Gdmaxse (gabe)'s brother took some amazing hi-res photos last weekend of us running. I like these alot better than the videos...usually I just get the crappy ones that my wife takes with my compact camera....

 

 

 

Irish it looks like your back tire is wider than the front, is that just the picture, or are the drugs I'm exposed to through work affecting my brain?

 

it's funny, I was thinking the same thing...all 4 tires are 225/45/17, a little smaller than spec. Rims are 17x7.5 (in the front this time) and 17x8 in the back (I usually run the 17x8 up front, but wanted to even out the tire wear a bit....

 

Josh, you need SFCs like there is no tomorrow....look at the chassis flex in the 2nd and 4th pics

 

You must have bionic vision. Please tell me where you're looking to see that....

 

Bodypanel Reflections

 

With all due respect, you're looking at bodypanel reflections to determine that the chassis is flexing? Body rigidity is something manufacturers improve in percentages, not factors. Chassis flex is something you see like on high HP drag cars when they launch, and many of those cars are not as stiff as a recent production cars.
I'm not disputing that there is no flex, but to look at body panel reflections and come up with that diagnosis is a bit extreme.
I think what you're seeing is just the natural curvature of the rear quarter panel and that distorts the reflection somewhat.

 

Most of the twisting occurs at the front and in the middle of the chassis. Look carefully at the picture you can see it.

 

ehhh, I'm still not convinced, but I'm letting it go...
I mean, how fast does one have to go to see that? Need to eat more carrots....

 

High levels of grip + large steering angles = stress on the frame. Albeit its not like the body is twisting 3" off axis, but it is noticable

 

preaching to the choir, though I'm not convinced that I want to add 70 lbs to the car and be permanently screwed up to STX in SCCA......

as to "seeing" body flex...eh...hmm.....

while there definitely IS body/subframe flex in my car, I don't think it can be seen in the photos...the reflections play tricks on the eyes. I see what you're talking about, but then again, I can also see that on the I30 pics, and he DOES have SFCs......

I'm also not convinced SFCs would help out in small autocross courses as much as they do in road racing....one of the nice things about some flex is keeping the rear inside wheel on the ground (traction) instead of lifting it off...

at any rate, I'll get them eventually, but it's not high on my list of things to spend my money on at the moment.....I still haven't been beaten at any events this season by any FWD 4-door over 3000 lbs (just by the MS Proteges), so at the moment I'm satisfied with the setup

add them to the long list of things I need for autocross:
-coilovers
-lighter wheels
-seat/harness
-wider tires (if I'm going to STX, might as well go wide)
-SFCs
-more power
etc

 

SFCs dont weigh close to 70...its more like 30-35

 

yeah, it's 35...I'm not sure why I had 70 in my head

oh...yeah, I meant the "super-double SFC's"

 

You're way more screwed in SCCA than that with SFC's. Stage1 bumps to Street Mod while Stage2 goes to Prepared I think.

 

I'm a bit rusty on my f0cking SCCA "war and peace" rulebook

...now I remember why I quit going to SCCA events 10 years ago, too much BS to deal with....I will probably not run series anyhow, since I don't care at all about points/season standings etc....that, or more likely will just stick with the local autocross stuff and run some NASA events instead (with their slightly less **** rulebook). That, and I decided not to renew my SCCA membership this year anyhow...

...I really resent SCCA for taking things that I bought for "daily-driver" performance (lower tie bar and 235 width tires) and making them ridiculously over-weighted in the classing. But this is not the time or place for me to rant on that subject.....

 

Just run STX and nobody's gonna care about the LTB at the local level. Remember that Solo2 is competition based unlike HPDE events. Move to Time Trial competition and again you inhereit "**** lite" rules. NASA has their CCR, Midwest Council has their 250page GCR, etc. If I ran NASA with race tires I'd be put up against V8 Mustangs, S2000's, 300ZXTT's, and a whole bunch of other class D rides that doesn't sound too fun.

 

yeah, but since I don't run series, or run all that regularly it doesn't matter anyhow....I just run for fun...If winning was my goal, I'd get a faster, lighter car.

 

But I still think NASA isn't as "****-like" as the SCCA. EMRA out this way seems to give you some leeway, but I haven't graduated to time-trial events yet, at least not until my NASA membership runs out.
I run SCCA but never bothered to officially join, because I don't run enough events to where it makes sense.

 

No offense, but you aren't seeing chassis flex. These cars are on street tires and non-race suspensions. While they are placing high loads on the chassis, they aren't comprising the rigidity. It isn't like the Maxima is built on a wet noodle chassis.

 

He has springs and high grip tires. And as much as you'd hate to think so...the maxima is a wet noodle (the 5 and 5.5 gens are sig more rigid than any that came before, but hardly what you would call stiff).

I run JIC coilovers and I could feel the inner rear wheel lifting in corners before I added SFCs

 

I'll agree that there is plenty of chassis flex on the maxima - that's what you get with unibody japanese cars......in any case, I agree to that point, but don't agree that you can visually see it in photos....

 

You must be DA MAN. I raced and track evented a 1985 CRX-Si (1st Gen)for FOUR years, and I could never tell when the inside rear was off the ground unless someone told me afterward. That car had a beam axle. I've even asked drivers with more experience than me, (especially those that raced VW Rabbits and Golfs) and they could never tell. How do you FEEL that? Again, I'm not trying to be smart here, just wanna know where you're coming from....

