3.5" Exhaust Sytem

[GPModJ]

A while back I posted a message asking if anyone had experience with Torque Tech Exhaust Systems in Georgia. Well, I finally got my 3.5" system installed and it seems to fit pretty well.

I've got Hooker Super Comps up front running into the 3.5" system. I've got an "H" type crossover and Flowmaster series 30 17" mufflers. Here's a photo of the tips. I'll post photos of the underside too.

BTW, I recall being warned that a system from Torque Tech might not give all the ground clearance you'd expect. That's probably true for this system. But then again, it's 3.5" and I didn't expect a lot of clearance.

[GPModJ]

Here's the exhaust tips:

[GPModJ]

Here's the view from the axle forward:

[GPModJ]

Here's the view from front to back:

[GPModJ]

And here's a closeup of the bend around the axle. The fellow who did the installation told me there was *no* room for error. That being said, I'm not hearing any banging or clunking back there.

[THOR]

GP, You is a maniac
Love that 3.5 inch exhaust, looks mighty good ;D
how's it sound? Like a proper 5 litre eater ought to ?
With the 3.5, it occured to me that it might sound like a
7 litre eater

[GPModJ]

I'm planning on recording the idle for my car site. I'll post a link when it's up. I think it sounds awesome with the new 468 and lumpy cam.

I'm going to be pretty conservative for the next long while. The work I've done this year has really cost and that's it for a while. I'l probably do some stuff that doesn't cost much until I have the engine / exhaust paid for.

[THOR]

I'm sure it sounds great, look forward to hearing the recording. Post more pics of the gnarly GP when you have a chance or a link to your website as well ;D

[GPModJ]

Hey there,

I've got a recording of the new exhaust system now. Of course, the sound is different depending where you stand in relation to the car but the recording gives a bit of an idea of what the system sounds like. Here's an URL where you can click on a link to open an MP3 file.

http://www.69grandprix.com/index.php?pageID=photos&size=full_size&photoID=7

[THOR]

Hi Kerry,
I listened to the recording. Soundz awesome !
Make sure you plan on coming to Tiger Run, you will have a blast !

[GPModJ]

Thanks. I like the sound too. Can't wait to really get on it once the engine's broken in.

If I hadn't blown up the engine the first time, I'd probably have been at Tiger Run this year. I look forward to next Tiger Run.

[THOR]

Kerry,
How did you record your car's idle ? What type of recorder did you use?

[GPModJ]

I've got one of those mini-disc recorders with a small Sony stereo mic. I just set the recorder on a curb close to the car and set it to record. I used the headphone jack to get the recording to the computer and used CoolEdit 2000 to save the file to a "wav" file and then convert it to an MPG.

You should be able to do the same with a cassette recorder and a decent mic.

[ManicMechanic69]

Hey, I also ran with the Torque Tech system, 3" in my LeMans, did it when I first finished the car when back when I still had some lumbar disc's surviving.....about ......hmmmmmm...I'd guess maybe in '96!?!
I have never had ANY ISSUES with the product :D It still looks and performs fantasticly :!: :!: I even slammed it into the aspault hard enough to colapse the down pipe about 2 years ago( Last yellow I ever ran!!), and the TT pipe was undamaged :!: Had to replace the Bucky's built down pipe and the manifold studs but that was it.
I will be putting TT pipe into the 73-455 TA I am current building, although most likely it'll be the 2.5" kit.
Manic :twisted:

[GPModJ]

Yeah, I'm pretty happy with the system so far. I'm amazed the 3.5" pipes fit and still don't smack anything while I'm driving.

I have to say though, the Flowmaster 30's are pretty loud with the 3.5" pipes. But then again, when is that a bad thing?

[GPModJ]

Here's an update on the exhaust. I've got about 1,500 miles on it now and about 500 or so miles ago I developed a clear rattle. The rattle sounded like it was coming from the exhaust but I couldn't pin it down, as it was intermittent and seemed to last only for a minute or two at idle.

The other day I crawled around beside the car while it idled. It sounded as though it was coming from the inside of the mufflers. Bummer, I thought because the mufflers were new and they seemed to have developed a rattle.

The very next day while cruising home from work, the car suddenly sounded as though one of the mufflers had fallen off. When I got home and looked underneath, the crossover pipe had broken away from the passenger side pipe.

This morning I took it into the place that installed the system and they repaired it in about 20 minutes but it looks as though this will be an ongoing problem if I stick with the existing design.

