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AWD - Power goes to rear wheels first during launch?

Started by metroplex, December 15, 2017, 04:48:06 AM

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metroplex

I used FORScan to enable the power display that shows where the power goes (front/rear wheels) that is enabled at the factory for the Explorer and the new Fusion Sport (maybe other models as well). I noticed that when I take off, that the power goes to the rear wheels first. The only time I see most of the power in the front is when I am cruising. There's a small sliver of bars on the rear wheels all the time at speed.

Anyone else notice the same thing? I'm just wondering if the RDU clutch system is locking more often than it should.
Previously: 2014 SHO
12.4 @ 110.9 mph

Current: 2017 Fusion Sport

lamrith

My '13 SHO PP is the opposite.  Mostly FWD, the backs start to roll in once it launches if I am on the power a bunch, but normal day to day it is mostly front biased.  Though I notice off the gas coasting or light braking that it is more rear.
'13 Sho PP, SCT x4, AJP 92-Octane rev6 (14psi&20spark) NGK 6510, 3Bar, K&N CAI, PPE Catted DP, Dynomax Axleback, 20*9.5 Voxx Lago w/ 275/40-20 GMAX AS-05.

FoMoCoSHO

I have the gauge enabled in the 15 and it showed pretty much what I always felt.

When you nail it, power moves to the rear initially then moves forward as MPH increases. In the rain with AJPTurbo traction, a 2-1 WOT downshift at 25 would show it dumping almost all the power to the rear.

On the Lincoln, however, it seems the power goes to the front initially and moves to the rear as the fronts lose traction...and it really sucks, lol. There is no gauge but that is the behavior that has been described many times about gen 4.1...I never understood the complaints but now I do. The torque steer is vastly different between the two generation because of this.


Macgyver

So Ford actually got something right from 2014 on thereabouts ?

f8tlSHO

My brother borrowed my laptop and put fordcan on it, and used to to do sync 3 upgrade in his mustang. Can I use it to load this awd gauge you guys are talking about?


Sent from my iPhone using Tapatalk
2013 Non PP Unleashed 93 E20 3 Bar Tune, K&N drop in 12.491 @ 110.96 120's IAT
Now tuned by ajp...looking to go faster
E30 tune on14psi full weight including 2 child seats,race like a real street car.
12.433 @110.8 140's IAT; Mustang Dyno 332hp / 386tq

FoMoCoSHO

Quote from: f8tlSHO on January 14, 2018, 03:47:29 PM
My brother borrowed my laptop and put fordcan on it, and used to to do sync 3 upgrade in his mustang. Can I use it to load this awd gauge you guys are talking about?


Sent from my iPhone using Tapatalk
We loaded mine with IDS

ecoboostsho

Quote from: f8tlSHO on January 14, 2018, 03:47:29 PM
My brother borrowed my laptop and put fordcan on it, and used to to do sync 3 upgrade in his mustang. Can I use it to load this awd gauge you guys are talking about?


Sent from my iPhone using Tapatalk
You can. I just did. There are instructions on the Forscan forum.

Sent from my XT1650 using Tapatalk

2013 White SHO w/PP, Gearhead Tuned, 3 Bar, 160T, Plugs...Mess with the Bull and you'll get the Horn. :)
Previous 2011 Tuxedo Black SHO w/PP - 12.89 1/4 Mile

Gray Brick

I had a torque steer problem when the front / rear tires were inflated drastically different.
2013 Ecoboost Ford Flex
AJP Tune (ATP+2) in progress , Livernois HPFP, 3 Bar MAP, UPR Catch Can, 100% Methanol w/ braided steel lines, 3" Downpipes -->2.5" X-pipe --> 2.5" Magnaflow exhaust, 2.5" air inlets to each turbo with cone filter, Custom water to air intercooler with chiller
275/40-20 Front 315/35-20 Rear Tires
---12.419ET/112.43MPH @ 5150 lbs in the 1/4---

Izzybird

Quote from: f8tlSHO on January 14, 2018, 03:47:29 PM
My brother borrowed my laptop and put fordcan on it, and used to to do sync 3 upgrade in his mustang. Can I use it to load this awd gauge you guys are talking about?


Sent from my iPhone using Tapatalk

Directions here as well.
https://www.ecoboostperformanceforum.com/index.php/topic,6953.0.html
Wife's '15 SHO non PP

