Why does a 86.5 rev faster than a S4
08-13-2007, 05:06 PM
#31
Team Owner
Thread Starter
Anyway with the clutch pedal released (foot off), the whole drive line is spinning (Flywheel,clutch discs,intermediate plate,pressure plate,throw out bearing,driveshaft and intermediate drive shaft and the main shaft in the transmission)with the exception of the pilot bearing as it is turning the same speed as the captured clutch plates/driveshaft, The THROWOUT BEARING SPINS ALL THE TIME whether the clutch is pushed in or let off, the PILOT bearing only spins when the drive shaft is not spinning or the car is coasting in gear with the clutch pedal pushed in. the clutch pack including the intermediate plate if installed and the pressure plate all spin with the flywheel as they are all bolted to it. So to check for a bad pilot bearing press in the clutch trans in gear, this will let the pilot bearing spin.
To check for a bad throwout bearing lightly press on the clutch this adds some load to the TOB and will change its loading. If you hear a constant squeal with the foot off the clutch , this indicates a bad torque tube bearing set, or bad TOB
To check for a bad throwout bearing lightly press on the clutch this adds some load to the TOB and will change its loading. If you hear a constant squeal with the foot off the clutch , this indicates a bad torque tube bearing set, or bad TOB
08-13-2007, 05:45 PM
#33
Team Owner
Thread Starter
Shane how are you?, Hey have you ever noticed how your early 32 valve engine revs faster than a S4? Any thoughts?
08-13-2007, 05:56 PM
#34
Sharkaholic
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Well to compare mine to an S4...
I was racing on a closed circuit track one day with Heinrich, under the utmost safety conditions.
We were pretty much door to door. So both 5sps, one '86.5 one '87. Real close in acceleration.
Against an auto well the auto isn't going to have a chance. Even an '86.5 auto.
I can say that mine too climb through the RPMs rather fast. It is one of the reasons I like them so much.
I was racing on a closed circuit track one day with Heinrich, under the utmost safety conditions.
We were pretty much door to door. So both 5sps, one '86.5 one '87. Real close in acceleration.
Against an auto well the auto isn't going to have a chance. Even an '86.5 auto.
I can say that mine too climb through the RPMs rather fast. It is one of the reasons I like them so much.
08-13-2007, 08:14 PM
#37
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Originally Posted by Tom. M
hahahaha.....waiting the arrival of godzilla for rebuttal 
Later,
Tom
(one of those sluggish 89GT thingies...)
Later,
Tom
(one of those sluggish 89GT thingies...)
Hell I guess I could dig out all that video from our Torque Freaks Dyno day, and time how quickly each of them goes from 3000 to redline. We had everything there from OB's to twin turbo S4 and a GTS.
08-13-2007, 08:17 PM
#38
Team Owner
Thread Starter
Hey lets investigate, there might be more here than we thought
08-13-2007, 08:19 PM
#39
Don't forget about the different rear ratio's....with my 2.73...don't think even your euro lay shaft equipped 86.5 would rev as fast as mine....
Just for reference..the GT revved so much faster than my 87AT at the dragstrip..that my first outing with the GT...I hit the revlimiter in 1st, 2nd, and 3rd ..
later,
Tom
89GT
We'll have to try that match up again this trip to Sharktoberfest.... are you heading down?..
Just for reference..the GT revved so much faster than my 87AT at the dragstrip..that my first outing with the GT...I hit the revlimiter in 1st, 2nd, and 3rd
..later,
Tom
89GT
We'll have to try that match up again this trip to Sharktoberfest....
are you heading down?..
08-13-2007, 08:27 PM
#40
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Originally Posted by Tom. M
Don't forget about the different rear ratio's....with my 2.73...don't think even your euro lay shaft equipped 86.5 would rev as fast as mine....
Just for reference..the GT revved so much faster than my 87AT at the dragstrip..that my first outing with the GT...I hit the revlimiter in 1st, 2nd, and 3rd ..
later,
Tom
89GT
We'll have to try that match up again this trip to Sharktoberfest.... are you heading down?..
