CR 427 parts availability?

[rbgray1]

Originally Posted by MaSnaka

A retune will be in order with better exhaust. But I'm sure everyone already knows that.
I used Classic Chambered for my muffler upgrade. Sounds better too.
John

MaSnaka,

I'm getting ready to order from chambered exhaust replacement mufflers(30") to replace the mufflers on my CR1 1990 build. Did you go with packed or unpacked? Slight concern for me because the car will be kept in a gated Florida community when I'm done rebuilding it and I'm a little concerned about upsetting too many of the neighbors late in the evenings.

Not sure how much if at all the outer packing around the muffler tube will restrict power (look at the pics on Classic Chambered's website), but just predominantly deaden some of the harsher sound.

[moore_rb]

Originally Posted by rbgray1

Not sure how much if at all the outer packing around the muffler tube will restrict power (look at the pics on Classic Chambered's website), but just predominantly deaden some of the harsher sound.

Correct - packing does not reduce performance in a glasspack - it simply reduces noise.

The first time I re-did my car's mufflers, I shot some video to compare the sound of the stock CR mufflers, versus the 30 inch glasspacks:

[ame]https://www.youtube.com/watch?v=rLjC3GdzjHU[/ame]

[rbgray1]

Originally Posted by moore_rb

Correct - packing does not reduce performance in a glasspack - it simply reduces noise.

The first time I re-did my car's mufflers, I shot some video to compare the sound of the stock CR mufflers, versus the 30 inch glasspacks:

https://www.youtube.com/watch?v=rLjC3GdzjHU

Moore_rb,

Thanks for the response. I noticed from your video that there is a small bracket just past the collector to mount the front of the exhaust to the frame. This attachment point doesn't exist on my original CR 1 design. Maybe explains why I kept breaking the rear mount on the side pipes (triangular bracket with three holes near the turndown). I welded up a beefier steel plate bracket that no longers breaks. My plan is to completely rebuild the side pipes with new Classic Chambered packed tubes, new turnouts, and fabricate new brackets before I send of to North Carolina for Ceramic Jet Coating.

Did you add this front mounting bracket or was it part of your original kit? Or thinking more about it, is what I see on your video just past the collector an O2 sensor for your EFI?

BTW, sounds great! My concern is I have a stroked 351W, larger than normal cam and the engine dynoed at 442 HP when my engine builder tested in on the dyno. Even though it's still technically a Small Block, the sound with the stock CR mufflers is very loud. More than enough power (if you can ever say that) for this lightweight car. Hell, my 2010 C6 Vette has 434 HP and it's a blast drive and weighs almost 1000lbs more.

[rbgray1]

Originally Posted by rbgray1

Moore_rb,

Thanks for the response. I noticed from your video that there is a small bracket just past the collector to mount the front of the exhaust to the frame. This attachment point doesn't exist on my original CR 1 design. Maybe explains why I kept breaking the rear mount on the side pipes (triangular bracket with three holes near the turndown). I welded up a beefier steel plate bracket that no longers breaks. My plan is to completely rebuild the side pipes with new Classic Chambered packed tubes, new turnouts, and fabricate new brackets before I send of to North Carolina for Ceramic Jet Coating.

Did you add this front mounting bracket or was it part of your original kit? Or thinking more about it, is what I see on your video just past the collector an O2 sensor for your EFI?

BTW, sounds great! My concern is I have a stroked 351W, larger than normal cam and the engine dynoed at 442 HP when my engine builder tested in on the dyno. Even though it's still technically a Small Block, the sound with the stock CR mufflers is very loud. More than enough power (if you can ever say that) for this lightweight car. Hell, my 2010 C6 Vette has 434 HP and it's a blast drive and weighs almost 1000lbs more.

Moore_rb,

I watched your video again and realized the piece I saw just past the collector is an O2 sensor. Thanks again.

I am still wondering if anyone else has ever had a problem with the this rear bracket breaking? I triple checked all engine mounts and trans mounts and all are good. Just the massive force on hard launches causes enough flex in the sidepipe to break the thin bracket material. I'll TIG together some new ones from thicker guage steel when I remake the pipes. Also interesting is that I only ever broke the driver side rear bracket.