60 replies to this topic

[VS Legend]

A Volvospeed Public Service Announcement

To: All Volvospeed Members and Visitors
Subject: Do Not Try Handbrake Drifting in Your AWD Volvo

In an All-Wheel Drive (AWD) Volvo, power is sent to the rear wheels whenever one of your wheels loses traction, detected by a difference in rotational speed among the four wheels. This is basically true for both viscous coupling and HALDEX-equipped vehicles. Because of this, trying to throw the handbrake (also known as a parking brake or emergency brake) can damage the powertrain if you have a Viscous Coupling system.* Don't let this happen to you. Don't try to drift by using your handbrake. In fact, you probably shouldn't do it even if you don't have AWD. Because I'm pretty sure it's illegal. Like... about 60% sure. And it may damage your handbrake even if you don't have AWD or aren't stepping on the accelerator.

This has been a public service announcement from VS Legend.

On Haldex** vehicles with a manual transmission, depressing the clutch while the handbrake is applied could eliminate the risk of powertrain damage.

But the handbrake on a Volvo is still not designed to be used in this way; damage to the braking system is still possible.

Volvospeed is not responsible for you being an ass and using the handbrake for any purpose other than parking, nor am I.

* Haldex systems are allegedly supposed to be disengaged when the handbrake is engaged.

** Per the discussion below, this probably will not help with viscous coupling-based systems.

[Dan A]

I call bullshit.  I happen to know that Volvo engineered the handbrakes on the XC specifically for this purpose in mind.  In fact "XC" is actually an acronym for Xtreme Cornering.

[Deimos]

VS Legend, on 27 January 2012 - 09:08 PM, said:

On vehicles with a manual transmission, depressing the clutch while the handbrake is applied could eliminate the risk of powertrain damage.

Wrong. If you believe this, you don't know how a drivetrain works.

[JN2k108]

Dan A, on 27 January 2012 - 10:23 PM, said:

I call I'm dumb.  I happen to know that Volvo engineered the handbrakes on the XC specifically for this purpose in mind.  In fact "XC" is actually an acronym for Xtreme Cornering.

Roflmao hahahahaah

[kalvin]

I see nothing in here about FWD Volvos. In that case I shall continue doing handbrake drifts whenever I can.

[s_moneh]

how it is illegal? wtf?

[JVC]

Explain this to me then...



Pull the e-brake, rear wheels are disengaged and can dyno FWD...

[Swag Swag]

Man there are some VS members coming out of the woodwork from like 4+ years ago lately lol

[Oreo931]

Isn't this common sense?

Title should be changed to "PSA: Don't drive like a douche"

You should not be surprised if you do an ebrake turn/drift/whatever and something on your car breaks (or something breaks your car).

[Burn-E]

Yeah, like a curb buried under the snow.

OP, was this court ordered PSA or did you just learn something from sad experience today that you felt the need to confess?

[Deimos]

JVC, on 28 January 2012 - 05:20 AM, said:

Explain this to me then...



Pull the e-brake, rear wheels are disengaged and can dyno FWD...

Haldex might be able to handle that... but if you tried it with a 98-00 your viscous coupling would go pop and you'd really be FWD only.

[Bonus Lane Man]

JVC, on 28 January 2012 - 05:20 AM, said:

Explain this to me then...



Pull the e-brake, rear wheels are disengaged and can dyno FWD...

Remember that I also pulled the Haldex fuse to disengage the Haldex.

[Deimos]

Exactly, the newer AWD isn't full time, the old one was. Not remembering this can make things go boom.

[T5power]

Deimos, on 28 January 2012 - 10:58 PM, said:

Exactly, the newer AWD isn't full time, the old one was. Not remembering this can make things go boom.

what? IIRC older one was definitely not full time AWD. only when it sensed slippage, just like the newer ones. different hardware and software in the later models but general principle was the same. even the newer R's and AWD's aren't full time. maybe the new S60 T6 AWD's are 50/50, but 98-00 R's were the economical AWD, only sending power to the back when needed.

