y2kse - I had to unscrew the three front precat bolts and two nuts to loosen the pre-cat - the stock y-pipe came off pretty easily after this. I was able to install the y-pipe (Stillen) pretty easily as well. It really helps if you first remove the pre-cat heatshields to better get at the bolts/nuts attaching it to the manifold. I did have to modify the Stillen Y a bit though to better fit it to the two manifolds and to attach it to the triangular rubber mount before the main cat. Is yours attached to this mount?

I noticed pretty much the same things you did. I'm also able to cruise at 110 and it feels like 65!

The main thing I don't like about the the y-pipe is the loss of some low-end torque. I may just go back to the stock Y after I get Don in Texas's VB mod done this weekend. It's becoming pretty clear to me, and maybe this is stating the obvious, that real performance limitation on the auto-max is the tranny (I know you got a manual - smart move!). The stock y is a pretty good design imho and it's also "equal length/tuned". It's also pretty clear to me that the pre-cats are not all that bad since they do contribute to low-end torque via the slight backpressure they present. In other words the y-pipe certainly helps in a big way the closer you get to the top-end but it's not that great for everyday driving where you aren't reving the engine that much particularly with an automagic.

 

It makes sense that you had to loosen the front pre-cat bolts, sleepermax. There's just no other way to remove the stock Y-pipe short of cutting the flange off. Had I not had a new pre-cat bolt installed recently for one that fell off (believe it or not) and had it not taken 3 days for the bolt to arrive at my dealership, I probably would have told my mechanic to take a shot at loosening the bolts. But if he'd broken a bolt, I'd have been up **** creek without a paddle, and I knew it. Better safe than sorry, I suppose. And he can always weld the flange back on if I need to install the stock Y-pipe at a later date.

I didn't notice any additional reduction in low-end torque with my Y-pipe over what I experienced when I installed my catback system. I don't tend to drive my car under about 2,000 rpm and the engine pulls really well starting at about 3,000 rpm. So there's a range of about 1,000 rpm where I lose a little torque. But for what I get on top, it's well worth the tradeoff.

 

Under hard throttle, the bottom of the car would vibrate pretty hard. So i took that bracket off, and no vibration or anything.

 

My only concern is that the bracket isn't there to support anything. It's there to prevent your exhaust piping from striking the ground in case it comes apart for some reason. If the piping comes loose under speed and strikes the ground at just the right angle, you could end up having a really bad hair day.

I'd suggest you try installing some washers and lowering the bracket if possible rather than removing it altogether.

 

To tell you the truth the Intake makes more noise than the Y-Pipe does. But the two together under WOT is DA Bomb! I'm not doing a cat back just yet because I still want the car to be relatively quiet under normal driving conditions. If a touring cat back comes out that will improve perfomance I'm all over it.

 

How far up are the front pre-cat bolts? I have 10" and 6" extensions....will these be enough? I was hoping I wouldn't have to remove the front pre-cat....but lets see how it goes....

 

UMD_MaxSE, the 10" will be fine. You'll also need a 13mm extended lenght socket to get at the two nuts on the engine side of the precat. There are three bolts on the radiator side you'll need to loosen as well. You'll first need to remove the precat heatshields - you'll need either a 10mm or 12mm wrench, can't remeber which. A torque wrench won't work since it's a very tight space. You probably won't need to remove the precat entirely, just loosen it. Don't retighten it until you've installed the Cattman y. I also recommend that you let the car cool down completely, preferably overnight since the bolts are much easier to remove and loosen when they and their surroundings are cold.
Also an adjustable wrench will well when removing the o2 sensors. You'll need a UV joint for your socket wrench to get at the bolts attaching the stock y to the rear manifold.

