Really considering this Micro Tuner for my 4.6 4x4 5 speed, but I wonder if I should even remove the rev. limiter and top speed limiter. I have reached the rev limiter twice since new and it seemed to wind out REALLY high, don't know if it's safe to go too much past that. Does the Superchip program completely remove the rev. limit or does it just bump it up to a still safe level? Also, I have Pro Comp AT's in a 33x12.50R17, so I don't know how fast I can safely go with these tires. I have never hit the speed limiter and I have buried 100 once. Felt fine to me, but don't know if I'll ever need to surpass that. Mine must be set to 108. Don't know that I could even reach that though with these new tires. What do you guys think? Thanks!!!

BTW, do you guys have any advice on getting past the sticker shock of going to 91 octane? I spend about $130 a mo. on fuel as it is.

-AR

 

Hi Jackal,

You're gonna wear my fingers out!

All kidding aside, of course the rev limiters are completely different functions from top speed limiters. We don't like to see any engine without an absolute rev limiter at a bare minimum. The top speed limiter can certainly be done away with or raised so high the vehicle could never hit it, it's just up to the vehicle owner to know the speed rating of their tires, so they don't have a tire failure from too much speed. But the rev limiter needs to be intact.

With Superchips tuning, you are always going to have a safe rev limiter. The only way to get us to *remove* a rev limiter (or set it so high that it accomplishes the same thing) is to sign a waiver, that's how strongly we feel about rev limiters.

It does not hurt your engine to hit the rev limiter even with the Superchips tuning, the engine is designed & made to be able to turn that many rpms and more, actually, so we always keep the rev limiters safe. If we didn't, you'd be reading about blown engines left and right here!

The factory absolute rev limiter is very conservative, and we generally raise them, but only a little bit, 300 rpm in the manual-transmission F-150's. We do that so that if they get in a passing situaiton on a 2-lane road, that extra 300 rpm may be enough to keep them from needing to upshift while passing, so they can keep both hands on the wheel & their eyes on the road, we consider that a basic safety modification.

There is also a "no-load" rev limiter, which is in effect when you have the clutch pushed in or are in Neutral or Park (this is true for both automatics and manuals, both have no-load as well as absolute rev limiters). The no-load rev limiter is always significantly lower than the "absolute" rev limiter, to protect the engine against higher rpms when there is no load on the motor.

The no-load rev limiter we do not change (unless it's a custom application say, for a drag car, where there is a need for a higher rpm launch at the drag strip). Most no-load rev limiters run about 4000-4500 rpm or so in these Fords, and we leave them alone, they are there to protect the engine from overspeeding with no load on the motor.

Your engine will still have safe rev limiter with the Superchips tuning. The bottom line is you don't need to worry about such basic things like that, no chipmaker would just remove a rev limiter in their non-custom programs, as that would obviously be an open invitation to blown engines. Very basic, and nobody removes rev limiters like that.

Last, you aren't going to be spending as much more money on gas going to premium with the Superchips tuning as you think, the fuel costs analysis has been done many times. Assuming the national average delta of 20 cents per gallon between 87 & premium, the maximum increase in fuel costs runs not more than $100 per each 10,000 miles driven, & many people have smaller increases.

One of the *worst* things you can do for the performance and fuel mielage of any vehicle is to buy gas based on price, as that only assures getting a lower energy content, which reduces both mileage and performance. The off-brand, no-name and Mom & Pop gasolines are the last thing that should be used. Even some brand names fuels are lower in energy (BTU's), like Exxon, for example. This is true both for performance and fuel mileage, you always want the highest energy content fuel you can get.

 

LOL!!! Thanks again Mike, my reason for posting is so that anyone who knows, can satisfy my concerns, not just yourself. Also, so the next person who may have the same question can do a search. There is so much to these trucks, how do you keep it all straight? Wait, that's another question.

Just when you have time, (never?) please check my "Dyno" thread here in the Chips section. Thanks!!!

-AR

 

Hi Jackal,

You mention the search feature & that's a good point, as you'll probably find that if you actually use the search feature (I've started using it more myself after all this time), virtually all of your questions (and those of a lot of other people, of course) have been asked & answered many, many times before here on F-150 Online. It's somewhat the natiure of the beast, we always have new people joining, and so there will always people who are starting form square one, so a lot of material does get repeated. If everyone used the search feature before asking any questions, we'd probably blow up part of the Internet backbone or something!

Now of course as soon as I say that, you'll come up with something nobody else has ever asked!

I have responded to that other thread in some detail, though I don't have time to go look at those other links, I think that info should give you the answers you're looking for & some other relevant information that should be helpful as well.

Have fun,