Plastic Fantastic tew

[SuperBuickGuy]

So. Track night in America.

f**k Washington, its traffic and the idiots who think choo choo trains solve anything.

Nothing is so annoying as reserving 3 hours to drive 1 1/2 hours then realizing at hour 3 that you're not half way there.

HOWEVER.

I got home, unloaded my car and saw a huge oil slick where the trans continues to leak. Probably would have blown it up at the track - so I guess I dodged a bullet, but still annoyed that I missed yet another opportunity to race.

[SuperBuickGuy]

time to resolve a cooling issue... the cap needs to be the highest point

the fix


with a new top 'hose'


oh the good old days...

[SuperBuickGuy]

got my degree plates today


hmmm 23 degrees



does it matter? the wheel moves rearward quite a bit at full lock



so here are the numbers... at 10 degrees, there is very little ackerman

but at 30 degrees, the other side is 23 degrees



in other news, that's a friend's 73 C3... we're replacing the rear suspension.... it had troubles, lots and lots of troubles


thankfully one of those troubles wasn't I had put the Buick in the way of dropping it down on the lift

[SuperBuickGuy]

First thing today... fix a broken side lens

drill hole, run a screw/washer in.... fixed

this is an issue, don't know the solution yet... I suspect I need to brace the front more....

time to get serious about steering.... that's a tire temp gauge (for those who don't know)

I did go from 1/8" in to 1/8" out.... I'll do a temp test in a day or so... I still have some other alignment stuff to do - but the 'drive around the block' is it's quicker steering.... I need to get it up to speed, though and see how it really does
cheap slide plates - don't steal from the kitchen....

oh good grief.... for those who wonder why I do most stuff myself - a professional did this (gasket)

people may wonder why I don't have many friends.... I ask them to do things like this


in other news, my brake lever is the problem - a new-to-me is on its way

[SuperBuickGuy]

First step... measure
for those with my eyesight...
1/8" toe in, 98" wheelbase

[fatguyzinc]

a lot of times upping the REAR swaybar rate helps with understeer on a vette....
but be carefull, you may be flirting with OVERsteer at that point, and on a C3
when she does decide to step the rear end out it goes quite quickly........

course you done installed some kinda new fangled rear assembly in yers, so
i dunno how that one will react...

[hauen]

Is there anywhere you can do repeatable testing in similar conditions to get tire temperatures? It sounds counterintuitive, but I'd also try running with 0 toe or maybe even a tiny bit out. I'm too lazy to look up your front end settings so maybe you're already there. I'm inclined to think maybe you need more front spring since slaloms are all transition, which the sway bar does a lot of the heavy lifting on (no pun intended) and a stab on the brakes causes that quick bit of weight transfer that loads up the corner, bringing the bar into play. But I'm not Herb Adams, crap, I'm not even Duke Southard, so take it all with a truckload of Morton's.

[SuperBuickGuy]

next problem to solve. Not sure I have my head wrapped around the how/why... so here it goes.

The problem is tight-turn understeer. (on the entry). Slalom, the car is quite nimble; but if I have to go around the end of the slalom and head the other direction, understeer city.. tires are a Toyo, 320 tread wear (though the magazines put them with 200 tread wear tires).... I run 32 psi (have changed up and down to no real change). I can resolve 50% of the issue by a tap of the brakes....

thoughts? suggestions? things to look at?



I'm adding this for my reference - but criticism of it is welcome

Corner Entry
The first question to ask now you have identified the understeer as occurring in corner entry is, are you entering the corner after being hard on the brakes? If the answer is yes then you have two options to solve the understeer:
1) Increase front damper rebound stiffness. If you have high or low speed damper adjustment then increase the low speed rebound stiffness only.
2) Reduce the front brake bias.

If the answer is no then you must ask yourself another question, are you entering the corner at high speed or mid to low speed? If the answer is high speed then one of the following options can be used to solve the understeer:
1) Reduce front ride height
2) Increase front aerodynamic downforce. If only the rear is adjustable then reduce rear downforce.
3) Check tyre pressures with a gauge to ensure that the tyres are operating within recommended hot temperatures. Increase or decrease pressures accordingly.
4) Check tyre temperatures with a tyre pyrometer and make sure that the temperatures are distributed by between 10 and 15 degrees Celsius between edges with the inside being the hottest. If the inside is too hot then increase positive camber. If the outside is too hot then increase negative camber.

If the answer was mid to low speed then one of the following options can be used to solve the understeer:
1) Increase caster angle
2) Increase front toe out
3) Reduce front ride height
4) Check tyre pressures with a gauge to ensure that the tyres are operating within recommended hot temperatures. Increase or decrease pressures accordingly.
5) Check tyre temperatures with a tyre pyrometer and make sure that the temperatures are distributed by between 10 and 15 degrees Celsius between edges with the inside being the hottest. If the inside is too hot then increase positive camber. If the outside is too hot then increase negative camber.

Mid Corner
The first question to ask now that you have identified the understeer as occurring at the mid corner section is, does the car bottom out? If the answer is yes then the below answers can solve the understeer:
1) Increase front coil spring rate. This can be achieved by installing stiffer springs or increasing pre-load.
If the answer is no then the next question to ask yourself is, does the front of the car roll excessively? If the answer is no then the following solutions can be applied:
1) Soften front coil spring rate
2) Increase front damper rebound stiffness. Front compression stiffness can also be reduced slightly.
3) Reduce front ride height.
4) Soften front anti-roll bar stiffness.
5) Increase negative camber on the front wheels.
6) Lower front roll centre or raise the rear roll centre.
7) Check tyre pressures with a gauge to ensure that the tyres are operating within recommended hot temperatures. Increase or decrease pressures accordingly.
8) Check tyre temperatures with a tyre pyrometer and make sure that the temperatures are distributed by between 10 and 15 degrees Celsius between edges with the inside being the hottest. If the inside is too hot then increase positive camber. If the outside is too hot then increase negative camber.

If the answer was yes then the following solutions can be applied:
1) Soften front anti-roll bar stiffness
2) Increase front damper compression stiffness. Increase low speed if you have a high or low speed option.
3) Increase front coil spring rate.
4) Make sure there is no excessive droop in the front suspension causing the inside front to lose traction.
5) Raise the front roll centre.

Corner Exit
For corner exit understeer there are no more questions to ask. One of the following solutions can be applied:
1) Increase front damper rebound stiffness
2) Check tyre pressures with a gauge to ensure that the tyres are operating within recommended hot temperatures. Increase or decrease pressures accordingly.
3) Check tyre temperatures with a tyre pyrometer and make sure that the temperatures are distributed by between 10 and 15 degrees Celsius between edges with the inside being the hottest. If the inside is too hot then increase positive camber. If the outside is too hot then increase negative camber.

[SuperBuickGuy]

dusty, but pretty much ready to go again

even gear still inside

[DirtyWhiteBoy]

sounds like a blast!

[SuperBuickGuy]

Sounds like the two of you (you and the car, I mean) got thru the weekend w/o calamity so that's a BIG win!

Dan

the biggest win

[DanStokes]

Sounds like the two of you (you and the car, I mean) got thru the weekend w/o calamity so that's a BIG win!

Dan

[SuperBuickGuy]

I went, had a blast, took a friend, now he wants to set his C3 to race (the red one in this thread)....

and it is what I expected, my car is far better then me... I have much to learn - but it's a lot of fun.

[Monster]

In other news, Track Night in America is something I'm doing in August. Finally get the car out where I can wring it out... this weekend, Autox, a couple weeks later, a track night... about flippin' time.

[silver_bullet]

Best of luck ! Have a fun filled event!