GT3 Lack of Underseal - Cost /Benefit Analysis
Discussion
As I understand it GT3s & GT2s lack underseal & just have an E-coat.
I'd be interested to understand Porsche's justification for this decision, specifically:
(1) How much weight is saved by omitting underseal;
(2) What is the empirically measured performance difference between an undersealed GT3/GT2 & a non-undersealed equivalent - both in linear positive & negative acceleration & lateral acceleration on a variety of surfaces of varying friction coefficients;
(3) What is the delta in the expected average life expectancy of a non-underseled v an undersealed 911 broken-down by region/market.
On the Rennlist 996 GT3 board, Colin Belton of 9m has documented the chassis restoration of a 996 GT3, and the degree of corrosion and lack of rust protection on these cars makes for sobering reading & raises serious questions about Porsche's decision to exclude undersealing protection.
Has anyone questioned Porsche as to the reason for this omission?
I'd be interested to understand Porsche's justification for this decision, specifically:
(1) How much weight is saved by omitting underseal;
(2) What is the empirically measured performance difference between an undersealed GT3/GT2 & a non-undersealed equivalent - both in linear positive & negative acceleration & lateral acceleration on a variety of surfaces of varying friction coefficients;
(3) What is the delta in the expected average life expectancy of a non-underseled v an undersealed 911 broken-down by region/market.
On the Rennlist 996 GT3 board, Colin Belton of 9m has documented the chassis restoration of a 996 GT3, and the degree of corrosion and lack of rust protection on these cars makes for sobering reading & raises serious questions about Porsche's decision to exclude undersealing protection.
Has anyone questioned Porsche as to the reason for this omission?
I understand (rightly or wrongly) that where Porsche offers a lifetime bodywork warranty - this is conditional upon annual inspections at your OPC. Miss an annual inspection & the guarantee is invalidated. This must drastically reduce the number of bodywork claims which are honoured.
Penguinracer said:
(2) What is the empirically measured performance difference between an undersealed GT3/GT2 & a non-undersealed equivalent - both in linear positive & negative acceleration & lateral acceleration on a variety of surfaces of varying friction coefficients;
No-one will know this - when making a performance focused car as light as you can, you don't bolt on bits you know you don't need to see how much worse it would make it.The rear wiper is another good example of the same ethos - all 996's except GT models had it as standard (I appreciate it became a cost option for standard 997's, but that's more to do with economics i.e. if people want this, here's how we can make more money out of them
).I suspect you're getting mixed up between seam sealer, underseal, E coat and primer.
All the shells will have been seam sealed, all will have been E coated, and all will have been primered too. Where the 996 GT3/2/RS shells differ from the C2/4 Turbo etc, is they don't have huge amounts of rubberised underseal hosed on the under the underside of the wheelarches.
Spraying Waxoyle on the bottom of the floorpan (especially on the seams between the "chassis rails" and the floorpan itself) will ensure moisture and salt don't get in there.
The inside of wheelarches get shotblasted, as they have nothing applied to them but E coat, primer (and if you're lucky, a hint of top coat) it doesn't take much to shotblast the minimalist protection away and leave the metalwork open to the elements. That's what appeared to have happened to Ben's car on Rennlist.
All the shells will have been seam sealed, all will have been E coated, and all will have been primered too. Where the 996 GT3/2/RS shells differ from the C2/4 Turbo etc, is they don't have huge amounts of rubberised underseal hosed on the under the underside of the wheelarches.
Spraying Waxoyle on the bottom of the floorpan (especially on the seams between the "chassis rails" and the floorpan itself) will ensure moisture and salt don't get in there.
The inside of wheelarches get shotblasted, as they have nothing applied to them but E coat, primer (and if you're lucky, a hint of top coat) it doesn't take much to shotblast the minimalist protection away and leave the metalwork open to the elements. That's what appeared to have happened to Ben's car on Rennlist.
I'm not quite sure what the underseal policy is?
My 996 Tip had been sprayed with a hard brown wax on top of seam sealer, primer and a colour coat.
My Mk1 GT3 seems to have had the same treatment.
