Sounds good... any idea if the Y pipe will attach to the cats, or directly to the headers?

Seeing as how I've got a 2005, I'm really looking forward to some sort of off-road pipe that will at least eliminate the 3rd cat, that my 2005 has.

Not sure when the resonator changed to a cat, but mine has one.

 

One of the things i did differently than rock a lex is I did do the 2.25 with the Xpipe and some magnaflow 14829 muffs. My experiance from this setup is that it did give a noticeable amount of HP mid to uptop. The next day(great timing) my k&n intake came in and I put that on to and from both those mods together there was a definant difference in power. My buddy who test drove the car before and after each mod also thought there was a very noticeable difference. Ofcourse this is all but dyno. I didnt really feel a drop down low, but I didnt feel a gain eather.

 

If created it will be a direct replacement for the factory Y pipe, will bolt to the stock cats and will not have a third cat. To be worthwhile for naturally aspirated applications it must create more power without hurting low end power or drivability.

 

I am glad you are happy with your duals. I am unaware of anyone doing a back to back dyno test with this type of mod compared to the stock pipe. I donated a racing style merge collector to the very first S&S header user (gawd) from which a replacement 2.25" into 2.5" replacement Y pipe was built. It was tested against the stock GS400 Y pipe as well as a stock GS430 Y pipe with the third cat. All three pipes were within 1 hp of each other peak power HOWEVER the larger pipe significantly impacted low end response making the engine FEEL sluggish at lower RPMs.

Now, there are many possible reasons for this and therefore it is not a condemnation of 2.25" piping. It does though show that there is MORE going on here than simply putting big pipes on. An X design is completely different from the factory design and dual 2.25 pipes are WAY more capacity than the factory single 2.36" center pipe. Dual 2.25 pipes have a combined internal cross section of over 7 inches vs. under 4 inches for the single 60mm/2.36" factory pipe.

That factory center pipe has supported well over 100hp over stock power levels with supercharged engines. What exactly is best for a stock engine and or one with S&S (or other) headers? Since I don't have that answer I am not recommending people spend for something that may not give any improvement.

You stated that your "butt" dyno says you had a gain. That is good but is not something that I can rely on for direct comparison. If your system bolts to the stock cats it would be VERY interesting to do some back to back testing with a stock system. Would take a couple hours or wrenching, some gaskets and some testing (dyno or dragstrip or even GTech)

If someone in Houston Texas wants to work on this I am game to assist. I even have the full data version GTech Pro Competition model that downloads dyno graphs to a computer. The testing would include driver impressions (very important) along with actuall acceleration and dyno graphing.

 

Yea the butt dyno is by no means a way to get accurate gains or losses. But at the same time its nice knowing you can feel a difference. I have dynolicious on my ipodtouch Id be willing to participate in some simple number gathering with you to see if perhapse my setup has different numbers than say setup with catback and stock ypipe.

Ever since I got my 20inch donz on the lowend has always been slugish. It was actually interesting my buddy with a is350 runs 20inch Iforged and we lifted his rear rim with a 265 and mine with a 255 and mine were SOOOO much heavier never weighted them though.

 

I kinda agree with jb on this one. That is not a bad stock center pipe at all. A couple of interesting things for all to know.

1. That center Y has kind of a Venturi makeup. That means that its good for scavaging the exhaust from the head.

2. The Y acutually has a long speration wall plate in the middle that keeps the gas comming in from the left and right from hitting each other and directs them into the single center pipe.

The Best mod in your case would be to have someone cut the center Res or Cat out as close to the body of it as possible. Put the same size straight pipe in replacing it.

I think that with some good fine tunning of your neo, after those mods will hit very well.

 

My being cheap and with some curiousity has me wondering: Is it possible to share Neo settings if like cars have like setups to gain some power? Or does every car need to be individually tuned on a dyno?

 

...not sure; it would probably work but not as good as for your specific car. I am setting up my new dyno appt. 2 weekends from now. I will keep you guys updated.

 

Glad to hear you got things running right again and I'm looking forward to hearing your impressions after the tune.

 

Alright man--pins and needles I'm on over here, I say! What'd you get??

 

Im with you frank. I want results!!!!!

 

You said "two weekends from now" on 1/28, so you're forgiven.

Today's not a "weekend", and Sunday most shops aren't open, so I BETTER HAVE SOME DAMN NUMBERS BY TOMORROW NIGHT!!

 

lol....I know I know, no excuses...things have been pretty crazy over here the last 3-4 weekends as far as more wedding and honeymoon planning. I don't think it would go over well if I was like, "babe, I can't go to the travel agent today because I have to get my car tuned and dyno'd to make my car faster." lol...I would get slapped. I promise, I will try to go this upcoming Saturday as I don't forsee this weekend being booked (by my fiance) as of yet.

 

Congratulations on the upcoming wedding!

 

Hey, thanks man. I hit a small bump in the road. My car still feels good but that damn crack must have opened up on my front driver side cat (loud exhaust leak sound); I guess the welding didn't hold. I'm bringing it back to the shop to see if they can re-weld it better. If not I will have to try to either find a used cat or buy new from Carson...they want $800 for it (new) .

I am really waiting for an optimal time to tune and dyno it as I want the most accurate and best power numbers. This situation is becoming a PITA because I know there are many of you that want to see how much power can be squeezed out of the NA Lexus V8 with just bolt-ons; and I just can't deliver yet. Sorry guys...I'll let you know ASAP!