Is anyone running their truck over 6000 rpms. After I sent my superchip back due to 100mph power problems, I decided to try another chip. I am not saying who makes it, yet. But anyway, the chip has a 6200rpm shift point, only when held in and shifted manually. Just installed it so I cant really give a good performance report yet. I am going to the track Friday to test. Is it unsafe to run above 6000 rpms, the superchip guy said it was. He said the crank could not handle it. But I do know a guy that has this chip and the asp pulley and has not had a problem yet. But I am a little scared to push it that hard. If anyone is running over 6000rpms, or has any input on this topic,please post. Thanks!

99 White
#2163
6-9-99
Airaid
__________ chip

 

The Crank, Pistons, and rod should not (could but not likely) have a problem with it.
But Your valve train will, over reving you engine with cause high dynamic stress amplitude in your valve spring and finger followers. It is likely this will result in a no follow condition for the valves, which can cause alot of problems. You could eject keepers and caps, You could cause your valve spring to set (get shorter and lose load), you could damage your cam, you could crack your finger followers, you could damage your hydralic lifters.

This is a very bad Idea...

I worked in a valve train test lab, in testing we have broken everything in those ways before. 9 out of 10 time your redline is set by your valvetrain. Don't do and be safe.

 

Nevermind your valvetrain, your supercharger would be spinning 15250 rpms, way past its' limit. If your friend also installed the ASP pulley, his Eaton would be turning 16,260 rpms, and will be dust soon!

I would seriously consider not using the chip, and I definately wouldn't believe the person who said they are using both without any problems.

 

If the Eaton supercharger has a 14000 max RPM from Eaton I would think they put a safety margin in there. And also if it ever did reach a higher RPM than rated how long is it there. I'm sure there failure tests run constant RPM not short bursts like we would do. I agree that the valves would be the problem a 6200 RPM. The stock springs probably wouldn't keep the valves from floating at that speed.

 

Not that the valvetrain is not important, but does the lightning 4R100 use a 12"" or 11" torque converter? I seem to remember reading on the supercoupe site that the ford 12" TC, found on the 4R70W will "balloon" after 5400 RPMs and disintegrate shortly thereafter.

 

Scotto,

Eaton did build in a safety margin, which is why the stock application runs 700 rpms below the limit. That is your safety margin. In the applicaton that Caka is talking about, you would be overspinning the supercharger for 13% of the rpm band, and since that 13% is at the top, it's also going to be the slowest going. That being the case, the supercharger will be overstressed for a large part of any acceleration run, time wise.

The supercharger at its' peak will be spinning 14% higher than its' stated maximum, and almost 20% higher than what it was originally intended. To use your logic that high rpms should be ok because "It's not there for long", we should be able to turn our motors up to 6200 rpms, almost 20% higher than their stock limit, because "It's not there long", and we shouldn't have any problems, right?! Wrong!

It's odd how you can believe that it's bad to do that to the motor, but perfectly fine for the supercharger.

 

No company would put there max limit at the failure point. I have spun an Eaton m-90 at over twice the stock speed for years with no problems. The Eaton website has had those limits there since before the Lightning came out. The 14000 RPM limit also has to do with the amount of heat the supercharger will be putting out. Being that our unit is intercooled it would not affect us as much either.

 

Why would you want to run the motor at 6200 RPM when all the dyno test to date show max HP at or about 4800 RPM. There would be nothing to gain. With the automatic shifting at 5500 the tach will drop to about 5000 RPM keeping the truck at or close to it top output. There is no reason to push it that hard.
Also the crank in the 5.4L has a bad shake at about 5700 RPM, and running at this would soon shake it right out of the motor.
I see no reason to push it this hard! Nothing to gain.

------------------
Andre Terranova (1-18-1947)
<*(((><
isa4325@flash.net / "1-BAD-TK" Texas Tag,
Red Lightning / Red Premier Tonneau Cover,
Red Shadow Cowl Cover / SuperChip,
3:73 Gears / K&N Filter,
Edelbrock muffler, Interceptor,
Laptop Computer at Side,
G-Tech,
Best Time 12.986 @ 107.54 "Tweeked to the Max".
[05-11-1999 #1132]
"Certificate on the Wall"


"Only Little Boys Wear Bow Ties"

 

Does a chip control the shift RPM point. That would be a way for people to go that have pulleys and do not want to exceed the max rated supercharge RPM.

 

Scottodog
Yes!


[This message has been edited by isa4325 (edited 02-18-2000).]

 

Superchips set the rev limiter on the Lightning at 5700 rpm in the Superchip Flip Chip for several reasons. Most important, it is at approximately 5820 rpm that there is a harmonic vibration that can cause catastrophic engine failure, Ford SVT knows all about this, and so do a lot of Lightning owners. So it's not a good idea to twist the motor to that point. Now of course it takes some sustained running at that rpm point to generate the forces needed to cause that damage, but there is no sense in taking that risk, not for a street-driven vehicle under warranty. In a racing application perhaps, but not in any other case.

Superchips will not set the rev limiter higher than 5700 rpm on this engine unless the owner gives us a written statement that holds us harmless if any damage results, due to this harmonic frequency point's potential for causing catastrophic engine failure.

Superchips has had Lightnings turning 6500 rpm on the dyno and the motor has lived, but only because it flashes thru that harmonic resonance point very quickly. They recommend that you do not twist that engine higher than 5700 rpm in anything other than a racing situation, where you are deliberately taking risks to achieve a result.

The Eaton blower can take a lot of rpms and survive, provided it doesn't stay there long. Almost any piece of equipment can exceed it's design specs for brief periods, but you're taking a risk when you do. If you are aware of the risks and want to take them anyway, fine, that's an individual decision.

If it were my Lightning, it would never see anything beyond 5700 rpm, there just isn't any need unless it's a true racing situation, but to each his/her own.

Our bests to all,

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Online Superchip ordering system:https://www.f150online.com/scpp/index.html