Breaking all 4 loose on the highway, 1G AWD.

[bh4000]

Tuning my car Saturday - working my way toward 30psi. I dialed my Hallman MBC to 27psi. I drive out to my spot, go WOT in 2nd gear (auto), and to my suprise spun all 4 wheels at around 65mph. This is a 1G AWD, Auto, making around 550hp and weighing 2500. I've never spun all four on the highway before, is this normal? The car still has a OEM viscous center diff, EVOIII clutch rear diff, so I'm not sure if there is some funky torque split happening. The car has newish Michelin AS3+ tires, 235/45/17. The car stayed completely neutral, but it was unnerving.

The road was dry, maybe a little dew on it, temp was around 70F. The sun was still low and hadn't hit the road yet.

I'm trying to figure out if this is the new norm at this power level, or if I just hit a slick spot in the road.

 

[We're on Boost]

Hmm, well, AS3+ tires at 235 should be good enough. That is better than mine probably. The road surface, if it was a little damp and cold, that could be it. The auto in 2nd gear, I have no idea, I've only ever had a manual in my car.
Anyway, my car which I normally drive at the 550 awhp level, will pull WOT all the way through 2nd gear (manual) without breaking loose, if the road is dry and is not all cracked up. My car is also heavier, it is "full weight".

But you said "The car stayed completely neutral". To me, that suggests that it was only the front wheels spinning. Because my car which has a locked center differential (it has a PPG spool in the center diff) is pretty hard to keep on the road when all 4 break loose. It wants to skew one way or the other as soon as break-loose happens, and I have to be very quick with the correction, or else just shove the clutch pedal in to abort. And if it breaks loose, it is all 4. It has no choice in the matter because the center diff is locked. Or it's possible that it can be one wheel in front and one wheel in the rear that breaks loose. But when you have a limited slip diff at either front or rear, the chances of only one wheel at each end getting loose are less.

Your car with the normal viscous center diff, I'm not sure because my car has never been that way (I had a welded center diff when the car was more stock) but I think it could break loose the fronts without breaking loose the rears. Especially if the dilatant fluid in the center diff viscous coupling is run low or otherwise not limiting the slip like it should. That way your car would stay pretty stable in a straight line.
Do you have a way of knowing that the rears were broke loose in your case?

 

[CrackedDSM]

My edge puts down roughly 350awhp and 450lb ft of torque(on 93, it’s 400awhp on E) as well and I can also vouch that when all four wheels rip it’s definitely not remaining neutral. It likes to kick the butt end out and the front end pulls the other way.


I have worse tires than both of you though. Was honestly probably a bad spot in the road you never noticed before because of a lower power level.

 

[1990TSIAWDTALON]

I put mine in the ditch ass backwards when I broke all 4 loose in 2nd at 34psi.......
It definitely didn't drive "neutral"
Auto car with welded center dif and rear viscous.
I remember thinking "Oh shit, I'll have to get the four wheel drive truck...."
Lmmfao. Backed into the field I was trying to slide into and drove home. Got a video but I won't post it

 

[bh4000]

Thanks for the input so far.

I think for now I will only test once the road is warm. I have abs sensors in the back that I could wire into my data logger, but honestly it would be a lot of work. I don't have abs sensors in the front.

My first thought was to get a set of max performance summer tires, like pilot sport 4s, but then I remember that those crack at temps less than 40f. If it were May I would probably do it, but rolling into September it just doesn't seem like it's worth the effort.

 

[We're on Boost]

It likes to kick the butt end out and the front end pulls the other way.

Yeah, like it wants to rotate. That's the feeling I get when it happens. But so far I've only had that happen (in 2nd gear) if the road is a little wet or there is something else wrong with the road.

Backed into the field I was trying to slide into and drove home.

Do you mean you drove your Talon cross-country?