Might be right IDK. Hope not, as I can floor it in N and it will stop right away. But I have ran my truck over 5grand in drive before on accident :roflmao: about 5400 I think.
lly bent valves
- Thread starter 05greendmax
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Might be right IDK. Hope not, as I can floor it in N and it will stop right away. But I have ran my truck over 5grand in drive before on accident :roflmao: about 5400 I think.
Holy ****balls!!! 5400???? Ive seen low to mid 4s but ive onlt seen above 4500 on built sled dedicated pullers. Lol thats winding her up all right. What was the accident if u dont mind me asking?
It was something dumb I don't remember exactly what it was. But I was testing a rev limiter and I put it in 4x4 low so it would go up in rpms faster than 2wd so I didn't have to hold it there as long. Rpms went up quick driving around the house and they kept climbing lol. I obviously didnt have it set right. But anyways I saw 5 grand for a sec and kept going just alittle bit more at a time cause I was curious lol. I don't think I saved that log, I believe I was just displaying the data at the time. I will chevk tomorrow though, hope I got it.
EDIT: maybe I thought it had a limiter, but in reality it didn't at the time. I think thats it, and I was testing the shift points... That sounds right to me, I think?
EDIT: maybe I thought it had a limiter, but in reality it didn't at the time. I think thats it, and I was testing the shift points... That sounds right to me, I think?
Fwiw i run 4200 rpm sled pulling stock heads still zero issues still ticking 
also ive accidentally put ky truck in third and ran to the 8th were i hit my 4500 rpm limiter still no issue my heads have 242k on them to
also ive accidentally put ky truck in third and ran to the 8th were i hit my 4500 rpm limiter still no issue my heads have 242k on them to
:driving:
well arnt u lucky iwish i could post my pics on here of how bad my valve realy is.....
it just crazy how much stuff i f- ed up on my truck on the stock turbo and fuel system at the time i guess im hell in wheels
Fwiw i run 4200 rpm sled pulling stock heads still zero issues still ticking
well arnt u lucky iwish i could post my pics on here of how bad my valve realy is.....
it just crazy how much stuff i f- ed up on my truck on the stock turbo and fuel system at the time i guess im hell in wheels
i couldnt tell you how many times i hit 4850 on stock heads! My valve springs were shot after 4 years of that though!
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Matt I'm still really really confused why you have spent so much time trying to fix this motor and all the mechanics that have worked on it when you could of just bought a used/junkyard lly and threw back in it and been done. Then part your motor out to recoup some of the money. Cause your not "building a motor" really just head studs is all your putting in it. Sorry I'm just confused by all this because it has been going on for like a year!
imo mark a built motor can blow up to .....its 13k just to have your bottom end built thats nuts i beat my truck to death and yes its been almost a year without my truck
i personally messed up from the get go not taking it to caleb yes i know this now should a woulda coulda
but im in now im to far into it to pull out now i was in a big rush to figure out what was wrong and came to bite me in the ass every step of this whole process
and to awnser your question y i didnt throw a junk yard motor in it is because there isnt a single motor in any junk yard around me that i could get for a decent price they all want 8 k plus thats stupid ill pay 3k no more if its in a junk yard it proly been beat harder then mymine has
i personally messed up from the get go not taking it to caleb yes i know this now should a woulda coulda
but im in now im to far into it to pull out now i was in a big rush to figure out what was wrong and came to bite me in the ass every step of this whole process
and to awnser your question y i didnt throw a junk yard motor in it is because there isnt a single motor in any junk yard around me that i could get for a decent price they all want 8 k plus thats stupid ill pay 3k no more if its in a junk yard it proly been beat harder then mymine has
Fuel limit enable 4000rpm
Fueling re-enable 3950rpm.
Works well on my trucks. Its great for when the honders at the local meets decide to have a 2 step battle. Bouning off 4k in a duramax shuts them up real quick.
Fueling re-enable 3950rpm.
Works well on my trucks. Its great for when the honders at the local meets decide to have a 2 step battle. Bouning off 4k in a duramax shuts them up real quick.
I don't see how that makes any sense.. if the computer isn't telling the injectors to fire then how is the fuel "already there" To climb above the limit?
When you are under a large load and using all the power, it is dumping fuel in, when in an instant, you have no load, there is fuel still there. Go try it, bet it goes past your 4k limiter :thumb:
so what youre saying is that there's residual fuel left in the cylinder that re ignites on the next revolution? I'm just trying to figure out where this fuel is coming from if not the injectors?
Your right. Not gonna argue. If you want to look at a log when it is commanding 0mm3 at 4200 but revved out to 4600 let me know. That was just on a nasty flare. Break an input and see what happens.
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A long explination
The computer does shut off the fuel, and the injectors do (or should) stop firing immediately; however, you can still over-rev if the load suddenly disappears.
Here's the (long) reason why:
First, it takes some time before the computer shuts off the fuel. These computers are smart, but not super smart. They don't see the RPM increasing wildly and shut off the fuel before redline, like a (impossibly superfast) human would. The computer simply does what it is told and holds full throttle until the RPM actually gets to the limiter, THEN turns off the fuel.
Once the fuel is turned off, there are still 1 or 2 cylinders that were in the process of firing, and the already-injected fuel has to burn. Remember, we are already AT redline when this happens. This is at least 80 mm^3 per cylinder, and a LOT more on tuned trucks. If you look at a log of a truck in neutral, it doesn't take much fuel (30 mm^3 or less) to hit redline with no load, so even a couple cylinders at 80 - 200 mm^3 will spin it past redline in very little time. The more power you make, the more you'll overshoot redline.
And finally, the engine has not only kinetic energy (it wants to keep turning), but an applied impulse that was accelerating it. That impulse does not immediately disappear when fuel cuts off. Though realistically, I suspect this doesn't contribute significantly compared to the second point.
Hope that explains why and how you'll overshoot your specified redline if you break something.
The computer does shut off the fuel, and the injectors do (or should) stop firing immediately; however, you can still over-rev if the load suddenly disappears.
Here's the (long) reason why:
First, it takes some time before the computer shuts off the fuel. These computers are smart, but not super smart. They don't see the RPM increasing wildly and shut off the fuel before redline, like a (impossibly superfast) human would. The computer simply does what it is told and holds full throttle until the RPM actually gets to the limiter, THEN turns off the fuel.
Once the fuel is turned off, there are still 1 or 2 cylinders that were in the process of firing, and the already-injected fuel has to burn. Remember, we are already AT redline when this happens. This is at least 80 mm^3 per cylinder, and a LOT more on tuned trucks. If you look at a log of a truck in neutral, it doesn't take much fuel (30 mm^3 or less) to hit redline with no load, so even a couple cylinders at 80 - 200 mm^3 will spin it past redline in very little time. The more power you make, the more you'll overshoot redline.
And finally, the engine has not only kinetic energy (it wants to keep turning), but an applied impulse that was accelerating it. That impulse does not immediately disappear when fuel cuts off. Though realistically, I suspect this doesn't contribute significantly compared to the second point.
Hope that explains why and how you'll overshoot your specified redline if you break something.
ojk just got the truck back and wow im disappointed egr delete did nuthing at all to lower any egts then i put the lml manifold on that did nuthing as well im just out of things elese i ncan do to lkower egts 70 mph im at 900degs thats way to high im thinkin i have a boost leak