997 Gen 2 DFI Engines - Woes finally sorted?

997 Gen 2 DFI Engines - Woes finally sorted?

Author
Discussion

tomw2000

2,508 posts

194 months

Saturday 7th May 2011
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whoami said:
MC Stradale
That's the chap. Will give my thoughts next week smile

Phooey

12,574 posts

168 months

Saturday 7th May 2011
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911p said:
Phooey said:
I would deffo consider a PDK...
Would you go PDK or manual next time then?
Deffo PDK. I don't use the car for track - all i do is rip the countryside up a bit and pop here and there, and PDK is more than capable of getting me from A-B quicker than my manual.

tbh, i have fallen out of love for the manual gearbox on my GTS. From day 1 (3 miles on the clock) it has suffered clutch judder. It was found to be faulty - had marks on the flywheel - nothing to do with abuse. I had a new clutch and flywheel. It still judders. 200 miles after the NEW clutch i also encountered the clutch pedal not fully releasing on a spirited start. Zip will back me up on this one. Changing gear once moving is fine... very very refined and direct, but stop-start moving in traffic is not good.

The box on my GT3 was unrefined when cold (stiff and slightly notchy) but when warm.... the best manual stick i have ever used to swap cogs with :bliss:

Akajak

887 posts

238 months

Saturday 7th May 2011
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Slightly off topic, but the Gen1 997 has just been Awarded the mantle of usa's most reliable car according to a 2011 survey of 2007/8 cars carried out by JD Power

Martian O

2,734 posts

161 months

Saturday 7th May 2011
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My Turbo 'box/clutch is fine. You know you want a Turbo! biggrin

Wills2

22,666 posts

174 months

Saturday 7th May 2011
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I've had clutch judder and the burning smell of a clutch that won't fully release on a sprited step off myself, both went away as the miles went on.

Can I ask Phooey, do you regret changing?


Phooey

12,574 posts

168 months

Saturday 7th May 2011
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Martian O said:
My Turbo 'box/clutch is fine.
...and that's what gets my goat. Do you not even get a LITTLE judder when creeping with low revs?

Phooey

12,574 posts

168 months

Saturday 7th May 2011
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Wills2 said:
I've had clutch judder and the burning smell of a clutch that won't fully realise on a sprited step off myself, both went away as the miles went on.

Can I ask Phooey, do you regret changing?

I know that smell VERY well. I only dialled up approx 3-4k rpm and dropped the clutch. Was trying to get away from Zip in his turbo. Instead i ended up stranded on the spot, smelling of fish, and stuck behind a Fiat Multipla!


No. I don't regret changing. I never got to use the GT3 enough unfortunately. I DO miss it occasionally though, especially when you get an hour of free time and a nice dry day frown

Martian O

2,734 posts

161 months

Saturday 7th May 2011
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Phooey said:
Martian O said:
My Turbo 'box/clutch is fine.
...and that's what gets my goat. Do you not even get a LITTLE judder when creeping with low revs?
Nope, nothing at all.

Wills2

22,666 posts

174 months

Saturday 7th May 2011
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Phooey said:
Wills2 said:
I've had clutch judder and the burning smell of a clutch that won't fully realise on a sprited step off myself, both went away as the miles went on.

Can I ask Phooey, do you regret changing?

I know that smell VERY well. I only dialled up approx 3-4k rpm and dropped the clutch. Was trying to get away from Zip in his turbo. Instead i ended up stranded on the spot, smelling of fish, and stuck behind a Fiat Multipla!


No. I don't regret changing. I never got to use the GT3 enough unfortunately. I DO miss it occasionally though, especially when you get an hour of free time and a nice dry day frown
Ah well you can't have everything!

