Ok guys i have spent about 2 hrs reading different things on programers and i think im about to buy a diablo.But i have a few questions and would like some of your input on.The first on is i kind of screwed up on the wifes 1999 F-250 with a 5.4 she needed tires so i took it in and had some put on well while i was there i asked the guy is there anything bigger that would fit and fill the wheel wells in and of course the answer was yes and i bought them.The truck had a 245/75/16 stock now it has a 265/75/16 BFG all terrains.I figured it out and these new ones are a little over a 1 inch taller well this hurts me because we have a 30 ft travel trailer plus my enclosed Race trailer.I noticed the truck shifts threw the gears pretty fast and if you stand on the throttle it wont let the rpms climb it will shift around 4000 or so i think.Im sure the tire issue has something to do with it.The truck has always had trans fluid changed and filters so im not worried about that and it has a trans cooler on it.I also notice some spark knocking with a heavy load on.She runs 89 in it all the time.What do u guys think of a diablo with this truck and the issues im having.Thanks guys

 

The Diablo will help power considerably, and will allow you to change the speedo calibration, plus adjust the shift points. However, if you're getting spark knock under a heavy load with 89 (or even 87) octane something is wrong and needs to be addressed (the tuner is not there to fix problems).

 

wait a minute.... I am having trouble with changing the speedo calibration on mine... I just got a predator for my 2001 5.4L SCrew and I am running 315/75R16's and when I go in and change settings it seems to accept the changes as it writes to flash memory BUT when I check it with my GPS the speedo is still off... took it to the stealership to get it re-flashed to original stock just in case there was another tuned program in there (what a waste of time and money that was) and when I used the predator and changed several parameters using different tire rpm's and axle ratios the end result was the same... the speedo is still off as if I had not installed anything. I do notice a difference in performance especially during shifting at high rpm's and I also have seen a slight increase in gas milage but not much (I just replaced my fuel filter, could be as a result of this) so I imagine that the pcm or ecu knows of the changes just doesn't display them at the gauge.... has anyone else had similar problems?

I tried tech support at diablo sport and wasn't too thrilled with the response I got which only leaves me with the tiniest of urges to send the unit back for a refund but the only thing holding me from doing so is the overall performace of the unit... thats why I would like to know if this is a common problem OR only limited to me and my vehicle or maybe a defective unit or something along the lines.

[truck speed 55mph = GPS speed 59mph, truck odometer reading 1.0 mile = gps odometer 1.12 mile] this is irregardless of whether it is tuned or not

 

You can change axle ratio and also tire revs...on the tire revs you have to do a calculation (I think).
I had a 90 bowtie and if you reved the engine the spedo would jump and the odometer would roll up.

 

I had the same calibration problem with the Predator on my '99 Expy 4x4. I had the stock tire size for an Eddie Bauer (265/70/17) but when I first added the tune the speedo was off by 3-4 mph (checked with a GPS.) After a frustrating and mostly uninformative call to Diablo, I was able to divine that the Predator's tune is based on a standard XLT setup, which has smaller tires and wheels. After playing around with the tire revs and axle ratio settings and confirming with a GPS, I was able to get the speedo back to proper calibration. Lots of trial and error!

When I installed larger tires (315/70/17 for any of you guys searching for info on larger tires on a stock truck–works like a charm!) the speedo calibration was a problem again. I found a tire rev calculator to determine the revs per mile and entered it into the Predator tune but that put it off by 6-7 mph! After more playing with the speedo calibration in the tune I was able to get it just right. I think it would be pretty hard to get it right without the GPS or a friend on the highway with a cell phone.

 

I finally got the problem solved. The folks over at Diablo Sport e-mailed me a custom tune that I uploaded to the predator. I then reprogramed the ECU with the custom tune and now the speedo calibration is right on the money with that of the gps... I like the predator unit overall but dislike the fact that I can't do everything like they claim I can like changing RPM shift points, live data streaming to PC and turning off top speed limiter.... just to name a few.

 

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I have never tried a Diablo but I have a Hypertech Power Programmer and can tell you that I love being in control of just about every part of my truck. It is very time consuming. I can't feel much of a difference but the 0-60 time is shorter. I am looking for a cheap dyno so I can try it out to know just how good it is.

 

Was the download a custom tune or just an updated firmware I think j is the latest out. If it was a custom did they charge anything?

 

What other performance mods are available aside from the Diablo? I see people talking about a chip so I presuem they are available, but where from? What's the diference and are they better then a Diablo? Are they more expensive?

 

www.motorhaven.com for a large selection of chips and tuners.
They both accomplish the same thing, the differences are that tuners allow you to modify the tune that is supplied and come with a diagnostic code read. Diablo has both chips and tuners, and there's SCT and Superchips as well.

 

Supposed to have part throttle shift point adjustments now, but I can't find it anywhere. I just updated to the r52M update.

EDIT- Nevermind. After being told twice by Diablosport directly that it would allow MPH shift point adjustments for part throttle applications, they now say that it will not aloow these adjustments. Very disappointed about this, 2 different guys said it has this option, then the first guy comes back and says that it doesn't. Bummer.
I'm still pleased with the throttle response and other adjustablities that I have, and would recommend this unit to anybody, I just wanted to keep it from shifting into 2nd so soon under light throttle.

 

My Hypertech allows me to change the shift points from 4500 to 5500 and anywhere inbetween. To get off the beaten path here has anyone read about the Hyperpac??? It's like the G-Force $200 deal but better. It sounds like can read anything that is possible to read. the only thing is is that its $800 for any vehicle Ford, Dodge, or Chevy.

 

I am expecting my Predator in tomorrow, I have a 5.4L V8 F350 with Gibson headers, free-flow cats, dual Flowmaster 4", and a K&N filter. Do you think I will require a custom tune to get the most out of the Predator, or will the tune it comes with be pretty close? Do they charge for custom tunes?

 

The Predator recommends to use 91 octane fuel but what if I use a higher grade fuel? I run 98 octance however 93 is available.

And what about temperatures? Typically the temperatures over here are in the low 20C but in the summer months (June - Sept.) it can get as hot as 48C!! Does this effect the Predator at all?? Although I have not experience any issues related to the hot temperatures, should I do anythign to the truck to help it run better in these hot temperatures particularly when I add a Predator?

Thanks