333pg333

Yes for sure Rod. Just small steps and no illusions either from my p.o.v. More, just throwing some ideas to the boards in general and seeing what comes back. As mentioned, merely moving up in spring rates will meet diminishing returns. Just wonder how far the ceiling is over where we're at presently?

thingo

I think there is a lack of rigidity that has to be addressed.
Besides the chassis the modern cars also have a lot of braces across the suspension.

JDS968

The issue of rigidity is something I've been thinking about for a while...

If a 924/944/968 were caged such that the structure connected to the suspension pick up points at all four corners, and to the unibody at key points including all four corners of the roof (to ensure rigidity in all three dimensions), is there any reason why the car could not be made as rigid as any modern high-performance sports or racing car, assuming that the cage is welded to the car securely enough to make it functionally one piece with the body, and that it can be made arbitrarily rigid between any two particular points?

mikey_audiogeek

Short answer: There's no reason it can't. I agree this is the way forward for the 944 shell. All later cars have the benefit of FEA (and crash regs) to end up with vastly stiffer shells. As Chris and Eric (amongst others) point out, increasing suspension stiffness compensates for bad suspension geometry, up until the point that chassis flex (nice undamped spring) becomes significant. Then it's either a) stop or b) increase your spend rate...

Edit: Just making it clear that I agree with JDS968. Damn it's difficult to answer null questions succinctly!

gt37vgt

Your really making me feel mad about my car Now Pat. MY car realy needs to compared back to back with yours as they have been developed very differently yours has nice coil overs hard springs brand name sway bars and mine has very modest bilsteins home made sway bars and heaps of work with revised geometry to reduce toe change and chamber change on the rear and similar on the front . anti swat and ti dive minimal bump steer ect

Julian Allen

Spammer.

Chris White

Have you ever seen a track car lift an inside wheel? That would be 100% load transfer....if both wheels stay on the ground its less than 100%. You can affect the load transfer.

You can vary the side to side load transfer for each axel and fore and aft (the CG does not change as much under braking with stiffer springs)

Chris White

Finch runs an NA not a turbo, and it’s a full tube frame chassis. I am sure he would be glad to help….for a fee….a rather large fee.

A strut suspension will never be as good as a ‘modern’ design….we can come close but we will never be able to get both front tires flat on the ground….!

David Floyd

You need something like the ex Woodie W car to be "The Big Dog" on track, as you can tell by the description not much left from the stock car, fastest 944 Turbo based car I've seen.



"The race car you are looking at is the fourth and final 944 Turbo built by Worldwide Motorsports. It started life as a 1987 Porsche 944. The tub was stripped and acid dipped. It was then fixtured to our in house surface plate, the floor and firewall were removed and a complete tube chassis was fabricated inside the remaining tub. It was then painstakingly assembled with the best components available. Many of the parts on this car are one off pieces made by some of the most respected names in the racing industry. No expense was spared in building this car! This car currently holds lap records at Lime Rock Park and Watkins Glen. Car has PCA and SCCA log books.

Chassis:

Full tube frame with removable tubular front clip (shock towers forward)

1.5x.095 DOM cage with NASCAR Door bars, Tilton Pedals with remote reservoir and brake bias adjuster, Momo steering wheel with integral push to talk for radio, Sweet quick release steering wheel coupler, Borgeson collapsible steering shaft, Kirkey Deluxe Road Race seat, Removable firewall and transmission tunnel. Many other tricks as well.

Body:

One of a kind Carbon fiber IMSA/Trans-Am style clam shell nose and Front splitter/under tray by Crawford Composites (we own the molds). Fiberglass door skins, Rear quarters and Rear bumper with extensive modifications. Carbon fiber Crawford rear wing. All Lexan Glass.

Roof drip edges filled and radiused. Many other tricks here as well.

Front Suspension:

Bilstein Coil-over Strut, All pick-up points converted to Spherical bearings. Billet Aluminum, Center Lock, Pin Drive Front uprights with huge Double Row bearings by Fabcar Engineering (we own rights and drawings). Billet Aluminum front lower control arms, Porsche 944 turbo cup car steering rack with spherical bearing tie rods mounted in double shear. Ferrari F50 Brembo calipers with aluminum brake hats and floating rotors. 17x 11 3 piece BBS wheels

Rear Suspension:

Bilstein Rear coil over shocks, all pick-up points converted to Spherical Bearing. Fabricated rear torsion tube with Billet Aluminum caster/camber adjusters. 996 twin turbo rear calipers with aluminum brake hats and floating rotors 17 x 11 ½, 3 piece BBS wheels

Engine:

500+ hp 2.5L 4 cyl. Turbo. Motec M4 engine management and Data Acquisition, Dry sump oiling system, Carrillo Rods, JE Pistons, rotating assy. Balanced, Dual Ceramic ball bearing turbo, hand built 321 Stainless Steel equal length header and merge collector with Tial waste gate, All internal engine parts coated by Swain Coatings. Block converted to Steel sleeves, Cylinder head and block o-ringed, Fidanza Alum. Flywheel, ARP Studs everywhere. 944 NA cylinder head with extensive porting and flow testing. Carbon Fiber Barrel Valve intake by Jon Milledge Engineering.

