Can a STOCK 996TT Motor Put Down 800-900RWHP?
#46
09-30-2009, 11:17 PM
Mike is pushing almost 800rwhp on pump+meth, and our pump is not as good as pump in east coast either. Ours is junk
#47
10-01-2009, 03:26 PM
Just out of curiosity why would the bent rods necessarily be linked to measured engine torque. Or, I guess the question could more clearly be stated; would it be a correct to assume that the measured torque represents some sort of upper bound on the stock engine rods?
Couldn't it just as easily have been a fuel, or timing, issue that resulted in pre-ignition.
Looking at the photo's; the force required to buckle the very short rod must have been enormous.
Couldn't it just as easily have been a fuel, or timing, issue that resulted in pre-ignition.
Looking at the photo's; the force required to buckle the very short rod must have been enormous.
#49
10-01-2009, 04:12 PM
I'd like to see someone spend the money and put a SPI 800 package on a 996...so far to my knowledge they are all on 997's. Tim replaces everything you mention above (of course leaves the heads stock), so hard to say how close the performance would be, but I bet it would be pretty close.
I agree though that a 997 is cheaper to mod to decent hp levels compared to a 996....
I agree though that a 997 is cheaper to mod to decent hp levels compared to a 996....
#50
10-01-2009, 04:14 PM
Just out of curiosity why would the bent rods necessarily be linked to measured engine torque. Or, I guess the question could more clearly be stated; would it be a correct to assume that the measured torque represents some sort of upper bound on the stock engine rods?
Couldn't it just as easily have been a fuel, or timing, issue that resulted in pre-ignition.
Looking at the photo's; the force required to buckle the very short rod must have been enormous.
Couldn't it just as easily have been a fuel, or timing, issue that resulted in pre-ignition.
Looking at the photo's; the force required to buckle the very short rod must have been enormous.
the rod, it is likely to have produced other severe damage to the
pistons, head gaskets etc, and we should presume that it would
be reported if that were the case. Yes, the force needed to bend
rods is big, but so is the force needed to supply over 400 ft/lbs of
torque at a crank radius of much less than a foot, at the piston
speeds reached at 7000 rpm. pistons and rods must be engineered
with some margin, but not too much, else performance suffers *and*
extra strain of the weight is passed down to the crank and bearings
etc. It should not be surprising that Porsche designed a closely
optimized setup for about the power output the motor delivers as is,
and that those who go on power-adding adventures will be discovering
the systematic limits one-by-one as they are tripped over.
#52
10-01-2009, 05:49 PM
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I thought that was the plan, but that he asked Tym to tune it way down. Did he ever put it on kill mode?
#53
10-01-2009, 07:06 PM
Just out of curiosity why would the bent rods necessarily be linked to measured engine torque. Or, I guess the question could more clearly be stated; would it be a correct to assume that the measured torque represents some sort of upper bound on the stock engine rods?
Couldn't it just as easily have been a fuel, or timing, issue that resulted in pre-ignition.
Looking at the photo's; the force required to buckle the very short rod must have been enormous.
Couldn't it just as easily have been a fuel, or timing, issue that resulted in pre-ignition.
Looking at the photo's; the force required to buckle the very short rod must have been enormous.
There was no signs of pre-ignition on the pistons and the head gasket was fine. The only sign of problems was a ticking noise after the launch that we could not identify right away.
#54
10-01-2009, 07:55 PM
we did turn it down from 21 psi to 18 psi for him. we want him to get used to the power level without wrapping it around a telephone pole. once he gets the used to the power, we will turn it back up. right now, i think he is very happy. also, once we tune it on C16, i am quite sure it will make 750+ rwhp.
Last edited by dk996tt; 10-01-2009 at 07:58 PM.
#55
10-02-2009, 11:06 AM
David,
There was no signs of pre-ignition on the pistons and the head gasket was fine. The only sign of problems was a ticking noise after the launch that we could not identify right away.
There was no signs of pre-ignition on the pistons and the head gasket was fine. The only sign of problems was a ticking noise after the launch that we could not identify right away.
What would you consider to be signs of pre-ignition on the piston?
Could it be that this engine saw only a few rev's (one or two even) of pre-ignition and then once the rods had yielded, the compression ratio was significantly degraded that pre-ignition stopped? Would you expect to see this evidence, of one or two ignitions, on the piston?
I am not trying to be argumentative. I learn the most when I carefully push back a little.
The ticking, I would think, could have been flat spots or derformations in the bearings, or wrist pins, that hammered on reversing loads during a rotation cycle.
#56
10-02-2009, 11:26 AM
David, by 'pre-ignition' you mean detonation, correct? Not just combustion started too
soon, right? In order to make a significantly greater than planned-for force, we would
be looking for an explosion, which could chip off or deform the upper outer edges of
the pistons where they cantilever out over the topmost piston ring. That, and blowing
out the head gasket...
And as to clicking, flatspots in bearings at either end, or if the piston pins
bent slightly, they would become like a mini crank where they would rotate
to extend the length between the piston and the crank when the piston
was being drawn out of the cylinder during the intake cycle, and then they
would snap to the other way to shorten the distance when the piston was
resisting pressure, during either the compression or exhaust stroke. Just
thinkin...
