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#1
01-21-2026, 11:54 AM
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Quieting 9 sec. car
Winter project is to make the 67 more street friendly. My 10.00 index class requires mufflers. I have been running a 3.5" X pipe and flow master FX mufflers (straight thru) dumped at the axel. It is rather loud on the street. When I start the car in the garage wife hears it in the house 200' away. The drone inside the car is extreme.
I decided to add 3" tailpipes with resonators. I made 3.5" to 3" cutouts after the mufflers. Also I made divertors to direct the exhaust to the tail pipes when cutout are capped. Only thing I couldn't find in stainless was the cutout caps so made them out of 1/4" ss plate. Car with the tailpipes is 50% quieter. You can actually talk in the car. No louder than my camaro street car. Neighbors will love it. As soon as the track opens I will do back to back testing with and without tailpipes. |
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#2
01-21-2026, 03:43 PM
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Looks nice ! I like doing exh work.
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#3
01-21-2026, 03:49 PM
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really well thought out with the deflector and the cutouts, i had never seen anyone start the trip over the axle with a cut out. that is brilliant.
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1968 firebird cameo white on red 400 4 speed 1969 carousel red firebird 455, richmond 5 speed 1964 gto pump gas, 505 IA2 EHeads, EFI, 92 mm turbo ice cream getter in process now.... 1970 lemans hardtop, gto clone Atoll Blue 1972 Maverick powered by 2004 gto ls1 and t56 6 speed, 8.8, fox strut front end, wifes car |
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#4
01-21-2026, 05:38 PM
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Nice job!
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#5
01-21-2026, 06:16 PM
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That looks amazing! I like the cut out location and deflector as well, great job!
__________________
1967 GTO 416 5-spd streetcar 11's on HP low 10's 150 shot 1965 GTO 10-71 Littlefield high-helix retro/Bird (untuned) 8.44 @164 3500+lbs 10.5W's SOLD! 1964 421 GP-Sold 6.0 cert. Fiat bodied altered blown alcohol Pontiac IAII-Sold |
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#6
01-21-2026, 07:07 PM
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Really amazed how noisy the roller lifters are when your car is quiet. Must be the link bars.
Was looking into electric cut outs but way to expensive. |
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