bronson7

Great to hear this Jamie. Down the road, if/when I still have my gt3 and it's out of warranty and your fix has proven solid, is there any chance a Canadian can get the parts for the fix or is it more to it than just getting some parts? Just curious.

MaxLTV

100 hours is not that much. These are race car numbers, and in races criteria are very different - if probability of failure or performance loss increases by even 1%, it may be worth rebuilding just in case. Very different for us weekend warriors without 7-figure sponsorships.

FWIW, Porsche claims GT4 Clubsport should not need a rebuild for 20,000 race miles, which makes it to 250 race hours, which is probably twice as much in HPDE hours. So here you go. Yes, GT4 CS is lower power per liter that GT3RS, but race speeds of GT4CS have been vastly faster than HPDE speeds of GT3s. Basically, the throttle is pinned to the floor much higher % of the time.

Jamie@dundonmotorsports

The parts required aren't necessarily difficult for a trained Porsche tech to install. What were concerned about is the residual damage in the engine from circulating ground cam and finger follower for x,xxx miles.

As part of our upgrade we plan to go through each engine we do and look at the wear areas, or even offer the upgrade as part of a rebuild or performance rebuild to ensure that all the areas that were possibly affected are resolved.

What we don't want to end up happening is we apply the upgrade to an engine that was bearing damage or cylinder seal issues due to ground metal bits circulating and becoming liable as we were the last ones in there.

Unfortunately there has to be a CYA portion to this...

Macca

GT3 cup engines have 50hr top end requirements. I've seen 991GT3/RS driven quite hard on track with their owners matching Cup times on slicks from only 1 or 2 generations ago. 100 hours plus seems reasonable IMO.

I've run 993RS and C2 track spec for years - I would definitely be in for top ended work on those nines after 80 track days. Valve springs, retainers, valve guides, exhaust port cleaning, timing (with manual lifters), cam timing, Ramps and possibly chains. Call it 10k all in with labour as its a bigger job to drop on my 993 too. Mezger engine etc...

250 race hours for Maintenance schedule for GT4 CS sounds absolutely crazy. In fact unbelievable. Can you post a scan of that?

Alan C.

I bet PAG didn't clear this through the cleaning lady.

MaxLTV

I had a non-US brochure mentioning 30000 km between rebuilds. I cannot find it now. I'm not 100% sure it was directly from Porsche, so it could have been wrong. I googled this, mentioning 20k miles, but I'm not sure how credible it is either: http://www.brrperformance.com/blog/?p=3338

So the bottom line is this info can be incorrect. Some people on this forum own gt4 CS cars, so maybe they can clarify.

FWIW, Radical warranties their race engines for 40, 50 or 60 racing hours, depending on the model (e.g., here: http://uk.radicalsportscars.com/sr1cup/faqs.aspx "Is there a warranty on the engine?
Yes. Radical and Porsche are the only companies in the world who provide engine warranties for race cars. Ours covers the engine for non-driver induced failures and the only stipulation is that it is refreshed after 60 hours use, which is more than enough to cover two seasons of racing in the Radical championships including testing.") and Ecoboost engines are rated at 10,000 km, and those are cheap Ford engines boosted to 460hp out of 3.5 liters.

100 hours sounds too little out of a street engine made with much more exotic materials and newer tech (and the price to match). What's the benefit then if you can get the same power and longevity out of a similarly sized Ford engine for a fraction of the price?

hf1

+1
The 8500+ rev limit or the high hp/liter are not good excuses for the dismal robustness.

The standard (non-GT) 2009+ DFI 3.4/3.8 engines (currently also in the GT4/CS) appear to be much more robust. It now also becomes clear why the Cups delayed using the new GT3 engine all these years. I don't think anyone (including PAG) would have chosen a 8500+ rev limit for the GT3 had they known the headaches that would come along with it. I'd trade a lower rev limit for extra 100hrs of engine life, without question. In retrospect, probably so would PAG. They flew too close to the sun and got burned.

hf1

I've seen 996 Cups with 200+ hrs on their engines -- at that point maybe not racing but still hauling major DE a$$.

Macca

Porsche tax I guess. Ive recently seen a thread with the Ford part number and official price for a 2.3 Eco Boost engine (350 bhp) for my incoming Focus RS. Lets just say I can buy a new short and long block (i.e. replacement engine) for less than a full set of OEM discs, pads and tires for my 991 GT3! Excludes install labour of course...

