Headers for V8 cars, Please read
Pole Position
Joined: Apr 2004
Posts: 2,666
Likes: 77
From: FL
At some point will there be a consise post as to what we need in total to do the headers right (Y pipe, unbolting engine for install?, EGR?, Heat shields fitament, ETC) and a complete price for a kit with everything we need?
I am interested but the length of this thread gets me dizzy...
1. Does the engine need to be unbolted?
2. Can the stock heat sheilds remain?
3. Is there an option to have them delieved heat coated?
4. Will the Y pipe be sold with the headers?
5. What and why would I remove the EGR?
Did I miss anything?
I am interested but the length of this thread gets me dizzy...
1. Does the engine need to be unbolted?
2. Can the stock heat sheilds remain?
3. Is there an option to have them delieved heat coated?
4. Will the Y pipe be sold with the headers?
5. What and why would I remove the EGR?
Did I miss anything?
Driver
Joined: May 2005
Posts: 132
Likes: 0
From: Texas
Originally Posted by jbrady
Actually all of these cars SHOULD run a higher capacity Y pipe to get the most effect from upgrading the headers. That said, the GS400s will NOT need a custom Y pipe to actually fit and function. It is just better if they do. It would have been nice if the mounting of the LS400 and GS400 were the same as then one custom pipe could have been produced for both cars.
To confirm on the GS430 vs. the GS400 I will want to test fit the 400 Y pipe to the 430. If that fits I want to test fit the 400 cats and Y pipe on the 430. That will confirm fitment. However, all of these cars need a Y pipe upgrade. Anyone wanting these headers should plan to at least some point upgrade the Y. If you have a GS430 or other 430, and really want the headers, my recommendation is to buy them now. Wait until another 430 owner who plans on upgrading the Y pipe anyway does so. Once that is done we will know if the stock pipe fits or not. Worse case scenario is you decide it is not what you want and you sell the header to someone who wished they got on the first production run when they had the chance. Truthfully, this is a small risk reward ratio.
To confirm on the GS430 vs. the GS400 I will want to test fit the 400 Y pipe to the 430. If that fits I want to test fit the 400 cats and Y pipe on the 430. That will confirm fitment. However, all of these cars need a Y pipe upgrade. Anyone wanting these headers should plan to at least some point upgrade the Y. If you have a GS430 or other 430, and really want the headers, my recommendation is to buy them now. Wait until another 430 owner who plans on upgrading the Y pipe anyway does so. Once that is done we will know if the stock pipe fits or not. Worse case scenario is you decide it is not what you want and you sell the header to someone who wished they got on the first production run when they had the chance. Truthfully, this is a small risk reward ratio.
I agree 100%. If you are going through the trouble of replacing the manifolds w/ headers you might as well go the small extra step and have a new front exhaust pipe (i.e. y-pipe) fabricated. Then bolt up a cat back system and beat the s#*^ out of 540's all day long.
It's going to cost me lunch but I'm trying to get my parts guy to make a call to his distributor to compare y-pipe's so we don't have to battle the friggin heat here in Texas by making the comparo ourselves!
Driver
Joined: May 2005
Posts: 132
Likes: 0
From: Texas
Originally Posted by CinFulxGS4
At some point will there be a consise post as to what we need in total to do the headers right (Y pipe, unbolting engine for install?, EGR?, Heat shields fitament, ETC) and a complete price for a kit with everything we need?
I am interested but the length of this thread gets me dizzy...
1. Does the engine need to be unbolted?
2. Can the stock heat sheilds remain?
3. Is there an option to have them delieved heat coated?
4. Will the Y pipe be sold with the headers?
5. What and why would I remove the EGR?
Did I miss anything?
I am interested but the length of this thread gets me dizzy...
1. Does the engine need to be unbolted?
2. Can the stock heat sheilds remain?
3. Is there an option to have them delieved heat coated?
4. Will the Y pipe be sold with the headers?
5. What and why would I remove the EGR?
Did I miss anything?
Until there is an actual guinea pig questions 1 & 2 will remain unanswered. The repair manual does not have a procedure for removing the exhaust manifolds. However, when removing the heads the exhaust manifolds remain attached until the heads are removed. Hopefully head removal won't be required and a more reasonable method can be used.
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Originally Posted by CinFulxGS4
At some point will there be a consise post as to what we need in total to do the headers right (Y pipe, unbolting engine for install?, EGR?, Heat shields fitament, ETC) and a complete price for a kit with everything we need?
I am interested but the length of this thread gets me dizzy...
1. Does the engine need to be unbolted?
2. Can the stock heat sheilds remain?
3. Is there an option to have them delieved heat coated?
4. Will the Y pipe be sold with the headers?
5. What and why would I remove the EGR?
Did I miss anything?
I am interested but the length of this thread gets me dizzy...
1. Does the engine need to be unbolted?
2. Can the stock heat sheilds remain?
3. Is there an option to have them delieved heat coated?
4. Will the Y pipe be sold with the headers?
5. What and why would I remove the EGR?
Did I miss anything?
