Ratchet

Here are a couple of pics of starting to install the screw jacks in the front of the car

The first pic shows the tops off the original spring pockets cut out (sitting on blue rag) and a new 1/4thick plate welded in place.

The drill is sitting in a bushing that I made up it is in the hole that the screw will pass through. I put the k member back in the car and drilled through the bushings to locate the starter holes for the hole saw to cut the clearance holes for the jack screws.


The next pic shows the plate welded in place from the other side with the nut for the screw jack placed in location.


Finally here is a pic of the K member completed with Screw Jacks installed and ready to go back in the car


It Seems like almost a year since I started this but here is the K Member finally put back in the car. ( Had to completely strip the car fix rust spots and paint engine compartment and inside doors etc before I started to reassemble.

MdFormula350

nice work, are you planning on putting new engine mounts in? should be a piece of cake with it out.

slowTA

iTrader: (1)

Wont the screws hit the strut towers? I would sure like to see some pics of the whole thing installed, keep us up to date.

Zepher

iTrader: (1)

What are those for?

Dewey316

sweet setup. what springs are you goona use? that should be really nice for setting corner weights

MdFormula350

i was going tO ask that also, but didnt want to sound dumb

Zepher

iTrader: (1)

I don't mind sounding dumb. I know a lot, but not everything.

Dewey316

i assumed those were screws for wieght jacks on the spings, for making slight adjustments to the spring rate.

or for you 'nascar' guys 'wedge' adjustment.

but i may be wrong, hopefully he will post details.

breathment

ya im confused too.. im getting a little behind here on my "thirdgen inovations" having to work and drive a differen't car..

johnyIROC

You got it, that's exactly what they are.

And yes, a hole is being drilled through the front "frame rail" big enough for the bolt to stick through.

With screw jacks, the car can be setup for an oval, auto X, or drag all from a 5 min adjustment under the hood.

The weight jacks allow the ride height to be adjusted simply by cranking the screws up or down. And for the strip you can pre-load the right rear in a matter of minutes.

We're also using KYB AGX all around to make it fully adjustable.

Ratchet

Yup What Johny Said.

And yes we will be putting new motor mounts in. Car was a V6 all this work and we are doing the V6-V8 swap at the same time.

ontogenesis

k, i want alot more pics, i want a ton of info, and i want how-to's...this sounds real bad ***

Ratchet

As for Spring rates We are thinking about either
800 front and 170 rear or
900 front and 190 rear.

The first combo will give you 1.5 cycles per second and the second one gives you 1.6 cycles per second.

Anyone got any suggestions?

slowTA

iTrader: (1)

OK, you are going to have to explain that cycles per second thing!

But no matter what, I think it is going to a personal prefference kind of deal.

Ratchet

There are litterally chapters of books written on cycles per second as it pertains to high performance handling but to put it as short as possible:

cycles per second are how many times in a second a spring goes from compression to rebound and back to rest when the wheel contacts a bump.

the lbs per square inch of the springs as well as the suspension geometry affects the cycles per second of a given chasis.

a bumpy track requires a chasis with cycles per second of around 1 per second while a very flat track or road can have a suspension system that cycles at 3 cycles per second.

if the cycles per second are two high for a given track or road the tires will bounce and loose contact with the road. if the cycles per second are too low then the car will have a lot of body roll a be very lazy.

Sorry for the verbal diarea I probably should have never brought this subject up in the first place

Zepher

iTrader: (1)

This is some good info.
I am getting into road racing really soon and this should help out a bit.

slowTA

iTrader: (1)

Well if you are going for a rate between 1 and 3 then it looks like the car will be pretty soft for a race car anyway. I would really like to see how you come up with those numbers. I would think that your shocks and struts would have a huge affect on that rate, and I can't imagine how a formula would be able to compensate for that. Of course if KYB was able to supply you with the constants for their settings then it might be possible.

It sounds like you are going to have one killer setup on your hands. I would recomend the Tokico adjustables instead, but thats only because I use them and have heard that their warantee is pretty good.

blacksheep-1

Ratchet, I've been looking at your work and it is absolutely fantastic, to be able to fabricate like that is an awesome talent. That being said, you must be really really bored.

Ratchet

Added pic of K arm in car today 1/15/04

ckeene502

i had 900# springs from global west and they where great to me but i had 185 in the rear all in a 91 z

keene

BruteForce

A spring will only cycle as fast as the damper will allow it to. That is why you need a very good raodrace quality shock with high rate racing springs.

You planning on some circle track racing with that car? Why the weight jackers, You have individual wheel scales.

Ratchet

Thanks for the suggestion. I am starting to lean towards the 900lb front springs.

How did it ride on the street bumpy or ok? did the car push going into a corner hard ?

Ratchet

Planning on running in King of the hill races at Delaware international speedway. 1/2 mile paved oval. also plan on drag racing and autocrossing. Screw jacks and adjustable shocktower spacers and adjustable struts and shocks

Scew jacks allow for adjusting cross weight 50/50 for drag racing and autocross and 58/42 or someplace around there for circle tracks. Rear screw jacks can also be adjusted to give more bite at the drags.

BruteForce

Thnak you , however, I know what they do. I asked if you have scales to set them ? Scales are expensive.

Ratchet

No I don't have a set of scales but there is a good chasis shop a couple of blocks from my place that has scales I can use to do set ups.

BruteForce

How then are you going to be able to alter things at the track for setups at the different tiathalon events- you'll have no Idea what you have or what you are changing to experiment without having to drive back to that shop- Hope its close by

food for thought.

