic balancer is known to come apart also, so be sure to put a solid BHJ balancer on your preemptive maintenance parts list.
 
#6 ·
I bought the car brand new in Alaska. We drove it only during the summer months (3-4 months) then stored it indoors during the winter months. Had a project truck I was working on, only room for one vehicle at a time, so the car went into storage. It sat there for 3 years. Ended up buying a home in Phoenix, shipped the car down in 2012. Now gradually working on a few things...
 
#7 ·
The exhaust causing blown head gaskets is pretty much a myth. Most blown head gaskets are due to high mileage, poor maintenance, detonation, or a combination of the above. Of course if you are cranking up the boost and/or overdriving the blower, having a restrictive exhaust is going to make it harder to keep detonation away, but on a stock vehicle, or even a well tuned modified one, the exhaust is not going to cause your head gaskets to blow. As for the MLS gaskets, that’s great and all if you are rebuilding the whole engine, but for them to seal properly, the block has to be decked, so on a regular head gasket job, I usually just go back with the composite gaskets, but with the ARP head studs. That will hold up to all but the most extreme builds.
 
#8 ·
I have a ‘93 5spd. Blew the left HG at about 77k. Had the exhaust redone 2 years later. The left down pipe goes into the top of the converter (the gas has to do a sharp 90* inside the cat), also the down pipes are double walled. So, they are not as big as they look. I read an article that someone wrote a bunch of years ago. If I remember correctly, He had blown the HG’s and done some damage. So, after completing repairs, he started drilling holes on both sides of the different features in the exhaust. Wide open throttle, high RPM’s, 11 psi boost, he stated that there was 15 psi back pressure at the left down pipe.
I don’t Romberg the configuration on my ‘90, but my ‘93 being a transition year. It had 3 cats.
If you can warm the engine a little, remove the air inlet to TB and maybe the drivers side IC tube and whatever will make room to get to the manifold. Spray the bolts and nuts with liquid wrench or other penetrating oil and let it sit. Chances are you will break a bolt or stud. Just take it easy.
 
#9 ·
I have a ‘93 5spd. Blew the left HG at about 77k. Had the exhaust redone 2 years later. The left down pipe goes into the top of the converter (the gas has to do a sharp 90* inside the cat), also the down pipes are double walled. So, they are not as big as they look. I read an article that someone wrote a bunch of years ago. If I remember correctly, He had blown the HG’s and done some damage. So, after completing repairs, he started drilling holes on both sides of the different features in the exhaust. Wide open throttle, high RPM’s, 11 psi boost, he stated that there was 15 psi ' back pressure at the left down pipe.
I don’t Romberg the configuration on my ‘90, but my ‘93 being a transition year. It had 3 cats.
If you can warm the engine a little, remove the air inlet to TB and maybe the drivers side IC tube and whatever will make room to get to the manifold. Spray the bolts and nuts with liquid wrench or other penetrating oil and let it sit. Chances are you will break a bolt or stud. Just take it easy.
After reading several posts, I’m now a little leery about changing out the stock manifolds to headers. SCP has all the items to change over...Kooks mid-length and long tube headers, cats, exhaust and mufflers. Thinking it might be better to just leave stock manifolds, and change everything from there back.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top