JakeFusion

iTrader: (7)

Hi all, I am wanting a very good handling car for use on public track days and SCCA solo events, as well as just fun driving around back roads. I don't plan to drag race, so I'm not worried about that, but I would like a suspension that plants the rear, so when I come out of corners, I have traction. I have a 99 Trans Am and I'm trying to figure out what will make it handle like the Vette without making it feel like a boxcar (cept for the feeling like its on rails part).

So, after some research, this is what I've come up with:

H&R Stage 2 Coil Springs (600#/200#)
Koni Single Adjustable Shocks
Strano Custom Hollow 35mm/22mm Performance Sway Bar Kit
UMI Single Adjustable Lower Control Arms
UMI Lower Control Arm Relocation Brackets
UMI Single Adjustable Panhard Bar
UMI 3-Point Subframe Connectors
UMI Tunnel Brace Mounted Adjustable Torque Arm
BFGoodrich g-Force K/D 275/40-17 F and 315/35-17 R Tires on lightweight Fikse Rims

What do you guys think? Anything else, something you would change/delete?

Thanks!

Sam Strano

iTrader: (41)

I think we need to talk... Lots of things on the list aren't very high on the priority list IMHO, and will also remove you from the classes the car would be most competitive in. Some things are flat out not appropriate for a car on a track or autocross. You wheel/tire combo can be hugely improved upon, etc.

There are some things that are huge but missing such as, but certainly not limited to an upgraded Limited Slip unit, good seats (car is only as fast as the driver can make it and flopping around it NO help). better brakes, and so forth.

I think you should take the time to do you research fully. Pick up the phone and call me. And by the end of conversation, whether or not you agree with me or not, you'll have a much better idea about where to go and in what order.

Adrian87GN

iTrader: (5)

Yes if you are serious about this call Sam. You're about to spend alot of $$, don't spend it in the wrong places.

Cal

iTrader: (1)

Ditto. I bought a lot of parts for my car before I started autoXing or had even heard of Sam Strano. Most of those parts I've had to change out, not all at once, but as I learned there were much better options. It saves a lot of money to only have to buy each part once.

Some of your choices sound good to me, and some not so good. An additional important item to consider is a good worm gear posi. Sam can set you up with the right kind.

jyeager

Since you mention the posi, what type of diff. is best for road racing? I was under the assumption that the Torsen was superior to a standard clutch-type posi.

Sam Strano

iTrader: (41)

Helical diffs are generally regarded are "better" for uses involving turns. A Torsen is a helical differential, but not the only one. They just happen to make the most kick-*** one for the 7.5" rear.

JakeFusion

iTrader: (7)

I should mention I have a 12-bolt with an Eaton posi and 3.73s on the way with a LS2 402 making about 530rwhp. Also, I have a Baer Extreme 13.5" Alcon 6-piston front big brake kit waiting to go on with the wheels.

I plan to run 315s all around on road courses, and 275/315 on the street.

With that said, I could go QA1-ended LCA/APHB, but I want this car to be somewhat manageable on the street.

Cal

iTrader: (1)

I run QA1-ended LCA/APHB on the street and haven't had any issues with them. Can't even tell they are there in normal driving.

I'm pretty sure you can get a Torsen type posi diff for a twelve bolt. I suggest you quickly call up and see if you can cancel out of that Eaton.

dailydriver

Last time I checked, you could not get a T2R for a 12 bolt, but that may have changed. I believe you can get a Detroit True Trac, but as Sam will tell you, these have only slightly more bias than our stock/OEM 10 bolt Torsens.

Cal

iTrader: (1)

Yeah but any worm gear diff would be much better than a clutch based posi. I'm not sure if it was the True Trac I rembered or not. I have a 9 inch, so I don't pay that much attention to 12 bolt stuff.

