BROKE CRANK AT THE RACE TRACK!!!
08-24-2007, 08:20 PM
#106
Rennlist Member
Tom,
I have never extensively tracked my Porsche, but in my road race cars I have a fair amount of experience. I tend to be conservative using the redline, as sustained revs seem to take life out of the engine. For an amateur sport, that seems like a waste. Therefore, I tend to spare the engine by upshifting about 500 rpm shy of the redline. I know I give up some speed, but Ihaven't lost a motor.
I don't know if that is reasonable in a tt where the redline seems quite low. But, I also don't think that shifting right at redline significantly improves acceleration in our cars.
Anyway, I'm posting because I would love to see you keep your enthusiasm, which will be sapped if you lunch another engine. Good luck and keep us posted!!! AS
I have never extensively tracked my Porsche, but in my road race cars I have a fair amount of experience. I tend to be conservative using the redline, as sustained revs seem to take life out of the engine. For an amateur sport, that seems like a waste. Therefore, I tend to spare the engine by upshifting about 500 rpm shy of the redline. I know I give up some speed, but Ihaven't lost a motor.
I don't know if that is reasonable in a tt where the redline seems quite low. But, I also don't think that shifting right at redline significantly improves acceleration in our cars.
Anyway, I'm posting because I would love to see you keep your enthusiasm, which will be sapped if you lunch another engine. Good luck and keep us posted!!! AS
08-29-2007, 05:03 PM
#107
Instructor
Join Date: Aug 2007
Posts: 110
Likes: 0
Received 0 Likes
on
0 Posts
All GT series cars AND turbo's received the updated reinforced engine case.. The engine case used in prior years was based off the 964 castiing. This casting had provisions for the oil drain tubes that ran from the cam housings to the engine case. With the addition to the water cooled liners and heads these drain tubes were omitted. BTW, Porsche had to install two large oil sump pumps on each side of the engine.
With the tubes removed, the engineers were able to provide a corrigated reinforced casting in the engine casting..
With the tubes removed, the engineers were able to provide a corrigated reinforced casting in the engine casting..
08-29-2007, 05:12 PM
#108
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
That's incorrect.. Each turbo engine (and GT3)has sump pumps driven off each exhaust camshaft. With the addition of these sump pumps, there is no need to have oil drain tubes. With the drain tubes removed, Porsche reinforced the casting.
08-30-2007, 10:41 AM
#109
Rennlist Member
Thread Starter
Tom,
I have never extensively tracked my Porsche, but in my road race cars I have a fair amount of experience. I tend to be conservative using the redline, as sustained revs seem to take life out of the engine. For an amateur sport, that seems like a waste. Therefore, I tend to spare the engine by upshifting about 500 rpm shy of the redline. I know I give up some speed, but Ihaven't lost a motor.
I don't know if that is reasonable in a tt where the redline seems quite low. But, I also don't think that shifting right at redline significantly improves acceleration in our cars.
Anyway, I'm posting because I would love to see you keep your enthusiasm, which will be sapped if you lunch another engine. Good luck and keep us posted!!! AS
I have never extensively tracked my Porsche, but in my road race cars I have a fair amount of experience. I tend to be conservative using the redline, as sustained revs seem to take life out of the engine. For an amateur sport, that seems like a waste. Therefore, I tend to spare the engine by upshifting about 500 rpm shy of the redline. I know I give up some speed, but Ihaven't lost a motor.
I don't know if that is reasonable in a tt where the redline seems quite low. But, I also don't think that shifting right at redline significantly improves acceleration in our cars.
Anyway, I'm posting because I would love to see you keep your enthusiasm, which will be sapped if you lunch another engine. Good luck and keep us posted!!! AS
08-30-2007, 10:44 AM
#110
Rennlist Member
Thread Starter
All GT series cars AND turbo's received the updated reinforced engine case.. The engine case used in prior years was based off the 964 castiing. This casting had provisions for the oil drain tubes that ran from the cam housings to the engine case. With the addition to the water cooled liners and heads these drain tubes were omitted. BTW, Porsche had to install two large oil sump pumps on each side of the engine.
