UMW stage 2B dyno results.......
#16
Rennlist Member
A Dynojet chassis dyno can't provide this number. For a RWD 911 I would add about 10-12% to guesstimate the crank numbers.
powdrhound, the dyno shop can easily supply the uncorrected numbers if you ask them and it would be nice to see them to understand how the turbos do at elevation. Either way the '15 Z06 numbers certainly confirm that your 996TT is strong.
powdrhound, the dyno shop can easily supply the uncorrected numbers if you ask them and it would be nice to see them to understand how the turbos do at elevation. Either way the '15 Z06 numbers certainly confirm that your 996TT is strong.
#17
Rennlist Member
Thread Starter
I go through about 5 gallons in a 30 min session. I usually start 3/4 full and refuel each time. If I start full then I could do 2 sessions but I don't like to track the car with much less than 1/2 tank.
#18
Rennlist Member
Thread Starter
A Dynojet can do a "coast down" test. After the peak rpm of the run is reached you put the car in neutral and let it coast back down while it is still recording. When you have let it coast down to a desired drum speed you hit the stop button on the wand to end the recording of the run. On the graph you display "negative hp" which will show what the drive train hp loss is. Its probably not a 100% calculation of drive train loss but gives a very good idea.
#19
It seems that 10-12% number is fairly accurate. If you look at the Hp figure on my car and the '15 Z06, both dynoed virtually identical at 590 and 589 with the advantage of cooler OAT going to Chevy. Add 10% to that and you get 649. I would imagine the 650 published figure from Chevy is a certified no BS number and probably a minimum figure for the average production engine meaning that the true average figure is probable 650 or slightly better. 10-12% seems very plausible..
#20
Nordschleife Master
I have stock k16's so I would see quite a bit of improvement switching to a similar setup as what you have. I was contemplating getting a new Z06 during its second year run once we find out if there are issue's with it and if it will over heat under track conditions.
Sounds like I could save a lot of money just doing some turbo replacements, tune, diverter valves, injecters and intercoolers and get the same hp in my current ride and yet still be well under the weight of the Z06.
#21
Rennlist Member
Thread Starter
sounds like with your setup your burning normal fuel rate.
I have stock k16's so I would see quite a bit of improvement switching to a similar setup as what you have. I was contemplating getting a new Z06 during its second year run once we find out if there are issue's with it and if it will over heat under track conditions.
Sounds like I could save a lot of money just doing some turbo replacements, tune, diverter valves, injecters and intercoolers and get the same hp in my current ride and yet still be well under the weight of the Z06.
I have stock k16's so I would see quite a bit of improvement switching to a similar setup as what you have. I was contemplating getting a new Z06 during its second year run once we find out if there are issue's with it and if it will over heat under track conditions.
Sounds like I could save a lot of money just doing some turbo replacements, tune, diverter valves, injecters and intercoolers and get the same hp in my current ride and yet still be well under the weight of the Z06.
#22
solid baseline, looking forward to build pics and review
7GT2 gearing will be nice!
7GT2 gearing will be nice!
#23
A Dynojet can do a "coast down" test. After the peak rpm of the run is reached you put the car in neutral and let it coast back down while it is still recording. When you have let it coast down to a desired drum speed you hit the stop button on the wand to end the recording of the run. On the graph you display "negative hp" which will show what the drive train hp loss is. Its probably not a 100% calculation of drive train loss but gives a very good idea.
Finding the "true" crankshaft torque with a road/wheel dyno
The "coasting method" may be done with a lot of, if not most, different brands of the road/wheel dynometers.
But it is significantly different in order to try to factually measure the trans tax since most areas with friction taxes the torque flow vs a crank dyno in a proper dyno cell.
First of all the might the tax situation not be the same in coasting mode (i.e. only friction torque load) vs the entire transmission being exposed to the full load of engine torque?
Some of the friction areas on the taxing side:
Wheel: Tire temp and pressure steady? Shore value and width of drive tires? Wheels in //?
Bearings: Shape new-old and settings? Viscosity of grease/oil? Temperature of the grease/oil?
Gearbox/diff: Overall shape new-old-blueprinted? Straight cut/spiral cut gears? Viscosity of oils? Steady oil temp? Case flex above a certain torque load resulting in somewhat distorted angles?
If/when testing in acceleration/decelleration mode: Inertia values of the entire transmission as well as the above variables in a steady stable state?
Etc.
Obviously may "the coasting method" be used in evaluations if the above is taken into acconut i.e. constants.
Btw: Seldom will the typical road/wheel dynomometer have a better resolution and repeatbility values below 5% even if being calibrated between each round.
(Oem engineering typically use crank dynocells with resolutions & repeatability valuse below 0.1%.)
Slalom996T
#26
Rennlist Member
Thread Starter
I don't believe it's set in stone but I think the 2b kit generally includes Kevin's zero clearance turbos, injectors, intake mods, and his tune. My car already had the RUF intake manifold and turbo inlet pipes which are very similar to the UMW variety. I think an exhaust is also needed for 2B. You don't need rods if Kevin detunes the output of the turbos down low like he did in my case.
Last edited by powdrhound; 01-13-2015 at 12:20 PM.
#27
I think typically the 2A kit includes turbos, 5bar fpr, and a tune.
I don't believe it's set in stone but I think the 2b kit generally includes Kevin's zero clearance turbos, injectors, intake mods, and his tune. My car already had the RUF intake manifold and turbo inlet pipes which are very similar to the UMW variety. I think an exhaust is also needed for 2B. You don't need rods if Kevin detunes the output of the turbos down low like he did in my case.
I don't believe it's set in stone but I think the 2b kit generally includes Kevin's zero clearance turbos, injectors, intake mods, and his tune. My car already had the RUF intake manifold and turbo inlet pipes which are very similar to the UMW variety. I think an exhaust is also needed for 2B. You don't need rods if Kevin detunes the output of the turbos down low like he did in my case.
#28
Rennlist Member
Thread Starter
The 1000 mile break-in is painful especially if you don't street drive the car much.
#30
Rennlist Member
Thread Starter
Engine was removed yesterday and it is currently fully disassembled. No real problems with the engine. IMS thrust bearing showed some wear. Crank thrust bearings also showed some wear due to the clutch interlock (the interlock has recently been removed which allows you to start the car with clutch released just like on all the ROW cars). Rod bearing showed a little distress but nothing major. Valve guides showed some wear. Pistons and liners were like new...