Just for reference..the GT revved so much faster than my 87AT at the dragstrip..that my first outing with the GT...I hit the revlimiter in 1st, 2nd, and 3rd
..later,
Tom
89GT
We'll have to try that match up again this trip to Sharktoberfest....
are you heading down?..
Not sure I'm heading to Sharktobefest but plan on hitting the Texas Third Coast event.
08-13-2007, 11:00 PM
#41
Burning Brakes
All information contained within is generalized
DISCLAMER: information written below is not accounting for perfomance diferances caused by "Air intake volume" or Exhaust pressure.
Well all this info is great.
Iv been contemlating this issue for some time now... here are some of my thoughts.
1. one V8 to another V8 same "basic" size (and piston angle)no mater 16 or 48 valves "should" rev just as fast as another ( not talking auto to 5 sp) stroke and balancer/crank weight will make a diferance....as will cams.
2. most modern cars seem to have a "slow" response. i think its designed as a safety precaution. and to make a smother ride. Reasons to slow the motor revs are plenty.
Smother ride, better gas millage, lower stress on the drive train(5 speeds), better traction(esp in snow
) possibly to even keep the motor in a beter"sweet spot"(iv seen some throttles with a cam that changes the response amount in the middle of the throttle travel.
3. some motors seem to rev up just fine but are slow to return, this gives a slow rev feel, this is only slow in "sound" not in performance. (like adding spin to a top that hasnt stopped spinning, revs even hit redline faster in the second blip if you dont wait for the revs to completely fall. (THis i would think is just how you would want a 5speeds throttle to react
.)
4. our cars were made as GT's ie: fast smooth rides not tire burning high reving demons
.....but i like most want to remove some of the "padding" and let this "Porsche" stretch its legs......so this winter im going to remove the linkage from a 79' 5sp and install it on my 82' should Lighten up the peddle feel (82' is stiff peddle) and possible quicken the responsiveness.
Im also going to unbolt the TT in hopes of I.D.'ing my vibration issues, i will see how she revs then.
Well all this info is great.
Iv been contemlating this issue for some time now... here are some of my thoughts.
1. one V8 to another V8 same "basic" size (and piston angle)no mater 16 or 48 valves "should" rev just as fast as another ( not talking auto to 5 sp) stroke and balancer/crank weight will make a diferance....as will cams.
2. most modern cars seem to have a "slow" response. i think its designed as a safety precaution. and to make a smother ride. Reasons to slow the motor revs are plenty.
Smother ride, better gas millage, lower stress on the drive train(5 speeds), better traction(esp in snow
) possibly to even keep the motor in a beter"sweet spot"(iv seen some throttles with a cam that changes the response amount in the middle of the throttle travel.3. some motors seem to rev up just fine but are slow to return, this gives a slow rev feel, this is only slow in "sound" not in performance. (like adding spin to a top that hasnt stopped spinning, revs even hit redline faster in the second blip if you dont wait for the revs to completely fall. (THis i would think is just how you would want a 5speeds throttle to react
.)4. our cars were made as GT's ie: fast smooth rides not tire burning high reving demons
.....but i like most want to remove some of the "padding" and let this "Porsche" stretch its legs......so this winter im going to remove the linkage from a 79' 5sp and install it on my 82' should Lighten up the peddle feel (82' is stiff peddle) and possible quicken the responsiveness.Im also going to unbolt the TT in hopes of I.D.'ing my vibration issues, i will see how she revs then.
08-13-2007, 11:11 PM
#42
Burning Brakes
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Maybe an improper flappy valve , out of tune MAF or a number of other things make an S4 not rev as fast?
From a logical standpoint, if both an S3 and S4 are geared the same, in good running order, then the S4 should be slightly ahead in most cases.
But then again, the engines do come out of the factory at different HP levels, even between the same year 928's. It could be as simple as fine tuning and adjustment to maximize hp and torque.
From a logical standpoint, if both an S3 and S4 are geared the same, in good running order, then the S4 should be slightly ahead in most cases.
But then again, the engines do come out of the factory at different HP levels, even between the same year 928's. It could be as simple as fine tuning and adjustment to maximize hp and torque.