I found loosening the pre-cat to be the easiest way to remove and install the y. I feel like a pro now that I've done it twice in the last two weeks - once to install my Stillen Y and then a few days later (when I though I had come up with a great way to do an Ooglie Cali/Fed conversion) to remove the precat to partially hollow it out (after relocating the two rear o2 sensors). Which, by the way I've decided has been a mistake. It definitely helped the top end, but I lost even more low end torque. And, this is the part that I'm kicking myself over, I have been unable to locate a used front pre-cat anywhere in the country through car-part.com and it's $461.00 with our Org discount from Dave B! I had to try it for myself - I just wish I'd located a replacement one before doing it.

 

sleepermax: thanks for the tips....luckily I have all the tools including a huge breaker bar if needed I may have to get a deep socket set though....I think I only have a 14 mm deep socket......thanks once again!

 

Do your own catback, PhatGuy. Why pay money for a name brand when any decent muffler shop can create a custom mandrel-bent catback for half the cost or less? And the performance will be identical to the name-brand catback.

 

ok, dumb question, again, but since my y-pipe's in the mail already, I'm curious. You say that you lose some low end torque, but only below 3K or so RPMs. My question is, does the extra boost at the upper RPM's make up for the loss on the low end? I guess what I'm really asking is your 0-60 and 1/4 miles will still improve, right? I'd hate to have to cut it down to only picking my races on the highway...thanks!

 

I wouldn't be too concerned, nc00max. I think you'll be pleased with your performance after you install the Y-pipe.

 

I think the reason sleepermax lost some low-end is because he gutted a bit of the front pre-cat. I think if instead the entire front manifold was replaced with the fed spec manifold, then there should not have been any loss. The front pre-cat is huge....if you gut it, there is a lot of empty space there

 

I feel like I just upset the school teacher or something... hehe.
Anyway.. The ECU did squat for the situation, they at that point in time ordered a replacement coil for coil #1.. and I replaced it.. and BAM. Problem and engine light have been gone for 2 weeks now. BUT! I must still add that the car has ping'd twice on two seperate occasions after this.. so.. my of my original two problems.. the hesitation / detonation is gone.. but the pinging shows up every once in a blue moon.. but goes away quickly. I'm going to order the whole coil replacement set (minus 1) and throw them in there.

-b

 

I think someone said that their Y-Pipe made the car HELLA LOUD! Do you have a different muffler, cat/no cat etc...
I have to be very sly with my mods because my wife can't understand the mod bug! She hates me spending money on cars (which I have done since we met)! I really want to add some HP to the car but I don't want it too loud because the warden will send me to the hole!!!!

 

I suspect that the Y-pipe will be hard to cover up, 2000 SE. Even if you keep the rest of your exhaust system dead stock, the Y-pipe itself makes a hissing sound under acceleration. It's not real loud, but it'll be noticeable enough for your wife to realize that something is different. Then again, I suppose you could blame it on an exhaust leak you'll get around to fixing "some day".

 

Thanks for the info, I think I can get by with the hissing, I was more worried about the loud whining or high piched sounds (like weedeater on steroids)!

The wife definately noticed when I took the cats off of my GT stang! She was waiting outside the door because she heard me haulin A$$ down the street!

 

Well I'd recommend you start with the Y-pipe first and let her get used to that before you install your catback exhaust. And when you DO install your catback, plan to include a resonator as part of your purchase. There's just NO WAY you'll be able to cover it up otherwise.

 

yeah - that's right. I was very happy with the y-pipe and front pre-cat combo. I just thought I could be even happier if I gutted it - but not quite.

 

Ya there is a hissing sound for sure especially if you have a high flow intake as well. But when you punch it there is a combo of hissing but as well as rumble. Not obnoxious but really nice. The intake will make more noise than the Y-Pipe. If you wanna keep the noise down I would say go with Y-pipe and Oscai conversion. I love the sound of the Y/intake.

 

With the OSCAI, the Y-pipe is all rumble with a little bit of hiss. My Max definitely sounds mean as hell. I like it a lot, but the local constabulary might not.