 

Springs don't equal a race suspension. He isn't running R-Compound tires(in fact I don't know what tires he is running?). The chassis isn't flexing to the point where you can see it. It is obviously and optical illusion or reflection that you are seeing. I had a 5th gen Maxima and tracked it a few times, it was a pretty solid platform how I had it dialed in. The chassis does flex a bit, just jack your car up on one side and open the doors as evidence. We aren't talking about Fox body Mustangs here.

 

I've only done it once that I know of....and I only know because I could feel it hit back down as I reversed direction in the course (it was a hard sweeper followed by a switchback).....

MAX2000JP - no, not a "race" suspension....no coilovers or especially stiff springs, just maxspeeds/illuminas and the other stuff.

Tires are Hankook ventus R-S2, which are fairly comparable in grip to Azenis....

 

I had a similar setup(Eibachs/KYB's, RSB, FSTB, and probably some stuff I am forgetting). It worked very well, but was a comprimise for a street car. Coilovers and chassis bracing would have helped considerably, especially in helping remove understeer. The next time I would have went to the track, I would have probably ran something like Kuhmo Victoracers or RA-1's. Once you have been to the track a few times, street tires really hold you back.

 

True dat. They do hold you back after a while, but they really help in learning/practicing car control and can be a lot of fun too.

 

When you feel the car start to rotate like its gonna spin, then back off a bit and the wheel hits the ground again you should be able to feel that plenty

 

Ok, man. Thanks.

 

Get this back on topic a little bit. BTW, E55AMG2, I doubt your rear tire was lifting because of chassis flex, if that's what you were trying to imply on post #22.

Irish44j, your car "looks" fine....when I went to auto-x last season I saw stock old gen preludes and even WRX's with MUCH more body roll than that. I'm talking about 4 to 5 inches (dare I say 6?) of wheel/fender gap during quick sweepers. It was so funny watching it

 

What would it be then? There is no way I was compressing my rear suspension enough to lift a wheel with 8kg springs on my FLT-a2s. There is hardly any weight back there to shift around...and there was no bracing (in terms of SFCs or an RSB).

 

I gotta say, it's really hard to see his chassis flex. I think I see it in pic 2, but not so sure about pic 4. I certainly don't see any on the pics of my car, although there are more pics in the DC section....and my car is dirty
Josh- Although your lack of LSD may hinder your times, it sures makes for a cool pic

 

They lift because there is more body lean than suspension travel. it's as easy as that. has nothing to do with chassis flex. if so, then why is it that every BMW I see at the track is lifting an inside tire through the corners? I know their frames are considerably stiffer than ours.

 

heh, yeah tell that to my torn up RS2s I'll have to be a little lighter on the gas next event, got a little excited with that saab lighting up the tires all the way around the track and wanted to 1-up him.....not even close to the forest-fire smoke he was putting out!

definitely hindering my times, but hell I'm still 5 and 0 against maximas and "maxima-derivitaves" this season though your marked improvement throughout the day has me a little worried for next time Nick...

 

I'd make one addition to this. Body lean is a part of it, but it's more related to the stiffness of the bar and the suspension. The stiffer the bar and the shorter the wheel travel, then when the car leans, you'll get the fire hydrant salute. With a beam axle, you'll get that happening more just because there is limited wheel travel to begin with. Next time you go to the track, look to see if there are any old Italian cars there (Fiats, Alfa Romeo etc.) Those cars lean like crazy, but they don't lift the inside wheel. They have long suspension travel, soft bars AND in most cases, independent suspension all around. It looks weird when you see them corner, but they stick almost as good as some stiffer cars.

 

10kg springs up front, 8kg springs in the rear.....body lean isnt an issue.

 

Body lean is still an issue, even though it's roughly 1/3 of what you had stock.
with weight transfer comes body lean. it's simple physics. more weight transferred to the outside wheels means the outside springs will compress and the inside springs will extend.. Even at 10kg springs (I'm guessing roughly 550lb/in without doing the math) that means in a 1G corner, you will be putting an EXTRA 1000lb on your front outer wheel. that weight has to come off somewhere, which will be the inside front wheel.. so almost zero on your inside front, and about 2000 on your outside front. at 550lb/in on springs, that meand there will be roughly a 4" height difference between corners.

YES, the CAR WILL LEAN. no matter how big of a spring and sway bar you're running, the car will lean.

the huge sway bars also magnify the problem, since they try to keep the suspension from changing. when the car is leaning hard in a corner, it's going to compress the suspension on the inside wheels, possibly lifting it off the ground when the sway bar is pushing up more than the body weight is pushing down.

remove the sway bar and you will have more body lean, but you will also probably pick up the inside rear less than if you had the bar installed.

 

oh.. just a bit of illustration..
I'm running 450lb springs (roughly 8kg/mm) front and rear, with sus tech sway bars on both ends.
Also running a seam-welded rear crossmember, FSTB, stage II Lower Tie bar, and stage 2 SFCs. if this car ever has any appreciable chassis flex, it's going to start popping welds.

http://blehmco.com/pics/track_pics/h...4/188%2006.jpg
http://blehmco.com/pics/track_pics/h...4/188%2012.jpg
http://blehmco.com/pics/track_pics/h...4/188%2016.jpg

 

I still don't understand how that Saab was spewing out so much smoke. At first I thought he had blown up his engine with all the smoke that was coming from the wheel. I'm sure you have just as much power as he does, yet you really only put out 1/10th the smoke he did. Even with crappier tires I don't see you smoking them that bad.....
And don't worry, I probably won't be able to catch up to you for another event or two