lspower

i had straight dual exhuast with nothing else, then i added the x pipe, so much more power then just duals. Its a must!

hobojoe

hmmm interesting well i would have to say after reading and all im sold on the x pipe, sooo i will be cutting out the whole old system from the cats back and then an xpipe into 2 magnaflow polished mufflers, now who things on a 91 should i go 4" or 3" tips and 2 1/2" or 2 1/4" piping?

steveski

Most folks recommend 2 1/4" piping rather than 2 1/2". I have 3" tips however 4" would look even better. FYI, I cut my bumper with a utility knife.

hobojoe

hmmm utility knife huh? it doesnt make it look all jagged? 2 1/4" it is then.

PureDrifter

iTrader: (10)

i used a dremel

hobojoe

that i could see, is it a pain to like get them to match so they look the same?

Neofate

iTrader: (1)

Logically -- X vs H pipe , think of the air flow. As the exhaust pressure comes down towards the H pipe it has a direct unrestricted flow (no bends, etc) to the tips. Though also has the (middle equalizer pipe) to allow the gas pressure to equalize. IE: If one side is pushing more than the other, one side will have a lower (or more negative) vacuum . That side will virtually suck some of the other sides exhaust down the pipe. Which will equalize/balance things out -- Better on the engine, and better on performance and sound.

On the X pipe.. Same principle, just think of design. Gas's rushing down the headers.. the hit the X.. and don't have a straight line to the Tips.. they have to move, and in the middle they mix.

Both pipes do a similiar overall thing for the performance and engine/sound -- But due to design you can see how they would act very differently. With a healthy engine I prefer an H pipe. But that is just personal preference.

You can mix an X pipe with Y brand of muffler and get Z sound. You canmix and H Pipe with Y brand of muffler and get a different sound. Then you can mix an X pipe with C brand of muffler and get D sound. So you have lots and lots of options, and sound configurations possible.

Flowmasters are notorious for an 'X' RPM drone. With other exhaust variations notorious for their pulse. I personally dislike Pulsing more than the drone, if I had to pick one over the other. Though don't be discouraged there are so many different Mufflers out there you can get any sound you desire if you research it properly.

Obviously the best way to get a desired result is to listen to an LS400 that has exhaust, and copy it. You will get the same sound.

You can hear a great exhaust sound on say Cadilliac STS V8, and copy the configuration and it sound like *** on your LS. Each engine has a distinct sound unalike any other.

For instance, I can always hear a 5.0 liter, or 4.6 modular mustang coming. It is that distinct to my ears. Also just as an aside, the LS 400 V8, stangely enough, has a similar tone to the 302 Ford engines. It is muffled so much that it is hard to hear stock, but when opened up the tone generated is 'similar' *not the same at all* but similar. A pleasing sound, powerful sound, smooth.

To your questions:

Piping, go with 2 and 1/4. No need for 2 1/2.

Tips, go with 3inch.

Though on tips it is just looks preference, and that is the only reason I say go with 3inch tips. I don't think an LS400 looks right with absolutely monster exhaust tips. We aren't drag racing these things.

But on the same token I don't like 22inch rims,.. but I do like 18-19 maybe even 20inch rims, of the design that is pleasing to me. Stock lexus rims while looking 'fine', leave a good bit of room in that wheel well for aftermarket larger rims. (different subject, but applies in the *personal* preference reference)

Don't let anyone tell you what size you MUST get,.. on tips. Look around, and get what *you* think looks good. Afterall, it is your car, and you have to live with the decision. (Tips are also the least expensive part of the equation, and can be changed fairly easily).

When you get done, be sure to make us a video.

hobojoe

NEO wow thanks very very helpful! i will be making a video when it gets done too. you explained it perfectly Thanks!

Neofate

iTrader: (1)

It wasn't all that -- Just common sense. Also the main point in it was go by A) personal preference on looks, and B) On sound find something you have heard in person or possibly in a video and KNOW what it will sound like on your car. --Then there is no dissapointment after installation.

I look forward to the Video -- When you make it, make it longer than the 5-10 seconds clips I often see.. Rev up the engine a bit,.. Try to get sound from driving at a range of speeds. (Easier said than done I know) -- Maybe a friend could ride with you and help.

Have fun with it!

hobojoe

Thanks yea defiently got the main points and i defiently do agree that a 3" tip would look way better but like you said its all preference!

steveski

I tried my Dremel but it didn't have the power. The knife worked very well and was smooth - depends on how steady your hands are If you have a good dremel then I would use that obviously. Since mine didn't work I didn't have a choice.

steveski

H-Pipe is just older technology - well before the X-Pipe.

nosechunks

And x-pipes aren't a restriction as Neo states, They flow better and scavenge exhaust better then an H pipe.

Brandicus

iTrader: (6)

^umm... Im pretty sure neo recommends the h pipe in his writings.. you might want to reread that.

Neofate

iTrader: (1)

Heh, Brandicus..

Actually I said I 'preferred H-pipes on a 'healthy' engine' -- But I just explained the differences in shape/design of the two in my post. I never actually said "one is better than the other". -- Because I don't believe that to be honest.

I have seen H pipes be better applied, and vice versa.

Though as was stated, the X pipe is a 'newer' technology. I know it is big science and highly involved, but I have never seen the mystery in exhaust systems. (Sound wise is a different story).

Anyhow, I think the guy decided on Headers to X pipe, to 2-1/4 piping to Magnaflow's with 3inch tips.

I would say that is a sound decision. (Pun not intended)