The pictures show what the front and rear arches looked like after I had removed all of hardened/damaged wax with a steam cleaner.
Rust had just started to attack the metal where stone chips had damaged the coating. All traces were ground away, painted and drenched in several coats of new hard wax.
The shot of the rear arch shows where rust had just started.
The front is better covered by the wheel arch liners and hence virtually rust free.
I suspect that some of the thick underseal processes may actually allow rust to develop further as it is usually unseen before a hole appears. A few coats of wax over 13 years seems to have been quite effective so I am not complaining.
I think it well worth a decent steam clean and rewax every 3 - 5 years or so to preserve the integrity of the chassis.
My 996 Tip had been sprayed with a hard brown wax on top of seam sealer, primer and a colour coat.
My Mk1 GT3 seems to have had the same treatment.
The pictures show what the front and rear arches looked like after I had removed all of hardened/damaged wax with a steam cleaner.
Rust had just started to attack the metal where stone chips had damaged the coating. All traces were ground away, painted and drenched in several coats of new hard wax.
The shot of the rear arch shows where rust had just started.
The front is better covered by the wheel arch liners and hence virtually rust free.
I suspect that some of the thick underseal processes may actually allow rust to develop further as it is usually unseen before a hole appears. A few coats of wax over 13 years seems to have been quite effective so I am not complaining.
I think it well worth a decent steam clean and rewax every 3 - 5 years or so to preserve the integrity of the chassis.
Penguinracer said:
I understand (rightly or wrongly) that where Porsche offers a lifetime bodywork warranty - this is conditional upon annual inspections at your OPC. Miss an annual inspection & the guarantee is invalidated. This must drastically reduce the number of bodywork claims which are honoured.
I believe the Porsche Rust warranty is:3 Years on the GT cars
12 Years on the non-GT cars.
The Guarantee says:-
10 year protection against rust holes provided it is inspected yearly after 2nd year.
It says cars manufactured without original under body protection are only for 3 years. (I believe the heavy wax coat IS the underbody protection) Mine certainly has never been coated with anything else.
My GT3 service history shows body inspections by Porsche into its 6th year so I can only assume they would not have been stamping the inspection page if it was not covered?
10 year protection against rust holes provided it is inspected yearly after 2nd year.
It says cars manufactured without original under body protection are only for 3 years. (I believe the heavy wax coat IS the underbody protection) Mine certainly has never been coated with anything else.
My GT3 service history shows body inspections by Porsche into its 6th year so I can only assume they would not have been stamping the inspection page if it was not covered?
Edited by Pugley on Friday 6th December 11:37
Oh how little you know your friendly OPC....hopeydaze said:
A scary read for a new owner of a 996.2 GT3. Its been inspected and I'm told the seam seals are good.
Best advice seem to be a good steam clean with wheels removed followed by a wax seal treatment. I wonder if an OPC like Bristol can do this. Ant thoughts before I give them a call?
As I stated earlier in this thread, my OPC at Reading offered this to me for about £70.Best advice seem to be a good steam clean with wheels removed followed by a wax seal treatment. I wonder if an OPC like Bristol can do this. Ant thoughts before I give them a call?
Penguinracer said:
(1) How much weight is saved by omitting underseal;
I think its about 5KG?This is the original rennlist thread referred to by the OP:
http://forums.rennlist.com/rennforums/996-gt2-gt3-...
Edit, found some articles while I was bored:
Polished bliss also posted this photo set up from a Gen 2 996 GT3 detail and said the underbody protection wax was still intact on that car:
http://www.pistonheads.com/gassing/topic.asp?t=123...
There is a Gen1 996 car getting underbody treatment here:
http://www.cumbriacarstorage.co.uk/corrosion_prote...
Edited by Carl_Docklands on Friday 6th December 14:17
sidicks said:
sidicks said:
Is this for the later series of GT cars or just for 996's and 997.1's ??
Can anyone confirm, please?!http://www.6speedonline.com/forums/gt3-gt2-gt/2385...
Can't find anything about the 991 GT3 yet.
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