JAndersson

When I get my car to perform as it should I'm planning to get a new custom build exhaust. Right now it feel like the fuel pump is going bad so I have ordered a new one.

But back to my exhaust question. Planning to have custom exhaust system made from the center resonator and back. See picture below for comparison. (It's the stock exhaust on a 1 gen LS400)


The pipes are going to be 2.5" (nobody sells 2.25" in Sweden) and I'm planning to have 4 high flowing mufflers (2 per side) because I still want the car to be quiet, louder then stock though. My goal is more horsepower and a nicer exhaust tone. The company that's going to build the exhaust is Ferrita which are well known in Sweden when it comes to exhaust systems. (http://www.ferrita.com/index.php)

My questions are;
Will this be a satisfying setup? Or am I better of with a true cat back system? The reason why I'm not going true cat back is both a price issue and that another exhaust builder company told me that changing out the first part of the exhaust system from the cat's and back with the center resonator will not do much because it's quite good as it is.

The price I got was 9500 SEK (~1200$) which is a fairly good price for being in Sweden. Keep in mind that mounting and tailpipes are included and the material is stainless steel (planning to keep the car for a long time).

So what do you guys think?

Schnitz

iTrader: (5)

$1200 ain't cheap. It's up to you, but I removed my rear 2 mufflers, added 2 twin oval tips and I love the sound. Cheapest easiest route.
I don't know how much hp the stock system restricts.

jcrome04

Wow... I got mine done for ~$400 with all parts and labor. Not cheap at all.

Have the new piping start from AFTER the stock Y-Pipe. You should use 2 resonators ("glass packs") and 2 mufflers, instead of 4 mufflers.

2.5" will be LLOOUUDD

JBrady

While it is possible to build a better than stock system... most will end up with a system that is worse than stock.

There is not much power to be gained in building a custom cat back system. The sound change on a custom system is also an unknown until it is built. Exhaust systems are just like a musical instrument and every bend and transition will create different sounds. You may or may not like the finished product.

I HIGHLY recommend simply removing the back two mufflers. This is a quick cheap and easy test. It will slightly increase sound without a cruising drone. If you like the result simply have pipes installed in place of those mufflers. There is a slight performance gain because it is LIGHTER in weight!

Alternately you could remove the center mufflers and keep the final mufflers. This is a little more involved and you may or may not like the result.

I do not advise spending money on a 2.5" system.

JAndersson

Thanks a lot for your answers guys. I think I need to rethink this.

avalon42

iTrader: (1)

I think if you are going to spend $1200 beans you better get some headers instead.

gmacrae

What about installing some UCF20 manifolds for a start? Surely a cheap upgrade to the log style UCF10 ones.

I've just had an exhaust done on mine. 2.5" piping from the centre muffler - nice Y pipe - 2x2.5" pipes running to 2.5" straight thru resonators at the back of the car. So i've replaced the 4 stock rear mufflers with just 2 straight thru resonators. The sound is wicked, it does drone when cruising around town below 2000rpm but at 100kph/60mph the car is almost silent again. The low speed rumble is quite addictive, warm idle noise is still fairly quiet.

There is truth in the fact that you dont want the pipework too big but its only really important for the first half of the exhaust. Down the track i'll put in a more complex 2.5" centre muffler (chambered, not quite straight thru) and 2x2" pipes up to the headers.

I'm real happy with the exhaust on mine and im sure the car has gained some torque/throttle response down low.

PureDrifter

iTrader: (10)

you do realize that 2.5" piping on the 1uz (NA, stock ecu) results in a crappier torque curve especially down below right?

2.25in piping has been proven to be the best compromise.

avalon42

iTrader: (1)

http://www.headermania.com/mm5/merch...ory_Code=LEXUS

Just plain sexy.

JBrady

Pure, his current system is using a 2.5" center pipe that splits into dual 2.5" pipes out back. By keeping the front half of his exhaust the response did not get hurt like it would have with 2.5" from each manifold.

At one time I recommend 2.25" but now I am not convinced and currently recommend keeping the stock front Y pipe for most cars. The only area that I would recommend changing is on the 1995-2000 LS400s there is a sharp cut and welded section of 2.36" pipe immediately out of the catalyst outlet. Fabricating a nice 2.25" mandrel replacement for that section is adviseable although I have no actual testing to back this up only my experience and intuition.

