Any full 3" setups here?

I'm trying to piece together a full 3" system for my F-1A-94 5.3l build and can't seem to find anything as a complete setup. I'm expecting 25+ psi and well over 900 hp so I figured a 3" system was warranted.

I ordered the JBA midlength headers that end in a 3" collector, however the 3" h-pipe they reference appears to not be in production anymore. Also, their only available 3" catback (JBA 40-2625) has 2.5" intermediate tubes to fit with the stock 2.5" midpipes.

I'm thinking I can just get that catback and have an exhaust shop fab up a simple catted h-pipe to connect the midlength headers and the 3" mufflers of the catback.

Any other ideas? What have you done for a full 3" setup? Thanks!

Ran a Ford engine. It was super easy then. Engine swaps usually entail fab work. Doing it yourself isn't difficult... just takes a little patience. Or have an exhaust shop build you one...

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Didn't Mac used to have a 3" catback? I seem to remember dealing with one on an old buddies Cobra. Does ARH or Stainless Works make a 3" set up? Full length headers might be more beneficial to you as well.

mighty mouse said:

Ran a Ford engine. It was super easy then. Engine swaps usually entail fab work. Doing it yourself isn't difficult... just takes a little patience. Or have an exhaust shop build you one...

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It is a Ford engine. It's a FRPP Boss 5.0 block with a stroker rotating assembly. I ran a similar set up to what he has in my old 01.

I have a full 3” stainless works exhaust on mine.. you can get just the cats back from Lethal Performance...

Ah! I've seen a hundred F1 5.3 GM combos. Shame on me for assuming.

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Haha thanks guys, yes it’s a 5.3 boss block motor. All 3” catbacks I’ve seen have 2.5” intermediate pipes to work with the stock diameter midpipes.

SW is extremely expensive, I think having my exhaust guy make me an h-pipe would be the best route. The JBA 3” catback is $540, after buying better 4” double-walled slash tips and cats I’m thinking I can be out the door for $1k all done. The SW catback and midpipe is $1500-1600 plus I would still have to have them modified to mate up to the JBA headers.

Also I chose the midlengths because they make dropping the trans and clutch work much easier.

Mac/bassani/SW all bolt on options with 3”

I was all about 3” all the way but engine builder convinced me it didn’t matter much. From their testing on 2.5 vs 3” catback once you are past the midpipe, most exhaust gases are expanded and/or burned off. Was told header primaries and midpipe are way more significant. So ditch the mid lengths!

Jameeson said:

Mac/bassani/SW all bolt on options with 3”

I was all about 3” all the way but engine builder convinced me it didn’t matter much. From their testing on 2.5 vs 3” catback once you are past the midpipe, most exhaust gases are expanded and/or burned off. Was told header primaries and midpipe are way more significant. So ditch the mid lengths!

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All except for the SW catbacks are designed to bolt to the 2.5” stock midpipe so they are not full 3”. SW stuff is extremely overpriced. You’re right, a 3” catback does nothing if the midpipe and the manifolds stay stock diameter. Removing the 2.5” restriction in the collector and midpipe is where I expect to see the gains, even with 1-5/8 primary midlengths. Again, they make driveline maintenance much easier compared to longtubes plus they have zero ground clearance issues. I hated scraping my longtubes on everything when I had my first Cobra.

JetmechF16 said:

All except for the SW catbacks are designed to bolt to the 2.5” stock midpipe so they are not full 3”. SW stuff is extremely overpriced. You’re right, a 3” catback does nothing if the midpipe and the manifolds stay stock diameter. Removing the 2.5” restriction in the collector and midpipe is where I expect to see the gains, even with 1-5/8 primary midlengths. Again, they make driveline maintenance much easier compared to longtubes plus they have zero ground clearance issues. I hated scraping my longtubes on everything when I had my first Cobra.

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You are right on only SW being true 3”, did not realize that

FWIW, a buddy is around 800rwhp with Bassani mids, mid pipe, and Magnaflow catback. I'm pretty sure that's all 2.5".

