Does anyone here know what the diameter of a 1988 subaru gl exhaust?

hi,

 short answer is no,  because the pipes are actually double ,, a smaller pipe inside a larger pipe, front to back.   the pipe you can see, the outer one,  is  "about 1- 3/4"  maybe, but the actual diameter of the inner pipe is much less, maybe 1-1/2 or less.  you will get some discussion on what size is best for these cars,  but the OEM pipes are not what they appear to be,, you cannot judge the size by the outside pipe, the inner pipe is the real exhaust size and it's pretty small.

O.D on my stock pipes was 1 7/8.  I'm willing to bet it was whatever the metric equivalent of that is.  I just had the exhaust on my 87 done and went full 2 inch from the engine back.

O.D on my stock pipes was 1 7/8. I'm willing to bet it was whatever the metric equivalent of that is. I just had the exhaust on my 87 done and went full 2 inch from the engine back.

Do you get backfiring from lack of back pressure? Is there still a cat? My car backfire a lot while going through the gears and I'm trying to figure out how to fix that

You might check the bolts that hold the exhaust pipe to the bottom side of the cylinders, and retighten them if at all loose.

I don't know exactly the inner size of the original exhaust pipes on the EA82's, because I removed them more than two decades ago; but seems to be a little less than two inches; I bet it is around 1¾", and they have a Heat Shield in certain areas.

 

Do you want to change the Whole Exhaust or certain parts of the Pipes?

 

 

... I just had the exhaust on my 87 done and went full 2 inch from the engine back.

 

My Weberized EA82 Subaru "BumbleBeast" Runs with same full 2" from engine to the tail pipe, since year 1993, as I explained on my Build thread with Photos (Link at my Signature). No pre Catalytic nor catalytic, only a "Y", a straight pipe and a simple muffler, and it never Backfires at all.

 

Kind Regards.

there is no such thing as backpressure. it is called scavenging, or exhaust pulse reflection, which creates a charging effect. stop confusing people. Otherwise what you mean to say is 'exhaust restriction' (this comment in general in response to the word 'backpressure', not aimed at any one person or comment))

Edited May 21, 201411 yr by MilesFox

Do you get backfiring from lack of back pressure? Is there still a cat? My car backfire a lot while going through the gears and I'm trying to figure out how to fix that

 

I still have the "collector cat" but its aftermarket from magna flow.  The second cat I junked.  I'm using a 2" in and 2" out magna flow muffler also.  I don't have any backfiring during normal driving while going through the gears.  I got a little burbling when I went from 5th to 3rd going downhill at about 60 when someone pulled out in front of me.

I still have the "collector cat" but its aftermarket from magna flow. The second cat I junked. I'm using a 2" in and 2" out magna flow muffler also. I don't have any backfiring during normal driving while going through the gears. I got a little burbling when I went from 5th to 3rd going downhill at about 60 when someone pulled out in front of me.

I have pretty much the exact same setup, except stock y resonator, no cat, and the same magnaflow muffler. I'm thinking it might be because my asvs aren't blocked off. Ill try that and post back. Sorry OP I didn't mean to hijack your thread