Need Upright/Spindle Information, ++++

[tyoneal]

To All:

I am currently planning on using the stock spindle with the Howe Tall Upper Ball Joints. The Brakes will be Wilwood Radial Mount Design (No Caliper offset, like Original Disk Brakes) Global West UCA, Hotchkis Sway Bar, ATS Steering Box, Penske Double Adjustable Shocks. Wheels will be 17X8, 3.75 Offset (I think) Tires will be 245X45X17. Full Cage. LD 3-Link. 17X12 Wheels 315X35X17 Tires. Spax Double Adjustable Shocks in Rear. Weight Jacks on all 4 Corners. Original cleaned up and re-wielded SubFrame.

What are my choices for the best handling Performance Given these Parameters? (Other than Driving Lessons)

Is there a particular Spindle that one would recommend that would work instead of the original?

My Guess is, I am pretty much set as far as suspension is concerned, however is there is something I have over looked that would make a big difference what would it be?

I plan to move the engine rearward as possible without destroying the firewall and dash, and saving weight where I can. Engine is a worked over LS3, behind it is a Tremec 3550, 5-Speed.

Does anyone make a subframe that I can Run the parts I have, would be lighter, and allow for some Large Front Wheel/Tires? (295-315 Range)

Thanks,

Ty O'Neal

[David Pozzi]

Penske shocks are expensive, are you sure you need to spend that much? Why mix shock brands?

I would go with a 255X17 front tire minimum, A 275 might be possible if your car isn't super low. A 9" or 9.5" rim is needed for the 275. I don't think a 295 is going to fit inside the wheelwell and turn without hitting, it would take some major surgery. Another problem with the stock sub is, there is a fair amount of scrub radius (depending on wheel offset) that makes the wheel move forward and rearward a lot when it turns.

How are you going to run weight jacks on all 4 corners and still have shocks?

Only moving the engine a couple of inches isn't worth it in my opinion. Too much work and too many changes to gain a couple of lbs off the front wheels. Better to focus on making the front end lighter with other lightweight components.

[tyoneal]

Penske shocks are expensive, are you sure you need to spend that much? Why mix shock brands?

I would go with a 255X17 front tire minimum, A 275 might be possible if your car isn't super low. A 9" or 9.5" rim is needed for the 275. I don't think a 295 is going to fit inside the wheelwell and turn without hitting, it would take some major surgery. Another problem with the stock sub is, there is a fair amount of scrub radius (depending on wheel offset) that makes the wheel move forward and rearward a lot when it turns.

How are you going to run weight jacks on all 4 corners and still have shocks?

Only moving the engine a couple of inches isn't worth it in my opinion. Too much work and too many changes to gain a couple of lbs off the front wheels. Better to focus on making the front end lighter with other lightweight components.
==================================
David:

Thanks for your response again, I really appreciate you taking the time to write. You have been around these cars so long, your kind of like speaking to an oracle.

In any event here are the answers.

I have the two brands because the DA Spax Shocks are new and they came with the 3-Link and were valved for it. I have the Penskes on the front because they are shocks I can use forever and re-build and/or upgrade if I ever wanted to, and I can have them re-valved easily. The Technology of this brand is amazing. I know they are outrageously expensive, but the adjustment is decently easy for me to do with my replaced right shoulder. When talking to Tyler, he said they were overkill to a point, but the quality of the shocks and tune-ability is a fairly big factor. (FWIW: I have bought so many things for this car that are technically overkill, that it has been rather funny) I do have an extra set of 3-piece Kinesis that are 17X9.5 that will hold a 275 very easily, along with a matching set of 17X11's. At this point I really want to Run the Mini-Lites as I almost Never see a set and I always loved them on the Trans Am cars.

I have the 245 mm for the front so I can run a matching set of Sumitomo HTR Z Tires. I am expecting to go through several sets taking lessons and they seemed to be the best bang for the buck in the 315 mm size, otherwise I would have the 255 mm.

The weight jacks have been installed to allow the car to be easily balanced with me in it, and to making it easier adjusting the ride height (Remember my Shoulder), hopefully without changing the efficiency of the suspension.

When I saw these set up, while not inexpensive by any means, I thought they would be worth it to me to make things in general just easier to do some adjustment on the car. Since my Crash, anything I can do to keep from working so hard doing simple task, and to keep the level of my frustration down. They were $900 for a set of 4 not including installation, but I can adjust the rear weight and ride height from inside the trunk, and from under the hood for the front. Laying on my back and working "up" is very challenging now.

The books I have been making my way through, talk extensively about getting the car properly tuned for the track, and at the speeds you will be running, plus giving the car correct balance, proper anti dive, anti squat etc. etc. etc. This will give the Tires the best chance of staying in proper contact with the track, and biting into it as efficiently as possible. Once the tires lose proper contact and traction, it doesn't matter how much you spent on everything above them, your sunk. (I know you already know all this, I was just referring to the book so my response might be more readable for other people)

Then you also have the proper aerodynamics (As best as you can) in place as well) I still have to get this in place.

Don't know if any of this makes any sense, but your input on my thoughts is welcome, whether good or bad, I just want to learn as much as I can, and as correct as I can.

BTW: My Mini-Lites are made by PS Engineering. He's a really nice guy to work with, and the Black Powder coating in the center looks great on the red car.

Don't spare any words if you are so inclined, I will honestly try and follow your advice as closely as possible.

