Headers for a Celsior/LS400

[Celsiorous]

Hi,

I have recently purchased my second Celsior. The previous owner has had the honeycomb removed form the cats and left the cat casing intact. Due to this any time I touch the throttle I get a loud horrible tingling resonation that sounds almost like a bad exhaust leak.
I live in New Zealand and at the moment we do not require cats by law. I want to remove the sound coming from the gutted cats. I have been told that if I replace them with straight pipe I will get alot of noise anyway, so I was advised to replace the cats with some small resonators or after market cats.
My question is basicly whether there are headers available for the LS400/Celsior that anyone can recommend because if im going to spend the money to do all this work replacing the cats i thought why not just replace the headers and bolt the exhaust straight on.
I would appreciate any comments or suggestions.
Lextreme, I have listened to the exhaust note of the SC400 with Greddy MX mufflers hosted on this site, is this a 1UZ?

Thanks

 

[Lextreme II]

Hello Celsior,

Yes its 1uzfe. Removing cats will not increase noise that much. U should remove it or you can get an after market cat for it. I would suggest u remove it.

 

[Celsiorous]

Thanks Lextreme, so you think that straight pipe will not cause too much noise?
The SC with the Greddy MX's sounds great, that is the kind of tone im after as I dont want it too loud. Do you think I could expect any performance gains over standard if i copied that SC's exhaust setup?
I have been reading through these forums which are great, is there any update on the GP headers?

 

[Lextreme II]

JBrady and I was discussing about creating a X-Pipe for the Lexus V8. Its just talk for now...

 

[JBrady]

Removing the catalyst substrate from the cat housing leaves a larger open can that resonates loudly... not desireable and often less performance than with stock cats. At the very least replace with straight pipes.

Almost any header will be better than the stock manifold. I would advise using 1.5" primary pipe and fashion the collector to have the smallest volume or area possible, preferably like a merge collector. Keep the pipe from the headers relatively small, 2.25" is the max I recommend and is a good choice for most applications. Definitely run an X pipe or Y pipe configuration. Pay attention to the Y intersection and treat it just like the header collector recommendation.

 

[Pro]

replace the bloody cat' ferkristsake.

we have to suffer here in OZ (no ozone layer remember) because of silly people all over the world removing their cat's for a 0.05% gain in RWHP, while putting out worse emissons then leaded fuel.

a high flow cat won't hurt horsepower at all and will sound better. so why remove it?

 

[Celsiorous]

Thanks JBrady, by the looks of things I am going to have trouble finding any headers and probably wont be able to afford getting some custom made, so for now I will replace the cats with straight pipe.
Sorry im a noob when it comes to exhaust. Would you recommend putting some straight through cobi's or something similar instead of the cats to reduce the noise or is it not worth it?
Also would you recommend running 2.25" pipe for the whole exhuast?
After reading your other posts I am considering running from the cat position back:
2.25" to a Y then 2.5" to a Y then 2.25" to two Greddy Mx's.
Does that sound around the right sorta idea. Sorry to be a pain its just I only can really afford to do it once and dont really understand how the exhaust components affect the power range. Before reading your posts I just thought bigger was better for performance. lol

 

[Lextreme II]

You dont have much choice. Try this www.rushimports.com.au

 

[Celsiorous]

I have followed the link Lex, will Soarer headers fit into a Celsior/LS400 engine bay? Id be stoked if they do cause ive read all the good feedback about them.

 

[LSKid]

If the LS400 is the same as australia no the headers from a soarer wont fit!

I had mine custom made!

What year is the celsior?

try this link http://lextreme.com/forums/showthread.php?p=36554&posted=1#post36554