LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Why is everyone scared to rev past 6K with heads/cam cars?

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Old 10-03-2006, 07:47 AM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

Originally Posted by bunker
At 7k I'm only making about 5rwhp less then 6600 where my peak is more less of 420rwhp sae.
I am willing to bet that many people rev well past their HP peak similar to what you stated above. It must be the wow factor or something.

If you are only losing 5HP by extending your revs by 4K I would certainly argue whats's the point and why is it worth the risk?
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Old 10-03-2006, 08:34 AM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

Originally Posted by wrd1972
I am willing to bet that many people rev well past their HP peak similar to what you stated above. It must be the wow factor or something.

If you are only losing 5HP by extending your revs by 4K I would certainly argue whats's the point and why is it worth the risk?
So your RPM's don't drop as much and put you out of your powerband. If you shift where your power peaks your just going to drop way out of your powerband on your shift. My car peaks at 6-6100 but I shift at 6500 because it holds the power flat all the way out there. I never drop below 5K in my car when I'm racing. So do you shift yoru car at 5300 since thats where your power peaks?
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Old 10-03-2006, 08:36 AM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

we spun the stock bolt on motor to 6400+ on the top end, it liked it!
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Old 10-03-2006, 08:42 AM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

H/C Sprayed Stock Bottom on a 175 Here, 106Kmi bottom end Revving to 6800, lasted 2 1/2 years until Cyl #1 Dropped a valve seat..... Bottom end was perfect though..... Shame
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Old 10-03-2006, 08:46 AM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

I shift @ 7k.
Stock bottom end I shifted @ 6500.
I spun 2 rod bearings in the burnout box.
Now I have shiny forged stuff.
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Old 10-03-2006, 06:14 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

Originally Posted by wrd1972
I am willing to bet that many people rev well past their HP peak similar to what you stated above. It must be the wow factor or something.

If you are only losing 5HP by extending your revs by 4K I would certainly argue whats's the point and why is it worth the risk?

Originally Posted by speed_demon24
So your RPM's don't drop as much and put you out of your powerband. If you shift where your power peaks your just going to drop way out of your powerband on your shift. My car peaks at 6-6100 but I shift at 6500 because it holds the power flat all the way out there. I never drop below 5K in my car when I'm racing. So do you shift yoru car at 5300 since thats where your power peaks?

Please notice that I said WELL PAST their peak. "WELL past" implies around 500+ RPM, I never said to shift at peak HP, how did you interperate this? Maybe I should have been more specific.


My car performs best if shifted at 5800 RPM after about a 5450 RPM peak HP. I think you missed the point of my post. I have read that many people are reving all stock headed and cammed with bolt-ons at 6300 RPM.

I am very well aware that you dont shift at peak HP but many get obsessed with higher RPM's that are well out of their powerband.

If you are truly peaking at 6100 RPM I would tend to think that 6300 RPM would be closer to being your optimum shift point, of course I dont know your car and dont have a dyno chart to go by.

Last edited by wrd1972; 10-03-2006 at 06:25 PM.
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Old 10-03-2006, 06:24 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

you should only shift to the next gear when you would be making less power in your current gear then your next.
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Old 10-03-2006, 06:26 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

My combo peaks around 6500+ and probably pulls all the way to 7k but I have my limiter set at 6.7k shifting at 6.5k or so. 95000 miles on a stock bottom. Never a single issue with the motor, ever. If it lets go, it lets go but I doubt it'll ever come close to doing so before I rebuild it. Stock bottoms are pretty good for what they are so rev where your combo makes power and dont worry about it. Just take care of your engine and it will return the favor.
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Old 10-03-2006, 07:11 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

i shift at 6500 and have taken it to 6700 on a couple shifts while racing my buddy's z06.

this is on motor, on the spray i will still shift at 6300-6500 lol

stock bottom end here, but only w/ 40K miles on her.
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Old 10-03-2006, 07:33 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

i usually shift around 6700
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Old 10-03-2006, 07:49 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

i rev my 94z to 6800 rpms on a stock tack witch is probibly more like 6500 rpms if the tacks off like every 1 says.. 135000 miles on bottem end fresh topend but takes it no problem....zooom zooom zooom
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Old 10-04-2006, 10:04 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

Originally Posted by wrd1972
I am willing to bet that many people rev well past their HP peak similar to what you stated above. It must be the wow factor or something.

If you are only losing 5HP by extending your revs by 4K I would certainly argue whats's the point and why is it worth the risk?
Exactly!!!!
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Old 10-04-2006, 10:43 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

Very true.....Just about every stick car I've been for a ride in...the owner is almost always reving it too high inbetween shifts.....and then many of the other guys are just guessing where they shift cause their still using the stock tach.........also, for the other fellow that was saying that there's not much difference between a two bolt block, and a four bolt block....well nothing could be further from the truth.....if you could see how much the main caps move around on a two bolt block at 6000rpm's compared to a 4 bolt block, you wouldn't believe it(Im talking like a night and day difference).....this movement and excessive harmonics can directly lend itself to MANY engine failures.....it's just that many guys don't know enough to link the two...................Joe
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Old 10-04-2006, 10:58 PM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

I'm thinking it's because of the horror stories of people spinning a bearing. They seem to automatically think it's the rev's that killed the motor and not a dirty install.
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Old 10-05-2006, 11:43 AM
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Re: Why is everyone scared to rev past 6K with heads/cam cars?

Originally Posted by steve9899
Would be interesting to plot poster's age vs. recommended redline...


I'd have to completely agree with you on that one. I'm a starving college student so I'm keeping my car below 6200 RPMs -- the longer the factory short block will last the better.
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