Salil022

iTrader: (1)

Are there any high flow cats and headers available for 99SC400? i am looking to do the exhaust flow little better and want to hear the real V8 sound...any sugestions or ideas would be appreciated!!

thanks

vwynn

iTrader: (4)

hi flow cat? go for Magna flow or osmething

Headers? S&S heads.

v8 sound? do what we did. Straight pipe. With stock cats of course

Blizzy

iTrader: (-1)

S&S headers are best for the stock motor: $600

High flow cats: Magnaflow 59955 Metallic Substrate Spun cats ($115) will outflow every cat short of Random Technologies' Cats (which cost over twice as much). The stock cats flow really well to begin with. No cats flows the best.

V8 Sound: get rid of the resonators and put on some less restrictive mufflers. This alone will make your V8 be heard. No cats would make the system louder as well. Or, do what the above poster did: no mufflers...crazy!

A full exhaust from the S&S headers back will not only sound amazing, but it will increase power across the entire RPM band. All told, it will probably put you out ~$1500 after installation.

SClean4

I'm going to do a cutout, which seems like the best of both worlds: The sound of no mufflers when the butterfly is open and when you want the the stock sound back, close the butterfly.

Salil022

iTrader: (1)

Thanks guys, would i have check engine light on with magnaflow cats? and wehre can i get these from

vwynn

iTrader: (4)

most if not all exhaust shops have magnaflow high flow cats.

as for the CEL.. i dont think it should be a problem.. as long as your o2 sensor is fine.

SCpwner

If it were my opinion i wouldn't even bother spending the 115 dollars for a maximum of 5hp ~ it honestly isn't worth the money when you could put 115 towards getting a resonators delete to go with your new mufflers and still have money left over. This is just imo though.

Dx3

iTrader: (13)

He speak the truth!

Jonny

jgscott

iTrader: (1)

I would not follow that advise. This comes up new about 2x's a month. Here ------ https://www.clublexus.com/forums/sho...hlight=jgscott

SCpwner

Just an fyi... that center "cat" is a RESONATOR. What i was talking about being deleted. The stock cats are very high flow as they are and again by replacing them with "high flowing" cats it is not that much of a difference especially since he has a fairly new car he has no worry about having to replace them for a good while if they die out.

Salil022

iTrader: (1)

i am going to get the resonator's removed next week sometime and get some magnaflow mufflers...and in the future header's but don't know what kind of header's are available for 98+sc400

Dougspeed

iTrader: (2)

I just had my exhaust custom made recently. I just replaced all exhaust piping with 2.25" piping. Replaced the center resonator with a Magnaflow x-pipe, and just deleted the other two resonators. I kept the stock mufflers with the new piping and man, it's LOUD, a nice deep rumble. I can't imagine needing to replace the mufflers unless you want to relieve a little bit of backpressure.

jgscott

iTrader: (1)

Not correct again.
1. Depending on the Model, year, and version, sometimes it's a actual Center Cat not Resonator

2. The stock Cats are Metal Substrate already. But there are aftermarket Cats that will outflow them.

SCpwner

Ok well all in all the third cat is not needed especially if there are already 2 sitting there. My point overall was why would you spend 115 dollars just to ~4hp. Just delete the dam thing and free up all of the back pressure. No matter if i am incorrect about the third cat my main issue is and was the money spent for hp/torque.

ScottURnot

iTrader: (33)

If you are doing a complete exhaust I would say you will HP gain would be much more than 5HP. I did S&S headers through Magnaflow cats, X-pipe, resonators, and Mufflers. All magnaflow and stainless 2 1/2" mandrel bent piping.

Only other HP increasing mod at that time was BFI air box.

It did 230 HP 247 ftlbst Most stock SC's cant even break the 200RWHP barrier.

How does it sound? Click this!
http://youtube.com/watch?v=boEmvLzu_vw