With the tubes removed, the engineers were able to provide a corrigated reinforced casting in the engine casting..
With the tubes removed, the engineers were able to provide a corrigated reinforced casting in the engine casting..
thanks
08-30-2007, 06:17 PM
#111
Any chance we can get this made into a "sticky"?
Mike
Mike
08-31-2007, 01:15 PM
#112
Rennlist Member
Thread Starter
I think when Kevin gets the motor and analyzes it more info will come.
Again, my initial reason for the post was to let all (esp track and drag racers) know these engines can let go. Why it happens and how to PREVENT it was the primary data I was looking for. Hopefully more will come.
I have changed my track driving habits slightly since the new engine. First I avoid type 1 over revs as they may cause more damage then I had thought.
Also dont run the gas down to empty like I used to.
In the process of adding an oil temp gauge, new boost gauge, A/F gauge, and and EGT gauge. As well as a shift light.
Although this may seem like overkill, I think we may need alittle more real time monitoring of the engine when driven hard and long on the track. Some of my sessions are an hour long and previously for me that was alot of boost and redline driving. I am now somewhat more careful.
For "people" with any mods I am "told" the car is truely not dependable in track situations. I really think that affects alot of us on this forum.
Your opinions about any of the above are as always welcome
tom
Again, my initial reason for the post was to let all (esp track and drag racers) know these engines can let go. Why it happens and how to PREVENT it was the primary data I was looking for. Hopefully more will come.
I have changed my track driving habits slightly since the new engine. First I avoid type 1 over revs as they may cause more damage then I had thought.
Also dont run the gas down to empty like I used to.
In the process of adding an oil temp gauge, new boost gauge, A/F gauge, and and EGT gauge. As well as a shift light.
Although this may seem like overkill, I think we may need alittle more real time monitoring of the engine when driven hard and long on the track. Some of my sessions are an hour long and previously for me that was alot of boost and redline driving. I am now somewhat more careful.
For "people" with any mods I am "told" the car is truely not dependable in track situations. I really think that affects alot of us on this forum.
Your opinions about any of the above are as always welcome
tom
08-31-2007, 10:40 PM
#113
The tt I just bought with GIAC redlines at 7K. I short shift at 6K.
09-01-2007, 08:27 AM
#115
Race Car
Wow Tom! I just happened onto this post..............what a bummer! Sounds like you got a lot of track miles on that motor though. The GT3's aren't rated for much more IIRC. No consolation I know, but at least it wasn't as bad a s wadding up the car 
And hey, what an excellent series of "what not to do" additions to your instructor's collection
And hey, what an excellent series of "what not to do" additions to your instructor's collection
09-01-2007, 08:42 AM
#116
Well, what I plan to do from here on out is to shortshift it around 6RPMs, and to change the oil before every track weekend. I'm also debating switching to something a little heavier in the oil category... Tom's loss could be our gain...
Interestingly, the only time I've ever gotten into the rev limiter was at watkins glen after the motor started losing boost due to some CEL codes that kicked it into limp mode.
Mike
Interestingly, the only time I've ever gotten into the rev limiter was at watkins glen after the motor started losing boost due to some CEL codes that kicked it into limp mode.
Mike
09-10-2007, 11:34 PM
#118
Rennlist Member
Thread Starter
Wow Tom! I just happened onto this post..............what a bummer! Sounds like you got a lot of track miles on that motor though. The GT3's aren't rated for much more IIRC. No consolation I know, but at least it wasn't as bad a s wadding up the car
And hey, what an excellent series of "what not to do" additions to your instructor's collection
And hey, what an excellent series of "what not to do" additions to your instructor's collection
The old engine is soon to be on its way to Kevin at UMW's for the long awaited autopsy.
hopefully we will learn some new info to help us in the future soon!!
09-14-2007, 11:51 AM
#119
Race Director
The forces that the rotating parts see is squared based on the rotational velocity omega. Acceleration is omega^2 * radius, and force = mass * acceleration. Stresses are typically linear with force, but there can be material and geometric effects which make the relationship non-linear.
