Subject: Re: Factory Opti at more than 6900 engine rpm by Aboatguy on 2009/12/21 19:28:24
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LT4BUD wrote: Quote:
Aboatguy wrote:
So what's the highest RPM you've seen on your LT1?
Far as I know the LT4 & LT1 opti's are identical....so 6300 is no big deal as far as the opti goes....limiter on LT4 is 6400 with 6300 redline
On my modded LT4 I am using the stock opti with rev limiter at 6800...mine is not a track car but it has been up to 6700 or so quite a few times with no problem..
Your response is the exact purpose of this thread. Many folks denigrate the opti...however, GM thought it was good enough for 6400 rpm (they always put a fudge factor in too) and most OPTIs last tens of thousands of miles if not hundreds of thousands....not bad for a factory distributorQuote:
Josh wrote: The opti only ever sees cam RPM, not crank RPM, so it's not seeing anywhere near 7K. If it can't handle 3500 RPM's without falling apart, there's something wrong.
A 396 I was part of awhile back saw 7K nearly every day, and for 50+ pulls on the dyno with an MSD opti with no issues.
If you take the MSD unit apart, the insides aren't of any greater build quality than an OE unit. The wheel is still wobbly as hell, and none of the other stuff appears to be a higher quality. I can't see it handling sustanined RPM better than a stocker, but who knows.
AFAIK every mechanical distrubutor on a 4 cycle internal combustion gasoline engine travels at Cam rpm....the point is folks talk doom and gloom and feed into the fix for a problem that doesn't exist. Hence my datalog at as close as I could get to 7K without hitting my fuel cutoff in D/3rd gear.
