Home Made Celsior/LS400 Headers

[Lextreme II]

These headers were made by Wayne Dyke. Heres the pics of the system Streamline Exhausts in newton, South Australia
did on my LS400! The headers were custom made by him as well!
System has custom headers to twin Stainless internal & external hiflow cats
to stainless X pipe to twin stainless resonators out to Stainless internal &
external straight through mufflers with yep stainless Tips to finish it off!
All pipe work is also stainless 2.25in!

It made a fair difference to stock power & sounds awesome!!!

 

[Pro]

even length, good collector and al mandrel bent.

top work!

i'll bet frieght was a bitch!

 

[JBrady]

David,
Are you reporting this for someone else? Did you buy another stock LS400? I am confused about who is using these. You or someone else?

The design looks good although I am not a fan of the large collectors. Typically equal length needs much longer tubes to achieve a tune for low end power. As David Vizard puts it equal length is only helpful if they are the CORRECT length. Otherwise the main objective is velocity with reduced obstruction and ideally anti-reversion. The pipe diameter looks smaller than the flange size and there is a pipe inside pipe step to bridge the size down. Maybe these are flanges from Rush Imports headers that Streamline Exhaust started with.

It would be nice to see pics of the rest of the parts and any other details such as how the cars low speed response and power feels.

What do you mean by inside and outside high flow cats?

 

[Lextreme II]

i am posting for someone...

 

[LSKid]

ok Ill clear it all up!

I bought a stock Australian delivered Lexus LS400 & had a freind that owns an exhaust centre. we had a look at the origional system, as you know its very restrictive so we started from scratch. I had a look around but I couldnt find anyone anywhere worldwide that did the headers for the RHD LS400. He said he'd do the complete system custom headers the lot!

The headers are all mandrel & each one is 24inches long, all flanges were locally made in South Australia, Australia.
The Cats have stainless internals instead of the usual ceramic internals. The outside is also stainless.
All piping is 2.25inch which was the best size for the motor in back pressures & all that stuff & also kept it quieter than a 2.5 inch would have been.
The rest of the system goes as follows from cats around to X pipe through to twin resonators out to mufflers with tips!
Dottom end has improved alot & actually is & feels quicker!
It was a long & teedious job but it was worth it in the end!!

Ive attached some more pics of the system!

If you want any more pics or info you can email me at [email protected]

 

[Celsiorous]

Wow that is a nice system, id be very interested to hear more about the performance gains you noticed. What X pipe and mufflers did you use?

 

[LSKid]

X pipe was just your standard 2.25in stainless X pipe! Mufflers were Supercat straight through 2.25in with stainless packing!

Havent dyno'd it yet as Im waiting on a new Throttle position sensor but other than that the gain is rather noticeable!

Was well worth it.

 

[jibby]

That is nice, damn I have the 2 1/2 piping from the headers to the high flow cat to the straight thru mufflers, and really thought that bigger exhaust piping helped with flow I guess I was wrong.... I love the gains I got with my setup and I don't think I will be switching back to the 2.25in piping.

Why aren't more people running straight pipes on these cars? Why is it so necessary to have the X and all those bends? Anyone know the lowdown on this?

 

[LSKid]

The X pipe is ment to make it easier to tune the car!

I couldnt run straight through piping as i need ground clearance in Australia!

 

[Celsiorous]

X and Y setups are used to increase the scavenging and flow of the exhaust, check this thread for more details http://www.lextreme.com/forums/showthread.php?t=4058&page=1&pp=20

 

[streamline]

the flange plates were ordered wrongly (not by any fault of mine) people that wouldn't listen to me, thats why the step was there unfortunally. Regards Nigel. Streamline Exhausts Newton...S.A.

 

[jibby]

Hey, I just read up on the exhaust systems and the importance of the X or two Y exhausts sectiions..interesting to say the least ... My question is since I am running the larger 2 1/2 inch ill advised piping on back half of my exhaust system (non mandrel), and straight thru mufflers in addition to a high flow cat, would changing out the Stock Y pipe to let's say JBrady's re-designed Y's really make a difference in my setup? Or would that cause problems at lowend for me? Anyone got any suggestions for me I have no clue... Just thinking about this, what real gains can you expect from changing Y's it looks like not a big deal?

I am not an exhaust expert on these Sc's. I have read most of the JBrady and other exhaust threads but none of them cover my exact setup.. I also got a stock 1993 torsen Supra LSD, stock sc400 tranny, and also good stall rate Dragon Torque converter for lowend on this car.. Would any of you guys suggest me getting the Y or is it overkill with addition to the headers that are on the way and about to be installed. Here is yet another pic of my exhaust setup?

 

[SCV8]

The factory "y" is the most restrictive part of the stock system; the two tubes are pinched to help with quiteness/smoothness/equal pulse/smog.
It's the only part, along with the center resonator(cat on your CA spec car) that I have replaced so far, as the oem SC mufflers are all a straight though design like a performance system will tend to use, and not at all what I expected to find under a Lexus.
Headers are the next bottleneck, with the tractor-like design from the factory, then tubing size I suppose, however plenty of cars make good power with just a 2" pipe.

 

[jibby]

SCV8 thanks alot for the reply. Wow, I find it so very hard to believe that the stock Y pipes are more restictive then the factory designed mufflers, and headers....if that is the case I would like to upgrade my Y pipes immediately if not sooner...as long as it will not kill my lowend or throw off equal pulse....Smog I can careless because I am moving to Florida shortly anyway......Well John if you are reading on this and agree with what SCV8 is saying, then sign me up for two Y's!!!!!!!Let me know.....

PS. I am going under my car to take a real close look at these restrictive stock Y pipes.

 

[jibby]

One more question for SCV8 did you notice a power increase after you changed your Y's out and how loud did it get????

 

[SCV8]

There was an increase in power, and the sound is now louder as well, but there is no drone during cruising, and the car sounds like a Mustang for the most part.
The exhaust note is nicer with the timing advanced through the piggyback, the oem timing-settings make for higher exhaust temps.

 

[Anaema]

those are sweet headers.

 

[jibby]

I will look to give it a go, thanks!!!!!

 

[Broker]

Are the exhaust and mufflers and everything the same on the SC400 and LS400?

 

[pull_85]

hi im a bit late i only got my car two weeks ago,

is there an email or an address someone has of this streamline in newton so i can go ask them if they will do my celsior?

thanks