The Project Pad

that looks much better. nice (semi) parallel links.

I'm not sure about the lower rear roll-center decreasing understeer. Your basically making the rear less stiff in roll, which is much like taking off a rear sway-bar. Try to keep the roll-centers the same distance from the center of gravity both front and rear. Unfortunately calculating the CofG is very difficult. Having a moveable roll-center would be an awesome tool for tuning handling balance. This could be accomplished with eccentric adjusters at the inboard-end of the wishbone, or just with a few mounting points, or perhaps both.
Cheers,
Grant

you're right!

have you been to claude rouelle's seminar?

Yeah, be careful with moving the RC's around D--A change like you've made there is fairly dramatic, and arbitrary things don't always work out . The roll center should roughly follow the CoG (Edit: damnit, beaten above!) if you want to keep everything working as it should be...reduce oversteer with differentials, spring rates, or swaybars instead.

Sam

Did you install your updates?

while i'm still very interested in modding my suspension to fit 10" rims on my car with wide tires... i HIGHLY suggest reading this...

http://forums.tdiclub.com/showthread.ph ... ight=brace

i'm not interested in screwing my car up handling wise, and redesigning suspension bits certainly isn't something remotely impossible in terms of doing it properly, but i DEFINITELY want to arm myself with as much good sense about doing it as possible, and keeping the car still safe to drive as you'll find explained there on the first page. i haven't been that enlightened in a while about something so widely misconstrued as the term "understeer" is explained there. man, i've only gotten through one page can't wait to read the rest!

hope you guys enjoy it as well and thanks to grantmac for the help/link!

I'm glad you like that thread. It really made me completely rethink what I wanted out of my Golf, which lead to me being much happier with the stock suspension :slap:

mmmm, 265's...





just a tad under the 10" rim width, and these tires are a really over square design with the bead protectors.

i can gain about .5-.75" tire clearance on the front fenders by pulling the front side out.. and it doesn't really change the looks any which i'm happy about..






i'm still working my way through the suspension thread, and i maybe investigating the effects of moving my strut uprights inward about 2.5" with adapters between the spindle and strut housing, and modding the tower.... i can't run the suspension analyzer on Vista, so i have to just wait until i get home to do more legit calculations :frustrated:

Holla dem rimz is tightzzz

that looks AWESOME!

You're ballin' now!

well, right in line with that suspension article, my stock 4kq suspension setup has about 2 degrees of positive camber on the outside wheel, when i turn the wheel 10-30degrees for a turn! at no point do i get negative camber on the front wheels. very interesting indeed....


stock castor is 2 degrees positive camber. i switched the drivers side spindle out for the pass. side, which moves the wheel forward about .5", gains 2 degrees positive camber for a total of 4 degrees, but the camber sweep stays the same during steering... 2 degrees positive. *scratches head.

i'll swap some more pieces around and see if anything changes and then edit again.


:update:
i swapped control arms, and ball joints, so the ball joint sits about as far forward as it possible can, and i 8 degrees of positive castor, and finally! 1 degree of negative camber on turning in...

You suck, those look awesome!

derracuda wrote:mmmm, 265's...

On my 4k racecar, the 15x9.5 Hoosier slicks were 22.9" in diameter, which is approx. 2.5" smaller than the typical 265/35-18. The photo below shows the clearance to the inner fender brace at what was normal ride height ... add in a tire that's taller by 1.25" (half of the 2.5" in diameter) and push it to full bump, and the tire will likely come into contact with the brace. Not a big deal to clearance everything as necessary, but you'll also need to reshape the rear of the fender well and possibly the fender openings because the tire will almost certainly come into contact with them as it's turned (unless you restrict full lock, as I had to do on the racecar, which would be silly on a street car).




