sharkster

Hey mdrums, remember you're comparing apples and oranges here Not only are the dynos different but the cars you are talking about are 6speed cars, which are easy to dyno. Nobody that I know of has yet dynod the PDK car but a figure of roughly 20% is about right for that car and throw into the fact that there's a 7speed PDK tranny in there... So their baselines (one was done on a different dyno altogether) were done on different transmissions and different set ups so it'd make sense. We are running 91 octane they're running 93 octane out there, no? The important thing to remember is the _before_ and _after_ which we ran on the same car (over and over), on the same day/conditions with just that one modification being the difference and hence delta. Hope that helps! I'm sure when we dyno a 6speed car it'll likely give a higher baseline but again Stasis' dyno is well-known for reading lower than others (a good thing in my book). Take those two cars you're talking about and I bet they'd likely have dyno'd a lower baseline today on the same dyno. Hope that helps....

mdrums

sharkster, thanks for the reply and understanding I am not doubt or putting your deal down but just me trying to learn something. I totally understand about the 3 different dyno's used by the 3 different vendors plus the operator, weather, data input for weather and so forth. I understand the 20% value for the all wheel dyno a PDK car has to use and the 14% value that the 2wheels drive 6 speed cars get to use.

I forgot you have to use 91 octance and that would make a few HP difference, around 5hp at most I have been told. So am I think this correctly...take your 309 baseline, add 20% and get 371 add 5hp for the 91 vs 93 octane and get 376hp at the crank?

thanks for the help! Mike

Dan@SharkWerks

Hi Mike,
I know Alex is not at a computer so I will try to help.

It's a bit early for me and my dyno math is a little rusty from years of inactivity:
But I think if the car loses power going from the flywheel to the wheels, you'd use something like:
385 * 80% = 308 HP
(wheel HP = 80% of flywheel horsepower)
or
385 - (385*20%) = 308 HP

Adding 20% back on top of that is not the same as subtracting 20% from the gross HP, because you're losing that 20% of the difference to the engineers at Porsche and that big'ol AWD dyno. If this is correct then to go from wheel HP to flywheel HP I think you'd take wheel HP / (1-drivetrain loss)... or 307 / 80% = 384 HP.

^^^ Again - I could be very wrong here, but this is the way I understood it.

gota911

Your calculation above is correct. 80% of 100 HP = 80 HP but 120% (adding 20% back) of 80 HP = 96 HP. That's because you are adding back 20% of the lower number. But 80 HP / 80% = 100 HP .

Or you could use the reciprocal calculation as a multiplier, which is 100/80 = 1.25, then 1.25 X 80 HP = 100 HP

So 308 / 80% = 385 HP, or
308 X 1.25 = 385 HP.

Restless

Sharkster,

You made comment about the Tech Arc springs working well on the 997.2 model, and that you could actually recommend them with the new model. Have you tried those springs on the older 997 Non-Pasm cars (05 997 C2 is what I have)? I was think about changing the springs on the 05 C2 and possibly the shocks (going with the Blistein Sport shocks). Any comments??

mdrums

Thanks Dan, totally understand it now...thanks for the explaination...just trying to figure it all out as compared to other dyno readings for other mods. I know it's hard to compare but I find all this very interesting of sorts.
Thanks again!

sharkster

Hey Restless, I must admit that we've done the TechArt springs before on the 997.1's before with pretty good success but not with the Bilstein sport shocks as well. I would say it'd be an experiment but likely one that somebody has done. I do know that the springs were designed around that stock shock though so I'm not sure if it'll be too stiff of a shock as a result?

No worries mdrums and I see Dan got there before me on that and summed it up It's hard to compare indeed but again try looking at the deltas and the before/after (as long as those are the same conditions) as much as you can. On your car you'd need to get a baseline and then dyno as you change things if you can (much easier on a 6speed) and just go to the same location etc.... Keep things consistent.

sharkster

She's no longer called Kermit... Give it a name:

sharkster

Hey fellas, here's a suspension-a-polooza update for project ZTadpol. We've gotten quite a few new toys in this week so I thought I'd give you a little sample of some of the suspension changes in store. In many ways thanks to the 6speed community and friends we've made we've actually been working behind the scenes with the team at RSS. Their manufacturing expertise/ capabilities and their ability to work in-house is so paramount. In fact, they've long been cranking out some of our parts and have been making parts for just about everyone for donkeys years. Their full line has been available for 996/997 cars for a while and our 09 997 is no different and hence we've been hammering away at suspension components for the more ardent track folks.

This includes an adjustable toe steer kit (also replaces the inner bushing with a steel monoball) as shown here:

And compared to the stocker

Adjustable rear links:

And compared to stock:

Also on tap are the adjustable thrust arm bushings (which do away with the neoprene):

And finally the monoball lower control arm kit.


Our rear end being worked on by James:




Dan will be releasing all of the info etc... over the next few days but for now that's a taste or you can head over to the suspension section on the site and dig around

Chris from Cali

Great stuff, Alex... Looks like I'll be seeing you in August.

Likemystoppie?

Chris, lovin the Sig mang!!

sharkster

Hey Chris sounds like a plan mate!

sharkster

The light's a little better today and with the rotors off (more on that in a second...) you can get a better idea of the level of adjustability and just how we're rid of most of the "cushy" stuff

sharkster

Now on to the two piece rotor upgrades. The 997S 09 comes with 330mm front and 330mm rears so not only are we going with a lighter weight two piece slotted/drilled rotor but these can actually bolt on with caliper spacers to fit 350mm ones (also still lighter).
All four stock vs new:

Front RSS one comes in at 22.16 pounds:

Smaller stock one is still heavier at 23.24 pounds

New larger rears at 17.7 pounds:

Old smaller stockers at 19.86 pounds:

sharkster

Fronts installed:

Rears installed:


Darn rain is killing us today tho