[ds968]

these engines were not designed for track duty. .

And I'd say even less so an automatic transmission one ; I have to question the "wisdom" behind the 2 gears downshift idea on a car which is especially not designed for racing and even in normally aspirated form has significant torque , which ultimately puts way too much stress on not just the engine components when the RPMs shoot up to redline in no more than a second, but it takes its toll also on the flex ( damper ) plate, which we all know by now is not the strongest part as things go...

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[flash]

a lot of this goes to reapplication of previous technology without proper testing.  just look at the belt assembly.  they widened 1 belt, and added an hydraulic tensioner on it, but did nothing else to beef up the assembly.  yet they doubled the torque on the engine, and added a whole lot more heat.

 

the same could be said of the suspension.  more weight, more power, bigger wheels, more load, but not much beefed up.

 

these cars are GTs.  as such, they do just fine, and in fact better than most.  push them too hard though, on old tired parts, and they break.

 

as for the transmission, i have an idea that may prevent that from happening in the future.  i need to read up on the setup though to see if it will work.

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[wildcat]

My issue with the #4 piston is the intake valves.  On warm up there was a tick tick tick that could be heard over the engine.  Once the engine warmed up it disappeared.  It has been eliminated without getting into the head partly by re-seating the fuel rail and in particular the injector. I noticed that while the engine was running, if I pulled the spark plug cable to that piston and then replaced it, the ticking stopped, which is what led me to re-seat the rail.  There was no apparent leakage from the rail or injector.  It would be practically impossible to determine that was the culprit if something had happened to that cylinder due to insufficient fuel. And you do have to watch out for that black hole that it doesn't sneak into your wallet.  

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[flash]

if your injector was ticking, then you need to have them cleaned and new o-rings installed.  this is common at this point in time.  frankly, injectors should be cleaned every 5 years or so, just as the fuel filter and check valve should be changed.

 

none of this is relative to dan's car though.  the injectors were new, and i believe he just changed the fuel filter and check valve

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[ds968]

Correct, the fuel filter and check valve were replaced about a year ago.

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[flash]

so, the only remaining fuel system items to be checked are the pump and regulator.  easy enough to do.

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[ds968]

When it rains it pours...the transmission flex ( dampener ) plate which is not even 3 years old and has only about 30,000 miles has a 4"  tear / crack in it.  As if the complete engine rebuild  wasn't enough here comes more ! :angry2:  :wacko:  :angry:        

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[Rap]

When it rains it pours! Sorry to hear. Is this all?

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[az968]

Real bummer! Was that caused by the engine failure or ws it a contributor or just a bad part?

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[ds968]

Bob, ( AZ ) I have no idea, interesting question though ..


Bob, ( RAP ) Lol, " is this all ? " Not much else left ...


Bob, ( Flash ) any thoughts re Bob ( AZ ) question ?


Sheesh I feel like I'm in one of the Monty Python " Aussie mates " skits where everyone 's name at the table is Bruce ..

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[az968]

Bruce? That's my middle name.




Just kidding,it's Eric. No, Graham. Wait, its Michael. John? Or maybe Terry. I can't recall But I have a parrot you'll want to buy. Or is it a fish?

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[Bulti]

Extra torque from SC + flex plate = mayhem?

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[Rap]

Ds, not busting your chops. I remember two years ago when my tranny blew then two weeks later the engine blew. I felt like I was a lightweight in a heavy weight fight getting my brains battered. Seemed like no end in sight! There is light at the end of the tunnel. Are you in the tunnel?

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[unknown4u]

The damperplate has gone over the top of maximum torque when everything blocked while driving. The peak in torque is at that moment extremely high. So the plate cracked at that time..

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[ds968]

Makes sense .


One thing for damn sure ; I am never stomping on the gas pedal when at levels where the transmission downshifts two gears - at 300+ hp and 300 ft/lbs an immediate ( as opposed to a more gradual ) redline jump is not good for the engine and not good for the transmission. Flash may be able to adjust the car to avoid the 2 gears downshift to just one but even if that does not work I'm changing the driving M.O., and in the Tip I don't need to push the car that much....that's what the six speed is for and those can take a lot more beating, with a far greater safety margin ..

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[flash]

looks like my gut instinct and subsequent decision not to supercharge the white car, and instead buy the targa, was a wise one.  i was afraid that i would push it too hard, especially given how strong the engine in the blue car is, and how hard i tend to drive cars.  i probably would have blown something up very quickly.

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[ds968]

I think if anyone out there with a Tip is considering getting one of the few remaining SC kits, they need to be very aware of these two vulnerable factors : the sudden 2 gear downshift m.o. and the flex plate stress the additional torque will cause, when you stomp on it .

Not trying to discourage anybody from SC'ing a tip, but I believe you will need to be satisfied with the extra power's utilization in relative moderation; pedal to the metal off the line, stomping on it to the floor when you're likely to go into a double downshift = bad idea, IMO..

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[968Syncro]

Hey Dan, been following this thread for the past couple of months, didn't have much of value to offer.  Sorry this happened,

 

As a Tip fan, just wanted to add that I really love this trans -- probably in part because I use the car as a DD around town.  But I don't redline very often at all.   And of course I had the torn flex plate repaired a year ago, which caused a exploration of other cars (968 manual trans and others).  But very happy with the decision to get it repaired and keep the 968

 

But this reminds me of someone here on the forum who raced his 968 with a Tip.  It was a few years ago, maybe in Arizona or someplace.  He said that racing with the Tip was just plain faster.   As we've heard before, one of the arguments is that the engine has such a broad power band (torque/HP) that 4 speeds is enough.  Just guessing, maybe with the Tip there is less need to shift while racing.   But it also raises the question of how the flex plate holds up under racing conditions.

 

I did one thing a few years ago that probably was very dangerous for the flex plate.   Because of battery weakness, the Tip went into limp mode -- can't recall exactly, but I seem to recall it stayed in 3rd gear.   Without considering the implications, I was on a long downhill on the freeway, and thought it might be a useful idea to place the tip into neutral and coast downhill.  Well, at the bottom of the hill I put it back into drive and there a a really big shudder.  I believe in limp mode the controller doesn't try to match the engine RPMs to the current condition of the Tip (what gear it is in, car speed).  So it was probably similar to a manual trans, releasing the clutch, while coasting at 50 mph while the trans is in 1st gear (among other mismatched scenarios).  Huge stresses.

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[968Syncro]

Also, here is a tip :glare: .    The shop I used for the repair planned to buy a new flex plate for about $1,500.   But I found the Sunset had it for about $1,100 or so.  At first the shop said they have to use their regular suppliers, but it took some arguing to get them to buy the part from Sunset, took a few more days, but they finally agreed and still warranted the work.

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[ds968]

Pretty much the experience here with the cost of the flex plate ; two SoCal dealers quoted the same price : $ 1587 and that's before tax, so about $ 1745 total. At Sunset, including the shipping charges it came to $ 1230 .

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