Don't get me wrong- its a nice setup- but you will need portable scales to use it.

johnyIROC

You don't see NASCAR crews putting the car on scales during a pit stop. You can set the baseline on the scales... and then small adjustments are made by how the car feels.

BruteForce

Not if he's making drastic wedge changes from circletrack to drag to autocross all in one day while trying to remain competitive.

It would serve much better to adjust the car by a panhard adjustment device rather than messing with front end wedge change- thus changing front traction charateristics through playing with front ride height on-the-fly. Better done through rear wedge adjustment or panhard roll center height.

Every time you dial those FRONT weightjacks, you had better reset you steering geometry or you will not be competitve- you would be better finding a good allaround height & handling position and leave it there.

Ratchet

.

johnyIROC

Lots of guys here are running the ground control weight jacks with no problems at all, some are slammed to the ground. The "baseline" settings for drag, autoX and circle track will be recorded and used as a starting point each time and fine tuned from there... after the event is over the screws will be set back for normal driving. I really don't think you know what you're talking about, one or two turns isn't going to throw off your geometry a significant ammount during a racing event.... I agree you wouldn't want a ton of wedge in the car on the freeway, but obviously that isn't going to happen because after the event they will be returned to normal.

RegaPlanet

As you and Johnny already know I'm running the GC setup with 850 lb fronts and 175 lb rear springs. I'm really thinking about coming down to an 800lb front spring at a 10.5" free length height(currently the fronts are 9.5" free length). I ran the car at one autocross event this past year with the new setup but can't fairly evaluate. I was running on street tires with poorly damped(for racing) regular KYB's(not AGX's but Koni Yellows are here to replace now). One thing I will mention is the cars transitioning is AMAZING with such a high spring rate and being lowered some. Also Sam Strano has won an SCCA championship with Koni yellows, 800/150 spring rates, T2R diff and 16x10 wheels on Hoosiers. He and GC both seem to think the magic is right around the 800 mark for front and anywhere between 125-175 for rear.

The work looks good guys. Looking forward to racing with you this next summer

Dale

iTrader: (12)

can you guys clue me in to where you are getting these springs at please.

RegaPlanet

Our spring size is pretty common so most motorsport shops will be able to hook you up. Otherwise Ground Control distributes Eibach and Suspension Springs Specialists springs for pretty much any rate you could want.

Dale

iTrader: (12)

Thanks for the name brands.

I only have one local motor speed shop, clear on other side of town, and are not to friendly, and have to order everything.

I doubt you know any online places since you get them local?

RegaPlanet

Ground Control

ckeene502

hay rachet...i felt the car handled great. i ran stock wheels with 245/50/16 bfg comp zr's in front and255/50/16 comp t/a r1's in rear. i drove the car on the street and loved it. i also had the global west track link, solid bushings in front and herb adams solid lca's and panhard rod. but i also had kyb shocks....wish i had something alittle better. the car is gone but i still have all the uspension stuff on my 89 i am building . i want the weight jacks in the front but dont know if they will clear my headers.

keene

Ratchet

thanks for the tips on the spring rates. That magic number sure seems to be around 850lbs.??? i thinks um ah yeah thats the ticket 850lbs ?? me thinks.

As for screw jacks hitting on the headers: If you get your car set up to the ride height you want and measure the amount of interference with headers etc. (There shouldn't be any with our set up) you can then just cut that much off of the screw and eliminate the interference while still allowing for a significant amount of adjustment. Even if the screws are flush with the frame rail there is still about .75 of an inch adjustment available.

Ric

Ratchet

First of all I don't know of any events like these triatharace thingys you are talking about. Do they exist/// cause it would be a blast to do all three in one day or even one weekend.

Back to your comments though. You make some good points. The car is set up with 4 screw jacks. one at each corner of the car. There is an adjustable panhard bar in it with a solid bushing on the chasis side and a spherical rod end on the rear end mount. Got some other adjustable goodies also. The plan is not to jack the front end around ridiculously to get wedge into the car. All adjustments will be used as appropriate to the handling problem being addressed.

Ric

Chickenman35

Just a comment on spring rates and MFGs. I autocross my car and have got the suspension very well sorted.

I just changed all of the suspension setup on my car to use proper racing Hypercoils. I was using Suspension Specialists rear springs purchased through Ground Control.

I am not at all happy with the Suspension Specialists springs. Having rate checked my old springs ( they speced out at 170lb\in ), I ordered 175lb\in Suspension Specialist springs from Ground Control ( to go with their adjustable ride height collars ). The SS springs were way softer than my old 170lb\in springs. I'd think that this was a one off...except that a friends SS rear springs also seemed very soft.

Either way the problem has been corrected. We are now using Hypercoils all around. I have just install a set of 200lb\in Coil - Overs in the back. The car feels much better now. Before it felt very soft and droopy in the rear with the SS springs.

Now that I have the SS springs out of the car, I am going to take them over to my buddy's race shop and rate check them. I will post the results tomorrow....but I'm thinking they're going to be far shy of 175 lb\in.

BTW...car now has some very nice ride height adjusters front and raer. Not weight jackers...but far cheaper. Front height adjusters were $39.95 each. Front Hypercoils were $38.99 each and Rear Hypercoils Coil-Overs were $48.88 each.

Hypercoils are big race spring mfgs. Extremely good quality. Very popular with the Nascar crowd.