As for the judder and sticking clutch, as I said it happened to me when my car was new (I guess we have the same spec clutch and gearbox)

The judder does go with miles, and so does the sticky clutch. (well thats my experience)

Phooey

12,574 posts

168 months

Saturday 7th May 2011
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Wills2 said:


The judder does go with miles, and so does the sticky clutch. (well thats my experience)
Hope so. Cheers

Might be my OCD, but does make you wonder if the gen2 suffers with this scratchchin

Wills2

22,666 posts

174 months

Saturday 7th May 2011
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Phooey said:
Hope so. Cheers

Might be my OCD, but does make you wonder if the gen2 suffers with this scratchchin
Stop it! We've got enough trouble with the coking issue, nevermind clutch judder. biggrin

Phooey

12,574 posts

168 months

Saturday 7th May 2011
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hehe

J-P

4,350 posts

205 months

Saturday 7th May 2011
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Phooey said:
I know that smell VERY well. I only dialled up approx 3-4k rpm and dropped the clutch. Was trying to get away from Zip in his turbo. Instead i ended up stranded on the spot, smelling of fish, and stuck behind a Fiat Multipla!
FWIW I know that smell too! I had the sticky clutch thing going on but it's gone now wink




tomw2000

2,508 posts

194 months

Tuesday 10th May 2011
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tomw2000 said:
That's the chap. Will give my thoughts next week smile
OT: ok so I spent some time in the maser stradale this weekend. Even Managed to wangle a decent drive.
On iPhone now so won't do massive review. But very impressive noise in Race mode. Solid car. And the auto box was better than I imagined. It's not double clutch but changes gear well enough.
Any questions ask away.

tomw2000

2,508 posts

194 months

Tuesday 10th May 2011
quotequote all
tomw2000 said:
That's the chap. Will give my thoughts next week smile
OT: ok so I spent some time in the maser stradale this weekend. Even Managed to wangle a decent drive.
On iPhone now so won't do massive review. But very impressive noise in Race mode. Solid car. And the auto box was better than I imagined. It's not double clutch but changes gear well enough.
Any questions ask away.

Wills2

22,666 posts

174 months

Tuesday 10th May 2011
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tomw2000 said:
OT: ok so I spent some time in the maser stradale this weekend. Even Managed to wangle a decent drive.
On iPhone now so won't do massive review. But very impressive noise in Race mode. Solid car. And the auto box was better than I imagined. It's not double clutch but changes gear well enough.
Any questions ask away.
They look a big car so was it easy to hustle along a B road like a 911? or was it more a loud Grand Tourer than B road sports car?

tomw2000

2,508 posts

194 months

Tuesday 10th May 2011
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Wills2 said:
They look a big car so was it easy to hustle along a B road like a 911? or was it more a loud Grand Tourer than B road sports car?
It did feel a bit big to me and it felt wrong hustling along b-roads. But it was good at the job, did feel very rapid, though not sure the figs are much different to my own C2S.

So more very loud (in race mode) GT really as you say.

Very grateful to get a spin in it. The noise is very impressive - and I can see thats all the 'occasion' some would need to justify buying it.

Wills2

22,666 posts

174 months

Tuesday 10th May 2011
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tomw2000 said:
It did feel a bit big to me and it felt wrong hustling along b-roads. But it was good at the job, did feel very rapid, though not sure the figs are much different to my own C2S.

So more very loud (in race mode) GT really as you say.

Very grateful to get a spin in it. The noise is very impressive - and I can see thats all the 'occasion' some would need to justify buying it.
Occasion, that's the word, I feel that's the thing missing from the 911 that sense of occasion you get from the Italians.

I bet it was a lovely noise.

