Hey Dusty...

"Goggles Pizzano" (gogglespizzano)
03/14/2014 at 18:32 • Filed to: None

Stupid question: What's the benefit of Pre-runners being 2WD?

DISCUSSION (21)

Otto-the-Croatian-'Whoops my Volvo is a sedan' > Goggles Pizzano
03/14/2014 at 18:39

Yes, I wanna know, too.

Goggles Pizzano > Otto-the-Croatian-'Whoops my Volvo is a sedan'
03/14/2014 at 18:40

Thank god the question isn't as dumb as I thought. Thank you. :-)x

Otto-the-Croatian-'Whoops my Volvo is a sedan' > Goggles Pizzano
03/14/2014 at 18:45

Sure. And I know that Robby Gordon kicked some 4x4 Dakar ass, so there's gotta be something to it...

Nibby > Goggles Pizzano
03/14/2014 at 18:47

Saves weight?

Garrett Davis > Goggles Pizzano
03/14/2014 at 18:50

There are a few reasons that I am aware of, but I'm not expert. In no particular order:

Long travel independent front suspension is much harder to do when you have to worry about CV shafts and joints. Having to drive the front wheels really limits travel. This isn't an issue with the rear because they typically run solid rear axles.

That's a whole lot of extra weight on the front end once you factor in a differential, CV shafts, beefier spindles, a drive shaft, etc. Prerunners already do just about everything they can to shift all that front weight to the rear due to how terrible the weight distribution on a truck is.

Generally at high speed, they're doing OK for traction with just the rears. It's when you slow down that 4WD is the most beneficial, and ideally, that's not really an issue with these trucks as they usually have so much momentum already.

I could be totally missing the point here, as I'm more into the rock crawling side of off roading, but that's what I noticed.

Goggles Pizzano > Nibby
03/14/2014 at 18:52

Maybe. What ever reason I think of, I can't help but think it's not a strong enough reason not to go 4wd. Strange eh?

Nibby > Goggles Pizzano
03/14/2014 at 18:54

I'd never buy a non-4WD body on frame truck/SUV.

CRider > Goggles Pizzano
03/14/2014 at 18:55

At 70+ mph traction isn't really a problem. Pre runners use sheer speed to get through the desert.

TheLOUDMUSIC- Put it in H! > Nibby
03/14/2014 at 18:56

I imagine this, and more parts to break. Last thing I want to happen at 80 MPH over some nasty terrain is a driveshaft failure.

Goggles Pizzano > Garrett Davis
03/14/2014 at 18:57

Thanks. What you say gels with Nibby's answer very well. The CV shafts and joints make a lot of sense too.

Nibby > TheLOUDMUSIC- Put it in H!
03/14/2014 at 18:59

Why the hell would anyone go 80mph on anything but pavement?

mazuko1 > Otto-the-Croatian-'Whoops my Volvo is a sedan'
03/14/2014 at 19:08

In Baja all top classdesert race vehicles are 2wd.....4wd is just too front end heavy and ineffective at higher speeds..... The secret to moving fast over rough terrain is to keep the front end light......This is why dune buggies are rear engine configurations. Pre runners are typically heavily modified, yet still street legal vehicles that are used to examine the race course and take notes/strategize for the actual race. The 2wd configuration is preferred because it is simply better for moving fast.

mazuko1 > Otto-the-Croatian-'Whoops my Volvo is a sedan'
03/14/2014 at 19:08

TheLOUDMUSIC- Put it in H! > Nibby
03/14/2014 at 19:27

Kinja'd!!!

Because Baja.

Dusty Ventures > Nibby
03/14/2014 at 21:59

Because its fun! I've taken my truck up to about 105 on dirt and I'm in the stock class. Trophy trucks will go up to 130-140 and do 105 over three foot whoops

Dusty Ventures > CRider
03/14/2014 at 22:03

There's a lot less sheet speed than people realize. Average race speed for a trophy truck is 65-ish, my truck (still RWD) averages about 35-40. 35 is also about the most anyone is going to manage through a proper silt bed, and that's with a hell of a running start

CRider > Nibby
03/14/2014 at 22:12

Oh hell no you did not say that. Tell me you're trolling.

Dusty Ventures > Goggles Pizzano
03/14/2014 at 22:47

Sorry for the delay. I'm on the road transporting the rally car today so I haven't been on Oppo. Garrett and the others pretty much nailed it. Basically it's
1) To save weight, both of the overall vehicle and in the nose. A lighter front end floats the silt beds better and reduces risk of digging in and burying itself.
2) To increase the amount of wheel travel. More travel means being able to carry more speed over the rough stuff.
3) Simpler design and one less thing to break. With 500-1200 miles of racing and up to 100 miles between pits you want to reduce the number of things that can break as much as possible.
4) Tires, power, and momentum. Pre-runners and desert race vehicles spend less time going balls to the wall crazy fast than most people think (the winning trophy truck at any given race will have an average speed of about 65-70 and in some sections of the course will average as low as 10-20), but as a whole slowly slogging through bogs or crawling rock walls isn't really a concern. Furthermore the ridiculously engineered and ridiculously expensive ($500-800 each) tires provide an unbelievable amount of grip on loose dirt and through deep silt. Pair that with 300-1000 horsepower and so long as you don't do something stupid like come to a complete stop in a silt bed you'll be able to power through pretty much anything.

As a note, you don't need a bonkers long travel prerunner for these rules to hold true. My truck has about 300 horse, stock A-arms up front, about 8-10 inches of travel, 2WD, and with fuel, spares, and driver/co-driver weighs about 4600 lbs. If I were to make it 4WD it would be significantly slower and less capable in a desert environment.

Goggles Pizzano > Dusty Ventures
03/14/2014 at 23:53

You Dusty, don't need to apologize for anything. Thank you very much for the in-depth explanation, it's a question that's popped in my mind several times over the last year or so. Cheers!

Otto-the-Croatian-'Whoops my Volvo is a sedan' > mazuko1
03/15/2014 at 06:34

Cool, thanks!