CRG Discussion Forum
Camaro Research Group Discussion => Originality => Topic started by: aaronz28 on April 26, 2009, 03:50:44 PM
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hi, got a Sept69 build Z28.
currently have Gardner Chambered on it, but I want to put the correct system on, which I read to be the transverse with resonator system per Jerry's book.
Are there any documented cars built much later than the official change over that did not have resonators?
i'm only asking becasue I want my car to be as correct as possible, but would rather not put the resonators on.
car currently has headers so it isn't a big issue at the moment, but i plan to do some showing this summer and if I take the headers off, i'm gonna put the correct exhaust back on.
Thanks
Aaron
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The configuration of the OE exhaust system was coded on the chassis broadcast sheet box 198. Very few of these sheets exist; mostly it is the body broadcast sheet found in LA built cars. I have data showing 4 LA Z/28s all with "FM" systems spanning mid-January through April builds. A July Norwood Z/28 had "FS". There are no physical markers to indicate which exhaust system a car was built with.
The standard 1969 Z/28 exhaust system was initially the noisy & restrictive chambered set up. With small tubing, 4 mufflers and lots of bends it doesn't get much worse. When the noise complaints started to mount as of November 25, 1968 it was dropped as standard equipment. Owners that had been ticketed for excessive noise could have the system replaced at no cost. The interim replacement system was the single transverse muffler with no resonators much like the 67-68 Z/28 "deep-tone" dual exhaust system. This was also used in production for a short time. The Chevy recall notice goes on to state that by "approximately April" all Z/28s would be built with the muffler/resonator system and those that did not have resonators should be retrofitted. The problem with the April date is the undercarriage photos of the 02D-built ZL-1#3 that appeared in a 1969 road test. The photos show the muffler/resonator system; other than the manifold pipes the system is the same one the Z/28 used. This indicates the resonator system was available in assembly plants much earlier than the notice states.
Based on the dates Chevy stated in the notice and what has been learned over the last 40 years it is virtually a certainty that a September 1969 built Z/28 would have had the muffler/resonator system with chrome tail pipes.
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William,,
The FM denotes which system.
I have "FM" in the block 198 of my remaining portion of the sheet found on top of the tank from my 04C-LOS "Z11"
Jim
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William: I'd suggest that 'magazine road test cars' are not necessarilly representative of autos that are 'right off the assembly plant lines'.... :)
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ordinarily, I'd agree with this statement, but the ZL1 he is referring to is a well documented car and clearly lends credibility to this topic. Additionally, that car was right off the Berger Showroom floor.
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The #3 ZL-1 Camaro was not a 'magazine road test car'. It was ordered for stock by Berger Chevrolet along with a number of other COPO Camaros. It was delivered to them and remained in their inventory for some time. HP Cars magazine was looking for a ZL-1 Camaro to test and Berger agreed to it. The test was conducted in MI of course and the barren trees in the background of the dragstrip photos indicate the test was conducted early Spring 1969. The car still exists in original condition and there is no reason to think it was anything other than a production 1969 Camaro. Curiously, with a body number lower than the #1 ZL-1 it has to be the first one ordered.
I am aware that some of the magazine road test cars were supplied by the zone and may have been massaged a bit. Pontiac was notorious for this-the famous Car & Driver '64 GTO actually had a 421. Chevrolet doesn't seem to have messed with their zone cars at all and may have not been all that co-operative as other magazine Camaros had to be supplied by dealers. The L89 SS-RS PHR featured came from a dealer as did the Z/28-RS HP Cars did.
Car & Driver asked for and was supplied the Ultimate Ringer-a '68 Z/28-RS with JL-8, K-66 and a cross-ram. Despite street tires and 260 lbs over the SCCA minimum weight it managed to turn lap times at Lime Rock that would have qualified it for the middle of the starting grid for the T/A race there. Probably not a production 302.
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Hi William, you've been a wealth of information as has this entire site. Anyway, I have a 1969 Z/28, 05A Los Angeles build date from which I saved the chassis broadcast sheet (or most of it!). In box 198 I see the letters "FQ". Anything special you can tell me about the correct exhaust system it came with? Thanks.
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An 05A Z/28 could have had chambered [optional at the time] or the standard muffler/resonator system. It is close to the introduction date for chrome tailpipes but not close enough. The Z/28 with the 'FS' system would almost certainly have been equipped with the muffler/resonator/chrome tail pipe system. The codes may have changed for engineering revs not visually apparent. There are so few Chassis Broadcast Copies researching them is futile.
Thanks for the kind words. After 34 years, still not tired of it!
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For what its worth the number 1 and No. 2 ZL1's have an FS designated exhaust system on their build sheets.
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Would part# 3961396 be the correct muffler for the standard exhaust system?If not what would 3961396 be correct for??Thanks
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Would part# 3961396 be the correct muffler for the standard exhaust system? If not what would 3961396 be correct for?? Thanks.
My Chevrolet P&A has this description for part #3961396...
3.701 MUFFLER ASSEMBLY, Engine Exhaust
69 CHEVY, CAMARO w/ dual exh. (exc. H/Per., Sp. H/Per.)
Paul
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The FM denotes which system? Jim
In box 198 I see the letters "FQ". Anything special you can tell me about the correct exhaust system it came with? Thanks.
FM and FQ are both codes for the standard SB dual exhaust system.
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Would part# 3961396 be the correct muffler for the standard exhaust system? If not what would 3961396 be correct for?? Thanks.
My Chevrolet P&A has this description for part #3961396...
3.701 MUFFLER ASSEMBLY, Engine Exhaust
69 CHEVY, CAMARO w/ dual exh. (exc. H/Per., Sp. H/Per.)
Paul
Thanks Paul.I guess that would rule out L78 and Z28.
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Thanks Paul. I guess that would rule out L78 and Z28.
Yup.
Paul