Whats the highest rpm you can safely run a stock lt-1
Registered User
Joined: Oct 2003
Posts: 260
From: Wasaga Beach, ON, Canada
I agree that spinning past 6200 is a myth.
When my car was h/c I spun at 6800 all the time with no issues with the bottom end. Mind you I had lightweight valves, springs and retainers used and did regular oil changes every 4500km (3000miles).
Alot of the times I've witness spun bearings is when someone revs their motor to redline numerous times under no load. The oil pump cannot maintain proper pressure.
When my car was h/c I spun at 6800 all the time with no issues with the bottom end. Mind you I had lightweight valves, springs and retainers used and did regular oil changes every 4500km (3000miles).
Alot of the times I've witness spun bearings is when someone revs their motor to redline numerous times under no load. The oil pump cannot maintain proper pressure.
Registered User
Joined: Oct 2001
Posts: 584
From: NC Burlington
sitting still doing burn outs is one thing. a friend of mine had his bottom end put thogether buy this local guy who runs rails . he said doing standing burn outs with no load on the car will spin a bearing quicker than almost anything
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Joined: Mar 1999
Posts: 2,068
From: Kernersville, NC
Interesting you mentioned that....I remember the guys on Horsepower TV took out a bearing on their LS1 doing burnouts too.
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Joined: Oct 2001
Posts: 584
From: NC Burlington
thats why i kind of laugh when i see people doing burnouts. i am not saying it will happen every time. if you keep testing your luck it will go bad sooner or later.
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Joined: Jun 2003
Posts: 890
From: Dayton, OH
You are going to need the extra rpm's with that cam. On most cars, the 503 makes peak power at 5800 - 5900. Mine stayed flat all the way to the mid 6k range. Once I had the right springs in there, I shifted at 6600 all the time and went consistent 11.70's cam only.
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Joined: Jul 2001
Posts: 752
From: Double Oak TX
I don't see why you want to turn it past 5,800 since it slows down if you shift above that point. With some setups, you might go a little higher on the track to avoide an upshift, but in general, the factory limiter at 5,800 is in the right place.
As far as what is "safe", that's always a relative term. Loads go up as the square of rpm. The higher you rev it, the sonner stuff will break. I bet the limiting factor on a completely stock motor is valve float. The springs are pretty wimpy and the valves relatively heavy. Interesting that the LT4 has better valve springs and associated parts as well as lighter valves.
Rich
As far as what is "safe", that's always a relative term. Loads go up as the square of rpm. The higher you rev it, the sonner stuff will break. I bet the limiting factor on a completely stock motor is valve float. The springs are pretty wimpy and the valves relatively heavy. Interesting that the LT4 has better valve springs and associated parts as well as lighter valves.
Rich
Your post got me wondering so I pulled up dyno run #1 from my old 97SS making a whopping 283.5/308.7 with about 300 miles on the car. (Took me a while to make it to the dyno) In looking at the sheet but not doing the math, shifting about 6000 rpm looks about right to me.
Then I pulled up run #1 on my LT4 making 301.1/318.2 and for sure 6500 rpm (used a power program to raise the rev limit to 6500) was the best shift point.
Hey, I know it's hard on parts to take one up pretty high but so is giving one 100% throttle. but shifting mine now (dyno run a thousand and what?) @7200 rpm is like turning up "play that funky music white boy" to my ears. Still enjoy it.
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Joined: Jul 2001
Posts: 752
From: Double Oak TX
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Joined: Mar 2004
Posts: 189
From: Central Cali.
How is there no load doing a burnout? Brakes, tires trying to hook, ect.
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Joined: Aug 2002
Posts: 2,325
From: BC
Limiting friction is the maximum value of static friction, or the force of friction that acts when a body is just on the verge of motion on a surface.
Source: http://en.wikipedia.org/wiki/Friction
I guess the best wording would be less (much less) load while burning out. Also there are standing burnouts and LONG standing burnouts
Im guessing thats what he was referring to.
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Joined: Mar 2006
Posts: 2,307
From: Haverhill MA
Static friction occurs when the two objects are not moving relative to each other (like a book on a desk). The coefficient of static friction is typically denoted as μs. The initial force to get an object moving is often dominated by static friction. The static friction is in most cases higher than the kinetic friction. Rolling friction occurs when one object "rolls" on another (like a car's wheels on the ground). This is classified under static friction because the patch of the tire in contact with the ground, at any point while the tire spins, is stationary relative to the ground. The coefficient of rolling friction is typically denoted as μr.
Limiting friction is the maximum value of static friction, or the force of friction that acts when a body is just on the verge of motion on a surface.
Source: http://en.wikipedia.org/wiki/Friction
I guess the best wording would be less (much less) load while burning out. Also there are standing burnouts and LONG standing burnouts Im guessing thats what he was referring to.
Limiting friction is the maximum value of static friction, or the force of friction that acts when a body is just on the verge of motion on a surface.
Source: http://en.wikipedia.org/wiki/Friction
I guess the best wording would be less (much less) load while burning out. Also there are standing burnouts and LONG standing burnouts
Im guessing thats what he was referring to.
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Joined: Mar 1999
Posts: 2,068
From: Kernersville, NC
Well, let's keep in mind that the LT4 is four bolt mains compared to a LT1's 2 bolt mains. Not sure if it makes a difference, but people don't seem to have as many concerns with twisting up a 4 bolt compared to a 2 bolt.