Oooh, I just realized that the rods seem to have bent in a way that doesn't
just shorten them. They seem to have bent sideways so they are also now
wanting to displace the piston sideways. That, combined with any sort of
new play in the bearings would cause an ugly clicking, either as piston slap
at 90 degrees to what you'd normally expect it, or at the big end as the rods
got forced side-to-side...
Joe
soon, right? In order to make a significantly greater than planned-for force, we would
be looking for an explosion, which could chip off or deform the upper outer edges of
the pistons where they cantilever out over the topmost piston ring. That, and blowing
out the head gasket...
And as to clicking, flatspots in bearings at either end, or if the piston pins
bent slightly, they would become like a mini crank where they would rotate
to extend the length between the piston and the crank when the piston
was being drawn out of the cylinder during the intake cycle, and then they
would snap to the other way to shorten the distance when the piston was
resisting pressure, during either the compression or exhaust stroke. Just
thinkin...
Oooh, I just realized that the rods seem to have bent in a way that doesn't
just shorten them. They seem to have bent sideways so they are also now
wanting to displace the piston sideways. That, combined with any sort of
new play in the bearings would cause an ugly clicking, either as piston slap
at 90 degrees to what you'd normally expect it, or at the big end as the rods
got forced side-to-side...
Joe
Last edited by Joe Weinstein; 10-02-2009 at 11:46 AM.
#57
10-02-2009, 01:49 PM
cjv,
What would you consider to be signs of pre-ignition on the piston?
Could it be that this engine saw only a few rev's (one or two even) of pre-ignition and then once the rods had yielded, the compression ratio was significantly degraded that pre-ignition stopped? Would you expect to see this evidence, of one or two ignitions, on the piston?
I am not trying to be argumentative. I learn the most when I carefully push back a little.
The ticking, I would think, could have been flat spots or derformations in the bearings, or wrist pins, that hammered on reversing loads during a rotation cycle.
What would you consider to be signs of pre-ignition on the piston?
Could it be that this engine saw only a few rev's (one or two even) of pre-ignition and then once the rods had yielded, the compression ratio was significantly degraded that pre-ignition stopped? Would you expect to see this evidence, of one or two ignitions, on the piston?
I am not trying to be argumentative. I learn the most when I carefully push back a little.
The ticking, I would think, could have been flat spots or derformations in the bearings, or wrist pins, that hammered on reversing loads during a rotation cycle.
As for the ticking. You have no further to look than the picture of the six rods. Note the one rod where up by the wrist pin (right side of rod) there is evidence where the bent rod was hitting the crank.
My bearings were in great shape.
I'm not being argumentative either. My comments are based on my past experiences and represent only my opinion.
Last edited by cjv; 10-02-2009 at 02:20 PM.
#58
10-02-2009, 08:33 PM
We were not very easy on our's. We not only bent rods, but we cracked two Fiske rims.
How many times have you taken a SPI 800 to 7400 rpm's and dropped the clutch? I may add that is with a 3.17-1 first gear, LSD , Tilton three disc 7.25" carbon to carbon clutch (I believe we were the first to use the Tilton in the 996tt, we designed the setup for WEVO) and 265/335 tires. I'm not downplaying anyones work, but 700 plus foot pounds that are subject to moderate heavy to heavy use will destroy stock internals.
At the time I believe we were running about 640 plus a hundred shot of nitrous. That appears to be very close to what the SPI 800 is producing five and a half years later.
I'm going back to April 2004 Excellence by David Colman, I believe our 60 foot time was 1.5 plus seconds in 104 degree ambient temperatures. With ideal temps we would have been a full 2/10's faster.
Last edited by cjv; 10-02-2009 at 08:47 PM.
#60
10-02-2009, 09:02 PM
I know where this is going, but it has to be said. Dyno's are very easy on motors.
We were not very easy on our's. We not only bent rods, but we cracked two Fiske rims.
How many times have you taken a SPI 800 to 7400 rpm's and dropped the clutch? I may add that is with a 3.17-1 first gear, LSD , Tilton three disc 7.25" carbon to carbon clutch (I believe we were the first to use the Tilton in the 996tt, we designed the setup for WEVO) and 265/335 tires. I'm not downplaying anyones work, but 700 plus foot pounds that are subject to moderate heavy to heavy use will destroy stock internals.
At the time I believe we were running about 640 plus a hundred shot of nitrous. That appears to be very close to what the SPI 800 is producing five and a half years later.
I'm going back to April 2004 Excellence by David Colman, I believe our 60 foot time was 1.5 plus seconds in 104 degree ambient temperatures. With ideal temps we would have been a full 2/10's faster.
We were not very easy on our's. We not only bent rods, but we cracked two Fiske rims.
How many times have you taken a SPI 800 to 7400 rpm's and dropped the clutch? I may add that is with a 3.17-1 first gear, LSD , Tilton three disc 7.25" carbon to carbon clutch (I believe we were the first to use the Tilton in the 996tt, we designed the setup for WEVO) and 265/335 tires. I'm not downplaying anyones work, but 700 plus foot pounds that are subject to moderate heavy to heavy use will destroy stock internals.
At the time I believe we were running about 640 plus a hundred shot of nitrous. That appears to be very close to what the SPI 800 is producing five and a half years later.
I'm going back to April 2004 Excellence by David Colman, I believe our 60 foot time was 1.5 plus seconds in 104 degree ambient temperatures. With ideal temps we would have been a full 2/10's faster.
http://www.youtube.com/watch?v=r5xMyVaqtkU