Inside wheel spin

[RanciD]

Yesterday was the first auto-x event I've gotten my car to since upgrading my suspension. My setup is 225/50 bridgestones, 450 F/400 R ground controls on koni yellows and whiteline swaybars front and rear. I had both sways set on medium to get a starting point for where to go. For the most part the car felt great, handling was very crisp and neutral. In the gentler areas of the course the car it was working very well but coming out of the sharper sections I was fighting some serious inside wheelspin. The obvious answer is an LSD but this isn't an option without getting bumped up to STX. I'm sure my driving leaves a little to be desired as well but watching my competition (a subaru 2.5rs with somewhere in the neighborhood of 400 LSDs and AWD) he was definitely getting on the throttle much much harder and earlier than I could, putting quite a bit of time between us. Power to all 4 wheels is a little much to ask for from my 240 but I think getting it to 2 would be a good start.

My initial brainstorming involves going full still on the front bar and full soft on the rear to try and get some transfer to that rear inside tire. Changing spring rates is also relatively cheap and not out of the question, nor is stepping down to a stock rear sway. There's still quite a bit of time to be found in setup as I'm still running a stock alignment while waiting for my camber plates to arrive and I think addressing the inside wheel spin will open up quite a bit of time on the course. Hopefully by the end of the season (or maybe just by september when I leave for japan) I can show that Subaru driver the full fury of my open diff.

[Def]

My car would SERIOUSLY spin the inner wheel on T5 at Road Atlanta with an open diff. Like lose speed and spin it all the way up the hill at half throttle - it sucked. Tossed an S15 HLSD in there and no further problems.

As for your situation... I would try increasing the front roll stiffness and decreasing the rear and see if it hooks up a little better on the inside inner wheel like you said. I think you're going to end up fighting a losing battle though, the faster you go, the more lateral weight transfer, the less weight on the inside rear.

You might also want to look into tender springs, as you might be using up all your droop travel back there.

[jmauld]

An easy thing to try is to just unhook the endlinks on the rear bar. If that helps, take it off to get rid of the weight.

Running softer springs in the rear will give you more droop travel.

Are there any negatives to running tender springs?

[RanciD]

I'm not sure if I was actually lifting the rear inside wheel or not, I'll ask my friend if he noticed while he was working. I think for the next event I'll go ahead and disconnect the rear bar and see where that gets me. I know it's very unlikely I'll be able to outright get rid of the wheel spin but every little bit will help combined with some more seat time. I probably could have been a little easier on the throttle too.

[AceInHole]

Front bar on full stuff, lose the rear bar.

The rear will plant a LOT better like that. When I was first setting up the current car (DSP'ish level of build) I tried the whiteline on full stiff up front, with a stock bar in the rear (tried to get it to rotate a bit easier), and it just spun the inside rear all day with R-comps (285's all around). Once I disconnected the rear, it was a LOT easier to plant power.

If you sacrifice some steady state rotation for planting power, then do so. You can't throttle steer without power :P.

[racepar1]

What ace said plus LOTS of toe in in the rear. I used to do that with my open diff and rarely had problems with wheelspin. You also may want to consider stiffer front springs.

[spool_sample]

+eleventy billion on losing the rear sway. My car has been so much more predictable and easier to drive since I took it off, and it works well with my ham-fisted driving style.

If the car pushes, add rear spring in tiny bits until you feel comfortable and/or the car starts lifting itself again.

[vw_nissan]

Anyone still running a working vlsd? I have been trying to find a used vlsd to solve the wheel spin problem, but it's just so damn hard to find one. They are all on the west coast.....and it's too heavy to be shipped.

Have yet to try disconnecting the rear sway, but I would like to take advantage of our vlsd over the civics......

[RanciD]

vw_nissan, what class are you running in? If you're talking about the STS Civics you can only run a VLSD if you have the whole package with hicas and whatever else.

Thanks for the suggestions everyone, can't wait til the next auto-x to try them out.

[vw_nissan]

I run in STS. My car should have a vlsd, but I can never tell because it doesn't seem to have worked at all from day 1 I own the car.

What's the best way to confirm if my car did come with a vlsd or not?

[AceInHole]

Jack the rear end up, stick it in neutral, e-brake off. If you spin one tire, the other should spin in the same direction, since the VLSD should provide enough resistance to overcome the differential.

[racepar1]

After my first actual track event with no rear sway bar I can assure you that is will plant the rear MUCH better. The car was absolutely PERFECT on the throttle! It increased the weight transfer enough for me to lift the inside front tire coming off the skidpad turn at the streets of willow. It's kind of ironic though that one of the INSTRUCTORS has a VERY built fastback and was complaining of rear grip. I advised him to disconnect the rear sway, but he didn't even want to hear it. I guess instructors know everything.

[Def]

In my experience most people at the track think they know everything about making a car fast and aren't very receptive to advice.

[AceInHole]

That's generally true untill someone is faster than them to the point where you can either blame the car or the driver...

[jmauld]

What do you guys think of lowering the rear spring rate to help address the inside rear tire spinning? This should give up some oversteer and allow you to come out of corners a little more planted.

I was thinking of dropping my rear rates down from 450lbs to somewhere around 275-325lbs, and putting the stock bar back on. No bar previously.

I'm adding a bit of power and feel that I need to address how easily this car spins, considering that I could previously spin 2nd with 285s and only 160ft/lb of torque.

To better match the rear springs, I will probably drop my front springs from 500lb to 400lb springs