2. No heat shields.
3. Most if not all of the headers will be Jet Hot coated.
4. Not at this time.
5. None of the 1998 and newer cars have EGR, non issue.
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Originally Posted by TXGS
I agree 100%. If you are going through the trouble of replacing the manifolds w/ headers you might as well go the small extra step and have a new front exhaust pipe (i.e. y-pipe) fabricated. Then bolt up a cat back system and beat the s#*^ out of 540's all day long.
It's going to cost me lunch but I'm trying to get my parts guy to make a call to his distributor to compare y-pipe's so we don't have to battle the friggin heat here in Texas by making the comparo ourselves!
It's going to cost me lunch but I'm trying to get my parts guy to make a call to his distributor to compare y-pipe's so we don't have to battle the friggin heat here in Texas by making the comparo ourselves!
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Originally Posted by TXGS
Until there is an actual guinea pig questions 1 & 2 will remain unanswered. The repair manual does not have a procedure for removing the exhaust manifolds. However, when removing the heads the exhaust manifolds remain attached until the heads are removed. Hopefully head removal won't be required and a more reasonable method can be used.
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Originally Posted by CinFulxGS4
At some point will there be a consise post as to what we need in total to do the headers right (Y pipe, unbolting engine for install?, EGR?, Heat shields fitament, ETC) and a complete price for a kit with everything we need?
Lexus Test Driver
Joined: Jun 2002
Posts: 869
Likes: 1
From: California
Not sure if this has been mentioned in all the discussion on Y pipes, but I assume you would want to replace the "center" cat (at the end of the Y pipe) with an aftermarket hi flow cat? Random Technology makes some nice products for example, I've used them in the past. Would need to have a flange welded on for the mid section pipe to bolt to...
I know the cats at the end of the manifolds flow well, but this could be a choke point?
I know the cats at the end of the manifolds flow well, but this could be a choke point?
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Originally Posted by FutureGS400
Not sure if this has been mentioned in all the discussion on Y pipes, but I assume you would want to replace the "center" cat (at the end of the Y pipe) with an aftermarket hi flow cat? Random Technology makes some nice products for example, I've used them in the past. Would need to have a flange welded on for the mid section pipe to bolt to...
I know the cats at the end of the manifolds flow well, but this could be a choke point?
I know the cats at the end of the manifolds flow well, but this could be a choke point?
EV ftw!!!
Joined: Nov 2002
Posts: 8,947
Likes: 546
From: Lake Ontario
Originally Posted by jbrady
On 1998-2000 GS400s you will need headers only. Y pipe recommended. I may be able to offer a Y pipe but I am making no promises. The stock one will work but will be somewhat restrictive. I recommend 2.25" piping on the duals and 2.50 or 3.00 for the center pipe. No complete "kit" is planned.
Originally Posted by jbrady
Actually, on the GS400s it is a 60mm/2.37" resonator. Yes, upgrading to a slightly larger center pipe and duals is a good idea. Just keep it below 2.25" on the duals.
1. So you recommend 2.25" piping for the pipes that make up the Y pipe, 2.50" or 3.00" for the center pipe (or in my case a 2.50" X-pipe), and then finally 2.25" on the duals leaving the center pipe (in my case the X-pipe) to the resonators?
2. What exactly is the function of the resonators? Is it just to reduce the "loudness of volume" of the exhaust sound? If it is, are we talking a lot of noise, if I removed the resonators and replaced them with 2.25" pipes straight to the mufflers (and of course on the opposite end they are joined to the 2.50" X-pipe)?
I was at my mechanics place yesterday getting the oil and filter changed and I verified that there is enough space for the X-pipe I bought that I want to replace the center cat with.
Lexus Test Driver
Joined: Jun 2002
Posts: 869
Likes: 1
From: California
Originally Posted by jbrady
Actually, on the GS400s it is a 60mm/2.37" resonator. Yes, upgrading to a slightly larger center pipe and duals is a good idea. Just keep it below 2.25" on the duals.
With all your work on these exhausts lately, I would imagine that you are correct on this issue, but it would be nice to know for sure.
EV ftw!!!
Joined: Nov 2002
Posts: 8,947
Likes: 546
From: Lake Ontario
Originally Posted by FutureGS400
John, are you sure it is just a resonator? The reason I ask is that I was told by two different Lexus techs that it is actually a cat. Not that they are infallible but still.... If it is just a resonator, I'm wondering how necessary it would be to keep? In other words, it seems like it would be easier to leave off as long as the exhaust sound is not too loud. I'm pretty happy with the Carson Tuned sound level now...
With all your work on these exhausts lately, I would imagine that you are correct on this issue, but it would be nice to know for sure.
With all your work on these exhausts lately, I would imagine that you are correct on this issue, but it would be nice to know for sure.
Lexus Champion
Joined: Feb 2001
Posts: 3,124
Likes: 32
From: Texas
Originally Posted by Hameed
It is a catalytic convertor.
Please post a picture. this must be a California required part and possibly Canada?
I doubt this catalyst is too restrictive. If it were mine I would probaby just cut the cat of the factory pipe and weld it to an upgrade pipe. This is only one weld and would be relatively easy to reverse if needed.
Also, Hameed, I would not recommend a 2.5" X-pipe. The idea is to keep velocity high. The bigger diameter will slow the gases. It will work just not as well. Please post a pic or email it to me.