As it happens, I've got an appointment scheduled with a company called Lejeune Engineering. They specialize in metal fabricating for race cars and do custom exhaust systems. I am having the headers shortened so I have more clearance. Because Grand Prixs have the engine about one or two inches lower than A bodies, the headers don't have a lot of clearance.

Anyway, I'll see if they can put an "x" type crossover in while the other work is getting done. Hopefully, that'll fix the problem.

[THOR]

Bummer GP Mod
I had really good luck with the 3 inch Pypes system from performance years. It's set up to allow a number of installation options and the sound is cool too. Your race exhaust guys can probably make an x pipe system in no time flat but in some cases a ready made X can speed things up.
Let us know how it goes. How's the butt kickin' GP doing?

[ViolentBird]

:D Rite on........... I`d love to see that big fella stomp a stang...

[GPModJ]

Well, everything's sorted out for the time being. Man, you don't realize how many dominoes fall when you do one thing on your car. Talk about the Butterfly Effect!

Lejeune Engineering shortened the headers and they're now parallel with the oil pan and front crossmember. While they were at it, they installed a new "X" type crossover and tucked the rest of the exhaust up as close to the underside as possible. They do awesome work and even solved my header flange leaks while they were at it.

On the down side, when they did the work on the front end of the exhaust, they shortened it up by about 1/2". That meant the rear axle hit the exhaust whenever I drove over a dip of any kind. What made matters worse was the fact the brake lines were routed at the exact spot where the axle was binding on the exhaust.

I smacked the exhaust around over the weekend so I could drive it and took it in to have the tailpipes pushed back half an inch. That's done now and it doesn't bind at all.

Here are a couple of extra things for people to consider if they're thinking of installing big pipes. First, the exhaust is tight up against the crossmember. As the engine moves--particularly when you light 'em up--that causes one side to press harder against the crossmember. Eventually, I'll have to replace the flange gaskets and tighten stuff.

A solution to this would be a custom crossmember--something thinner that allows a bit of room for movement.

Second, I've got adjustable upper control arms in the car. because there's so little clearance with the big pipes, I have to be careful adjusting pinion angle, since adjustment is done at the top of the axle, which moves it back and forth--i.e. closer and further away from the exhaust pipes. If I want less pinion angle, I have to move the axle closer to the exhaust.

Not sure what the solution might be here. Maybe oval shaped exhaust pipes. Lejeune was working on a 1,400 HP Chevy II while I was there. They were installing a $5,000 exhaust system with oval pipe running the entire length to the back of the car.

All that aside, the exhaust note is now downright nasty. It's a bit quieter now but it's deeper. Kinda sounds like that demon Gandalf battles in the Lord of the Rings. I like! :twisted:

[THOR]

Another pesky detail solved. Right on.

I too went from an H to an X setup and at the same time I went from 2.5 inch to 3 inch main pipes. I recall being suprised at the difference in the exhaust note. It has the "big pipe" tone but is quieter with the X. There's a hard to describe sound dynamic with the X as well. ...some describe it as an indy-car type of whine. It even sounds great when you let off the gas after punching it. I could go on about this sound almost like a wine lover does about the richness of a particular red but I'll stop now :wink:

[GPModJ]

Update: The wife isn't a big Lord of the Rings fan and the loud demonic sound coming from the exhaust has got to go. So, today some Flowmaster 50 "Big Block" mufflers go on the car. We'll see if that queitens things down a bit.

I wanted to go with DynoMax Ultraflows but they don't come offset/offset, which is what I need. So, here goes--another experiment in sound science and matrimonial compromise. :)

[THOR]

Let us know how the vroom vroom goes now !

[1PROGTO]

Ear Plugs dude, Ear Plugs!! Alot cheaper than new mufflers.

[GPModJ]

Thor, 1PROGTO:

Yep, ear plugs would'a been cheaper, that's for sure! But the car's quieter and still sounds nasty when you get on it. I'm told, too, that the mufflers aren't supposed to restrict the flow too much so I'm happy there as well. They're big suckers--22" long, 5" deep, & 12" wide.

There's a lesson to be learned here in the end. It would have been much cheaper for me to simply go to someone in the beginning for a custom exhaust system.

- Super comp headers - chopped to gain clearance
- 3 & 1/2" exhaust - chopped & changed to "x" type (broke in the first place)
- FM 50's - replaced

[REED_RACING]

Loud Pipes Save Lives!