2006 mustang v6 auto, diablosport predator JLT tune 93 octane, firm shifts.

Wondering if anyone else has noticed a weird dip in their RPMs occurs about 1sec. after the 4-->5 shift at WOT, happens at exactly 104mph and 3600rpm every time. Has showed up on every data log, RPMs drop from about 3600 to 3300 with no change in pedal position. rev limit and speed limiter are off. It's weird because the car continues to accelerate and gain speed even though I can feel (and see on the log) a noticeable drop in RPM. Has this happened to anyone else? What parameter would correct this on the Predator?

also I hear a ton about SCT tuners but not much about Diablosport (got mine cheap so can't complain too much) anyone know if the email tunes are better than canned on the tool? Who writes/emails tunes for diablo? I'm running a canned 93 octane firm shift tune right now, but would like a bit more throttle response and change some of the shift points...

 

How many miles? Had a similar issue on our 2001 F350 V10 Dually except it was at around 2800-3100 rpm, especially noticable under heavy load. The answer turned out to be having the injectors cleaned and flow-matched, not the simple stuff at a local shop, but remove, clean, match, and re-install.

 

Could it be the car going into TC lockup? Not sure if it would do that at WOT but it seems to be a logical explanation for the slight dip in RPM.

 

Hey guys, @silverhorse my car is '06 with about 65k miles. I'll look into getting injectors cleaned, etc...is that only a shop job or can it be DIY?

@07...hmmm that's an interesting possibility as well...when I overlay "torque converter turbine speed (rpm)" it looks normal (no weird dip) but the "desired TC clutch slip (rpm)" drops to 0 and the "speed ratio across converter" rises from 0.93 to 1.0. not sure if that means anything to you, cuz I'm new to datalogging and I'm not sure what i'm looking at myself! (I can post an image of the graph if helpful).

 

That right there is your converter going into lockup if I am reading it right. "desired slip" is changing which is the computer telling the trans to remove all slip in the converter. "speed ratio" is showing the difference across the converter. So .93 means that the output side of the converter is spinning at 93% of the input side. when it changes to 1.0 it is the same as 100% where input and output speed match.

So someone correct me if I'm wrong but I think what you are seeing is when the TC going into lockup.

 

ok so if that is the case (and I think it is based on your post) makes sense to me, I wonder if that can be tuned using a hand-held tuner...I have diablosport predator. Or should I just live with it?

 

I'm sure it can be changed but I would have someone who does diablo tunes write a custom one. I doubt you would have access to change it in the file without having the correct software anyway. Becides if it is a canned tune one from a tuner will make you much happier.

 

cool...email tune is that much better from a canned tune? if it's worth the $$ i think i will get one done!

 

Yeah I think if you go with one of the popular tuners for diablo and you only have basic bolt-on mods then an e-mail tune will work great for you. Then if you have something that the car is doing that you don't like most places will make the changes and just send you the update

Give BAMA Tuning a call. I'm pretty sure they can do Diablo tunes, thats who's tune I have and I couldn't be happier.

 

BAMA said they did diablo tunes but don't offer the tunes for life, plus didn't want to mess with my intake set-up....I got Brent at DTP to write me a tune, seems pretty good but haven't had a chance to max out 5th gear yet on open highway (hope no cops reading this I have sent him a few datalogs to help dial in the tune, but I can't get my diablosport to log some of the parameters he needs. I read somewhere an older firmware revision had them, but the newer revisions don't? Weird. Anways time to search the net for an old software update to get the right logs!

 

Try contacting diablo and see if they can help you out with the old firmware or maybe even tell you how to get the info you need out of ur tuner.

 

good call...the new firmware logs most of the same parameters but they renamed a lot of them, so I had trouble finding them at first....also switched from logging with the hand-held tuner only to using the laptop instead, many more parameters available!

 

Hehe thanks for all the help and suggestions everyone. Finally got a nice tune written...took the v6 to the strip and ran 14.83 @ 91.7mph. I was happy esp. since all the HP junkies out there were guessing I'd do 15's Still gotta practice launch some more and fix shift points but should be able to improve that a bit next time.