SwedeSpeed - Volvo Performance Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
445 Posts
Discussion Starter · #1 · (Edited)
Performance of AWD (with driveshaft removed) vs. FWD....

I recently replaced a 2000 V70SE with a 2000 XC70 SE that has no driveshaft. I had my first opportunity to drive this car in conditions with limited traction, and I'm worried. I can get wheel spin from a standing start, get the tach up around 4,000-5,000 and traction control is not intervening. The car is just spinning it's wheels and generating torque steer. This would have never occurred in my 2000 V70 SE (which had STC, not just TRACS).

Is there something inherently different in the traction control systems of an AWD vs. FWD car?

TIA
 

·
Registered
Joined
·
637 Posts
They should perform exactly the same. I've never had a Volvo with TRACS or STC that would just sit and spin its wheels if they lost traction, so it sounds like something's wrong with it.
 

·
Registered
Joined
·
17,314 Posts
Below 25 mph STC will interfere and independently brake the front wheels to try to create traction. Doesnt work above 25 mph though for obvious reasons. Scan your computer for codes relating to ABS issues that may not illuminate a check engine light. Rebuilt modules are less than a hundred bucks. Can always try a junkyard one too. Throw a switch on the dash to control it as well, the wiring is there behind a dummy cover next to the sunroof rocker.
 

·
Registered
Joined
·
4,477 Posts
If your car doesn't come with the switch on the dash, you can't just put the switch up there and control it I believe. Don't you need a certain ABS module and the switch to make it work?
 

·
Registered
Joined
·
17,314 Posts

·
Registered
Joined
·
6,570 Posts
That's normal. I could spin tires with the driveshaft out, on new tires, in the rain in my old V70XC. However, once I was AWD again I could barely spin tires in the snow. Visco AWD isn't half bad.
 

·
Registered
Joined
·
445 Posts
Discussion Starter · #8 ·
If your car doesn't come with the switch on the dash, you can't just put the switch up there and control it I believe. Don't you need a certain ABS module and the switch to make it work?
I don't have the dash switch - but when I had the STC switch, it only disabled the STC not enabled it. What I'd like is for the TRACS system to actually function, regardless of whether i have the driveshaft installed. I realize that traction will improve 100% with the rears driving too, but I don't think the system is working as it should. I was under 25mph.
 

·
Registered
Joined
·
6,570 Posts
I don't have the dash switch - but when I had the STC switch, it only disabled the STC not enabled it. What I'd like is for the TRACS system to actually function, regardless of whether i have the driveshaft installed. I realize that traction will improve 100% with the rears driving too, but I don't think the system is working as it should. I was under 25mph.
Buy a new propshaft and live happily ever after. The car gets great traction under 25 with AWD because it has a locking read diff... And AWD. The ~200lbs in the back for the rear diff shift the center of mass rearward during acceleration. That takes force off the front wheels and they spin.
 

·
Registered
Joined
·
445 Posts
Discussion Starter · #10 ·
Buy a new propshaft and live happily ever after. The car gets great traction under 25 with AWD because it has a locking read diff... And AWD. The ~200lbs in the back for the rear diff shift the center of mass rearward during acceleration. That takes force off the front wheels and they spin.
I'm going to install a driveshaft by the time the snow flies, but as I said I don't think I should be getting any wheelspin at all whether it's installed or not. My FWD V70 steadfastly refused to do it and if the systems are the same, the XC shouldn't either.
 

·
Registered
Joined
·
17,314 Posts
Your XC has more power and torque than the SE. Enough to make a big difference. The 2.4 block with 13t turbo is a low end torque machine. In conjunction with a different weight distribution because of the added mass of the awd in the rear which is sprung weight, you have much less traction from less weight over the drive wheels and more ability to spin the wheels. Your tires are also on the smaller side as the XC runs 195 65 15 as stock. GLT models which are mechanically the same minus the AWD will spin the wheels. T5 models will do one tire fire burn outs if you're not careful. AWD is the solution as is not stomping on it if you don't want wheel spin. Go for better tires first then wider tires if you're not satisfied after adding the prop shaft.