YellowToy/A

iTrader: (1)

Jake

How low do u want to run u car. U need more spring rate to keep your car off the ground. I have ground control springs they let u adjust the ride heigth and pick the spring rate. Stock rate is about 300 lb/in and for stock ride height. That is OK. If u want to lower your car u need more rate. I lower mine to 26.5 that is about 3/4in. I have 400 lb/in spring. They work well for me. Sunny day car that will go to the track now and then. if u want more rate go with 450 but I think 600 might be more that u want. If you lower your car to far it will not handle, so be careful. You can get the ground control set up all the way around for 360.00$ good luck and I think the stuff on your list is good except for the springs.

JakeFusion

iTrader: (7)

H&R have 600 lbs linear front springs and they lower the car about an 1-1/4 to 1-1/2. Ground Control is something I've thought about, or even something like DRM or LG coilovers (but waaaay to pricey for aluminum bilstein/hyperco coilovers)

The only concern I have with a POSI is heat. The detroit locker is stronger than the Eaton POSI, because it has larger and heavier clutch packs.

Sam Strano

iTrader: (41)

He asked specifically about racing the car in autox and some track event. Things I not only do, but do *pretty* well as I have a 3 different SCCA National titles. 2 Solo 2 National Championships and a ProSolo series Championship.

You can get GC coil-over stuff from some places cheaper than I have them. And you can spend a LOT MORE to get coil-overs with non adjustable shocks. But what you don't get is the technical advice on spring rates, bar sizes, tire sizes and so on. If money is the absolute bottom line, then take Yellow T/A's adivce. If you are like me a willing to pay a few bucks more (and often I'm not more expensive on most things), then I suggest you pick up the phone and call the one person on this board who has direct experience with your needs and the results to back it up.

dailydriver

Lockers have clutch packs?? I thought it was either locked or unlocked, no slipping? Isn't one of the reasons DLs are stronger because they don't have clutch packs?

Cal

iTrader: (1)

That is correct. If it has clutch packs it's a limited slip diff, not a locker. And I would not expect anyone to want a locker for autoX duty, unless you like driving a pushy pig.

YellowToy/A

iTrader: (1)

Sam what he said is

"Hi all, I am wanting a very good handling car for use on public track days and SCCA solo events, as well as just fun driving around back roads."

NOT
"He asked specifically about racing the car in autox and some track event "

I am not tring to sell anything. Just give my view. Not everyone on here wants just your advice.

I wound never say "I suggest you pick up the phone and call the one person on this board who has direct experience with your needs and the results to back it up."

Any one who reads this board know u have the largest one. Other people have advice to. be nice

Cal

iTrader: (1)

Maybe Sam could have said it a little better way, but Sam's autoX setup is also excellent for "just fun driving around back roads." 550-600 lb/in front springs with 150 lb/in rear springs is not too harsh at all for the street, as long as you have some good shocks and don't lower the car too far. You don't want it riding on the bumpstops. I think the 26.5" ride height you cited is perfect.

Sam Strano

iTrader: (41)

And if he can have a car that's more than competitive in Solo, and a blast to drive on the street as well, why would he want to cut himself off at the knees classing wise for the autox? I take that into consideration, a lot.

And the fact is a fast autox car is going to be a fast street car. The dynamics of performance driving are the dynamics of performance driving. What changes between street, autox and the track is simply the ability to get more from the car safely.

Other opinions count, certainly. I just think you gave some poor advice in post #11 and was proving my point. Jake I'm sure is a big-boy and if he doesn't want to call, and at least hear what I have to say, that's his decision.

YellowToy/A

iTrader: (1)

Sam help me out here where is i wrong in post 11. Are ground control bad???? Are my rate wrong????? Do i not understand y u need higher rates????

dailydriver

From what I understand the Trans Am series cars run lockers, BUT these are purpose built, tube framed, 700rwhp, (4 link rear suspensioned??) race cars that throttle steer around turns anyway. Also, the rules dictate them running lockers, so if they could, I'm sure they would run a high bias Torsen type diff.