 

i don't know, but mine doesn't sound like anything!!
it just sounds like i have the intake but not the y-pipe..
many people thought that i only had the intake and no y-pipe....maybe i got the fluke..but mine just doesn't produce much sound...

 

I wish I could have made a recording of the inside of my car before and after my Y-pipe was installed. I mean it's MAJORLY louder with the Y-pipe. But I'm hoping the Magnaflow resonator will take care of that.

 

Obviously the y has a much greater impact on sound where the remainder of the exhaust is not still stock. With my stock exhaust, there is little difference at idle with the y - most of the difference is at WOT and even then I think it is a much intake as Y.

 

Well the resonator definitely helped. The car is still more aggressive sounding than before the Y-pipe was installed, but at least I can hear myself think now.

In another post, Desert Pearl suggested that if you intend to modify your exhaust system, you BEGIN with the Y-pipe. I definitely second that. A Y-pipe may not make a big difference in the sound pressure level of a stock exhaust system, but it certainly did on my aftermarket setup. If I were to recommend a specific approach to modifying your exhaust, I'd suggest you proceed from the front of the car rearward rather than from the rear of the car foreward like I did.

 

With regards to the sound, I have the stock cat-back setup and at idle the car is dead silent with the y-pipe. There is some slight hissing/buzzing because of the pipe though. I got rid of most of it by shaking the cat and flex joint, but there is still one bee left in there. I may try to header wrap the flex joint to se if that works....

 

If anything, I kind of like the "hissing" sound. It's not very loud and it lets me know that the Y-pipe is busily at work making horsepower I didn't have before. It certainly isn't what I'd refer to as "bees in a can". When I think of "bees in a can", I think of a buzzing sound akin to what I used to hear when one of my exhaust manifold bolts was missing and exhaust gasses were escaping from around the flange when the engine was cold. Now THAT was buzzing!

 

Finally got around to posting pics of my Ooglie Cali to Fed spec conversion. This is not something I'd recommend doing. Check out the links in my sig.

 

Cool, sleepermax. Just to make sure I understand, this is a complete how-to on a mod nobody should do, right?

 

the pics look good. Looks like the Stillen pipe still had some issues with the fit. On my Cattman pipe, it turned out that the fit was a little tight on the front flange, but everything seemed to line up fine. What kind of b-pipe are you using? The cross member that is just behind the cat does not seem to be doing anything for me. The stock b-pipe sits a couple inches above it. Anyhow, I have driven with the new Y-pipe a bit now and it seems to be getting quieter. Perhaps the flex joint is breaking in....

 

You got it. I know there's plenty of us who have thought about doing this. Like I said, you do gain top-end but lose some low end torque. I wanted to post it because there are several useful tips/ideas particularly regarding the Stillen Y install, lowering the front crossmember, and extending the O2 sensor wiring in case someone wants to replace the front manifold with a Fed spec manifold and do a Cali/Fed conversion the "right way". I think this would eliminate some of the issues I came accross.

 

It's just a custom B pipe I had done at a local muffler shop. I later had them install a glass pack resonator reduce the sound some. I think the cross member, for the most part, is just there as a precaution to hold the exhaust pipes in case the hangers fail or something else like this happens. Although the screws and cross member itself seem pretty heavy duty so this made me wonder if there also is some rigidity function to it.

It'll continue to get quiter - mine still seems to be settling in but now I think I'm going to look to sell it and go back to the stock Y! We'll see.....

 

Hey Sleeper nice work on your site! I had a question for you? Regarding the cross member piece how long of bolts did you use (with the 5 washers) when you replaced the stock ones? Five washers must have given you a lot of clearance for sure? Do you know the size of those bolts off hand?

Thanks!

 

Thanks PhatGuy. I think they were 1/4" to 3/8" longer. I couldn't find them anywhere at Home Depot or Lowe's ect (with the correct thread). So I went to a local shop that specializes in nut/bolts and got them there. Initially I tried 4 washers but the B pipe was still hitting it every now and then. Five did the trick!