R Soul

123 posts

164 months

Wednesday 17th August 2011
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Apologies for the OT post biglaugh

The following refers to the new Gen-2 DFI Cayman S' and not the DFI 997 (don't personally know the difference aside capacity/bore/stroke) but as I'm also interested in knowing some answers to MTR's original question (remember what it was kids? hehe) I thought the following might be interesting, it's from the following thread http://www.planet-9.com/cayman-interseries/39744-w...
posted by one of the guys running the USA-based Cayman Interseries Championship http://www.napletonmotorsports.com/
and http://www.caymaninterseries.org/

said:
We have learned that the new engine is perfect. No oiling issues, overheating, or bearing failures. Power steering failures are non exsistint since the fluid is cooled thru the engine cooler. No ABS issues whatsoever. We have over 30K track miles on the cars now with several 3 and 4 hour enduros,98 degree race weekends,rain you name it. They have performed without a "hiccup"
said:
We have not had a problem with carbon build up as you can imagine. These cars are run constanly at high RPM not like a Cayenne.
We do run some "secret sauce" in the fuel to keep the high pressure pumps lubed,other than that it's all normal. The power steering is an all new design
said:
Please keep in mind that the Interseries cars are STOCK
said:
As of now we have delivered 28 Cayman Interseries race cars. If you add up all the mileage from the cars it's over 60,000 RACE MILES!!!!
Below is the total engines replaced so far;


Didn't see any right??? How about transmissions replaced??? Well we did have to change 1 trans,but ONLY because of a misaligned shifter cable and it was causing a notchy 2nd gear downshift.The rest have been perfect. We have not had any power steering issues or engine over heating.

We have replaced some wheel bearings and a fuel pump...other than normal maintenance the cars have been trouble free.

We have moved to a "Guard" limited slip and also developed a special 6 piston caliper brake package from "StopTech" along with our own series "flash" for the ECU that was necessary for the ABS/PSM balance.
said:
We have not be using anything different than what you would use in normal good track prep. SRF brake fluid, Mobil1 Delvac trans oil and Mobile1 engine oil. We do add a external oil pump with a cooler for the trans and a third radiator for the engine. As for the Diff,we needed more grip than what the factory diff offered considering the type of tires and the suspension we are using.
said:
As of 12/15/2010, we have delivered 40 cars with about 100,000+ race miles combined...........!!!!!!!

Lee Davis, Ryan Eversley and Keith Carroll just won their class {3rd overall} in the 8 hour NASA race last week at Road Atlanta and never changed a thing during the race except tires.
We have run several 4 hour races,but this was the longest so far for the cars...we were impressed!!!

The engines have been extremely reliable with out any issues at all. We did have a few flywheel failures, so for 2011 we are going to change the rule to allow single mass units. We have not made a choice as to which type we will allow in the rules. Sachs has a new package with a light steel flywheel which might be the way to go.

We have had some axle issues due to heat build-up and the angles we run the cars. We change them out about every 2500 -3k miles just as a precaution

Under heavy use the shift cables tend to get out of adjustment,so as a matter of practice we have been changing them out as well.

The transmissions have been flawless,but they do run hot so it is important to change the fluid frequently. We use "Mobile1 Delvac"
We have switched the diffs to the "Guard" unit with some tinkering of the ramps.

The ABS is very sensitive and we have developed a ECU program that works very well with the "StopTech" brakes and "Performace Friction" pads that have been developed for the Interseries cars. Castrol SRF is a must.

All the other demons that were in the "Gen1" cars are non-existint.

All in all the cars are very low maintenance and have shown themselves to be reliable, fast and fun.
said:
We have found that under extreme racing conditions and with the type of tires and suspension we have been using in the "Cayman Interseries" cars we were not able to keep the tires from spinning/slip in the corners. We did experiment with changing/modifing the diff clutch discs. However, by changing to the "Guard" diff the performance has been outstanding without ANY abnormal wear or malfunctions. Matt has a great product.

In my opinion the stock diff is perfect for a street or lightly modified car,but if you are going racing or have a track only car, then you will probably want to change it.

The power steering fluid is cooled by the stock oil/water heat exchanger which also cools the engine oil. We have had ZERO issues with this system
Shame they didn't test sitting in traffic for an hour and then hooning it like a loon for twenty mins before a further traffic jam stint hehe still, sounds pretty positive stuff...

jackwood

2,607 posts

207 months

Thursday 18th August 2011
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I wonder if they have actually looked at the bores of any of those engines?