Exhaust System for LT headers
12-10-2014, 10:54 AM
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Car: 87' Firebird Formula
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Exhaust System for LT headers
Hello, I purchased some Hedman Elite Heavy-Duty Headers 68468 used from craigslist and am looking for an exhaust so I can install. I haven't found any full long tube exhaust systems for our cars for sale (not more than an exhaust shop would charge) so I'm looking at alternatives. I know it has to clear my 700r4. Anyway, my question is...
Would this exhaust system fit with minor modifications? http://www.ebay.com/itm/Camaro-70-74-Dual-Exhaust-System-Z28-In-Stock-Transverse-Muffler-/271539579970?pt=Vintage_Car_Truck_Parts_Accessories&hash=item3f39052c42&vxp=mtr
Would this exhaust system fit with minor modifications? http://www.ebay.com/itm/Camaro-70-74-Dual-Exhaust-System-Z28-In-Stock-Transverse-Muffler-/271539579970?pt=Vintage_Car_Truck_Parts_Accessories&hash=item3f39052c42&vxp=mtr
12-10-2014, 12:49 PM
#2
Re: Exhaust System for LT headers
This is completely custom territory. I heavily suggest you find someone who is competent with fabrication who can modify and work with your crossmember and get your ground clearance to something tolerable. It can be done, but most people arent able to put the time in to make it work. Otherwise, there's really nowhere for the pipes to go except under the crossmember. Go measure the distance between your crossmember and the ground and subtract the diameter of pipe you want to use. You'll probably want to stick with 2.5" pipes for that reason, and you'll be lucky to have 3 inches left.
Most exhaust shops wont touch that sort of situation, and a lot of the ones that will just dont give a hoot about doing a good job. So I hope you find someone that's competent and knows their way around these cars.
I would also suggest you run a single exhaust over the axle, also for ground clearance reasons. You can run a single 3" and modify any 3" catback to fit pretty easily, or a single 3.5 or 4" such as what Mufflex sells. But note ,those are not catbacks. Those are just over the axle pipes with mufflers. You still need to go custom to get the headers piped over to them. There's just too many sacrifices and concessions and modifications necessary to get hte pipes around the transmission for people to sell any off the shelf kits for it. Hawks sells something for their brand of long tubes, but they wont fit yours, and they dont result in very good ground clearance either.
This is roughly what you're going to want:
Note the heavily modified crossmember necessary to make that work.
If you want to do dual exhaust, just be aware that the muffler thickness will drastically reduce your ground clearance further. Going up the center with a single pipe allows you to put the pipe up into the driveshaft tunnel and allows you to put a muffler under the rear bumper where it doesnt eat up your under car space.
This is a pretty typical dual exhaust system:
Good luck, it can be done.
Most exhaust shops wont touch that sort of situation, and a lot of the ones that will just dont give a hoot about doing a good job. So I hope you find someone that's competent and knows their way around these cars.
I would also suggest you run a single exhaust over the axle, also for ground clearance reasons. You can run a single 3" and modify any 3" catback to fit pretty easily, or a single 3.5 or 4" such as what Mufflex sells. But note ,those are not catbacks. Those are just over the axle pipes with mufflers. You still need to go custom to get the headers piped over to them. There's just too many sacrifices and concessions and modifications necessary to get hte pipes around the transmission for people to sell any off the shelf kits for it. Hawks sells something for their brand of long tubes, but they wont fit yours, and they dont result in very good ground clearance either.
This is roughly what you're going to want:
Note the heavily modified crossmember necessary to make that work.
If you want to do dual exhaust, just be aware that the muffler thickness will drastically reduce your ground clearance further. Going up the center with a single pipe allows you to put the pipe up into the driveshaft tunnel and allows you to put a muffler under the rear bumper where it doesnt eat up your under car space.
This is a pretty typical dual exhaust system:
Good luck, it can be done.
Last edited by InfernalVortex; 12-10-2014 at 12:57 PM.
12-10-2014, 01:49 PM
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Re: Exhaust System for LT headers
This is completely custom territory. I heavily suggest you find someone who is competent with fabrication who can modify and work with your crossmember and get your ground clearance to something tolerable. It can be done, but most people arent able to put the time in to make it work. Otherwise, there's really nowhere for the pipes to go except under the crossmember. Go measure the distance between your crossmember and the ground and subtract the diameter of pipe you want to use. You'll probably want to stick with 2.5" pipes for that reason, and you'll be lucky to have 3 inches left.
Most exhaust shops wont touch that sort of situation, and a lot of the ones that will just dont give a hoot about doing a good job. So I hope you find someone that's competent and knows their way around these cars.