Transmission:

968 speed with Guard Transmission Race limited slip differential. Set up for Trans cooling. Hand polished CV joints. Custom shift rod and arm, Custom Trans mount and cross member.

Fuel System:

Custom 22 gal. Dual sump check ball collector fuel cell by Fuel Safe, remote roll-over valve, Stainless AN lines and fittings, electronic fuel level gage (that actually works), Billet aluminum Aeromotive fuel pump and filter.

Misc

Motec Data Acquisition dash and LED shift light, with lap timer and beacon
Torque tube mounted mini alternator
ARC touch pad control switches with built in circuit breakers
10 # Phoenix Halon fire system
AMB transponder
2 complete exhaust systems from Turbo back (1 with Muffler)
Spares Included with sale of car
1 complete fresh 2.5L engine exactly the same as the engine in car
1 spare header with Tial waste gate
1 complete Motec M4 engine management system with engine and car harness
1 968 gearbox fresh same as in car
1 set of drive axles
1 Complete set of Pin Drive Center Lock billet aluminum front uprights and hubs
1 Complete set of Pin Drive Center Lock Rear control arms and hubs
All suspension tools and service parts (nuts, bolts, spare drive pins etc.)
1 Set of Billet Aluminum Front lower control arms
1 Set of Front Rotors (1 L 1 R)
1 Nose
1 Front bumper
1 Front splitter
1Left and 1 Right front fender quarter
1Left Rear Quarter Panel
1 set of wing brackets
3 carbon Gurney lips for wing
1 set of Carbon Brake ducts
2 complete sets of BBS wheels
2 Radiators
1 Intercooler
1 Windshield

Porsche 944 turbo PCA GT 3 race car, fresh 500+Hp 2.5L Carbon Barrel valve intake, Motec M4 ECU and data acquisition dash, 6 speed, Crawford Composites body and wing., Billet Alum uprights . Center lock wheels. Full cage with NASCAR style door bars.3 sets of BBS wheels, spare engine and gearbox Huge spares package. Lap records @ Watkins Glen and Lime Rock. PCA and SCCA log books.

See link for full list and spec sheet.

$90,000 or best reasonable offer"
__________________

Duke

I think this topic is very interesting and hope something good comes out of it. I suspect it will end up very much like the previous "how to make a 951 handle like a GT3" thread (don't remember the thread name quite right..)

Here's my input:
1. I would say that body stiffness is no problem at all to correct with a proper cage.
2. It's easy to outpower a Cup. My car running 0.6 bar of boost accelerates faster than a Cup.
3. Even 996/997 run McPerson struts up front.
4. It's possible to come very close to their braking.
5. It's not possible to compete with the grip coming out of a corner due to the weight bias.
6. A transaxle design is generally pretty good and a 951 can be made light
7. Good aero is not too hard to set up.
8. Widebody allows for large tires
9. Last and most important - the main drawback is the rear suspension.

mclarenno9

Of course, but you can't affect the load transfer without changing CG height or the cars dimensions (wheelbase and track). There is one exception I can think of:

You can force an increase side to side load transfer by putting huge swaybars on your car. I don't know of a way to reduce it though!

Just because a car with stiffer springs doesn't roll/squat/dive as much doesn't mean that you have affected the actual loads at the contact patches of the tires. They will remain the same.

LS1Porch

Don't take this as an insult, but what i saw at the 8:00 mark was you getting passed by someone who had a much faster car (power-wise) who took a better line than you. Story of my life, lol! I don't think heavier springs or a stiffer chassis is really going to win that battle?

333pg333

Adam, if you drove my car now on the track you would think that it's a half decent package, and it is. Don't get me wrong here. I'm not trying to re invent the wheel...just make this wheel roll a little more efficiently.


Lol, none taken. I was going flat out (the only way I drive hehe) and deep trying to make him work for it. Even though he eventually goes past, he was behind me for a while. He had to try a little bit. As for the line, I was just off the entry point for this pretty fast 90o turn so had to stay off the gas for a little while and lose some speed before re commencing acceleration. We hit about 145mph down the straight and go through that turn at 120mph so it's fairly fast. If you get the entry point wrong it's hard to get back to the apex.

Nevertheless, I'm not trying to beat a Cup Car. I don't have any crazy illusions.
This is just an open question trying to get a few opinions. Feel free to say whatever you like.

mikey_audiogeek

Patrick, here's another thought: I've always reckoned that the 993/996 EVO uprights and track arms (and brakes woo hoo!) would fit the 944. Whaddayarekkin? Could be a step in the right direction.

333pg333

Mikey, I was heading in this direction a while back when I was looking to build something more custom than this current car. I wonder what sort of costs are associated with these items and would we need to go for the EVO versions?