Autox with 2.4L Ion3 - help w/ suspension

[scottherbert]

Originally Posted by BigBrother

First - to reiterate, yes, we are in DSP.

Second - Poly mounts are legal in STX, and so is HP Tuners. You can't change the injectors in ST, but you COULD get the stage 1 flash to get the higher redline and retune w/ HPT to keep your 42# injectors. As long as you run premium fuel only, you should be fine. Regardless - you don't have to run in SP if you don't want to just becuase of poly mounts.

Third - I think you'll find that tire idea not as swell as you think. Try it - you may be right and I wrong - but that's a LOT of tire under a car and almost all of the extra width will be outside. That's good - except it changes your scrub radius DRAMATICALLY, which will make the cars turn-in awkward. Also - hard to tell how the EPS will handle it. I really think that lowering the cars CG and tuning the suspension properly in conjunction with 245/45/17 rubber would out-handle a stock ride height on really wide tires. Maybe not out-grip, but certainly out handle. Autocross is a grip race - but it's also a handling race. If it was an oval with constant radius turns, sure - but it's not. I think you'll learn to hate slaloms with those shoes on. I could be wrong though... Oh - and your math is WAAAAAY off. a one-inch increase in radius - almost 2" overall diameter - is a LOT more than 1%, lol. In fact, it's almost 10%. I'm all for gearing it up a little for 1st, but teh VAST majority of an autocross course is spent in the middle of 2nd. I wouldn't want to lose that much gearing in the sweet spot to gain a tad more throttle at exit, dude. Modulate the throttle better, lol. A rear sway and stiffer springs - a good bit stiffer in back - will increase the effectiveness of the stock LSD many times over, so put some trust in it. Or try a very light left foot brake action with the hammer down leaving a corner - works wonders for getting teh LSD involved if you're getting too much spin. Oh - and more negative camber, too. I've got -2.5/-2.7 on stock suspension on 245/45/17 Hoosiers, and it's not enough according to the pyrometer. If you're not taking tire temps, you don't know if your camber is right.

Many short responses:

Actually, the figures are diameter, not radius (at least according to the spec sheets), I've already hit the rev limiter in 2nd with 225/45 x 17s on some autocross tracks (granted, most often at turn-in to the following big turn) but I hit it multiple times with 225/40 x 17s in San Diego at the National Tour Event there on each run, I have the stiffer rear sway and if I really need to stiffen the stock springs -- I'll use 'spring rubbers' ala NASCAR to add stiffness without changing the ride-height, I've seen the results of 245s and they aren't a dramatic improvement, I've considered moving up to 255s or 275s but the available aspect ratio (45) means a substantially 'taller' tire -- so the choice is move futher up to 297/315 or sacrifice more gear ration, I've used a light left-foot brake in an attempt to add 'load' to the LSD (the quaife is a 'torque-limiter' LSD, so no torque, no LSD) and I modulate on exit, I have run as much as 3.5 degrees of negative and the trade-off between accelleration slippage (LSD torque loading again) and corner stick didn't make it better, I own and use a pyrometer, I understand the scrub radius issue and accept that some initial toe-in will be required (probably as much as 1/4") to improve turn-in -- bottom line: it will be an interesting experiment...

BTW, one of the reasons I'm jumping from DS to DSP is that I don't like running with 'street rubber' (STX, etc.) -- slicks are more fun...

For the earlier response, I have multiple vehicles ,and since I commute 150 miles/day, and with the cost of 91 Octane, the Redline will remain a 'hanger queen' that gets driven 'only on Sunday at the races', so to speak. If I ever put it on the street again, I'll go back to stock injectors and flash and stock suspension settings.

At the two National Tour Events I've run over the past couple years, Texas City, TX and San Diego, CA, there were no tight slaloms -- high speed slaloms and a couple of quick 'off-sets' -- but no tight slaloms. So the set-up I'm planning to run should be perfect for what I've seen.

I like the thoughts, though. It seems like this thread is getting the serious autocross competitors on line -- and I appreciate it. We have to get back to the 2.4 issue, though -- next post.

