What is pipe diameter on stock H-Pipe?

[patdow1]

I can't say I ever heard this topic discussed, but does anybody know what the stock piping diameter is on a stock 87-93 5ltr H-Pipe? The reason I ask is I don't understand how to properly proportion the piping on my exhaust set-up. I have a set of Heddman Hedders 1 5/8", stock H-Pipe and Magnaflow 2 1/2" Cat-Back. I was thinking to get a 2 1/2"catted H-Pipe to even things out if the stock H-Pipe was like 2 1/4". Is this a good idea or am I just wasting money for minimal gains

 

[ninety15.0]

I think it is either 2" or 2.25" but its not really the diameter of that pipe that makes it very restrictive its all those crappy stock cats. I'm wondering what other mods you have on the car right now...but a 2.5" catted H pipe would be a decent investment especially if you have H/C/I or forced induction plans in the future...not to mention the exhaust tone will be much nicer!!! Goin with a catted H you shouldnt loose any low rpm TQ and you should pick up like 10 ponies in the end. Good luck man!

 

[Kdubslugga]

i beileve the stock diameter is 2.25, your definetly not wasting money with an Hpipe. Especially if you get an off road one, get rid of that crappy stock one with 4 cats!!!

 

[cevtv]

You guys are missing the fact that he is in CA.........he will NEED all 4 cats to pass the visual inspection...........

 

[sirr0bin]

stock h pipe is 2.25"

you could get a cat-less h pipe and swap the stock one in for smog tests, or get a h pipe with high flow cats and just keep it on all the time

personally, i'd go with the cat-less, but i love that rumble

 

[ninety15.0]

i dont know for sure and i dont see why you would need four cats to pass inspection. I dont think it matters how many cats you have it just matters that you pass the hydrocarbon and other tests. Im not sure that your statement is entirely correct. but then again i dont live in CA and glad not to.

 

[cevtv]

Trust me. In CA, and some other states, you need the actual number of cats as it came with from the factory. Do a search, there is a bunch of info about this.

 

[Idwitheld-1`]

i dont know for sure and i dont see why you would need four cats to pass inspection. I dont think it matters how many cats you have it just matters that you pass the hydrocarbon and other tests. Im not sure that your statement is entirely correct. but then again i dont live in CA and glad not to.

...um there is this thing called the "visual inspection". Basically, if it came with 4 cats, it gets tested with 4 cats.

I had a smog cert revoked because this jack-assss DEQ manger thought I only had 2 cats on my car. Open your fricken eyes! I see 4 OEM original cats on my 93 Frick-head!!! Don't think for one second that every state, every inspector is trained well and could actually point out critical components of a car (motor, tire, smelly exhaust tube thingies on the back of the car.....). Many are good (thank you God. Many are crack-pipe junkies.

Sorry for the rant.

 

[patdow1]

The only reason I mentioned that I was looking for a catted h-pipe is that currently I live in a condiminium and don't have much space for parts in my storage unit It aslo doesnt help that they don't allow me to work on my car in the parking lot. But there is a positive flip side to this in that I'm currently looking to buy a house by July so I can swap out a non-catted h-pipe when its time to pass the sniffer test. So is everyone in agreement that a h-pipe catted or non-catted is well worth the money and that the stock h-pipe is 2 1/4".

 

[patdow1]

Damn!! After reading this post once again, another question has to be asked? If I buy a catted H-pipe I may still not be able to pass the visual inspection of a smog test here in California because the aftermarket catted H-pipe eliminates two of the cats, so the extra money spent on a catted H-pipe could be very well be wasted. Correct me if I'm wrong but It would be best to get a offroad H-pipe instead of a catted one if I could swap the stock one in for smog test.
Thanks
Pat

 

[willys1]

Well,it would cost a little extra but you could get an off road h-pipe,buy 4 cats,gut 2 of them out,and put all 4 on the 2 1/2 in h-pipe.