Ksbga

Hey Guys. For some reason I find this club difficult to navigate? As in I can't seem to find answers to my questions in search... Thus I start my own thread. lol
My 1990 LS 400 has factory exhaust. I am wondering the "Risk VS Reward" with exhaust work.
I don't want to affect performance reducing back pressure, but I have to assume taking the 4 mufflers out and sticking some flowmasters under it wud help add a few HP? I had a Lincoln LSV8 and I did the same thing getting the 252hp up to 260...
Any advice wud be greatly appreciated!

Ken
1990 LS 400
92,700 miles

djsurfer

iTrader: (2)

I just recently did my exhaust system on 2 of my cars, first on my type R Integra and then on my 92 LS. With the integras 4-cyl all motor engine I ran a 2 1/2 inch straight pipe with great sound but managed to lose 2 hp somehow when dyno'ed. Then I re did the whole exhaust sytem on my 92 LS with a 2 inch pipe with new thinner mufflers and resonators for ground clearance and dual tip exhausts on the rear. Although I didnt dyno my LS I do notice a way better throttle response and also a very nice deep rumbling sounds when stepping on it or cruising around 1700-1800 rpms. Dont know what kind of "risk" youre running on doing an exhaust system. If it is about HP I wouldnt worry about it. Ive done correctly at a reputable exhaust shop, the rewards will be very great and nothing really to lose. I dont know what I like better in my exhaust system on my LS, the looks, the ground clearance, the sound or the throttle response. To me its all WIN WIN. I say do it and finish it off with some nice tips... heres mine before vs after (also coming from a car with 2x as many miles *178,xxx*) More noticable is the increase on my V8 than the decrease on my 4-cyl... Cheers!!

akitomk3

iTrader: (2)

can you post a video of that and more pictures of the whole exhaust systems?

TaffyK20si

I've been wanting a custom exhaust on my 2LS for as long as I've owned it. What made you go with the 2" exhaust besides the clearance? Is it raspy at all? I've heard a 2 1/4" that was really raspy. I can't remember if it was a 2 1/2" or 3" with x-pipe that I heard that sounded really good.

djsurfer

iTrader: (2)

Not sure how to post a video or putting it on youtube or whatnot. All I use for pistures/videos is my phone, but I will take more pics.

djsurfer

iTrader: (2)

I went with a 2" because I wanted as much clearance as possible and I didnt want it too loud. My type R is loud and I didnt want this V8 tu rumble too loud so I stuck with 2" all the way back, its not loud or raspy but has a decent rumble and deep whine at 1700 rpms. And on take off you can hear the sound, the sound diminishes after 1900 rpms which is fine. I did it more for looks and clearance than sound, but the sound is just perfect to me.

usoff89

iTrader: (2)

Reward, and no risk IMO. But the size makes a difference. I would stick with either 2in or 2 1/4.

Here is my setup. I did 2 1/4 and is tucked very well. If you look under the side of my car, the chassis is lower than the exhaust. My setup is a bit loud but not too bad. It sounds really good though, and not raspy.

pics

djsurfer

iTrader: (2)

[QUOTE=usoff89;7822156]Reward, and no risk IMO. But the size makes a difference. I would stick with either 2in or 2 1/4.

Here is my setup. I did 2 1/4 and is tucked very well. If you look under the side of my car, the chassis is lower than the exhaust. My setup is a bit loud but not too bad. It sounds really good though, and not raspy.QUOTE]

I like the way those single largo tips look, I was going to go witht that but decided on more tips and a wide chrome canister that could be seen from the sides aswell.

j2b4o

Check out lextreme forum there lots of threads on the subject.
Back pressure is a myth. What you need is a steady smooth exhaust flow.

The recommended way to go is to remove the front resonator and replace with an equal with pipe. After that replace the first set if mufflers with stock size pipe. Replace the rear mufflers with something with a better flow.
There are a number of people running this set up with boost and are not being limited by the piping.

usoff89

iTrader: (2)

With boosted cars, you want little back pressure and a decent sized pipe. With a n/a motor such as the 1uz, if you go to big on the pipe (such as 3inch) you will hurt performance. And if you go too small you can also hurt performance. I'm no expert, but I'm pretty sure back pressure is NOT a myth.

usoff89

iTrader: (2)

[quote=djsurfer;7822182]Thanks, I got a deal on them, and they fill in the factory cut-out in the bumper perfect!

djsurfer

iTrader: (2)

[quote=usoff89;7822211]Nice thats a double win, I wanted a bit more chrome (car being black) so I opted for the dual tips and cutout the rear bumper VERY carefully with a dremel and the opening came out perfect. I was very skeptical about cutting a newly painted car but I went ahead with it.

RA40

iTrader: (6)

This thread is the basics of the exhaust:
https://www.clublexus.com/forums/ls4...stem-mods.html

https://www.clublexus.com/forums/ls4...date-pics.html

I notice that some of the exhaust threads can be merged and updated for the FAQ in an upcoming revision.

JustADream

plenty of na cars run open header and see improvements. backpressure is a myth.

TaffyK20si

What kind of mufflers are these? Where did you purchase them from?