SC Exhaust Thread
#542
Lead Lap
iTrader: (8)
I recently replaced my stock mufflers with M2 Performance axlebacks. My planned "completion" of the exhaust upgrades is removing the center sub-cat, which is generally described as the most restrictive element of the SC400's system, and replacing it with a 2.5" straight pipe. I figured it would be a good introductory question on the Lextreme forums, but the Exhaust System sub-forum seems to be dead...
Several people have said to also replace the second Y-pipe prior to the resonators. Is that really necessary for performance, or is it more for aesthetics? It's a super simple replacement if I can just do a straight pipe and keep both Y's, but if keeping the second one compromises performance, then it's not worth the trouble replacing the sub-cat and leaving it in.
Columbia River Mandrel-Bending has the best options I've found if replacing it, with splayed 2.5" inlet and dual 2.25" outlets that would somewhat follow the stock Y-pipe's exit angle (unlike Magnaflow's #10758) and require less downstream modification to mate up. They have it in stainless steel (#MCL2S-2025-SS, $68), 6061 aluminum (#MCL2S-22525-AL, $68), and mild steel (#MCL2S-22525-MS, $58). How much difference does the material choice make if it's being mated up to stock mild steel downstream? Weight reduction would be the main difference, right?
Are there any better options out there to consider?
Several people have said to also replace the second Y-pipe prior to the resonators. Is that really necessary for performance, or is it more for aesthetics? It's a super simple replacement if I can just do a straight pipe and keep both Y's, but if keeping the second one compromises performance, then it's not worth the trouble replacing the sub-cat and leaving it in.
Columbia River Mandrel-Bending has the best options I've found if replacing it, with splayed 2.5" inlet and dual 2.25" outlets that would somewhat follow the stock Y-pipe's exit angle (unlike Magnaflow's #10758) and require less downstream modification to mate up. They have it in stainless steel (#MCL2S-2025-SS, $68), 6061 aluminum (#MCL2S-22525-AL, $68), and mild steel (#MCL2S-22525-MS, $58). How much difference does the material choice make if it's being mated up to stock mild steel downstream? Weight reduction would be the main difference, right?
Are there any better options out there to consider?
#544
Lead Lap
iTrader: (8)
Bump... Any thoughts on the best approach?
I took a closer look under the car and the second Y-pipe does look like some pretty small outlet pipes. I can see why that's considered one of the restrictive points in the system.
I noticed that Columba River Mandrel-Bending's stainless model is only 2" or 2.13" outlets, not the desired 2.25". I haven't called them yet to see if they have it in the right size, just unlisted. Also, I think I was wrong about the stock system being mild steel. It's actually unpolished stainless steel, I believe?
Edit: I'm also thinking the Magnaflow 10733 is worth a try. It's 2.5" for both inlet and dual outlet, so it would need a reducer to the 2.25" downstream pipes. It looks like a good match for the stock layout, though, and seems like it should be a very smooth transition. There wouldn't be any negative to adding reducers to it instead of having the proper 2.25" outlets to start with, would there?
I took a closer look under the car and the second Y-pipe does look like some pretty small outlet pipes. I can see why that's considered one of the restrictive points in the system.
I noticed that Columba River Mandrel-Bending's stainless model is only 2" or 2.13" outlets, not the desired 2.25". I haven't called them yet to see if they have it in the right size, just unlisted. Also, I think I was wrong about the stock system being mild steel. It's actually unpolished stainless steel, I believe?
Edit: I'm also thinking the Magnaflow 10733 is worth a try. It's 2.5" for both inlet and dual outlet, so it would need a reducer to the 2.25" downstream pipes. It looks like a good match for the stock layout, though, and seems like it should be a very smooth transition. There wouldn't be any negative to adding reducers to it instead of having the proper 2.25" outlets to start with, would there?
I recently replaced my stock mufflers with M2 Performance axlebacks. My planned "completion" of the exhaust upgrades is removing the center sub-cat, which is generally described as the most restrictive element of the SC400's system, and replacing it with a 2.5" straight pipe. I figured it would be a good introductory question on the Lextreme forums, but the Exhaust System sub-forum seems to be dead...
Several people have said to also replace the second Y-pipe prior to the resonators. Is that really necessary for performance, or is it more for aesthetics? It's a super simple replacement if I can just do a straight pipe and keep both Y's, but if keeping the second one compromises performance, then it's not worth the trouble replacing the sub-cat and leaving it in.
