HELP In G Stock

[wrxrevn7]

This is what i'm having problems with.  I need some advice on what to do next.

Thanks
Brian
http://forums.bimmerforums.com/forum/showthread.php?t=729900

[D. Clay]

Let some air out of the tires. Try letting a lot of air out of the tires. Like 15-18 lbs.
Sedans work better with more rear weight percentage. Maybe the spare tire helped the balance more than the weight slowed it down.
Try driving different lines. Going balls out into a turn is a good way to lose time coming out. Later apexes, more speed in the center of the turn, and roll into the throttle coming out. Drive slower and go faster. AutoX is a unique form of racing. A lot of low speed turns one after the other. 115 RWHP in a 2600 pound car isn't really overpowered enough to where you can't put all the power down.
When all else fails watch the fast guys and note where they let off, brake, etc.

[wrxrevn7]

I'll keep that in mind for the next event. So run a bout 30 psi in the tires?  

Thanks
Brian

[rsafier]

I definately would not be dropping pressure to sub 20psi levels for any reason at all. You'll just roll over you tires.
I ran the RT615s before and they are pretty grippy and decent sidewalls. In a 325is found they liked around 35 up front 30 in rear.
From what you describe in your other thread if its just way too loose in the rear increase your rebound up front until you hit understeer (not driver induced). Generally our E30s like full stiff front, full soft rear. I can't even go 1/4 turn in the rear rebound without being heavily oversteer biased. The other thing is you could just be a little too throtle happy. Tho on a 318is I find this less likely. I run a Turbo 325i in Street Mod. And just got my 318is and while you can get it to throttle oversteer some, it should be pretty managable assume your suspension is setup correctly.

Just to give you an idea on my setup:
Koni DAs: Front Full Stiff rebound, 4 clicks compression ; Rear full soft, 6 clicks compression. 500# front/ 600# rear springs, 25mm front sway, no rear sway. The car handles extremely netural. You can get oversteer by adjusting the car with throttle or brakes as needed. Of course I also am running massive 285s all around so its hard to do anything but go where you point it when you have that much rubber on the ground.

[wrxrevn7]

Thanks for the advice.  I will try the tire pressures at the next event.  And soften the rear up the rest of the way.

Thanks
Brian

[arthurc]

Nice to see another GS 318is!  I'm on Kumho V710 so my setup probably won't apply to you, but here's what I run:

225 V710 on 14x6.5 basketweave
1/4" spacers in front
4.10 LSD
BMW 0.5 degree offset strut mounts
Ireland Engineering 25mm hollow front bar, full stiff
Ground Control Koni SA yellows (diff valving from standard SAs), top adjustable rears
1/16" toe out
SS brake lines (not really worth the $$$ in my opinion)
Hawk HPS pads
Magnecor 7mm plug wires
ITG air filter

...basically fully stock prepped except for perhaps super-light custom exhaust and custom-built wheels (since nobody actually makes a 14x6.5).

I always run full rebound all the way around and generally 39lb front and 37lb rear.  My car pretty much handles like a pussycat and can be man-handled quite a bit.  I haven't found that the rear comes around much at all.

I think the front bar makes a huge difference, and maybe that's a big part of why I don't have rear grip issues.  The imbalanced roll resistance also lets you do cool things, like this:  http://www.carsonau.com/photos/displayimage.php?album=53&pos=669

I agree with most of the other advice - look to soften the back a bit and try to be smooth on throttle application on corner exit.  

I've been campaigning this car for 1.5 years now and having a lot of fun.  Depending on the depth of talent in your region, you should be able to run with the best in GS and near the top on PAX with this car.

Let us know how it goes!

[rsafier]

I ran my 5 year old dryrotted all seaons, busted rear shock mount, open-diff car today to a GS win against 8 others (tho newbs). Was pretty impressed really. A far cry from driving the turbo car, but still fun. Plus the paddock area was so small I would have had hell with lots of 3 pt turns on the 18x10s.

[scottiesharpe]

Nice to see another GS 318is!  I'm on Kumho V710 so my setup probably won't apply to you, but here's what I run:

225 V710 on 14x6.5 basketweave
1/4" spacers in front
4.10 LSD
BMW 0.5 degree offset strut mounts
Ireland Engineering 25mm hollow front bar, full stiff
Ground Control Koni SA yellows (diff valving from standard SAs), top adjustable rears
1/16" toe out
SS brake lines (not really worth the $$$ in my opinion)
Hawk HPS pads
Magnecor 7mm plug wires
ITG air filter

...basically fully stock prepped except for perhaps super-light custom exhaust and custom-built wheels (since nobody actually makes a 14x6.5).

I always run full rebound all the way around and generally 39lb front and 37lb rear.  My car pretty much handles like a pussycat and can be man-handled quite a bit.  I haven't found that the rear comes around much at all.

I think the front bar makes a huge difference, and maybe that's a big part of why I don't have rear grip issues.  The imbalanced roll resistance also lets you do cool things, like this:  http://www.carsonau.com/photos/displayimage.php?album=53&pos=669

I agree with most of the other advice - look to soften the back a bit and try to be smooth on throttle application on corner exit.  