I’m currently running 3” from the collector all the way back. I bought the bassani 3” cat back and the piece that necks down to 2.5 can be changed out to 3” since there’s a clamp there, I just called bassani and they made me the 3” pipes. All bolted together just like it would with 2.5” connections. I’m running Kooks LT 1-7/8x3” with their 3” in and out x pipe.

JetmechF16 said:

All except for the SW catbacks are designed to bolt to the 2.5” stock midpipe so they are not full 3”. SW stuff is extremely overpriced. You’re right, a 3” catback does nothing if the midpipe and the manifolds stay stock diameter. Removing the 2.5” restriction in the collector and midpipe is where I expect to see the gains, even with 1-5/8 primary midlengths. Again, they make driveline maintenance much easier compared to longtubes plus they have zero ground clearance issues. I hated scraping my longtubes on everything when I had my first Cobra.

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Jameeson said:

You are right on only SW being true 3”, did not realize that

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This is not true.

OP. Are you IRS or straight Axle? I am running full 3" Stainless steel all off the shelf items and none of it Stainless Works. That being said you can also have a shop make you a custom one.

I run Kooks 1 7/8 long tubes, kooks 3” x-pipe and bassani 3” cat back sounds amazing. When I switched to SRA I just dumped it before the rear end


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Awesome thanks for the bassani suggestion, I’ll give them a call about that 3” intermediate pipe. @GodStang yes I am still IRS, would you mind sharing brand/part #s of your OTS 3” setup? Thanks!

Kooks 1-7/8" X 3" Stainless Steel
Kooks 3" X-pipe Stainless Steel
JBA 40-2626 IRS Catback Stainless Steel. I swapped the mufflers out after a few years to a different 3". That is why two different mufflers in the pic above.

Just to give you an idea the only differences between a full 3" and a 2.5" to 3" is the small connector pipes that you can get new anywhere for cheap:

GodStang said:

Kooks 1-7/8" X 3" Stainless Steel
Kooks 3" X-pipe Stainless Steel
JBA 40-2626 IRS Catback Stainless Steel. I swapped the mufflers out after a few years to a different 3". That is why two different mufflers in the pic above.

Just to give you an idea the only differences between a full 3" and a 2.5" to 3" is the small connector pipes that you can get new anywhere for cheap:

View attachment 1549881

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Awesome, how did you like the JBA catback sound? Unfortunately for me there is no JBA 3” h-pipe available anymore so I’ll have to get my exhaust guy to make me one to match up with my JBA midlengths. I’m thinking I’ll just get the JBA catback (I like matching manufacturers when possible) and have the intermediate pipes changed out for 3”.

JetmechF16 said:

Awesome, how did you like the JBA catback sound? Unfortunately for me there is no JBA 3” h-pipe available anymore so I’ll have to get my exhaust guy to make me one to match up with my JBA midlengths. I’m thinking I’ll just get the JBA catback (I like matching manufacturers when possible) and have the intermediate pipes changed out for 3”.

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It was good:

Here are a few videos of the setup back then:

Just to follow up: I ended up getting lucky and finding a NOS JBA 6625HC, catted 3" H-pipe for JBA midlength headers, on ebay. You can tell they have been sitting in a box for years but are in pretty decent condition.

Cobra is at the fab shop right now getting custom intercooler piping made so I'll have them make some 3" intermediate pipes between h-pipe and catback. I will also have them weld the catback together once it is fitted and replace the crappy 3.5" rolled tips with 4" double-walled slash cut tips.

JetmechF16 said:

Just to follow up: I ended up getting lucky and finding a NOS JBA 6625HC, catted 3" H-pipe for JBA midlength headers, on ebay. You can tell they have been sitting in a box for years but are in pretty decent condition.

Cobra is at the fab shop right now getting custom intercooler piping made so I'll have them make some 3" intermediate pipes between h-pipe and catback. I will also have them weld the catback together once it is fitted and replace the crappy 3.5" rolled tips with 4" double-walled slash cut tips.


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Very nice find!

Nice find. I couldn't stand the sound of the H pipe that came with my JBA mids, so I cut the front half of the JBA H off and mated it to my X pipe and the car sounds good now.