My new custom exhaust for my 98 SC430
07-14-11, 02:02 AM
#31
I really dont want to be the bearer of bad new's. But there is a big reason Im switching back from my 2.25" mandrel bent X pipe true dual cat to rear setup. When I went from stock exhaust to the 2.25 X set up, I lost bottem end torque. Then I added S&S headers & I lost even more bottom end torque. Oh I had this slammin midrange & top end power but before 4K when the vvt-i kicked in, slug. Just look @ my dyno #'s in my sig. 1st one 400 w/x pipe. 2nd one 430 w/headers & X pipe. I gained 31whp & only 10lbs of tq. bcsc400 on here has a 99SC400 & he did this exact same Y pipe setup im posting here & his dyno's were (& I know every dyno is different) 270whp & 270wtq, & he's not even 430. So that being said. This is my 5th 400, 1st vvti & ive done this same X pipe on all my cars & its the same result. These car's were designed with a Y pipe & w/only 4 liter's of displacement & a very short cam duration over lap, thats what they need. There are several GS400/430 guys on here that are making the same 260-280 whp on the stock Y pipe.
1. 2.5" is too big
2. X pipe is not as good as Y pipe.
1. 2.5" is too big
2. X pipe is not as good as Y pipe.
07-14-11, 02:34 PM
#33
Hey THANKS fellas for the info! Soo a Y-pipe with 2.25 piping, remove all of the stock resonators straight to my Top Speed Pro 1 mufflers? Too bad the Top Speed Pro 1 muffler piping is 2.5 inch...gotta sell the X-Pipe now haha! Anyways, spd where are the video sound clips?!?
here is a link to the rear Y pipe I bought.
http://www.mandrelbendingsolutions.c...sh-Pipe/Detail
Last edited by spdrcr771; 07-14-11 at 03:31 PM.
Nice sound!
07-16-11, 06:50 PM
#41
Holy F***. Damn that sounds badass.
I got a full Tanabe exhaust on my GS430 basically because I wanted to tone it down with that car since the SC is the project.
But man.... Now I want the GS430 engine in my SC after hearing this. I am still rolling around with no mufflers since my **** got stolen. I can't decide what exhaust I should buy. I need to make a thread.
Badass work my man! So nice.
I got a full Tanabe exhaust on my GS430 basically because I wanted to tone it down with that car since the SC is the project.
But man.... Now I want the GS430 engine in my SC after hearing this. I am still rolling around with no mufflers since my **** got stolen. I can't decide what exhaust I should buy. I need to make a thread.
Badass work my man! So nice.
07-17-11, 01:36 PM
#42
Holy F***. Damn that sounds badass.
I got a full Tanabe exhaust on my GS430 basically because I wanted to tone it down with that car since the SC is the project.
But man.... Now I want the GS430 engine in my SC after hearing this. I am still rolling around with no mufflers since my **** got stolen. I can't decide what exhaust I should buy. I need to make a thread.
Badass work my man! So nice.
I got a full Tanabe exhaust on my GS430 basically because I wanted to tone it down with that car since the SC is the project.
But man.... Now I want the GS430 engine in my SC after hearing this. I am still rolling around with no mufflers since my **** got stolen. I can't decide what exhaust I should buy. I need to make a thread.
Badass work my man! So nice.
07-20-11, 09:03 AM
#43
Lexus Champion
Keep the stock Y pipe. Cut it off right behind the Y. Use a 2.5" mid pipe then buy the rear Y pipe I got, which is 2.5 into 2 X 2.25 then just run 2.25 to the axle backs make a flange & bolt up to the 2.5 Top speeds. The important part is the stock Y pipe into 2.5 mid pipe. Thats what keeps the low & mid range torque. After that its not that important. The other important part to making 20+ whp is the headers.
here is a link to the rear Y pipe I bought.
http://www.mandrelbendingsolutions.c...sh-Pipe/Detail
here is a link to the rear Y pipe I bought.
http://www.mandrelbendingsolutions.c...sh-Pipe/Detail
As noted KEEP the stock FRONT Y-pipe which merges two into one.
Cut AFTER the two pipes merge into one leaving apx 1" of the stock center pipe.
Use 2.5" tube for the middle single section OR get a TRUE 2.5" resonator which will have a SMOOTH internal surface that is at least 2.37" inside diameter. The Top Speed that I bought is not a true 2.5". The outside is 2.5" but the inside necks down to 2.13" and has sharp edges in the flow.
See the following link for pics on the TS resonator issues.
https://www.clublexus.com/forums/per...ml#post6546860
You want ALL pipes to slip inside the pipe it fits into in the direction of flow OR be smoothly butt welded with no slip. Do not use slip fit against the flow.
You can replace the REAR Y-pipe, which splits from one back to two, with the link given above by spdrcr.
Any rear mufflers including stock will work. If you use stock select the 2.5" to 2.0" rear Y pipe to split the exhaust gasses and make any transition between pipe sizes SMOOTH.
07-20-11, 02:59 PM
#44
Lead Lap
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Keep the stock Y pipe. Cut it off right behind the Y. Use a 2.5" mid pipe then buy the rear Y pipe I got, which is 2.5 into 2 X 2.25 then just run 2.25 to the axle backs make a flange & bolt up to the 2.5 Top speeds. The important part is the stock Y pipe into 2.5 mid pipe. Thats what keeps the low & mid range torque. After that its not that important. The other important part to making 20+ whp is the headers.
here is a link to the rear Y pipe I bought.
http://www.mandrelbendingsolutions.c...sh-Pipe/Detail
here is a link to the rear Y pipe I bought.
http://www.mandrelbendingsolutions.c...sh-Pipe/Detail
07-21-11, 06:34 PM
#45
I didnt look for the 4" kit but this is another resource for piping.
http://www.mandrel-bends.com/catalog/
http://www.spdexhaust.com/
http://www.mandrel-bends.com/catalog/
http://www.spdexhaust.com/