Izzybird

Quote from: Gray Brick on January 14, 2018, 11:52:20 PM
I had a torque steer problem when the front / rear tires were inflated drastically different.
I took the wifes '15 out Saturday evening and had a Audi A6 bite off more than he could chew, we were on a very slight curve in the road at about 35 mph when I laid in to it. Torque steer dang near yanked the wheel out of my hands and I looked like some kid yanking the wheel back and forth for fun. After I embarrassed his family and cleaned my undies, I checked the tire pressures. Drivers rear was pretty low. I'm so used to 35" truck tires that I simply didn't notice it being low, and I always do a visual. Think I'll actually check them from now on.
Wife's '15 SHO non PP

djxfactor

I glance at my AWD bias occasionally on my Torque gauges, and have noticed the same behavior...50% or more rear bias when I leave from a dead stop. I also don't granny from a dead stop either, so that may have something to do with it.  :))  AJP Tuned here, as well, on my 14 Flex EB.
2014 Ford Flex Limited AWD EcoBoost - Full Amsoil Synthetic Fluids swap in engine and driveline, SCT X4 Tuner w/ multiple tunes for 93 + Meth, Dash-mount Tablet running Torque Pro Gauges w/ BT Wireless OBD Adapter, 170 T-stat, 3-Bar MAP sensor, Denso 1step Colder Spark Plugs, OBX Catless Downpipes, Magnaflow Downpipe-back 2.5" exhaust system, Magnaflow 2.5" X-Pipe, MDesign Carbon Direct Cold Air Intake (Latest Gen), UPR 3-way Catch Can System, Devil's Own Stage-2 3-Bar Methanol Injection System with custom Tank/Pump mount, EcoPowerParts Black powder-coated Charge Pipe kit, TIAL Q Race BOV in Ruby Red color-match, Power Stop Z23 Brake upgrade on all 4 corners with Drilled/Slotted Zinc Rotors and Carbon Fiber-infused Ceramic Pads with color-matched Ruby Red calipers, Moog upgraded Sway Bar Endlinks, lowered on Megan Racing EZ Street coilovers, SPC Rear Camber kit, Verde Axis V99 Bronze 20x9 wheels wrapped in 275/40 Nexens, Custom forged 4 1/2" spiked one-piece steel lugs, Kicker CompRT 12" Sub in custom spare tire-well box, Polk Audio Carbon C500.1 mono sub amp, All-Fit Front Lip Spoiler, 3D Carbon Rear Wing, Ruby Red vinyl wrapped interior trim, LED-lit "FLEX" Door Sills, Full LED Interior bulb swap, Red LED Accent lighting throughout, SpiderMax 3D Kagu black laser fit floor mats for all 3 rows, LED Puddle Light swap, Tinted LED Tails, Windows Tinted all around.

NITSOOB

Interesting.. it does seem like the rear end squats significantly on launch
2013 PP SHO - 3.5" DPs, 3.5" Exhaust, 3" Coldside
Pending: 5-Blade billet wheel, AJP Tune
1/8: 8.4@86

Vortech347

#12
Our AWD drivetrain sends 100% of the power full time to the front wheels like a typical FWD car.  Then meets a ring gear/ driveshaft setup (PTU).  The rear wheels are driven only after the computer tells a clutch setup just before the RDU when to tighten up.  From what I've read it can only transfer around 150-200ftlbs of bias.

When launching it will lock up the rear as much as it can but the system cannot send nor direct power to/from the front wheels.  That's why they still torque steer like a mother effer, have a delay in rear wheels engaging, and why you'll have wheel spin in the front but not the rear. 

The gauge is just kind of a light show.

Now if you want to feel a REAL AWD launch not a helper system go launch an Audi, EVO, Suby, or Skyline.   All of those will suck the soul out of your chest. My mom's new S5 sporback has about what a stock SHO does HP wise. When you use launch mode it takes off at full boost at 3500rpm. The tires dont make any noises, it stays totally straight, and feels like a mustang on slicks.



Matt H.
2013 SHO Performance Pack, Daily, AJPTurbo tuned
2003 SVT Cobra 497rwhp/491rwtq, Self tuned, Cruiser
1990 Mustang GT 570rwhp/530twtq, Self tuned, Open Track
2017 F150 XLT 5.0

ncole

Whatever it is doing, since there is some discrepancy, I know it sends enough rearward to whip some really nice doughnuts in the snow!  I think a lot of wheel spin in normal driving comes from the fronts and that is simply due to weight transfer.  Take weight off the nose in hard acceleration and the fronts will tend to slip.  So I would safely say it never quite sends all of the torque rearward, and I don't think anyone really thought that.  Having said all that, there is a big difference in being tuned or stock.  Tuned, I have felt all four clawing and chirping (they kind of take turns, not at the same time) in first and then multiple tires chirp simultaneously on the up shift. Stock, you get zero wheel spin on dry pavement, unless you are also turning and then just the inner front might lose grip. I will say tuned that I thoroughly impressed my brother who run high 10's low 11's in an all motor C6 with my launch. It also makes my wife squeal and repeatably tell me she doesn't like it lol. It doesn't however seem to have a distinct pattern like my 2000 Outback did.  When it slipped, I knew which would slip and when it would stop and try another tire. I like that predictability.
2011 black on black SHO.  MDesign CAI, Livernois 93 Stage 4 Plus X RACE 3BAR (running some E85 in to boost octane), 160° Thermostat, Livernois gapped plugs, 3 bar MAP