Thanks for the thinking,
Scott

[scottherbert]

I should probably add that the 'big guys' (national champions) in DSP tend to drive the BMW 325is. We're talking about vehicles that arrive in a semi trailer with a semi tractor/motorhome combo pulling the trailer -- professionally prepped vehicles (bmmerhaus, etc.) -- running (effectively) all-out suspensions.

It's going to be a tough road to win in DSP so I'm looking at extreme measures.

Scott

[BigBrother]

Yeah, that's why I stay in DS and look at STX. I think the IRL has a shot at DS nationally (moreso the last 3 years, less so now but could pull something out) and could be really competitive and even trophy in STX assuming the WRX's aren't cheating (HAHAHAHAHAHAHAHAHAHAHA). I think it could surprise some people in DSP, but I don't see it winning.

I understand the diameter/radius measurement, that's why I quoted both. Funny thing though - in your list:

Summary Stats:
TIRE BRAND/MODEL SIZE DIAMETER TREAD WIDTH
Dunlop SP 9000 215/45 x 17 24.6" (stock) 7.9" (stock)
Hoosier A6 225/40 x 17 23.8" (-0.8") 8.9" (+1.0")
Hoosier A6 225/45 x 17 24.7" (+0.1") 8.8" (+0.9")
Hoosier A6 295/35 x 17 25.3" (+0.7") 10.8" (+2.9")
Hoosier A6 315/35 x 17 25.6" (+1.0") 11.6" (+3.7")

You list the diameter, and then in parantheses the additional width measured on one side, i.e., radius. A 295/35 is .75" taller on both sides, 1.5" taller overall. Not that it really matters, but when you do the math you have to use one or the ther, lol. Either way, it's... Nevermind, LMAO. I was reading it wrong this whole time. I was reading the 23.8 as the diameter for the stockers instead of 24.6. Curse my funky eyesight! :embarassed:

I "feel you" as they say re the camber and throttling out of corners, but IMHO you spend a lot more time with lateral loads on the suspension and very little time under striaght line throttle. If the tires are 30* hotter on the outside shoulder than the middle, than you're losing a lot of grip in the corners that could be got back with camber. Every time I've gone the other way - and I've tried - I got slower. Faster in this car seems to be slower in, even throttle, gentle throttle movements out roll into WOT as the wheel straightens. Took some getting used to as most FWD cars I've autocrossed could use the throttle like a switch just fine, lol.

Anyway, let us know how it works out, I'm certainly open to new ideas if they work!

Where were we on the 2.4 anyway, lol? Other than the fact that it's in GS now.

[scottherbert]

Biggest challenge now is finding a 'reasonable' wheel manufacturer. The one that seemed to be a reasonable selection (with steel wheels) now says he estimates the weight of the wheel to be about 45 lbs -- WAY TOO HEAVY. So that choice is out the window. I'm back looking at Panasport to get some custom wheels made, back to higher prices, but probably in the 16-20 lb range.

About DS vs DSP. Two of the national-level guys (BMWs) race here and one national-leve Acura ITR. When I check results from our events, events where we all race on the same courses, I find myself about 2 seconds slower than the national-level Acura ITR in DS and usually about 0.2 -- 1.0 second slower than the BMW 325is (plural) who race against me in class (DS -- I can, and do, beat everybody else). Checking further, I find I'm about 1.0 seconds faster than the 8-9 DSP cars who race in class (DSP) and about 2 seconds slower than the national-level DSP BMWs. If I'm already 1.0 seconds faster than the 'typical' DSP car locally and within 2 seconds of the national competitors on the same course -- and I'm still a stock DS car, I figure I can do the mods under discussion and be very competitive in DSP -- at least there's hope. There's absolutely no chance of winning in DS! (Note that SCCA is discussing moving the ITRs up to BS and moving the Redlines/Cobalets down to GS -- looks like everyone knows the problems.)

Bottom line: I think I'm being out-hardwared in DS and I'm not willing to wait another year or two for SCCA to 'fix' the classing problems. But I think I can mod the Redline enough to get much closer in DSP. If I can even 'scare' the BMWs, it would be worth it! They're way too smug...

You're right about STX. So long as the WRXs keep playing in STX -- with stock tires -- you'll never be fast enough (4wd vs fwd).

