Headers for V8 cars, Please read
I am very interested but a little confused. If someone could answer these questions I would greatly appreciate it. They will be going on a 95 Sc400.
1. Approximate labor time including reworking for the SC400?
2. The write-up says this about the 95 SC400 - No EGR provisions will be made so the installer will need to consider this if they choose to retain EGR.
What exactly does this mean? Oklahoma does not have inspections so I don't have to worry about that - but will this not mean I will have a CEL on all the time?
Thx,
Jonny
I am very interested but a little confused. If someone could answer these questions I would greatly appreciate it. They will be going on a 95 Sc400.
1. Approximate labor time including reworking for the SC400?
2. The write-up says this about the 95 SC400 - No EGR provisions will be made so the installer will need to consider this if they choose to retain EGR.
What exactly does this mean? Oklahoma does not have inspections so I don't have to worry about that - but will this not mean I will have a CEL on all the time?
Thx,
Jonny
#2 - all 1UZFE engines (Lexus V8) from 1990-1997 had EGR. These manifolds will not have the small 2 bolt flange that the EGR connects to. It is fairly straighforward to weld on a flange and route the EGR. Some simply block it off. There are many posts regarding this if you do a search.
Here is a picture of the SC400 manifold with the EGR flange showing between the back port and the catalyst flange.
#2 - all 1UZFE engines (Lexus V8) from 1990-1997 had EGR. These manifolds will not have the small 2 bolt flange that the EGR connects to. It is fairly straighforward to weld on a flange and route the EGR. Some simply block it off. There are many posts regarding this if you do a search.
Here is a picture of the SC400 manifold with the EGR flange showing between the back port and the catalyst flange.
Thx again,
Jonny
Thx again,
Jonny
Since yours is a 95 SC400, rated at 250hp/260tq, I am assuming (yes I understand the risk in doing so) that is shares exhaust manifolds with the 1992-1994 SC400s. In this case you should not have to pull the engine. Actually, I anticipate that the engine will not have to be pulled for any year or model, just unbolted and lifted slightly for clearance. The problem is with the newer twin tube manifolds for 1995-2000 LS400s and 1998-2000 SC400s (with 1996-1997 SC400s being an unknown at the moment) there is no room to remove the heat shields and these shields prevent access to the head studs/nuts. Since multiple people have successfully replaced the earlier cars manifolds with headers WITHOUT pulling the engine we know that is not a problem with early cars.
Ironically, the 2001+ 430 engines went back to a single tube design (which holds back power but heats the cats faster) and for these cars install may be easier than the 1995-2000 cars (excluding the 85 SC400). On the 430 cars a new downpipe/Y-pipe/catalyst assembly will need to be fabricated.
Here is another picture of the prototype to compare to the 1992-1995 SC400 passenger side exhaust manifold (with EGR) shown above. Notice the outlet location is farther away from the engine and the dramatic improvement in design.

On the gs430 I had it on the lift, some of the header bolts can be access from the bottom some from the top, seems no reason to pull the engine at all. There seems sufficient space to move around from underneath the car this is where most of the work will take place on a GS430. A mechanic with a lift and air tools with fancy ratchet joints will have a definate advantange on all the header swaps.

The reason this applies for 430 cars is that Lexus changed manifolds and that changes mounting location for the catalysts. They also went to a 3 catalyst Y pipe, 2 at the manifold outlets and one as the 2 side join into one. It would be VERY easy for a shop to simply build you an off road Y pipe without cats. You could add cats to this system for about $125 each. I would personally not cut up the stock system for parts but that is also an option.
Celebrating Lexus & Toyota from Around the Globe
On the gs430 I had it on the lift, some of the header bolts can be access from the bottom some from the top, seems no reason to pull the engine at all. There seems sufficient space to move around from underneath the car this is where most of the work will take place on a GS430. A mechanic with a lift and air tools with fancy ratchet joints will have a definate advantange on all the header swaps.
I vote that the user Anthracite doesn't get a set since he "can't be bothered" with the length of the project. Perhaps he'll make his own set!
lol! Yeah, ok, that's mean, but, I can do without the "world revolves around me" attitude he displayed.John, the amount of time and effort you have put into keeping this project alive, working with the fabricator's, updating the thread, etc is under-appreciated. We'll all be in-debted when you pull this off and we're the benefactors.
On the headers: I too am a litle worried about the sound, that is my only caveat to wondering if I'll be happy with them. The price is probably not going to be an issue.
Do you have any idea how the header coating would compare to Jet-Hot in durability? Opinions?
Thanks John! Looking forward to the continued updates!
Allan
1. Trd has no headers for 2004 and 2005 , lookin for a pair for my truck, and if there is will it bolt up to my factory exhaust, or do i need to make mods to put them together.
currently all i have for mods on this truck is a K@n filter and a Borla cat-back exhaust system for alittle extra power and nice sound. anything else out there for external bolt for more horsepower needs.
Any info on this would be appreciated!!!!!
I bought them for my SC400 TT project, and am making a set instead...Better fit for my car if I make them.
Let me know if you're interested...If not, they are going on eBay.
Ryan Allen