Columbia River Mandrel-Bending has the best options I've found if replacing it, with splayed 2.5" inlet and dual 2.25" outlets that would somewhat follow the stock Y-pipe's exit angle (unlike Magnaflow's #10758) and require less downstream modification to mate up. They have it in stainless steel (#MCL2S-2025-SS, $68), 6061 aluminum (#MCL2S-22525-AL, $68), and mild steel (#MCL2S-22525-MS, $58). How much difference does the material choice make if it's being mated up to stock mild steel downstream? Weight reduction would be the main difference, right?
Are there any better options out there to consider?
Several people have said to also replace the second Y-pipe prior to the resonators. Is that really necessary for performance, or is it more for aesthetics? It's a super simple replacement if I can just do a straight pipe and keep both Y's, but if keeping the second one compromises performance, then it's not worth the trouble replacing the sub-cat and leaving it in.
Columbia River Mandrel-Bending has the best options I've found if replacing it, with splayed 2.5" inlet and dual 2.25" outlets that would somewhat follow the stock Y-pipe's exit angle (unlike Magnaflow's #10758) and require less downstream modification to mate up. They have it in stainless steel (#MCL2S-2025-SS, $68), 6061 aluminum (#MCL2S-22525-AL, $68), and mild steel (#MCL2S-22525-MS, $58). How much difference does the material choice make if it's being mated up to stock mild steel downstream? Weight reduction would be the main difference, right?
Are there any better options out there to consider?
Last edited by t2d2; 09-11-14 at 11:19 AM.
#549
Lead Lap
iTrader: (8)
Perhaps I should have started a second thread for this, but someone surely would have said to merge it into the SC Exhaust Thread... I found a new possible fit for the downstream Y-pipe: the Wesdon WES-U4-3 on Amazon for $38. It's 2.5" inlet to dual 2.25" outlets and long enough on the outlets that the straight part could be cut off, leaving the angled part as a fairly good match for the stock pipe layout. With a little luck, that could be tied in with minimal bending.
Looking on eBay, it appears Wesdon is just the seller of what is actually the Jones Exhaust U4-3, which can be had for as little as $20. The only downsides I see are: 1) it's aluminized mild steel, which probably isn't going to be quite as good long-term as stainless, and 2) the craftsmanship is a bit shy of artistic. It looks like an efficient splitter design, at least.
Looking on eBay, it appears Wesdon is just the seller of what is actually the Jones Exhaust U4-3, which can be had for as little as $20. The only downsides I see are: 1) it's aluminized mild steel, which probably isn't going to be quite as good long-term as stainless, and 2) the craftsmanship is a bit shy of artistic. It looks like an efficient splitter design, at least.
#550
Driver School Candidate
Join Date: Dec 2014
Location: FLORIDA
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
sc400 exhaust
The issue with the oem set up on the sc400 is that the cats are directly at the end of the manifold, which halts the scavenger effect from the cylinders, also they are huge so that there is a huge differential in airflow due to the air being dumped into a big open space, this is great for the 300 as turbos need this but for a normally aspirated engine as the 400 we need to encourage a scavenger effect, I feel that the best is to place the cat at the end of the engine pipe in a single form but use a free flowing 3 inch, and run a 2.5 inch pipe from the headers back to the join to the three inch then go to dual for the tail pipes to enhance the scavenger effect, remember that WOT is not everyones goal especially on a normally aspirated engine.
#551
Here you go; $60 at local muffler shop.
Cut out center section before Y, and after Y, weld in 2" pipe sections with a crossover at exactly the same place where the first Y was.
No drone, sporty rasp at full throttle on slightly ported 4.0.
The stock mufflers are straight thru just like aftermarket ones, so why would you make more of a project out of it, it's an exhaust?
Cut out center section before Y, and after Y, weld in 2" pipe sections with a crossover at exactly the same place where the first Y was.
No drone, sporty rasp at full throttle on slightly ported 4.0.
The stock mufflers are straight thru just like aftermarket ones, so why would you make more of a project out of it, it's an exhaust?
#553
Pole Position
Has anyone ever put a Tubi style exhaust on their SC?
Would love to hear one of the M5 ones retrofitted on the SC300
Would love to hear one of the M5 ones retrofitted on the SC300
#554
Driver School Candidate
TopSpeed Pro-1's on my 300. I like them but i get horribly disappointed with them when i'm surrounded by louder cars. My car might as well be stock.
92 Lexus SC300 TopSpeed Pro-1 Exhaust - YouTube
92 Lexus SC300 TopSpeed Pro-1 Exhaust - YouTube
thanks in advanced.
#555
Driver School Candidate
Join Date: Sep 2014
Location: NH
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
custom made 2.5" midpipe/x-pipe, stock cats, and tanabe medallion mufflers. I really like the sound, it doesn't drone and the in-cabin noise is barely noticeable unless I hit the go button.
Final Product..
Final Product..