[wh33lman]

I just installed the Pypes 2.5" system with Race Pro mufflers, Pypes downpipes, hi-flo Cats, and RamAirIII repro 2.25" manifolds.
My car is a 1981 Trans Am, with a 1973 400 4x-4H 98cc heads, 1970 cast intake, 1973 Quadrajet untuned (Cliff, where's my carb?)

Here are some of my observations..

1.) easily installed at home with regular tools. Sawzall for cutting pipe and breaker bar for tightening clamps really helps if you have no air.

2.) Get the band-clamps so adjustments are easier. Almost impossible to get them tight enough not to leak, but I'm welding it up when all ready. Not quite enough room for the stepped band clamp to be used at rear muffler connection. Pipe turns up too sharply for that clamp and leaves a gap.

3) Cast Iron manifold with steel studs, brass nuts and aluminum flange makes for several tightening sessions after heat cycling. The drivers side manifold has only 2 bolts, both of which on mine are too close to downpipe to use socket wrench, and one comes loose every other day. Probably try 2 nuts next.

4) The Race Pros mufflers are much quieter than my 12 year old Stormer 2-chamber turbo muffler system. Objective observation - pedestrians further down road don't turn around like they used to. But the comments from nearby pedestrians are just as sweet.

* 650-2000 rpm - little or no drone, but definitely declares a healthy Pontiac is under the hood. Easy conversation level, drive-thrus can hear you fine.
* 2300-2500 rpm - loud when cruising, very very loud when "on it" in the 45-60mph range. (3:08 gears) Not a time for conversations or cops.
* 2600-???? - very very quiet, you can barely hear the exhaust, it is eerily quiet. You could almost whisper a conversation to your passenger at 70MPH

5) Flow has increased. Car is more responsive, tires break loose a bit easier when pulling away. I'm now "bogging" a bit. Carb may need adjusting now.

6) Exhaust has a modern sound with the X-pipe, alot like an LS1 sound when "on it", but definitely not an LS1. Car performance feels much smoother.

7) Cat installation - a bit tricky. No instructions for this part and it differs from the supplied X-Pipe instructions. You have to install the X-pipe as far back as it will go, so you have almost the entire length of downpipe to work with. Only the last 12' of downpipe is straight enough to cut in Cats. Assemble system, without the Cats, then hold the Cat up to the downpipe and mark the section of downpipe to cut out for the Cat. The front connector of the Cat should lie just under the cross member, so the cat tucks in correctly behind it.

I am having a problem with a low passenger downpipe, but I am covering that in another post. I expect Pypes will get back to me today on that issue.

Overall I'm very pleased with the sound and installation. Once the downpipe is fixed, and the system is welded up to eliminate those couple of pesky band-clamp leaks, I'll be even happier.

[wh33lman]

Not a good night...went back under to tighten 2 bolt flange again, and the cast aluminum flange cracked.

I loosened up and re-aligned the system for the 3rd time and still the one tailpipe is way off, even though the mufflers are dead even and level.

So I'm not so pleased anymore...I'm off the road for another 3-4 days waiting for another cast aluminum flange, and it looks like I have to take the car into a shop to get the downpipe cut to the proper height and the tailpipe bent...and they won't be cheap, since they wanted to do the car in the first place.

By the time you add up the Pypes system, plus the downpipes, plus the flanges, plus the band clamps, plus the taxes and shipping, plus the shop time to fix it and weld it, it would have been $100's less to just go the exhaust shop.

[GTOWAGON]

loose the aluminum flange and get the cast iron ones i have had these on the wagon for going on 10 years and have never had to tighten them more than once a year. The muffler shop system would never have compared to the PYPES system.Also i doubt that the muffler shop will be able to make the downpipes fit better the problem is their pipe flaring machine needs a minum length to work and that exceeds what you need for clerance.Im sure C.Cass will help you out

[wh33lman]

Originally Posted by GTOWAGON

loose the aluminum flange and get the cast iron ones i have had these on the wagon for going on 10 years and have never had to tighten them more than once a year. The muffler shop system would never have compared to the PYPES system.Also i doubt that the muffler shop will be able to make the downpipes fit better the problem is their pipe flaring machine needs a minum length to work and that exceeds what you need for clerance.Im sure C.Cass will help you out

Pypes determined I was sent a Chevy pipe by mistake and are sending out a replacement.

I agree, cast iron is much preferred, but where do you get a cast iron flange for the 2.25" RamAirIII repro that will fit the Pypes 2.5" downpipe?

[GTOWAGON]

from performance years they have the flanges in cast iron and aluminum from what im told

[wh33lman]

Thanks...I'll call PY tomorrow. Their online catalog is a bit confused over the part number.

2 times it mentions the part but different part #'s.

I'm guessing it is the RPE660H.

Pypes should be offering steel instead of aluminum.

[Billy177]

My pipes system did not fit well either. The mufflers would hit the driveshaft and the tail pipes did not line up with the valance. After calling Pypes and being told that it was my headers fault even though both pipes were bent different and both too far. I had to cut them and re-weld them. Now the mufflers are in the right spot and with a little more tweaking the pipes will fit in the valences perfectly.