what can we do to make our cars handle with like these imports

[UNGN]

Originally posted by Turbo6inKY
What are you using for your rear control arm bushings? Still rubber? I'm trying to find somebody who's put in sphericals to see how much better it gets vs. the extra noise.

We are using ungreased poly. We are going to make them greasable (It's on the list of winter changes).

I was watching our race video last night. On the last corner, 1.5 miles from the north finish, we hit a rough patch at the apex (broken pavement) and the car hopped sideways 10 feet and we slid sideways at 110 mph through the weeds. It was totally controllable, but we'd like the rear suspension to be able to absorb those kind of hits when the car is cornering near it's limits on a given road and avoid off course excursions in the future.

The hit on the inside rear tire in combination with the monster sway bar basically picked up the whole back of the car and threw it sideways.

 

[Turbo6inKY]

You may want to look at dumping the poly completely. The control arm attachment points need to articulate laterally in addition to rotationally. The poly doesn't allow it. Rubber does, as do sphericals.

I had poly in mine, and in transitional maneuvers the rear end would bind up and the car would spin. I put the rubber back in and the spontaneous spinning has disappeared. Now, the only way I can induce oversteer is with the throttle or trailbraking too heavily.

What you experienced is pretty similar. Steady state, then something upset the car. The rear suspension bound up instead of articulating to absorb the impact, and you lost traction.

 

[DCTurbo]

I installed the Global West Negative roll system (frt upper control arms, springs,frt sway bar,rear control arm,no rear sway bar) with their Delum bushings. My wheels are the GTA 16x8" with 245/50 fronts and 255/50 rears. The front brakes are 12" 1LE. The car handles great on the street. I've never road raced the car but it gives the ricers a run for their neon seat belt cushions!

 

[UNGN]

Here is a video of our slide through the weeds. The corner had some nasty heaves near the apex and you can hear it getting airborne and landing just before we went off the road and I eased out of it. I don't think it slowed down below 100 mph the whole time. Speed at the start of the video is around 135 and the end is 140.

Weed wacking

 

[87grandnat]

daang that looks like it would be a blast!!!!

 

[Turbo6inKY]

Originally posted by UNGN
Here is a video of our slide through the weeds.
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That was a great save.

 

[UNGN]

Originally posted by Turbo6inKY
That was a great save.

I thought it would be a lot worse than it was. There's that moment when you feel the car airborne and say to yourself "this is going to be bad". The driver side front tire stayed on the road and I managed to get the car to get back behind it. The long wheelbase is definately an asset in situations like that. Earlier in the morning, the 2003 120 class winner spun his '65 Corvette in almost the same way... back tire off the road and a spin, except he spun for about 200 yards and hit a mile marker, ending in the ditch. A race prepped SVT contour in the 110 mph class got a rear tire off the road, bent a suspension member causing massive tow out eventually resulting in a double roll over after 1/4 mile of the driver trying to save it. LOTS of horror stories from this event, but we keep coming back, because it is too much fun.

Here is some more video from the event. It starts with the fastest part of the course: a 4 mile straight where we cruise at our 140 mph tech speed, then goes into the curves on the north end of the course. You can see the car catch air a few times. Towards the end of the curves I'm 7 seconds down for 120 and, I'm trying to hit the rev limiter (6K) in 4th which is 141 mph on a short straight and stay in it just a second too long and over cook a corner.

Check Point #3 to Custer County Line

 

[Ed Valvo]

Sounds like a V8? Or is it a 6?

 

[Turbo6inKY]

Originally posted by Ed Valvo
Sounds like a V8? Or is it a 6?

502 inch Chevy

 

[Ed Valvo]

My god! It fits?

 

[UNGN]

Originally posted by Ed Valvo
My god! It fits?

502/502

It's actually easier to change spark plugs with the 502 than on my turbo cars, has A/C too. I'd love to have a T/A block turbo motor instead of the 502, but I'm not made of money anymore.

 

[Ed Valvo]

Because you bought a 502/502!

Those runs look like a blast. It makes my track days look like a sunday drive.

 

[jsta6]

Originally posted by Ormand
Renthorin said"

It is "Project G Force", and it is here:Hot Rod's "Project G Force"
It was a complete build up, but the suspension and brakes part was not too far out. They did use the taller front spindles, and Baer 13 front discs.

What issue is that from?

 

[jsta6]

Originally posted by UNGN
Here is a video of our slide through the weeds. The corner had some nasty heaves near the apex and you can hear it getting airborne and landing just before we went off the road and I eased out of it. I don't think it slowed down below 100 mph the whole time. Speed at the start of the video is around 135 and the end is 140.

Weed wacking

OK, that just kicked ass...

 

[I eat Z06]

Been doin some more comparason. Pulled a turn at 66-68mph in the STi and 58-60 in the GN. Neither were skreetching tires. But I was feeling them lateral g's pretty well. Kinda dont wanna push the cars to their limits of "loosing too much traction".

Nick

 

[BigBlockOlds]

Its 20 year old technology but was done with mostly stock suspension:

FE3X Concept

Alignment specs:

Caster: 2 1/2 degrees

Camber: -1 1/2 degrees

Toe: 1/4" out

1.5" front sway bar, stock 3/4" rear bar, polyurethane bushings and Koni shocks.

The above alignments would wear the tires out pretty quick for a driver but I plan to give it a try on my '87 Cutlass when it gets out of paint jail.
I've been told that the Toe out is extreme and is what is going to wear the tires out quickly but will aslo provide a very quick steering response, which is what I want for my SCCA racing. And since the car is only driven maybe 5000 miles per year it won't be much of a concern.

 

[Turbo6inKY]

Originally posted by BigBlockOlds
Its 20 year old technology but was done with mostly stock suspension:

That much toe out will make the steering responsive. It'll be very twitchy on the highway and very prone to tramlining.

It could very possibly wear through a set of street tires in 5000 miles.

 

[BigBlockOlds]

Originally posted by Turbo6inKY
That much toe out will make the steering responsive. It'll be very twitchy on the highway and very prone to tramlining.

It could very possibly wear through a set of street tires in 5000 miles.

Yeah, thats what I've been told. But I'm going to give it a try and see what happens.
I may just upgrade to the G/W arms and set the alignment at 2.5* caster, -1/2 camber, and 1/32 toe and then go from there.

Out of curiousity, how would the car handle if you were to keep the FE3X alignment specs but just not run as much toe out?
Thanks,

 

[UNGN]

-1.5 is a lot of camber. If the toe didn't wear the tires out, the camber will.

With tall spindles, I wouldn't think you'd need that much camber.

We run -.5 camber and it's pretty visible.

1.5" is a pretty big front swaybar. The camber is probably to reduce the understeer this would cause. I'd go with a stiffer spring and less swaybar in front.

 

[GNVYUS 1]

Here is what helped big time for my GN www.p-s-t.com
The Super Kit was around that price of $360, then I added

Boxed lower and upper rear arms with PST poly bushings
Lowered the whole car 2" with PST springs
Run 265/295 tires on 15" rims
I use Aerospaces 10 3/4 four piston brake kit with stainless lines

If I wanted to compete today against the imports, all I would add is solid rear lower control arms, the HR Bar, and 17 inch rims with 275/295's BFG Drag Radial TA's on all 4's.