I would also suggest you run a single exhaust over the axle, also for ground clearance reasons. You can run a single 3" and modify any 3" catback to fit pretty easily, or a single 3.5 or 4" such as what Mufflex sells. But note ,those are not catbacks. Those are just over the axle pipes with mufflers. You still need to go custom to get the headers piped over to them. There's just too many sacrifices and concessions and modifications necessary to get hte pipes around the transmission for people to sell any off the shelf kits for it. Hawks sells something for their brand of long tubes, but they wont fit yours, and they dont result in very good ground clearance either.
This is roughly what you're going to want:
Note the heavily modified crossmember necessary to make that work.
If you want to do dual exhaust, just be aware that the muffler thickness will drastically reduce your ground clearance further. Going up the center with a single pipe allows you to put the pipe up into the driveshaft tunnel and allows you to put a muffler under the rear bumper where it doesnt eat up your under car space.
This is a pretty typical dual exhaust system:
Good luck, it can be done.
Most exhaust shops wont touch that sort of situation, and a lot of the ones that will just dont give a hoot about doing a good job. So I hope you find someone that's competent and knows their way around these cars.
I would also suggest you run a single exhaust over the axle, also for ground clearance reasons. You can run a single 3" and modify any 3" catback to fit pretty easily, or a single 3.5 or 4" such as what Mufflex sells. But note ,those are not catbacks. Those are just over the axle pipes with mufflers. You still need to go custom to get the headers piped over to them. There's just too many sacrifices and concessions and modifications necessary to get hte pipes around the transmission for people to sell any off the shelf kits for it. Hawks sells something for their brand of long tubes, but they wont fit yours, and they dont result in very good ground clearance either.
This is roughly what you're going to want:
Note the heavily modified crossmember necessary to make that work.
If you want to do dual exhaust, just be aware that the muffler thickness will drastically reduce your ground clearance further. Going up the center with a single pipe allows you to put the pipe up into the driveshaft tunnel and allows you to put a muffler under the rear bumper where it doesnt eat up your under car space.
This is a pretty typical dual exhaust system:
Good luck, it can be done.
I am completely fine with a Y pipe into a 3" single, into a crossflow muffler. I have a 3" inlet/outlet flowmaster in my garage from an old 4th gen formula I had. I didn't think about just getting a catback system and getting an exhaust shop to configure it accordingly. I could find a cheap 3" catback system, then just use my muffler.
The main reason for my posting a dual exhaust idea is because of reading how hard it was to route a Y pipe by the headers coming down so far and beside the trans.
12-10-2014, 03:31 PM
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Re: Exhaust System for LT headers
Justin89Formy probably has the best exhaust (D-port) --> $$$.
I went with Hawks
, Bruce sold me (he's good at that aspect), then...
His "fit like a glove" was an epic fail. It was a lot of money, and it was misrepresented for fitment. A quality custom set-up would have been cheaper in the long run, I think. Though the second shop I took it to in order to get it right, said it was probably better to buy the complete set-up, then expect to pay more in addition for proper fitment. With that expectation, no one would buy it.
There is no doubt that LT's with 3" tubes around an auto is tough. Setting proper customer expectations is paramount to customer service.
With all that said, it can be done, and I like the sound. Stainless Works did a good job (them or Kooks, IMO).
2" primaries into 3" y into single 4"
I went with Hawks
, Bruce sold me (he's good at that aspect), then... His "fit like a glove" was an epic fail. It was a lot of money, and it was misrepresented for fitment. A quality custom set-up would have been cheaper in the long run, I think. Though the second shop I took it to in order to get it right, said it was probably better to buy the complete set-up, then expect to pay more in addition for proper fitment. With that expectation, no one would buy it.There is no doubt that LT's with 3" tubes around an auto is tough. Setting proper customer expectations is paramount to customer service.
With all that said, it can be done, and I like the sound. Stainless Works did a good job (them or Kooks, IMO).
2" primaries into 3" y into single 4"
12-11-2014, 05:48 AM
#5
Re: Exhaust System for LT headers
Your exhaust system is OUT OF THIS WORLD AWESOME!!!!!!!!!!!!! I completely understand what you are saying and yeah, the clearance for exhaust can really suck. Delt with it on one of my previous firebirds at an exhaust shop. Brain wracking. Wish I knew someone that could whip up my crossmember like that.
I am completely fine with a Y pipe into a 3" single, into a crossflow muffler. I have a 3" inlet/outlet flowmaster in my garage from an old 4th gen formula I had. I didn't think about just getting a catback system and getting an exhaust shop to configure it accordingly. I could find a cheap 3" catback system, then just use my muffler.
The main reason for my posting a dual exhaust idea is because of reading how hard it was to route a Y pipe by the headers coming down so far and beside the trans.
