Hi,

I recently purchased an '05 coupe midpipe to replace my '04 6MT midpipe. I will be doing the install tomorrow. I have a couple questions for all the midpipe gurus out there (yes I have searched):

1. I have seen varying reports on gasket usage. Do I need gaskets at either end of the new coupe midpipe, or just one of the ends, or none at all? I ask this because I installed an HKS muffler last week and there was no gasket on the original joint between muffler/midpipe sections. I simply unbolted the stock muffler pipe, then bolted up the HKS pipe w/out gasket.

2. Am I correct in thinking that I will need to bend a heat shield & alter a crossmember(?) to allow for clearance issues? Most reviews indicate that the heat shield bend is a must, but the other piece that interferes is unclear.

3. I know it will be tight, but is this mod possible with only jack stands under the car (without a hydraulic lift)? When I installed the HKS muffler I basically
lay underneath the car with no jack at all - it was a royal pain, but I did it.

4. Are the bolt studs welded onto the front Y-pipe flange, or onto the midpipe flange (or no studs at all, bolts only)? When I put on the HKS muffler I had to use new bolt hardware to replace the studs that were welded onto the old muffler flange.


Thank you in advance...

 

I installed a G35 midpipe on my sedan using a lift at my friend's shop so I had a pretty good view of what had to be altered. The heat shield had to be bent slightly by hand, nothing major, about an inch. That takes a minute.
The bolts are the toughest part, especially the ones towards the cat. Use some WD40 and spray them every ten minutes for at least an hour. That might not solve the problem. I ended up getting out of those nut removers from Craftsman. The other side wasn't that much of a problem and everything fits into place nicely.

I later changed to a 06 midpipe since I didn't like the sound of the coupe midpipe too much. I did that on jack stands. One of the bolts next to the cat got "welded" again so I had to use the nut remover again. Obviously, it's harder when you are laying underneath the car but I did everything in one hour. Taking the nut off takes the longest.

 

1) New gasket for both front and back. HKS should have came with a gasket (different than OEM which is an O-Ring Coupe in back and some flat gasket for the front). The HKS comes with a thicker flat gasket.

2)Heatshield bend with hand, Driveshaft safety bar can remove and move up one bolt or hammer it with a mallet. Bends better if the metal is heated up as well.

3) Mine was done on jackstands. Bolts were a PITA to remove, heat was required and one bolt was cut off.

4) Bolt welded on Y-Pipe. Nuts attach on midpipe side.

 

^ awesome guys, thanks. the wierd thing about the gasket is that when i took off the original muffler last week, there was no gasket between the exhaust pipe and the sedan midpipe. the parts were original, had not been touched or tampered with to my knowledge. so i simply bolted the new HKS pipe up to the old midpipe and left it at that.

i just phoned the local dealer and am going to pick up new front and rear midpipe gaskets for the install tomorrow. i guess it's always a good idea to have them, i just found it strange that no gasket was on the original connection. i didn't look at the Y-pipe connection to see if it had one...

 

I installed an 05 coupe middy on my 03 sedan with just jacks. didn't used a lift at all. So it can be done.

As said before, the bolt WILL take some muscle to get off... I actually ended up snapped one when I was doing it. It was ok though because I ended up installed an HKS muffler later on.

Gasket should be used at either end. The OEM gasket from the y pipe to the midpipe will be re-used and the middy to the HKS should have one between them. The HKS came with a gasket, but like you said you didn't have one and you are picking them up. Use both of them on either side.

The heat shield takes all of 10 second to bend. I just took a rubber mallet and bent it a little with a couple taps and it's completly clear.

The install is pretty simple and straight forward. Took me about 2 hours only because of the bolts being difficult to get loose and the bolt being snapped. I ended up having to drill out the welded bolt attached to the OEM muffler and buy a new bolt washer and nut to bolt it all up. But like I said, I ended up installing an HKS about 3 weeks ago so it doesn't matter lol.

Goodluck with the install man. you will LOVEEEE the new sound you g makes with this setup. I've had this set up on my car for about a month and haven't gotten sick of it at all. I've gotten so many compliments and I still drive with the window down to hear it even though it's 15 degress out lol. Goodluck man.

 

installed the middy on saturday. wow - the combo of it and the HKS mufler really liven up the exhaust note. it sounds great, although we will see what rear passengers have to say next time i have someone back there.

 

lol glad to hear the install went well and you like what you hear.

I remember when I first turned the key after I put the hks and coupe middy on. I was in amazment.

anyone know a good Y pipe to pair up with this setup???

 

None. No verified dynos that they actually make power. What will happen though is you'll introduce some nice rasp.

 

you got a soundclip or anything I can hear? Not sure what you mean by rasp. Kinda like the m3 sound? I know it's crazy to compare lol, but my friend on my streets got an m3 and at WOT it sounds like a rasp.

You think a y pipe is worth it? I'm always up for better/more sound. But not lookin for a rice sound

 

What is the purpose of the midpipe mod?

 

mainly sound and weight reduction

 

you lose ~40lbs with the coupe midpipe - and that's always a good thing. and yes, the sound is great...