Only 117 mph ? Why

[03mara300b]

Ok, I have only had my 03 MM about 2 mos now. I read that it is speed limited from the factory for 117 or 118 mph max. Why ? The Mustang GTs are limited way higher and even the CVPI is limited to 129 mph ? Suspension and tires are not an issue. The only thing I can think of is because of the 3.55 rear. The CVPI has a 3.27 rear. Could the concern be vibration form the difference in gear ratio? Any way not that I will be at or above 118 mph ,but have been to 105 mph only for a few seconds on the test drive. The salesman was not along for the test drive to irritate me with dumb questions. Awsome having a Marauder now !

[ts-pa]

Here (http://www.mercurymarauder.net/forums/showthread.php?t=5163) is a good expaination and solution.

[CRUZTAKER]

Ts-pa's link spells it out.

The driveshaft has potential to resonate. Resonation damages the the entire driveline from tranny yoke to gears.

Easy fix.;)

[sabtaj1]

Yep. He is correct. At 140mph with 4.10 gears you get a good vibration on ur butt. LOL!

[Blackened300a]

some do, some don't

[rayjay]

some do, some don't

Yep a buck 35 and climbing and no vibration. Then I remembered I was on S rated snowtires, oops...

[Wagonmaster]

[quote=03mara300b;524665]........even the CVPI is limited to 129 mph ? Suspension and tires are not an issue. The only thing I can think of is because of the 3.55 rear. The CVPI has a 3.27 rear.quote]

As a side note CVPI's are available in both 3.27 and 3.55 rear gear ratios. One is limited to 129MPH the other is limited to 125MPH respectively due to the different gear ratios. There has been documented cases of CVPI composite driveshafts coming apart @ high velocities, thus the speed limter in these applications. My X-Calibrator tuned Marauder...ahem, has reportedly been to 143MPH w/o any vibration with a stock driveshaft, but thats not to say it wont during future endeavors ;)

GT

[ROB502]

Mine was cutting back at 123mph but since the tune Ive been 132mph.:banana2: The 92vette only goes 155 before the vss can't read any higher because the digital speedo starts blinking.:eek: Still climbing but no read out.

[Marauderman]

Mine was cutting back at 123mph but since the tune Ive been 132mph.:banana2: The 92vette only goes 155 before the vss can't read any higher because the digital speedo starts blinking.:eek: Still climbing but no read out.

Dang..I like your comments....but where u from????????????meaning ..where in SC ????

[ROB502]

Graniteville. You know where that big train full of clorine gas crashed :eek:and killed so many. Aiken county. 11 miles from where they play the Masters Golf in Augusta GA.:lol: golf i hope I never get that old...

[Vortech347]

145 down hill on my GPS with 3.73's giving it all she's got trying to keep up with a convoy of 500hp mustangs.

It vibrated from 80ish till 120ish then it was REALLY smooth. I think the Gov is there to keep the senior's from going to fast. :lol:

[sailsmen]

What is a more likely scenario that the laws of physics only aply to some Marauders or some cannot feel the vibration?:confused:

Better yet just have the drive shaft balanced, those balancing weights reduce the load and increase the torsional rgidity.

If you believe that try rubbing some Viagra on the drive shaft before the 100+ mph activity. Warning you may see blue, if so slow down.;)

[illwood]

What is a more likely scenario that the laws of physics only aply to some Marauders or some cannot feel the vibration?:confused:
There are probably some stock driveshafts that are balanced decently stock just because of manufacturing variation.


Better yet just have the drive shaft balanced, those balancing weights reduce the load and increase the torsional rgidity.
Balancing won't increase the torsional rigidity. That is a physical property based on the Modulus of Elasticity of the material and the O.D./I.D. of the shaft. Driveshafts are essentially torsional springs. Balancing weights prevent the driveshaft from vibrating like a guitar string and change the frequency response function of the driveshaft.


If you believe that try rubbing some Viagra on the drive shaft before the 100+ mph activity. Warning you may see blue, if so slow down.;)
LOL! :lol:

[fastcar]

I had mine up against the governer a lot of the time back from Atlanta. No vib at 119.
Since then, I did put on a tune, and now it will go all the way, but I haven't tried it yet. Hmm. You got me real curious now:D

fastcar:burnout:

[Kennyrauder]

That's why a metal metrix driveshaft is the way to go with a loop for extra safety. Best Regards Kennyrauder.

[Texas Boy]

so a tune will allow it to go all the way to 140?

[Blackened300a]

so a tune will allow it to go all the way to 140?

It eliminates the speed limiter so you can run all out until you run out of either gear, rev's or road.

[rayjay]

It eliminates the speed limiter so you can run all out until you run out of either gear, rev's or road.

or cojones.... :D

[Taemian]

Ok then, I guess my first mod for my bone stock MM will be the SCT tuner. Limits---begone!

[fastcar]

Ok then, I guess my first mod for my bone stock MM will be the SCT tuner. Limits---begone!

That's a good first step. Best bang for the buck: tune, gears and 3500 RPM PI torque converter. You do those three things, and you are probably looking at low 14 second time slips.

fastcar:burnout:

[sailsmen]

My best time DR Tune, 4:10 & UD was 14.274 / 2.168

Best + 3,000 PI & DR Cobra exhaust was 13.743 / 1.966

[fastcar]

My best time DR Tune, 4:10 & UD was 14.274 / 2.168

Best + 3,000 PI & DR Cobra exhaust was 13.743 / 1.966

Unbelievable! I love 13 NA MMs. You and 300A are my heroes. ;)

fastcar:burnout:

[Marauder]

I've had it up to 125 after the tune. No major vibrations but it was only for about 30 seconds.

[High-C]

Has anyone found the ceiling with 4.10's... I am curious where we run out of revs/gear... OD on/off etc... Maybe I'll have to do some late-nite research.:rolleyes: