Pypes manifolds, 2.5 inch exhaust and Race Pro Cross flow project
 

I put it off as long as I could but finally worked up the nerve to tackle the exhaust project on my 78 TA, 400 manual trans. I had bought the parts before I retired in 2018 but knew that once I started the job, I'd have to keep at it till it was done. Wise enough to know what I was getting into I am also old enough to be a little lazy about it.

I got the shop cleaned up and well supplied before I pulled the car around.

Day 1, cut off the old hammered exhaust system. Sawsall was the right tool for the job. Removed all existing hangers. Unbolted the old exhaust manifolds...twisted off one bolt on the drivers side...

Spent the next couple of days trying to clean up the broken bolt but it was flush with the head surface and defied my attempts to remove it. After an appropriate amount of time, I came to the conclusion that I would have to remove the head to do things right.

I ordered a top end gasket kit and a few other needed parts and started tearing down the engine. Removed the AC equipment and stored it for the future. Pulled carb, intake, valve covers, valley pan, and heads. unbolted everything that was in the way.

Cleaned up gasket surfaces and the shiny parts that needed a good cleaning. Ended up painting the heads and intake after cleaning everything I could get at. Built block off plates for choke and egr, Choke tube was rusted off and did not survive the removal. Traced vacuum hoses and eliminated most of them as I found broken plastic parts used to hook them up. Got the engine put back together and looking better than it has in years.

Pypes ram air manifolds bolted up well with new bolts. Cleaned up any parts that had to be removed for the install. Layed out new exhaust pipe system. Everything looked pretty good on the shop floor. I had a few band clamps for the install and would use regular clamps on the rest of the connections.

Like the instructions said, start from the back and work forward. I spent some time getting the tail pipes where I wanted them, not perfect but pretty close. I ended up trimming pipe a couple of places to get it right. Make small cuts as needed. When I hung the cross flow muffler, I struggled with the hangers. They didn't seem very solid and didn't put the muffler where I wanted it. I spent time on the internet looking at different hangers and ended up with something labeled for an F body muffler hanger.

Head pipes were bolted up loose and exhaust pipes were dummied to the mufflers. I worried everything for a couple of days till I thought I had things in place. Cut some length out of the system and started tightening clamps. Taking it slow seems to have paid off, everything came together quite nicely. No loose parts and enough clearance almost everywhere. I had to loosen the brake line clamp on the diff tube to move the line a little farther out of the way.

After making it a bigger job than intended, it was time to turn the key and hope for the best. Among the little jobs I did, included a new fuel line from the pump to the carb and a new speedometer driven gear in the trans. I cleaned bolts and replaced missing fasteners as I found them.

The engine fired up and had a good sound through the new pipes. The idle was off but it ran well enough to warm things up a little. I pulled the car back into the shop and went back over the clamps and other fasteners to make sure they were still tight. By this time, I was tired of the project and wanted to put the car away till the weather got better. This is the Wyoming winter that never seems to end though.

Here it is mid April and we've had a couple of days nice enough to get the car out and see how it runs. The sound is great, nice rumble and no drone. We've taken a few laps around town just to put some time on it. The speedo was not showing any sign of life but that's another job. The motor sounds great and of course I think it runs better than ever. I didn't realize how hammered the old pipes were till I cut them out. Restrictive and a loose pass side manifold. Now we have no exhaust smell in the car, better idle quality, and it sounds like a classic car.

Overall, I couldn't be happier with the Pypes system. I would encourage them to suggest options for muffler hangers and band clamps in strategic locations. The most valuable resource I had access to was time. There was no rush to complete the job, the weather was too nasty to make use of the car anyway.

Bryan

Bryan,

Any photos? I just bought the same system for my '74. I mocked it up on the floor and even got the tail pipes and muffler sitting in place before taking it back off. My biggest concern is cutting something I shouldn't. I got the brakes bled out today so I can start on the exhaust soon. How many of the pipes did you actually have to cut? Did you use the small straight extensions? I think the part number of those is PVM11.

Where in WI are you? I just installed 2 Pypes systems on F-bodies. I used the Pypes system in conjunction with the Ram Air Restorations manifolds and front connector pipes. I had to cut the RH over the axle pipe where it goes into the muffler, as well as trim the length of the 2 front head pipes to proper length.

Like the OP, it fits nice. Had to relocate the rear brake hose. No drone, and it woke the car up. Fits tight to the floors. Really nice!

https://i1043.photobucket.com/albums...ps3t5zz2ub.jpg

https://i1043.photobucket.com/albums...pse5ukbpnb.jpg

https://i1043.photobucket.com/albums...ps9b2pizjb.jpg

No pics, I did this with a floor jack and jack stands. I think the few fitting cuts were mostly on the drivers side tail pipe pieces. A lot of trial fit, mark, and cut work.

I had to cut each of the down pipes 10-14" after the rest was in place.

