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Discussion Starter #1
Anyone know the rpm limit of the 2004 explorer motor. Its stock internally. I do have a better driveshaft and torque converter. Im wondering if i can set the rpm limiter to 6300 and be safe on the back end. Thanks
 

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i spun mine to 6100 right after dumping fuel in it...and right after i started it for the first time, even had cut cats and "test pipes" on.
 

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ok thanks. I imagine that it will be fine just to cross the 1/4 mile. Im not revving that high in every gear so i think im good.
 

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My rev limit is currently 6500 on the stock bottom end. Probably a bit higher than it really needs to be.

-Rob
 

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I'm pretty sure the 4.6 is completely safe up to 6500. I think the limiting factor is the stock tc balooning.
 

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you should be fine.....I used to take my stock 95 4.6 and stock tranny, and DS, and TC, up to 63-6400 when I had the nitrous....never had a problem...
 

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Ok, now that we've established that 6,300 to 6,500 RPM is perfectly safe my question is:

How much more power is there to be gained between 5,500 on a stock T-bird motor and 6,500 RPM on a stock Explorer motor?

or even the same motor?

Say, between 5,500 RPM on a stock T-bird motor and 6,500 RPM on a stock T-bird motor?
 

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Ok, now that we've established that 6,300 to 6,500 RPM is perfectly safe my question is:

How much more power is there to be gained between 5,500 on a stock T-bird motor and 6,500 RPM on a stock Explorer motor?

or even the same motor?

Say, between 5,500 RPM on a stock T-bird motor and 6,500 RPM on a stock T-bird motor?
Stock, none. I do not have proof but history shows that a less than mild cam will fall on its face before that time in all the motors I have built. Limiting factors include intake, valves, valve springs, etc. You get the idea.
 

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Much of it has less to do with how much more power you can make in those final 1,000rpms (which isn't much with stock heads and intake) but the fact that you'll be able to be at a stronger place in the power curve in the next gear.
 

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Much of it has less to do with how much more power you can make in those final 1,000rpms (which isn't much with stock heads and intake) but the fact that you'll be able to be at a stronger place in the power curve in the next gear.
I believe you want to shift about 300-400 rpm above your power peak. It kind of depends on your torque curve and gearing in the transmission as well to find the optimal shift point. With my comp 262 cams, my horsepower peak is around 5300 rpms, so I don't necessarily gain anything from going to my 6500 rev limit. I had a few changes in my combo, and never quite got the shift point issues ironed out (I wish I had an Xcal 2 and not an Xcal 1). It did go to 6500 quite a lot, but I would go advertising that it's "perfectly safe." I believe 6200 is the most common number I've seen for the rev limit on the stock bottom end.

-Rob
 

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I believe you want to shift about 300-400 rpm above your power peak. It kind of depends on your torque curve and gearing in the transmission as well to find the optimal shift point. With my comp 262 cams, my horsepower peak is around 5300 rpms, so I don't necessarily gain anything from going to my 6500 rev limit. I had a few changes in my combo, and never quite got the shift point issues ironed out (I wish I had an Xcal 2 and not an Xcal 1). It did go to 6500 quite a lot, but I would go advertising that it's "perfectly safe." I believe 6200 is the most common number I've seen for the rev limit on the stock bottom end.

-Rob
It also depends on the "look" of your power curve as well. For example my 03 Mach 1 hp peaks around 5150 but it stays relatively flat for another 1,000rpms or so and then starts to drop off. Obviously in that situation I don’t actually shift until around 6,500 or so because my hp at 6,100 is pretty much the same as peak. However, if an engine peaks and the power immediately begins to fall off, which is common in 2v’s, yea the 400rpm rule is generally correct. 94TchikinV8 I have no clue what your curve looks like but I’m guessing that it probably falls shortly after peak.. Plus you’re running 262’s which are stockish style cams and really aren’t made to make power much over 5,200 rpms (with stock flowing heads/intake)

Plus I totally agree that taking a Bolton 2v much over 6,500 is a waste and not worth the risk in my opinion, even though it probably wont’ hurt a thing.
 

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Discussion Starter #13
i noticed on my dyno graph that the pi motor seems to keep making power at least another 500-700 past a non pi motor. Just an observation though.

Im wondering for crossing the traps so thats why im asking. 4.30 gears and 26 inch tires makes for some rpm at the big end.
 

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i'll tell ya one thing that I know for sure from datalogging....your car will accelerate even when its wayyy past the HP peak RPM.....obviously it's not gonna be accelerating as much as when you're near the torque peak, but never the less, acceleration is still positive way past the peak....datalogging is invaluable
 

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i'll tell ya one thing that I know for sure from datalogging....your car will accelerate even when its wayyy past the HP peak RPM.....obviously it's not gonna be accelerating as much as when you're near the torque peak, but never the less, acceleration is still positive way past the peak....datalogging is invaluable
So, you're saying that your car will continue to accelerate right up to the point that your motor tears itself apart?

I could have told you that without any datalogging. :tongue:
 

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So, you're saying that your car will continue to accelerate right up to the point that your motor tears itself apart?

I could have told you that without any datalogging. :tongue:


aint nothing going no where when this is put together:










;)
 

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aint nothing going no where when this is put together:

http://i169.photobucket.com/albums/u235/musico79/100_1051.jpg[/IMG]

http://i169.photobucket.com/albums/u235/musico79/100_1009.jpg[/IMG]

http://i169.photobucket.com/albums/u235/musico79/100_1029.jpg[/IMG]

http://i169.photobucket.com/albums/u235/musico79/100_1037.jpg[/IMG]


;)
Bottom end whore ;p
 

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Nice. guitar maestro. :thumbsup: So, how is that project coming?

As if everything in your sig wasn't enough you had t go and buy all that stuff... lol

It can happen, I was thinking more along these lines...

http://forums.tccoa.com/showthread.php?t=110932

And yes, I did read the details of this disaster.
 

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i noticed on my dyno graph that the pi motor seems to keep making power at least another 500-700 past a non pi motor. Just an observation though.

Im wondering for crossing the traps so thats why im asking. 4.30 gears and 26 inch tires makes for some rpm at the big end.
You'd still be under 6,000 with that setup considering you are traping around 104 that will put you around 5,800 at the line with 4.30’s 26 inchers and a 1:1 trans ratio. 6,200 would be 110 and 6500 around 115.



Check this link out it's great for figuring these things out. I've used it a million times trying to figure out if I should do a T-56 swap in my Mach. I love the .5 6th of viper spec trans but the 2.66 1st would kill my 60' too bad they don't make one with a 3.38 1st like my 3650. Oh well


Transmission Calculator

 
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