atr911

Hey guys,

I'm new to the turbo world but I'm contemplating a 996 turbo as my next p-car. Was hoping you pros could answer some questions regarding the chassis.

1 - Seam or spot welded body?

2 - Adjustable OEM struts (ride height?)

I'm sure I'll have more, but I'll start with this...

Macster

The Turbo's suspension does not allow for ride height adjustment.

I'm almost sure the majority of the body/chassis/tub seams are spot-welded. There might be a few seams arise from the joining of panels that Porsche has deemed necessary to be seam welded, but chances are these are buried deep in the body/chassis/tub and not visible to you unless the car was stripped down to bare metal, if even then.

Every 'weld' you can see otherwise is going to consist of spot weld(s).

Spot welding is a very good process when done right and it is done right. Spot welding robots have been around about as long as there have been robots.

Plus spot welding avoids the higher cost of full seam welding which if done properly would almost certainly require the body be pre-heated and then stress relieved after the welding process. (And then the body might need cleaning -- sanding -- to remove the welding berries from the splatter.)

Sure one of the common mods to any car being used in competition is seam welding the body but the cost is not a factor and the shop has the time to do the job in small steps to avoid the risk of warping the body/tub/chassis. And if it does it can possibly make adjustments using an alignment (Celette) bench or applying heat/cold to shrink the metal panels to bring the hard points back into acceptable position.

Sincerely,

Macster.

cannon1000

Don't know about 1.

2) The OEM Struts are not adjustable. The X73 option lowers them over stock and are supposed to be great...but still not adjustable. I am looking to replace mine...but with non adjustable springs & struts.

atr911

Understood, but I'm simply attempting to compare it to a GT3 chassis which is seam welded for stiffness.

Maybe I can put it this way: when you jack the car up from the rear, can you get three wheels off the ground?

Kevin

You are comparing apples to oranges..

If you are buying the TT for the track, then you might be better off with the GT3..

You will have to dump alot of cash into the TT to make it comparable to a GT3 for the track use.

BTW, yes when you jack up one jack point you will lift all three tires!

atr911

Well not just for the track but just contemplating the differences between the chassis. 450 HP for $45K.

Can dump a lot of money into a $45K car if it has the right chassis to make a fun little track toy for less than a 996 GT3 and more power and torque.

I'd remove the front diff and drive shaft, throw on some Giro Discs, Moton suspension and some solid bushings, a couple bits here and there. Only thing I'd probably do that would be overkill is remove the sunroof and replace with carbon (leave it bare, that's sexy).

Could be fun! Just contemplating it...

Kevinmacd

Why bother just go buy a GT3!

atr911

LOL I came here looking for turbo support! Guess eveybody wants a GT3

Kevin

How about a gearbox rebuild after the 2nd track season.. What about the clutch job after your 1st track day? Almost everyone of my HEAVY track customers have either REBUILT there gearbox, or they are planning the rebuild because the gearbox is dying. HEAT kills these boxes.

Macster

I've never jacked my Turbo up at one corner to see what else comes off the ground.

(Even when I jack my Boxster I use a jack on the other side and lift the car a bit to avoid twisting the body any more than I have to. While the Boxster is one stiff car for a roadster I do not seek to contribute to the creatation of squeaks/rattles by subjecting the body to any more flexing/twisting than necessary.)

In fact, I've never jacked the Turbo at all. Any lifting is done by a hydraulic lift (located in the dealer's service department) which picks the entire car up by the tires/wheels or picks the car up using the 4 lift points specially designed for that purpose.

If you are the type of driver to be affected by the fact the Turbo is not seam welded, you really should seek out a seam welded car like I guess the GT3.

Sincerely,

Macster.

Macster

Are these gearboxes that are dying of heat running clutches with the the cooling vanes on the clutch that are intended to cycle air in/out of the bellhousing and help cool the transmssion?

Sincerely,

Macster

Kevin

Mac, Porsche has cooling spray bars and a heat exchanger for the GT2 and GT3 gearboxes. For those that see over 10 track days a year, a gearbox cooler is a must.

5th and 6th gear die in the rear of the gearbox. From lack of fresh cool oil. Third gear also takes a beating.

atr911

Speaking to gt gears and other well respected pcar tranny shops, my understanding is that any newer Porsche that sees sessions longer than 25 minutes on a regular basis should be running a cooler. According to them (and they all seem to agree on this one), temps rise indeffinetly in an uncooked box used for track duty and reach maximum safe temp at around 30 minutes of track time. Apparently, the 30 min between sessions tends to cool it Down sufficiently.

Are you suggesting that turbo boxes heat up faster? Are the clutches inadequate to handle regular track use? Oddly, I just assumed that since they used the same engine cases as the gt series cars, that they use the same gear box with different gearing.

Suppose it makes sense that it wouldn't have spray bars it it wasn't made for track use, but my 997 doesn't either and with regular gear oil changes, it's stood up wonderfully to my 'abuse'.

Then again, the aisin box in the 997 has been referred to as bulletproof and estimated to be capable of handling ample more power than an n/a 997 would Put out.

Mikelly

Hmmm... Although I did rebuild my box, and have had problems with clutches, I did track my car about 18 days the first year without a problem with the clutch or the transmission. The car was purchased with a notchy 1/2 shift point that got worse with time. That said, my car has been very fast with the upgraded power mods and the clutch died only after I swapped to Kevin's Software.

I think these cars a more durable than is being depicted, but make no bones, it does need a cooler. Especially if you pan to run the LSD and track the car hard...

Mike

Macster

I was speaking of the Turbo tranmissions failing on the track, which is what I thought you were referring to.

Been reading through a copy of the Porsche 996 The Essential Companion Surpreme Porsche book and in the clutch section of the 996 Turbo it describes some cooling vanes on the clutch (not sure what part of the clutch) that help move air in/out of the bellhousing (which appears to be designed to facilitate this air movement) the idea being this air flow through the bellhousing helps cool the transmission.

The book also appears to say the Turbo engine is not some super GT1 derivative but a 'hybrid' engine. Which of course doesn't make this true.

Sincerely,

Macster.