His future plans call for 2.0" pipes from the manifolds/cats into some sort of chambered muffler. I do NOT recommend that. His current pipes are mandrel bent 50mm which = 1.97". Going to 2.0" is not worth any change and I recommend the stock Y pipe with its "squashed" pipes WHY do I recommend THAT? Because those squashed looking pipes are actually a VERY effective nozzle collector.

As for the chambered center muffler... again, that is NOT recommended. The stock is less than 60mm internally so instead I WOULD recommend a 2.5" single straight through resonator type center muffler.

His current 2.5" tailpipes are not hurting but they are heavier and larger than necessary. I recommend dual mandrel bent 2.0 or 2.25" pipes into a single or a pair of straight through 2.0 or 2.25" mufflers per side. The smaller diameter will not hurt power and will be lighter in weight and take up less room for better packaging. His current setup has single 2.50" straight through muffs per side which are fine but again larger than needed.

JBrady

The headers ARE recommend but are NOT direct bolt in parts for the LS400s.

Here are the needed fabrications to run the S&S headers on an LS400.

LS400: 1990 – 1997
The S&S Lexus V8 header will physically bolt to the engine HOWEVER these are NOT a direct bolt in with or to the remainder of the stock exhaust. Downpipes must be fabricated from the header outlets. Aftermarket catalysts can be installed in the stock catalyst location when building the downpipes. The stock catalysts can be re-located underneath the car and connected to fabricated downpipes although ground clearance will be less than stock. Aftermarket catalysts can be installed under the car when building the downpipes. Downpipes can be built without any catalyst provision at all. None of the applications are emissions certified. Eliminating the catalysts is a serious infraction and there is minimal power gained in doing so. Catalyst use of some kind is recommended for most applications. It is recommended that a flange be welded to any fabricated downpipe to connect the EGR system. Cars will operate with a deleted EGR system but EGR use is recommended. Flanges for downpipe construction are available for separate purchase.
Gaskets and bolts are provided but not recommended. The OEM gaskets and OEM studs and nuts are recommended. S&S Headers are not emissions certified.

LS400: 1998 – 2000
The S&S Lexus V8 header will physically bolt to the engine HOWEVER these are NOT a direct bolt in with or to the remainder of the stock exhaust. There are also a few areas that the headers are a very tight fit to underhood components. These areas should have aftermarket heat shielding or wrapping to prevent heat fatigue. Stock catalysts will bolt to the header outlets but the headers are shorter in length than the stock manifolds by roughly 2 inches and the bolt pattern is rotated. This means that to connect to the stock exhaust requires modification to the stock Y pipe and or creation of short connecting pipes to join to the stock exhaust. Alternately a complete custom Y pipe, X pipe or H pipe can be fabricated to connect to the catalyst outlets.
Gaskets and bolts are provided but not recommended. The OEM gaskets and OEM studs and nuts are recommended. S&S Headers are not emissions certified.

JAndersson

Have a Mine's ECU in the car. Does that made any difference in how the exhaust system should look like? And am I better of with new headers (like the ones avelon42 linked to) instead of a new exhaust. Or is both just a waste of money? Looks like it would be a PITA to change the headers.

JAndersson

Thanks for the clarification jbrady. No S&S headers for me then. Does anybody know if the headers that rush imports sell would fit on a LS400? But most likely am I going to leave the exhaust as it is until I can afford a supercharger kit.

gmacrae

Its still got the stock midpipe--cats-headers section, when i replace this, it will be with much smaller diameter pipework for sure. A friend of mine did the exhaust, he's owns a performance workshop that has mainly worked with 1uz's for the last 5 or 6 years. The main reason behind the large diameter rear pipework was just to deepen the sound, and like he said, it didnt adversely affect the torque at all, it improved slightly. Skips the tyres when pulling away from a stop in a straight line now.

gmacrae

That is the nastiest looking part of the stock exhaust, im sure there will be gains from removing these bends and the cats, which by now will be starting to clog up. But i doubt ill go for anything bigger than 2.5" centre pipe - 2 x 2".

edit: The stock front pipes are 50mm? really? I never measured them but if that's the case they can stay