Experimental Hushpower cat-back exhaust install complete! new video (4/28)

[Mindz]

already posted a video of the cold start this morning with open headers...




Blu808 spent 5+ hours on this exhaust cutting/rewelding/making it perfect. Here's the midway video




And below are the pictures of the final product.

[Blu808]

Fun project on a cool car!

The extra time was really well spent to make everything perfect. How did it sound/drive on the way home?

[Silver2SSRS6spd]

The exhaust install looks really tight with maximum ground clearance. Can't wait to see it in person. It looks like you forgot to connect your post cat oxy sensors.

[Mindz]

The sensors are there and connected. They go above the tranny brace. The video was taken halfway through the install.

Luke, the car drove pretty well on the way home. I thought I heard something like an air leak once or twice, but it sounded like the supercharger spooling up (just starting to at about 2000-2200 rpms) so I don't think it was the exhaust. When I drive it a little more, I'll listen more closely.

No surging/bogging down, although I haven't gotten on it. Overall I'm very pleased with the results.

[Mark Myles]

Originally Posted by Mindz

The sensors are there and connected. They go above the tranny brace. The video was taken halfway through the install.

Luke, the car drove pretty well on the way home. I thought I heard something like an air leak once or twice, but it sounded like the supercharger spooling up (just starting to at about 2000-2200 rpms) so I don't think it was the exhaust. When I drive it a little more, I'll listen more closely.

No surging/bogging down, although I haven't gotten on it. Overall I'm very pleased with the results.

I'm glad to see you installed the Hushpower muffs! You're the only one I have seen with this setup and I for one am VERY interested to see how you like it with headers.

I would appreciate any feed back regarding drone & tone after you've had a chance to drive it around.

Thanks for taking a "hit for the team"..lol.

M

[Mindz]

well the "hit" was the fabrication expense. In order to have this done by Good Guys or the Fest I had to have it fabricated myself. Flowmaster told me this morning that because it's "experimental" and I didn't want to wait for months that I am eating the fabrication expense.

At least I have a one-off exhaust for the hole in my wallet. I'll give you some feedback this weekend after the car is tuned and I can drive it a bit. =)

I'll be taking a cold start video with the exhaust on to compare it to the open headers tonight, and then tomorrow another cold start after it gets tuned.

[KILLER74Z28]

[flowmann]

Originally Posted by Mindz

Since I'm prototyping a new exhaust for Flowmaster, They've sent me two boxes. One containing the cat-back piping for the American Thunder 3" system, and the second box contains the Hushpower muffler axleback kits. Flowmaster prides themselves on creating performance and a tuned sound from stock vehicles. This provides me with 2 issues.

A) The American Thunder 3" cat-back system necks down at the factory connection point, so it won't connect to 3" catted mid-pipes (the very far end tip of the picture. I can't find a better picture)




B) The Hushpower mufflers neck down at the connection point to the cat-back piping (which is 3").



This means 100% that I'll need to cut and weld a 3" stainless pipe at the tip of the piping from the muffler to the cat-back piping. I figure I can make a sleeve or expand the front part of the catback piping to connect to a 3" catted mid-pipe.

Problem solved

With the addition of the Stainless works headers, another wrench is thrown into the plan. The Connection point of the catted mid-pipes now is moved to a few inches in front of the X-pipe. This means that I may be able to Sawz-all the cat back piping right in front of the X-pipe and just use a band clamp to connect the headers to the cat-back piping. Anyone know if this will work or if I need to expand one of the pipes to create a slip fit set up? The band clamps are about 2 inches wide.




That's what I've been contemplating and trying to learn about today as I've never had any experience with installing exhaust.

Any suggestions?

Mindz,

We know you've already installed your system, but this may help other people who may view this thread in the future for help. Congratulations on your great looking install by the way.

We've seen people cut pipes, butt them together and seal with a stainless band clamp as a temp fix for racing, but for a street car, we don't suggest it. Once you cut the pipes for butting together, you can't go back without additional headaches to weld the stainless. For best long term results your best bet is to expand the pipe enough to create a slip fit. Comparatively, butt-tig-welding stainless tubing properly is a real pain, especially on something as big a complete exhaust system.

LSXTV.com has this video and pictures of a Flowmaster Cat-Back install.
http://www.lsxtv.com/tech-stories/ex...a-2010-camaro/

This image shows the pipe reduction so that it's a direct fit to the factory system.

[Mindz]

Well it's butt-tig welded. Hopefully there will be a full cat back kit that includes a slip-fit and proper piping for the hushpower system, even if it necks down at the front to fit the factory piping. If not, I'll have the only one in the world. It'll be a claim to fame since it sounds so nice.

[jagssrsbeast]

I have American racing headers and the flowmaster american thunder. when I rev it up it is loud as hell and when i turn it on i turn off alarms sometimes too ha. It does sound like a tuned exhaust when i put the pedal to the floor. It idle it isnt that loud. It does have some drone but I like loud exhaust

[Jeanius]

Howd the tune go?

[B-rad]

Originally Posted by Mindz

Well it's butt-tig welded. Hopefully there will be a full cat back kit that includes a slip-fit and proper piping for the hushpower system, even if it necks down at the front to fit the factory piping. If not, I'll have the only one in the world. It'll be a claim to fame since it sounds so nice.

I have had a 3" axle back flowmaster system sitting in a box in the corner of my garage for a couple months now. I was planning on connecting them to my 3" exhaust from LG motorsports. Looks like maybe I better open up the box and see if I am going to be in for the same headaches when I do my install.

[Mindz]

Well, the axleback will neck down to 2.5, and it's notched so you won't be able to just "expand" it. You'll need to hack that piece off and replace it with a 3" piece of pipe. That's if the angle of the bend in the pipe will allow it to just mate up to your LG piping. I hope it does. =)

Jeanius,

Tune was pushed back a day and it getting done tonight while I'm here at work. I'm sure you can swing by Newtech and check it out if you want. I think they close at 5pm though.

[Mark Myles]

M