Sawsall and bench vise worked pretty well to hold things straight.

I am near Madison, way far south from you. I know where Presque Isle is because my friend and I used to go Muskie fishing and duck hunting up there.

How did you hang the muffler? I am wanting to use the stock hangars as I don't want to put holes in the floors. Did you buy their band clamps or get them somewhere else?
What year is your car and how did you relocate the rear hose? I was hoping not to have to modify anything.

My hangers are nothing more than L brackets slid through the stock rubbers that are bolted to the floor pan. No cutting or drilling on the body. The car did not have the original hangers. On a different note, the 78 I just did had the stock hangers and they work just fine.

I bought the band clamps at NAPA..........no big deal there.

As far as the brake hose..........I unbolted it from the bracket and reformed the lines to move it over. I resecured the line at the bracket just to have some sort of support.

The car is currently at my house and I do not have lift there to take any pics for you. I will have it back at my shop in the next few weeks and I can take some pics on the lift if you like.

Hope that helps,
Tim

Yes, pics would be great.

I have a 1977 T/A, and the drivers side over the axle pipe came REAL close to the fuel line and the axle brake line/hose had to be modified to prevent it from being fried by the hot pipes.

The last Pypes transverse system I installed, I used the stock hangers in the back for the transverse muffler. Actually I prefer to use stock repo hangers on all the systems I install. They seem to have more leeway as far as movement which I tend to believe helps subdue noise.

Unfortunately I don't have a good clear picture of those hangers but they are available reproduction. I too am one that doesn't like the parts store hangers and prefer not to drill holes in floor pans, which also tends to transmit that noise throughout the cabin.

The prototype Pypes crossflow system was mocked up on a ‘70 Firebird using the factory muffler hangers. An aftermarket L bracket was used. The L bracket had holes to accept 2 1/2” exhaust pipe clamps. The hangers shown below are from a ‘71 Firebird. I haven’t found any good replacement rubber yet. The repop ones would work fine.

Here are some original images from the first setup we created on Bob C's car.

I used stock style rubber insulated hangers with slots in them and the L bracket hangers you push through them on the last car we used this on, a 75 GTO/Ventura.

I recently installed the Pypes transverse system on my auto trans 70 TA. Other than the expected need to trim the individual pieces to get everything to fit right, there were two major issues I ran into:

- The LH side downpipe wasn't shaped/formed correctly to clear the backdrive linkage coming off the trans shifter shaft. I ordered a second downpipe thinking I just got a bad one, but they were the same. I had to significantly "re-engineer" the backdrive linkage to get it to clear the pipe.

- The kit from Pypes comes with no provision to hang the muffler properly. There's a couple of rubber straps to bolt in to the floorpan if you so choose... but seriously? I was hoping the stock hanger brackets would be able to work, but on my car where the muffler needed to be laterally to get everything else to work, it didn't line up under the factory isolators. So I ended up making a "hanger bar" out of a piece of steel bar stock that I cut up and welded together. Works pretty well - some pics below.

That looks like it worked out pretty good for you. Nice way of doing it.

I used the stock hangers up there on my 70 Formula and seemed to work okay on that car. The last system I did, several months ago on a 72 Formula I used the stock hangers also. I did however have to tweak things around the back drive linkage just like you mentioned.

I will be installing a transverse system in a few days on a 1980 Trans Am..I was also disappointed there were not any hangers included to hang the muffler. Maybe something they can address...makes more sense then bolting hangers behind the seats as the instructions direct. I will have to check my parts cars and see if I have factory hangers.

Every single system I've ever bought, whether it be Pypes, Flowmaster, Dynomax, Magnaflow, they all use their own generic exhaust hangers.

I always go the extra mile and purchase factory hangers for the particular car I'm working on, as most all of them are reproduced now. They do a much better job of isolating the exhaust from the car, which keeps the transmitted noises to near nothing.

They also go right in the factory spot..no drilling etc..I'm pretty interested in how this one is going to sound and fit...I'm thinking about possibly making a "hybrid" exhaust for my "fast car" After 35 plus years of having twin mufflers under various cars..one behind the axle is appealing!

Well my install went well. The best thing I believe I did was use a set of factory hangers for the muffler off a parts car. That set the muffler at the right height, I also used the factory tailpipe hangers,and the only real issue was I had was that to reloacate my flex brake line/splitter back about an inch and remount. I spent some time up front making sure the collectors would square up with the headers. Overall pretty easy install..only hangers really needed are at the rear all factory spots.
Sounds good quiet inside at 60 mph zero drone..sounds good at idle and full throttle.

:thumbup: Glad to hear that worked out so nice. Those factory hangers are the way to go in my opinion. Just puts everything where it's supposed to be with no fuss.

Just need something similar to support 600 hp plus and I'd be a buyer...maybe I will make up a hybrid system with cutouts