[Deimos]

The 98-00 ones did not have software and were purely mechanical. The only two things keeping it from being a perfect 50/50 front rear split was the viscous coupling, effectively a front to rear LSD, and the free wheel mechanism which disengaged the rear in the event of the rear wheels attempting to drive the propeller shaft, such as in the case of hard braking, to prevent drivetrain damage.

98-00 AWDs, XCs and Rs were like that. Totally different from Haldex.

Hussein and I actually had a conversation on that exact subject recently.

[NEU]

T5power, on 29 January 2012 - 12:16 AM, said:

what? IIRC older one was definitely not full time AWD. only when it sensed slippage, just like the newer ones. different hardware and software in the later models but general principle was the same. even the newer R's and AWD's aren't full time. maybe the new S60 T6 AWD's are 50/50, but 98-00 R's were the economical AWD, only sending power to the back when needed.

The first Gen AWD normally run 95%fr-5%rr power split all the time and when the VC slips it was able to send up to 95% of the power to the rear. I can feel the AWD working all the time and when run my as FWD I can feel the lack of power to the rears... I don't know how you FWD guys do it. Makes me really uneasy and light on the throttle especially in the wet.

[VS Legend]

Just to clear up a few things...

• Not all 2001 and newer Volvo cars with All Wheel Drive were equipped with Haldex.
  
• Volvo cars with viscous coupling All Wheel Drive are AWD full-time... in reverse.
  
• Full-time or not, the rear wheels will usually be spinning slower than the front when handbrake drifting.
  This means power will be sent to the rear wheels, whether you have Haldex or a viscous coupling.

NEU, on 30 January 2012 - 12:27 PM, said:

The first Gen AWD normally run 95%fr-5%rr power split all the time

If you mean the viscous coupling system, this is incorrect. I don't even think it's possible to do this with a viscous coupling system. The second, third, and fourth generation Haldex system does usually send 5% of the power to the rear wheels. I don't remember which Volvo cars have which generation Haldex AWD system off the top of my head. I thought the first one to have this was the first generation S60 / second generation V70 R.

Deimos, on 27 January 2012 - 10:26 PM, said:

Wrong. If you believe this, you don't know how a drivetrain works.

How so? If the clutch pedal is depressed, isn't the engine disengaged from the transmission and thus disengaged from the drivetrain preventing the engine from sending power the those rear wheels? I am not a mechanic (or anything remotely close to one) and don't know as much about how a car works as I would like, but I thought this was one of the things I understood correctly, so I would appreciate your explaining if I don't. I love to learn.

s_moneh, on 28 January 2012 - 05:09 AM, said:

how it is illegal? wtf?

Depending on where you live (in the US, anyway), it's generally considered careless driving, reckless driving, improper use of a vehicle, etc. if you do any sort of drifting on a public roadway or parking. You might even get arrested, depending on what mood the cop is in and if your state laws allow it.

[NEU]

VS Legend, on 30 January 2012 - 09:39 PM, said:

If you mean the viscous coupling system, this is incorrect. I don't even think it's possible to do this with a viscous coupling system.

Yes I do mean viscous coupling system (VC), and 95%fr-5%rr is what a Volvo AWD brochure from '98 I have said it did.

[Rod'sT-5]

Its been about 10 years since I went to Volvo School on the new S60 AWD, so I may be fuzzy on some things. The old style viscous coupling only started to transfer power to the rear when the fluid got hot. That happened from the input spinning, with the output loafing around. It would start to couple with the hot fluid, but never 100% lock-up.

The Haldex system would fully engage (100%) the rear wheels by the time the front wheels would spin 15 degrees,, very fast!
The system would dis-engage with the E-brake. We did that when driving the car at school (it was the 1st S60 AWD car in Florida)

IIRC, there was no proportional engagement, either 0% or 100% engaged.

[s_moneh]

speaking of handbraking, yeaaa its bs in the winter, i've given up hope in atleast trying to get some angle on the 850, its useless so i wont be doin it anymore