Im not sure about others on here but I run in small groups (max cars on track 15). I get alot of low traffic laps. Mostly we run between 70F and 90F ambient. Our Porsche Track Group (Rennsport Gruppe) typically rent a track to ourselves and run three sessions an hour. We break cars up into fast, medium and slow groups. I would have to say I drive as fast as I can (I cant see myself pushing on any quicker in a "race" with the same car. More often than not (especially if its a course Im not particularly experienced with) I run in Sport Auto. I record all my telemetry on Aim Solo DL with Smartycam HD Rev 2.0. When my E engine threw the CEL after almost 7000 miles (of which 2500 were track miles - 10 track days) I did a little study. On my local track (most frequent) I hot the rev limiter (or very near to it) in Sport Auto 80 times a session. So around 480 to 560 times in a full day. Over the life of that E engine it hit the rev limiter around 5000 times on the track. I confess in those early days i was also doing alot of fast back road driving (I only use MT) holding the gears in 2nd and 3rd near the limiter with the paddles. Probably the equivalent of another few track days at least....

Now Im no expert on this, but for a 125bhp/L NA engine with 9000 rpm and piston speeds vs piston mass pretty much at the edge of manufacturer limits (Im not sure even the Speciale gets anywhere close at 9000 rpm), run HARD on track (I get alot of low traffic laps) I would honestly not expect this engine to go without top end inspection/maintenance for more than 100 hours. For me I guess thats around 60 track days. So far on the last E engine I managed lets say the equivalent of 12 so that's a fail. On the G I have the equivalent of 8 and all is fine so far. If the G engine goes 30 days equivalent before the later cams and finger rockers are required (or Jamies, DMS equivalent part) then Ill be surprised.

I have one other friend here with E engine 991 GT3 who matches my track miles and driving efforts exactly. We both got new E engines at the same time in May 2014. His E engine failed one track day after mine in Feb 2016. He now has G engine with around 6 track days on it and all is fine (oil consumption like mine is lower than prior E engine). We also have a F engine comrade in our Rennsport Gruppe who has around 20 track days on their F engine 2015 991 GT3. Its a husband and wife team. Fair to say they arent running as hard as myself and comrade with the 2014 cars (E then G engine) but so far they have been fine and their oil consumption on track is between our old E and new G units.

These are cars and drivers Im intimate with. There were around 25 x 991 GT3 imported into my country officially. We have 3-4 other 991 GT3 owners of 2014 and 2015 vintage (E and F engines as no G engined cars were produced for our RHD market as far as Im aware). They attend our track days only occasionally and are not particularly experienced drivers so not running more than 7/10th so to speak.

Interestingly we have currently ZERO 991 GT3RS in our 35-45 strong Porsche private track group. Infact we have no regular run RS of any generation (we do have 5 x 996 GT3 and 1 x 997.2 GT3). We have 2 x GT4 with another shortly joining our ranks.

Of those approx 25 x 991 GT3 in this country three have had replacement engines. One was an F engine that just smoked too much from the time it was delivered and was deemed to be consuming way too much oil. That car never saw the track. Issue was assumed to be rings after much trial and error. Only two other engine at this stage have been replaces and thats myself and said comrade.

To the best of my knowledge (and I do try and keep my ear to the ground) at this time failures on 991 GT3 in our market have been limited to Thermostats (many and frequent), a failed strut in the 2015 F car run by husband and wife team and a failed PDK transmission (within 2000km of delivery street driven only). No PDK issues have yet surfaced on the heavily track run cars. To date PAG have replaced everything under warranty track or no track usage. I suspect my caliper "pucks" are cracked and I have some small chipping to the edges of my rear lights and now some condensation occasionally in my front lights, but after almost 3 years, 20 equivalent track days and a total of 15,000 accumulative miles on the chassis. I hope to get the lights and pucks sorted under warranty shortly but not sure how that will work out...

So, Ive gone a bit sideways here. Is 100 track or "race" hours acceptable for this engine? It depends how hard you are pushing the car and what ambient temperatures you see but for me I would say given my experience with other 911s and within our group that 100 track hours (60 full track days) would be within expectations. At that time i would expect to replace valve springs, guides, possibly rockers but not typically cams. Id probably be advised to do sensors, cam timing wheel and gaskets etc same time. This all assumes regular oil changes and annual spark plug replacement (as is no the required in our market)...