BTW, if you check into the GM websites, you'll find that the Cobalt SS setup to Time Attack uses custom Enkei 17" x 10" wheels with a 19mm pos offset (Enkei is really expensive and I don't think anyone but GM has the clout to get more custom wheels built).

Scott

[scottherbert]

As you know, the SCCA mantra is 'slow in, fast out' -- which works great if you can really hook-up under power, prticularly for RWD cars.

On the other hand, if you can't plant all of the power on the ground, particularly when one tire is less loaded, being able to carry as much speed as possible through the turn is the only answer. I've watched both methods and (depending on the day and the course) either works well. The trick is to figure out a way to get the most out of the capabilities of your unique vehicle.

Scott

[BigBrother]

About DS vs DSP. Two of the national-level guys (BMWs) race here and one national-leve Acura ITR. When I check results from our events, events where we all race on the same courses, I find myself about 2 seconds slower than the national-level Acura ITR in DS and usually about 0.2 -- 1.0 second slower than the BMW 325is (plural) who race against me in class (DS -- I can, and do, beat everybody else). Checking further, I find I'm about 1.0 seconds faster than the 8-9 DSP cars who race in class (DSP) and about 2 seconds slower than the national-level DSP BMWs. If I'm already 1.0 seconds faster than the 'typical' DSP car locally and within 2 seconds of the national competitors on the same course -- and I'm still a stock DS car, I figure I can do the mods under discussion and be very competitive in DSP -- at least there's hope. There's absolutely no chance of winning in DS!

Hmm. I don't know what to say to that, really. A 'good' local-level driver will be 1.5-2.5 seconds behind a national driver in my experience, so that sounds about right for DS. I think we can beat the ITR. Heinricy took a Cobalt to 2nd behind the ITR, and it was THAT ITR with THAT driver - has anyone else won in DS in how long? lol And the IRL should be quicker - slightly lighter, lighter/smaller wheels, slightly better weight distribution than the 'balt, although they do have the FE5.

Anyway - I don't see a bunch of ITR's dominating DS like the MCS does in G. DSP on the other hand - well, like I said, i don't know what to say. The FWD penalty SHOULD be way harder a hit in DSP than in STX or DS. The WRX is dominant in STX but I think it's weight and lag can be beat in a good FWD, particularly ours. Remember the Car & Driver test with the SRT-4 ACR/Ion Redline/Cobalt SS/RSX/WRX? Granted - those aren't solo II drivers and they weren't on slicks. But the interesting part was that they used the same drivers in all 5 cars, and the non-LSD Ion was 2nd in the autocross part of the test, .04 behind the stickier-tired and LSD equiped ACR. It was waaay ahead of the WRX with equal drivers. It's just too bad more national-level drivers don't srive the GM twins!

(Note that SCCA is discussing moving the ITRs up to BS and moving the Redlines/Cobalets down to GS -- looks like everyone knows the problems.)

Jesus H Christ on a crutch and his mother Mary - when the hell are they going to stop fucking up GS/DS - and now move the ITR to BS - in an attempt tp patch up the glaring problem that is the MCS in G-Stock?!?!?!?!?!?!?!?!!?!? The GS PAX is now higher than DS, they've dropped several cars that CLEARLY fit the bill for the traditional DS class (Spec-V, new Si, new GTi, and so on) while orphaning other cars in DS that should have been dropped as well (Mazdaspeed Protege is the obvious one) all because they won't put the fucking Mini where it CLEARLY belongs. Not that I WANT the damned things in my class, but c'mon! This is STUPID! The two classes are now interchangeable but not in a good way, and GS is still a spec-Mini class. In the meantime, a dozen good cars are orphaned, and the cars they dropped to compete are now supposed to run FASTER than the cars they were deemed uncompetitive with to get dropped in the first place in order to PAX well!! So now the ITR moves up becuase of one driver who doesn't even own one anymore? And our cars get dropped down - making the MX-6, Prelude, Celica, and a dozen other "should be" good cars in GS even less attractive!? OMG - the BoD is smoking SO much crack...

[FunkyStickman]

We might as well rename this the "General Ion Autocrossing thread"

Tell you what, I'll go ahead and make one, how's that?