The opposite is true in the winter. You want the skinny tires then to increase road pressure on snow. Good snow tires will get you 90% of what AWD with snows will. All seasons or anything else will suck in the snow. AWD makes you go when it's slippery ONLY if you can put the power down. Doesn't help you stop though, only tires can help that.
 

·
Registered
Joined
·
4,477 Posts
All true stuff. Someone else mentioned the weight distribution. I just don't think anyone wanted to type that much to explain it to him. Nice!
 

·
Registered
Joined
·
445 Posts
Discussion Starter · #13 ·
I appreciate all the replies, and i get what everyone is saying about having the driveshaft installed. Also, as far as tire sizes go, this is an SE so the OE size is 205/50-16.

I am going to get a set of snows, I have them on all my cars (except the Porsche, hahaha).

I am not interested in doing hole shots with the car either; quite the opposite.

So I come back to my original post: Why, with traction control (undefeatable), am I getting ANY wheelspin at all? How can that be right?
 

·
Registered
Joined
·
17,314 Posts
It's just the reality of the turbo fwd cars. It's going to happen. Unless I am very careful, I chirp the tires without STC intervention on my T5 and that's with a manual, clutch slipping, under 2000 rpm.
 

·
Registered
Joined
·
445 Posts
Discussion Starter · #15 ·
It's just the reality of the turbo fwd cars. It's going to happen. Unless I am very careful, I chirp the tires without STC intervention on my T5 and that's with a manual, clutch slipping, under 2000 rpm.
Thanks Scottish -

This is a little more than a chirp. On a hill in the rain last week I went half way up it with the both fronts spinning wildly, no TRACS light illuminating on the dash. Might as well not even had traction control at all.
 

·
Registered
Joined
·
17,314 Posts
Both? Doubtful. The P80 cars have an open front differential. Spin one wheel it just keeps going. That's why the STC system is there. Should independently brake the wheels momentarily to act as a limited slip diff would. It doesn't in reality. You may have been below 25 mph actual but if the wheels were making revs that the computer thought were too high, no STC intervention
 

·
Registered
Joined
·
63,543 Posts
You're OEM tire size is 205/55/16, NOT 50

If you pop out the blank switch cover the odds of the wiring for a switch should be there, it was in all my 2000 V70Rs.
Buy a TRACS dash switch, connect it up and you will have traction control that can be switched off.
 

·
Registered
Joined
·
445 Posts
Discussion Starter · #18 ·
Both? Doubtful. The P80 cars have an open front differential. Spin one wheel it just keeps going. That's why the STC system is there. Should independently brake the wheels momentarily to act as a limited slip diff would. It doesn't in reality. You may have been below 25 mph actual but if the wheels were making revs that the computer thought were too high, no STC intervention
That makes sense.... I'm going to have to hook it up to a scanner to see if there are any codes it's generating that don't cause a dash light to come on.

JRL - right, 205/55, typo on my part. I'll think about adding the TRACS switch. I can't think of why I'd want to disable it though. I have a driveway that would make a mountain goat blink. Put some snow on it, and I need all the help I can get which is why I'm concerned that TRACS is working correctly, whether I have a AWD or not.
 

·
Registered
Joined
·
2,887 Posts
AWD and good tires will make a LOT
more of a difference than TRACS.
TRACS can help you in marginal
traction situations, but AWD is a
much better all around solution.
 

·
Registered
Joined
·
469 Posts
That makes sense.... I'm going to have to hook it up to a scanner to see if there are any codes it's generating that don't cause a dash light to come on.

JRL - right, 205/55, typo on my part. I'll think about adding the TRACS switch. I can't think of why I'd want to disable it though. I have a driveway that would make a mountain goat blink. Put some snow on it, and I need all the help I can get which is why I'm concerned that TRACS is working correctly, whether I have a AWD or not.
I added mine in (and wrote that article ) so when I wanted to have fun it wouldn't cut power under hard braking or acceleration.

Sent from my SM-G900V using Tapatalk
 
1 - 20 of 27 Posts
Top