Thanks again,

Ty O'Neal

[David Pozzi]

Ty,
First, thanks for the compliment, but I can screw up just as bad as anyone, just ask my wife. :lol:

"I have the 245 mm for the front so I can run a matching set of Sumitomo HTR Z Tires. I am expecting to go through several sets taking lessons and they seemed to be the best bang for the buck in the 315 mm size, otherwise I would have the 255 mm."
Not sure I understand the above, 245's are limiting, 255's are getting there, 275's are where you'd like to be if you can manage to clear everything and be as low as you'd like. Are you saying Sumitomo does not make a 255 or 275?

I agree a compliant suspension is best, many guys haven't driven a "good" car, so they don't have a good frame or reference about how good their setup is, or how much better it could be. You can instantly go pretty quick by making the car super stiff, but to go faster you then need to soften it a little and give the shocks a chance to do their magic and keep the tires in contact with the road. Another pet peeve I see a lot is: you can have a balanced setup but have too much front brake bias which will put the car into an understeer mode on corner entry.

I'd like to see how the weight jackers were installed. The easier the shocks and weight jackers are to adjust, the more likely you are to take advantage of them.

I know Phil Schmidt, he used to vintage race a Lola T-70 like mine, - great guy!
David

[tyoneal]

Ty,
First, thanks for the compliment, but I can screw up just as bad as anyone, just ask my wife. :lol:

"I have the 245 mm for the front so I can run a matching set of Sumitomo HTR Z Tires. I am expecting to go through several sets taking lessons and they seemed to be the best bang for the buck in the 315 mm size, otherwise I would have the 255 mm."
Not sure I understand the above, 245's are limiting, 255's are getting there, 275's are where you'd like to be if you can manage to clear everything and be as low as you'd like. Are you saying Sumitomo does not make a 255 or 275?

Not in the same Type of Tire. The HTR Z were the only ones at the time anyway, that would be matching AND offer the 315 width. No 335 mm are made by them or I would have chosen them.

I agree a compliant suspension is best, many guys haven't driven a "good" car, so they don't have a good frame or reference about how good their setup is, or how much better it could be. You can instantly go pretty quick by making the car super stiff, but to go faster you then need to soften it a little and give the shocks a chance to do their magic and keep the tires in contact with the road. Another pet peeve I see a lot is: you can have a balanced setup but have too much front brake bias which will put the car into an understeer mode on corner entry.

I'd like to see how the weight jackers were installed. The easier the shocks and weight jackers are to adjust, the more likely you are to take advantage of them.

I know Phil Schmidt, he used to vintage race a Lola T-70 like mine, - great guy!
David

David:

Do you know Casey Putsch? He currently has a Lola T-70 for sale that I have been looking at. it's a beauty, are you familiar with it, or him? He races it at vintage races on the West Coast.

Were the Economy not so Strange, I might take a shot at it, they have always been a favorite of mine, along with the GT40's, and of course the 917's, those were the 3 cars I watched as a kid when they were racing Le mans.

Anyway, another question I have:

I have heard that when choosing the right tire and width, you design a car, then depending on the cars weight and the downforce generated by the aerodynamics of the body and ground effects, you then use the tire that would best serve the speed and the weight including downforce, and the turns they would have to negotiate.

It basically becomes a function of optimizing the pounds per square inch placed on the surface area of the tire that is in contact with the pavement. Too Small, and they bite good, but there is not enough tire to keep the weight of the car from pushing it off the road.

From the opposite perspective, to large, and the psi on the tire patch is not great enough for the tire to bite properly, and even though you have plenty of width, it is unable to attach itself to the road well enough, thus the weight of the car again pushes the tire and car off the road.

The Tire pressure, compound, and the temperature of the surface of the track and tire, allows someone to use somewhat different width tires, compounds, within a specific temperature range and pressure and have the equivalent amount of adhesion with a given weight amount.

In other words, AFTER you design the car, will you then choose the types and widths of the tires. That said, I wish I knew the formula for this. Then I could take the weight of the car and get a decent idea what the optimum tire width for it would be, instead of just trying to shove as much tire underneath the car as I can.

What are your thoughts on this, and more importantly do you have the formula for this answer?

Thanks again for your thoughts.

Regards,

Ty

[FreddieCougar]

I plan to move the engine rearward as possible without destroying the firewall and dash, and saving weight where I can. Engine is a worked over LS3, behind it is a Tremec 3550, 5-Speed.

Does anyone make a subframe that I can Run the parts I have, would be lighter, and allow for some Large Front Wheel/Tires? (295-315 Range)



I agree with David, moving the engine back would help incrementally, but not enough to justify the effort. You can run most of you parts with our sub, with the exception of the steering box. I don't know of any aftermarket sub that has any provisions for the stock box. Your arms and your anti-roll bar will work. The shocks may work, but we have not installed that particular shock on our sub, so we can't guarantee it. You will have room for a 275 in the front. It is hard to put together a cohesive package with parts from a variety of manufacturers, as we (manufacturers) can't possibly test/verify every part out there. I have found that most of the time, the best results come from using one vendor for everything, whether you are talking suspension, ignition, paint, whatever. Hope that helps!
Tim

[Silver69Camaro]

Ty,
I think you're making this too complicated.

All you need to do (on our cars) is put the largest front tire up front as possible, and but a rear tire on that is about 15% larger, more if you have tons of power.

Our frame can accept a 295mm with our splined bar and minimal steering stops, but I'd only recommend if this is a serious track car. Be realistic now. Too large of a tire takes more heat to work properly...if the heat is not generated, you might as well step down to a smaller tire. Brake rotor sizing works the same way.

There are formulas for what you describe, but honestly, they don't really work for what we do. People outside of OEMs don't have the tire data needed for such calculations; even if you did, it's only a starting point. Most racing teams run the largest tires that rules allow.