Those are just my thoughts although I know others may differ.

bigskyGT3

Macca a quick off topic question. Are you planning on tracking your Focus RS? If so, I hope you post a review on how it does. I'm interested on how the RS performs.

Macca

Hi mate. It was purchased as a daily driver, but initially I thought I may use it on the track as a cheaper alternative to the GT3.

After reading up on its track credentials, it seems in stock for it would east tyres (19" MPSC2 - not that much cheaper to buy than the 20" variants for the GT3 and from what Im reading the shoulders are toast withing 2-3 hard track days - much the same issue faced by the the GT4 fraternity). They drink fuel on the track as much as the GT3 too. So on face value a stock Focus will be a slower less precise track tool with only rotor and pad cost advantages over the GT3. A full set of OEM rotors is a faintly ridiculous $800 (all four corners!). Some have encountered high oil temps and RDU overheating. Ive purchased a cooling scoop for the RDU and dont run in Texas summers so probably all good there. However getting 400 bhp and 550nm from the Focus is now as easy as a Cobb AP with Tune+ program for $800 and another $900 for an enlarged inter-cooler, air filter and actuator. That gives you reliable 0-60 in around 4.2s and 1/4 mile trap speeds in the low 12s. More if you run E30 ethenol and buy the tune. As good as that is on the street it will require better oil cooling on the track. Once you have 400 bhp on tap now you really need more negative camber or else sell your soul to the tire gods. The factory suspension has -1.1F geo but needs more. No solution exits right now for this unless you want to replace it all with KW.

So in summer, after much research and though I figure bumping it safely for fast road work to 400 bhp/550nm for under $2K seems like alot of extra fun for the money. Taking it to the track regularly seems like diminishing returns when you have a Porsche in the garage to cover those duties. Ill probably run it at the track a couple of times but keep it mostly for road till there are cheaper tire/wheel options to play with and some way of getting the camber better suited. The aftermarket industry in UK and USA is forging ahead with this car so I expect we will see some interesting (and possibly eye opening) things done with them over time. Have to be patient...

bigskyGT3

Interesting. Thanks for the input and enjoy the car.

Macca

We arent getting anywhere near 100 hours. That's the point. 100+ hours would be an acceptable target IMO.

I know 4-5 996/7 Cup car owners. Most run in our national Porsche series and a few join us on our track days. None of them go more than 100 hrs without a drive train inspection and some form of rebuild. The engine may go longer but the cost to the wear escalates. Once rockers, springs and valve seals wear then its cams and risk of a dropped valve. Better to replace those relatively low cost components within spec before lifed or face much bigger bills later.

P.S. If PAG isnt pushing the envelope with new tech and designs for its CUP car then it wouldnt be moving the breed forward and would loose competitiveness. I think we will see the RSR go DFI in January. Porsche MS seem to be happy so far with the GT3R. Im sure by the time the RSR has put in a few seasons the bugs will be ironed out and the platform will be mature. If there is a 991.2 GT3RS I believe it will benefit significantly from the next 12 months of motorsport development on this engine...

fbirch

The older 996 Cups could be run for 100 track hours and some people pushed them further than that. They typically don’t blow up or fail at that point, but that refresh interval was adequate to ensure top level performance under race conditions on full race slicks. For a street car on street suspension being driven on street tires by a non-Pro, I’d be disappointed if 100 hours was the limit for the new GT3. It would be a different story if we were talking about a Pro driving 100 track hours on race slicks, but for a DE guy (even a pretty good one) on street tires, 150+ hours would be closer to the limit that I’d like to see.

If you assume a slightly above average enthusiast takes his car to a DE 8 weekends per year, and on each weekend he averages 2.5 track hours per day (5 hours per weekend), then in one year he’ll accumulate 40 track hours on the car. In four years he’ll accumulate 160 track hours. In that case the refresh interval would match the US warranty period, so that should be Porsche’s goal, IMO.

fbirch

I agree with the above. It would be very interesting to know if the GT3R guys are routinely changing heads/valvetrain at 50 hours or something like that. The rebuild interval may be such that parts are changed before the follower/misfire problem has a chance to manifest.