I've been campaigning this car for 1.5 years now and having a lot of fun.  Depending on the depth of talent in your region, you should be able to run with the best in GS and near the top on PAX with this car.

Let us know how it goes!

FYI - BMW 325is basketweaves are 14X6.5. I also have Falken's 195-60-14 on them.

I run 40 lbs all around on my 318IC (heavier) on auto-x, which is not really my auto-x car, but when the 2002 is  in peices, I take the convertible.

If your rear end is flopping around when you put power down (and we have such a scant amount of it to begin with!, then you need to loosen up the rear end. A stiff rear will transfer the weight to the outside wheel and LSD is applying torque to that wheel and when it slips, you slide out. Try a thicker front sway bar, or less rear wheel tire pressure. Do not go below 35 lbs on an auto-x though.

Shock settings really do not play a big role in auto-x. There isn't enough speed to put much energy into producing spring rebound, so there is no need to control it.  A few weeks ago ran stock Boge shocks on my 318i with low and soft Eibach springs on stock bottle caps with some no-name tires and it turned damn fast times! Squealed like a pig though. I'll post the video on Google if I can figure it out.

[rsafier]

Shock settings really do not play a big role in auto-x. There isn't enough speed to put much energy into producing spring rebound, so there is no need to control it.  

Are you kidding me? Why else would you have people in the stock classes at Nationals have $5K+ custom valved shocks?

At least personally I've found a lot more control using rebound adjustment on my shocks then I ever have from tire pressure changes.

[Mannix]

I'm not exactly Stock guy (more of an SP guy, with a stint in EP), but you're on the right track.  

You're missing two things, as far as I can tell:

A) Tires
B) Front swaybar

I'd start with a big front swaybar - as big as you can get.  That said, it sounds like you want help with what you've GOT, not what you could have:).  

Tire pressures - they sound too high to me, too, but more like 6-8psi.  As far as I know, the Azenis will behave like a normalish tire with regard to the "chalk" test - use shoepolish or chalk on the edge of the tire, see how far it is rolling over under load - optimize the front pressure with that (or better yet, a pyrometer), then leave it there.  For the rear, do the same, but once you've got the rear "right," you probably want to leave it alone.  

Konis - adjust the fronts to full stiff, put the rears on full soft.  If it pushes (which sounds like it'd be a welcome problem), take damping out of the front in 1/2 turn increments.  If you wind up full soft in the front, add 1/2 turn rear (are your rears externally adjustable, or remove-compress-turn?).  

I'm not sure the offset upper strut mounts are legal in Stock - Arthur, are they a factory recommended repair?  I guess they must be.  

Disclaimer - NOT suggesting you're cheating, Arthur!  I just don't know if those are legal in class; we tossed a competitor at Nationals a few years ago for putting the correct strut mounts in backwards(resulted in more caster on that car).  Just want to make sure - if those _are_ legal (and the more I think about it, the more I think they must be, unless they're some sort of ///M madness), get them.  Cheap, and camber helps.  Yeah, you don't want MORE front grip as it sits, but you should want more front grip - it is typically easier to make a car understeer than oversteer.  

Rule of thumb in Stock category:

The car must sit AS DELIVERED on the grid, with the obvious exceptions - front bar, catback, etc.  Just because another E30 came with 7s does not mean YOU can use them.  Just noted someone saying that on the other forum - dealer installed != ok, has to have been a factory option.  I am not aware of 7s being an option on 91 318is.  

Heh, was just sitting here thinking about it - I've driven my 318is on a few autocross courses; my wife used it for a couple of driver's schools.  Mine is set up similarly to yours - new control arms, M rear c-arm bushings (ok, so it is not stock _legal_, but it is not my primary autocross car), Bilstein Sports, new strut bushings, new tie rods, brakes, blah blah blah.  Stock swaybars, no LSD (dammit).  It has Yokohama AVS ES100s - about 85% of an Azenis.  All told, our cars are fairly similar.

Mine is not oversteery at _all_.  It is really fun to drive on an autocross course, I can make it oversteer, but it is not loose in the slightest. I don't think your tire pressures are so far off that they're creating the problem, quite frankly.  

How long have you been autocrossing?  I'm thinking the loose condition has to do (possibly, and please do NOT take offense - I'm trying to help) might be driver induced.  

I _can_ make mine oversteer (occasionally drifted it for giggles), but it is controllable.  It sounds like you're having trouble controlling the oversteer in yours.  I wonder if you're being too abrupt with it - if I wanted mine to rotate, I'd lift, turn in fairly abruptly (lift to load the fronts, then turn in while the rear is light), then catch it _with_ the gas.  IE, get it loose, get it to rotate, then transfer weight to the rear with the gas pedal.

It almost sounds like you've got the opposite - you're turning in late, abruptly, then worsening the issue with the throttle.  

