Rear Diffuser
Burning Brakes
Joined: Oct 2001
Posts: 983
Likes: 23
From: Northeast Ohio
One step forward, two steps back. My previous midmounted magnaflow exhaust setup droned too much for as much as I drive the car. Sounded great but was too much to enjoy the car. I went back to the original catback that came with the car which has 6" dia mufflers under the trunk and hang below the bumper cover...
So now I'm in search of a stock Ti catback which seems to be able to tuck up nice and high while providing a drone free sound.
This video shows the fitment of the stock catback very well and should work well for what I want to do with the diffuser:
https://www.youtube.com/watch?v=VDTnM5R751A
So now I'm in search of a stock Ti catback which seems to be able to tuck up nice and high while providing a drone free sound.
This video shows the fitment of the stock catback very well and should work well for what I want to do with the diffuser:
https://www.youtube.com/watch?v=VDTnM5R751A
Drifting
Joined: Jun 2010
Posts: 1,944
Likes: 48
From: CT
I am still working with someone to make an axle back system that's quiet enough and I plan on using some "kool mat" to protect the important bits in the rear but here's the carbon fiber diffuser I made. It has a radius on the leading edge so it can be adjusted up and down without creating a lip to trip up the air in the throat
Last edited by 383; Aug 3, 2019 at 09:31 PM. Reason: added images
Drifting
Joined: Jun 2016
Posts: 1,325
Likes: 325
2020 Corvette of the Year Finalist (track prepared)
C7 of Year Winner (track prepared) 2019
I am still working with someone to make an axle back system that's quiet enough and I plan on using some "kool mat" to protect the important bits in the rear but here's the carbon fiber diffuser I made. It has a radius on the leading edge so it can be adjusted up and down without creating a lip to trip up the air in the throat
Very much considering that. Not a lot of c7s with full aero
Racer
Joined: Oct 2012
Posts: 314
Likes: 61
Drifting
Joined: Jun 2010
Posts: 1,944
Likes: 48
From: CT
I did. I ran an aluminum version with fewer strikes and had great flow attachment and was able to run less rear wing but the aluminum reflected so much heat my transmission would "burp" fluid on really hot days and that made me nervous, so I pulled it. When I design an over axle kit to go with this diffuser I'll have some strategically-placed coolmatt.
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Racer
Joined: Oct 2012
Posts: 314
Likes: 61
I did. I ran an aluminum version with fewer strikes and had great flow attachment and was able to run less rear wing but the aluminum reflected so much heat my transmission would "burp" fluid on really hot days and that made me nervous, so I pulled it. When I design an over axle kit to go with this diffuser I'll have some strategically-placed coolmatt.
Drifting
Joined: Jun 2010
Posts: 1,944
Likes: 48
From: CT
Racer
Joined: Oct 2012
Posts: 314
Likes: 61
I am assuming you are doing that to have more clearance for the elevation of the diffuser. You can just divert the exhaust out the sides of the rear fenders and that provides enough clearance for the diffuser (at least it does on my C5Z). No need to waste energy fabricating something complex. I have also seen it done on a C6.
Last edited by C5Z06CE; Aug 5, 2019 at 12:10 AM.
Le Mans Master
Joined: Jun 2016
Posts: 5,446
Likes: 4,006
From: Cincinnati, OH
Anyone with updates? I've began the "cardboard template" stage. Still trying to figure out a streetable exhaust and diffuser design that will play well with each other. Custom boom tubes on a C5Z with custom baffles internals would allow very thin "mufflers" with tips only 2"x10" wide. That could sit above the diffuser.
If I had the ***** like C5Z06CE above I would cut a hole in the bumper for side exhaust
If I had the ***** like C5Z06CE above I would cut a hole in the bumper for side exhaust
Racer
Joined: Oct 2012
Posts: 314
Likes: 61
Anyone with updates? I've began the "cardboard template" stage. Still trying to figure out a streetable exhaust and diffuser design that will play well with each other. Custom boom tubes on a C5Z with custom baffles internals would allow very thin "mufflers" with tips only 2"x10" wide. That could sit above the diffuser.
If I had the ***** like C5Z06CE above I would cut a hole in the bumper for side exhaust
If I had the ***** like C5Z06CE above I would cut a hole in the bumper for side exhaust
Le Mans Master
Joined: Jun 2016
Posts: 5,446
Likes: 4,006
From: Cincinnati, OH
That means bidness!I’m not as fancy as CF so I was thinking to use 1/8” “alumacorr” “alumalite” or known as Aluminum Composite Material (ACM). Basically thin sheets of aluminum sandwiching a nylon plastic core.
Somewhat hesitant if I do a blown diffuser style and if the plastic core would melt.
C5Z06CE, any issues with the exhaust damaging the painted bumper being that close?
Racer
Joined: Oct 2012
Posts: 314
Likes: 61
That means bidness!I’m not as fancy as CF so I was thinking to use 1/8” “alumacorr” “alumalite” or known as Aluminum Composite Material (ACM). Basically thin sheets of aluminum sandwiching a nylon plastic core.
Somewhat hesitant if I do a blown diffuser style and if the plastic core would melt.
C5Z06CE, any issues with the exhaust damaging the painted bumper being that close?
Racer
Joined: Oct 2012
Posts: 314
Likes: 61
I used similar stuff and have described what I used in other posts. I have gone into detail before. Sorry to be so vague but just search my prior posts. I just cant bring myself to list all the things I did AGAIN.
Le Mans Master
Joined: Jun 2016
Posts: 5,446
Likes: 4,006
From: Cincinnati, OH
I was able to get on a lift and spend some quality time with cardboard and have 80% of the layout/look completed. With my side panels basically touching the rear bumper cover on the sides allows for a 4" diameter muffler to still have an air gap to the trunk and diffuser.
FYI for those curious. If you come horizontally back from the rear cradle 5.5" to come past the swaybar) then angle up with a flat panel until the panel will contact the c5 trunk, you CAN have ~21* of diffuser angle. Which seems like A LOT if a "functional" one is around the 12* range. This has the trailing edge of the panel about 2" from the raised section of the bumper cover where the tips usually sit.
FYI for those curious. If you come horizontally back from the rear cradle 5.5" to come past the swaybar) then angle up with a flat panel until the panel will contact the c5 trunk, you CAN have ~21* of diffuser angle. Which seems like A LOT if a "functional" one is around the 12* range. This has the trailing edge of the panel about 2" from the raised section of the bumper cover where the tips usually sit.
