GX470GT

will removing the rear mufflers increase performance?

I mean the ones at the very rear. Also, Is the exhaust on the gs400 similar to ls400?

Hilux22RE

Removing the rear mufflers will not increase performance from what i know of..
I Did remove the two rear Resonators on my 1991 LS400.

But what years are you talking about in the GS to LS Comparison??

3UZFTE

No, only noise. There 2 resonators, not to be confused with cats, and 3 mufflers. Try unbolting the mufflers at the rear axle and tie them up out of the way of the exhaust, rev the engine a few times and see if it's for you.

What's your definition of similar? Yes, their both V8s, yes they both have y-pipes with dual exhaust. The GS400 and later model LSs got a higher, I believe 10.4:1, which increased the power, as well as the introduction of VVT-i.

Hilux22RE

Are there not 3 Cats, 2 Resonators, and 2 Mufflers..?

At least that is how mine was.

radiokilla

Yeah same with my car. California cars have a 3rd catalytic converter in place of the 3rd resonator found on non-CA cars.

Hilux22RE

Now is the 3rd Cat needed?? Or can i get that S*** Cut off?? i was thinking about it but i was thinking it might affect the Smog status...

PureDrifter

iTrader: (10)

some UCF10s had a 3rd cat, but not all. you could probably ditch it without adverse effects but for smog....who knws.

Justinkm

iTrader: (1)

removing the 2 resonators and that 3rd cat is Ok Passed smog easily

maxx999

Just run open headers, you will probably lose power down low but gain it uptop and it will sound great!

3UZFTE

Sorry, I didn't know Cali cars had a 3rd cat, now I do.

acidfire52

Now that would be loud.

KoukiMonst

just run a cutout

PureDrifter

iTrader: (10)

this would help how exactly....?

fatcat2

dont do any of the mentioned above. messing with the back pressure of the exhaust will eventually(it will take a while but it will happen) start bending your valves. just get a custom exhaust from a muffler shop. they can tuck it up for you so it can be hidden if you would like.

Hilux22RE

How would reduced back pressure bend valves Exactly...? I Have never heard of this happening. any links to articles or info on this??