I am completely fine with a Y pipe into a 3" single, into a crossflow muffler. I have a 3" inlet/outlet flowmaster in my garage from an old 4th gen formula I had. I didn't think about just getting a catback system and getting an exhaust shop to configure it accordingly. I could find a cheap 3" catback system, then just use my muffler.
The main reason for my posting a dual exhaust idea is because of reading how hard it was to route a Y pipe by the headers coming down so far and beside the trans.
For the record, those aren't "MY" systems. The red car at the bottom is my car, but that's an old system. I now have a 2.5->3.5 system. But I have a T56 and a custom crossmember that allows for excellent ground clearance. I farm out exhaust work to Matt Walter generally.
Last edited by InfernalVortex; 12-11-2014 at 05:53 AM.
12-11-2014, 07:27 PM
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Re: Exhaust System for LT headers
With Long Tubes, there's no practical difference between a single exhaust and a dual exhaust as far as getting it around the trans. The pipes have to stay separate until around the mid section of the car, which means until that point, they're duals no matter what you do with them. The trouble with a single is that it can be difficult to get them up and over the axle when you're doing it yourself with big pipe. Its a bit of a complicated route. It's not awful or anything, but it requires you to take some time.
For the record, those aren't "MY" systems. The red car at the bottom is my car, but that's an old system. I now have a 2.5->3.5 system. But I have a T56 and a custom crossmember that allows for excellent ground clearance. I farm out exhaust work to Matt Walter generally.
For the record, those aren't "MY" systems. The red car at the bottom is my car, but that's an old system. I now have a 2.5->3.5 system. But I have a T56 and a custom crossmember that allows for excellent ground clearance. I farm out exhaust work to Matt Walter generally.
12-12-2014, 02:28 AM
#7
Re: Exhaust System for LT headers
Bigger wheels and "not lowering" is a huge mistake, I think. The car is going to have a much more aggressive feel and look lowered than it is with huge pipes hanging under it and 70's style huge wheels and tires on it. The ridiculous raked, air-shock look just doesnt work. All the modern trends are to eliminate wheel gap and get a sporty stance, because, well, it just looks a whole lot better. There's obviously a limit to what people can tolerate, but the difference between lowered and not lowered is HUGE in terms of appearance and feel. Going to larger WHEELS and keeping the same diameter tires (if you ever get tired of running old school 15's or 16's which now only have 2 legitimate summer performance tires left in our size, you'll pretty much be stuck with this diameter, as it's the most common in the wider, big wheel sizes) will make the wheel gap and the need to lower the car even more obvious and everyone is moving to bigger wheels these days for all the performance and appearance and tire availability benefits.
Im not saying to lower the car, there are things you need to do to make it a viable option and retain the correct geometries. But I am saying keep your options open. You owe it to yourself to have near factory ground clearance no matter what exhaust system you run. Unless you can get it done STUPID cheap and not feel bad trashing it in a couple of years when you just get fed up, do it right the first time.
Im not saying to lower the car, there are things you need to do to make it a viable option and retain the correct geometries. But I am saying keep your options open. You owe it to yourself to have near factory ground clearance no matter what exhaust system you run. Unless you can get it done STUPID cheap and not feel bad trashing it in a couple of years when you just get fed up, do it right the first time.
Last edited by InfernalVortex; 12-12-2014 at 02:31 AM.
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12-13-2014, 10:37 AM
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Re: Exhaust System for LT headers
I have full dual 2.5in with longtubes on my car currently. It is stock height, I used a pair of Sweet Thunder chambered mufflers tucked into the driveshaft tunnel just before it turns up over the axle following the factory path. These mufflers are basically just a glasspack with no packing that is pinched into 3 sections, they come in various lengths i believe i used 18inch. The sound is raw and loud a tad raspy at times, but during normal cruise both in town and highway windows up or down it is tolerable.
I had a y pipe similar to ones pictured above to a big single prior to this with a flowtech afterburner muffler and that sounded great too, the dual setup was mostly an experiment to see if I could and so far have stuck with it. There are issues however, driveshaft removal is near impossible with pipes in place, exhaust must be hung solidly and very tight to body where the mufflers are so there seems to be a bit more ambient vibration in the car from it.
If you want pictures or a soundclip I will see what I can do, car will be going up on stands pretty soon for some other work so it will be easy to grab a pic.
I had a y pipe similar to ones pictured above to a big single prior to this with a flowtech afterburner muffler and that sounded great too, the dual setup was mostly an experiment to see if I could and so far have stuck with it. There are issues however, driveshaft removal is near impossible with pipes in place, exhaust must be hung solidly and very tight to body where the mufflers are so there seems to be a bit more ambient vibration in the car from it.
If you want pictures or a soundclip I will see what I can do, car will be going up on stands pretty soon for some other work so it will be easy to grab a pic.
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