Anyway, I'm sure you'll figure it all out and the end result will certainly look cool, if nothing else. (FYI, this morning, my boss gave me an old 285/30-18 Pirelli Rosso that came off his Mercedes and I had it mounted on one of my 18x9.5 Corvette wheels so I can test-fit on my A4 tonight, when I finally get out of the office ... cross your fingers for me!)

i'm not afraid of clearancing under the exterior.... big tires shall fit!

ok, small update in the suspension geometry area...

i got the suspension analyzer downloaded onto another laptop we have so i could run my final ideas through it and see how it responds, and i think it's gonna work good. basically what i'm going to do is shift the strut tops in 1" and back 1" via camber plates, make adapters to go between the lower strut bolt holes and the spindle to put it back 2". lower the ball joints 1" somehow (still working on that one), raise the inner, lower control arm points with the rear higher than the front so that i get camber gain upon compression, and a bit of anti-dive built in.

all the while, my camber settings and toe won't go wickywild under suspension compression, and retain almost stock characteristics aside from a bit of added negative camber when turning from the added castor.

you're probably wondering why i'm not just biting the bullet and going UCA/LCA and here's why... there's more R&D into setting it up than i think i'm capable of doing/measuring, and not making it some unpredictable monster that i have to spend weeks and weeks trying to tune. while i'm still going to do some major surgery to the suspension pickup points, it's just to gain back the functions of camber gain, no crazy bumpsteer, and a higher roll center of the stock suspension.... while the car is actually 3-3.5" lower than stock ride height, lowering my center of gravity for a rather large effect.

furthermore, i plan to extend the same pickup point mods to the rear suspension without the added castor so that things in general stay together while dumping the car, and gaining huge tire contact patches to play with ... that should still have relatively decent breakaway manners like the stock car is designed to have. as it is, i can take a relatively stock 4kq and play with it in the corners, adjust where i'm pointed, and feel very comfortable about where i'm going to end up at the end of the turn. obviously it's not going to be a tail out M3, but hey, sideways isn't the fastest way around a paved corner it's consistency and predictability of the car in relationship with a good driver.

i took notice that in the eurotuner GP, that the Stasis TT was the fastest car around the track, with fwd, and a lot less WHP than the next runners up. granted they had the widest tires, they had the ol' mcpherson struts..just like an M3. also.. porsche 911's... all the new ones, mcpherson struts, and yet they are praised as one of the best handling cars out there, so there HAS to be some merit to the design working effectively and give positive feedback to the car. i think UCA/LCA cars in the supercar world are also used from a packaging standpoint.. super low hoods.. not because it's necessarily the best way to go. sure it has ultimate adjustability, but is all that adjustment going to fit my needs? i highly doubt it. and i don't need to spend thousands of dollars and hours trying to figure it out, just slighty mod it to raise the threshold of what the car is already capable of with the factors of inherent understeer to make the car safe.



pretty much my final suspension rendering..

oh, and for kicks, another MG'er sent me this....

http://www.wooddashexperts.com/customer ... p?cat=6850

@ the chrome trim sparkles where i specifically painted it matte black4 years ago

LOL! I noticed that, kinda funny, your car is famous!

derracuda wrote:oh, and for kicks, another MG'er sent me this....

http://www.wooddashexperts.com/customer ... p?cat=6850

@ the chrome trim sparkles where i specifically painted it matte black4 years ago

sweet tell them you want a royalty check for every hit on the image LOL

oooohm now there's an idea...

Morgan over on AudiWorld found her 4kq in a similar site and since shes a lawyer she got tough on them but just told them she could be bought off with a free t-shirt.

i'm getting off with my name being put in the photo for recognition 8) i don't mind the pic being used, but a little recognition would be nice

I think your making a very sound decision with the changes your making. Are you going to try it with just the ball-joints, control arms and spindles swapped before really modifying anything?
For when you've got it all back to gather:
http://www.turnfast.com/tech_handling/handling.shtml

Cheers,
Grant

P.S. Did you ever finish the "what is handling" thread?

i did finish the "what is handling" article and it helped bring me back in line with not going off the deep end in changing the suspension into something that i might not be able to tame, because that wasn't my goal at all. before i was thinking about how much more negative camber i could get and this and that, and i learned that more is only better to a certain point, and too much isn't going to help the car be predictable.

i found the description of the "Darter" funny, cause i know people who equate being able to yank on the wheel and get instant direction change to having a really good handling car, even though it has little to do with overall all performance of a suspension.

for anyone wondering how to get really really good response out of a 4kq/80/90 chassis, install delrin control arm bushings and you'll eliminate pretty much all slop in the steering response and he helps the chassis "set" faster. then go with some stiffer valved struts. big difference right there.

thanks a whole ton Grant for speaking up and giving me those links. i'm sure it's saved me a bunch of money and frustration in learning

sphericals at the inner? esplain pleases.