Just a thought/observation - I may well be wrong, but from what you've said, either you have a gross alignment issue or you're being too aggressive - don't slow down, but look ahead more, make bigger arcs, turn the car well before the cone, as opposed to after it.

Make sense?  That's the only way I can envision mine being uncontrollable/way too loose - if I was playing catchup and being violent with the car - it liked to be led into stuff - lift a bit, turn in, balance it with the throttle.

Just a thought!  Who is fast in your region?  IMHO, it does not matter what they drive - driving is driving, save A Mod or shifter karts - a stiffer, more responsive car might let you get away with more (but bite harder when it does), ehh, who knows - find a fast Stock category person, take them for a ride.  

Hopefully, that helps some - but in my experience with BMWs & autocrossing, I'd start out by putting the fronts full stiff, rears full soft (that'll help with inside wheelspin, too), make earlier inputs and be friendly with the gas - in mine, I was foot to the floor, well, all the damned time, but if you snap the throttle open while the rear tires are near their limit, they're going to let go - 115hp or 400hp:).  


Good luck, keep us posted!



Iain

[Mannix]

Oh, another thing -

Arthur - Packwood?  Has to be.  Wow, I need to go there....



Iain

[Mannix]

Are you kidding me? Why else would you have people in the stock classes at Nationals have $5K+ custom valved shocks?

At least personally I've found a lot more control using rebound adjustment on my shocks then I ever have from tire pressure changes.

Yeah, what he said:).  

I never really put much stock in custom shocks.  

Then I got some.

Wow.  At the time, 2000 season, we had a very quick FSP VW Scirocco, with Koni Yellows.  My codriver is bunches smarter than me, he grokked the shock.  We got Koni double-adjustables, custom valved for the car (wheel/spring rate, etc).

Our first event with them was at Peru, Indiana.  They seemed OK.  The car was not dramatically different, just good.  That course had a concrete seam that was RIGHT in the middle of a long corner, where the car was most heavily loaded.  It was bottoming on the camber plate HARD.  BAM.  It upset the car, too.  We kept adding compression damping (it was a T&T), doing more runs - about 5 clicks in, I made another run.  Left, right, left left right - turn in, wince, (bump) holycrapgoingtoofast.  

Wow....look at THAT!  It was dramatic - instead of turning in and bracing ourselves for the inevitable "that's gotta hurt SOMETHING," we could just turn in and plant it.  No drama.  No thud - you could hear the joint in the concrete, but the roof was not resonating anymore.  The car just got _better_.  Like all-over better.  

On a Stock category car, they're pretty much (IMHO) the biggest, most important thing you can do.   I'm not sure there's a huge amount of time in $5k Ohlins or JRZs or Motons compared to a good double-adjustable with custom valving, but they're very, very worthwhile.  

We recently put Koni doubles on the current autocross car (68 2002), and the results were similar - nothing -dramatic-, but quite a bit faster.  They replaced old revalved Rabbit inserts (they were good in their day, but they have about 1000 runs on them at this point) and off-the-shelf compress-to-adjust Koni yellows.  

Very much worth the effort - the car is Just Better now.  Hard to put one's finger on it, but it is better, and certainly worth the effort.  

That said, if cost is an object, single-Konis are very, very good - and they get you in the ballpark.  Great shocks are not going to add 1 second on a 60 second course - but they do add something.



Iain

[wrxrevn7]

Well I finally got the car to handle better and the tire pressures.  I have been running 29/34 f/r and at the last event, I started fighting the car again.  I put 1 turn in there rear and 1.5 turns in the front with 33/37 psi.  The car started to feel better and started tailing out.  But everyone was was having problems getting traction out of the corners.  I have been calming my driving down and less throttle.
The fast car in our region is a CS mazda speed miata.  In street tire I've place 1st once, 2nd a couple of times, 3rd the rest.  I mest up my last run and hit 2 cones after the timer otherwise I would have had 2 1st.  The car i'm competing against in street tire is a BS 350Z track edition.  Some times the HS focus but not offen.  
I have autoxing for 4 years and started with my 02wrx and plan on going back to it next year in ESP.  This is my 2nd year in the bimmer and having a good time.  I just wish I would have bought r comps in stead of falkens.
Everyone thanks for the help and still would the help if anyone has any comments or suggestions.
Brian

[b318isp]

This is what i'm having problems with.  I need some advice on what to do next.

Thanks
Brian
http://forums.bimmerforums.com/forum/showthread.php?t=729900

I think the easiest thing for you to do is drop the tyre pressures - with the pressures you run, the centre of the tyre will be taking a higher proportion of the load. For track days I use 36psi front and 32psi on the rear with 205/55/15 tyres. For autocross, start with maybe 2psi more than this. See if you can get a loan of an infrared thermometer and check for the evenness of temperature between the inside, centre and outside of the tyre. Adjust from there.

Get this right, then move on the suspension adjustments.

I'd also recommend getting some time with a tutor or other experience person to get lines and turn in points right as the E30 needs to be placed fairly exactly to get power down efficiently (if you don't have an LSD).

[wrxrevn7]

The car has the LSD in the car.