Hello folks,

So as the title states, i got 3.73 gears and MPT tune. Night and Day difference in the car really.

However, At full throttle, full flow, the car goes till 125mph approx and then it seems like there are no more gears and the car doesn't go any higher than that.

But, cruising mildly, i can reach even 135-140mph.

I have no idea if the 3.73 gears is causing this or the MPT tune. I have tried to contact them, but they have failed to try to fix it.

Do you think going to another tuner company, will fix the problem?

I actually don't even know what the problem is or what this is called :/

Help me

 

All my MPT tunes are set to 125mph limit for some reason. I think it is for 'legal' reasons, but i don't know.

When i (you) load a tune, go through the setting for things like tire size (revolutions per mile) idle rpm etc. You'll see on the speed limit setting it will be set at 125 mph. Set that to "OFF" and you'll be able to top out to one million mph

 

I went over the tune revision with MPT 3 times and the speed limiter was removed from the very beginning. That wasn't the issue.

I think MPT has not/cannot tune past gear 4-5/speed 120+

Im sure it's a tuner issue. I wanna know if anybody else has experienced this with my setup. (373 gears + mpt tune)

 

I've ordered 3 MPT tunes with the 'Speed Limiter Removed'. All 3 MPT tunes had the speed limiter set at 125 mph. As i load the tune, i go through the settings and set the speed limiter to 'Off'. I have 3.73 gears and my Mustang pulls very strong to 135 mph, this is where i let off because my wife got scared and started praying

 

I ordered a 93 performance tune and wow! What a great performing tune! However I've not driven it that fast to see if I have this particular issue. They're just aren't any places around here that are safe to cruise around at 140+ MPH. I have every confidence that my car wouldn't stumble however.

I noticed that when I loaded the tune, the setting for the speed limiter had been removed. I contacted MPT and they told me they remove the limiter and there are no constraints on top speed other than the RPM limiter. It seems that many people are mistakenly thinking that the SCT Tuner device's 125 MPH default limit, is the limit for the tune. It isn't. That is the firmware default limit for the SCT handheld. The actual limits for the tune have nothing to do with the default display. This is why they now disable the DISPLAY for that user option. It has nothing to do with the setting in the actual tune as it arrives to you. I don't believe they're trying to limit performance at all.

I've had 3 custom tunes on my 2014 now. I can tell you that MPT is remarkably impressive compared to any other I've tried.

 

I have MPT TUNE and 3:73 gears and she pulls amazing up to 140 mph. Never had any issues with it slowing down.

 

Agree.

 

I hope your not sucking in air from somewhere. Vacuum leak will burn a piston, 'fast'. I had a small hole in one of my hoses from my catch (oil separator) can. Made my Mustang run like crap. I would be checking your throttle body spacer if i were you. Maybe remove it and see if you still have the top speed problem

 

Thanks guys. Appreciate it!

 

I see you are running an aftermarket one piece driveshaft. Anything over 105 and my car vibrates violently from the driveshaft. Would recommend a splitter and spoiler for those runs. I have many upgrades to do to push past 120 safely. I don't think MPT would limit the speed like others have said so check your options in the tuner itself.