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Not sure how much more power you can get on pump mixed with MS109. We forgot to put it in sport mode which gives 12% more power so about 650 hp maybe on a nice cool day.
Here is a stock GT2 RS dynod by Edmunds. Dyno graph is similar apart from peak torque kicks in slightly earlier at about 3500rpm rather than 3800 rpm due to smaller stock compressor wheel. Also note a stock GT2 RS in this case only makes 580bhp on a roller dyno not the 621bhp Porsche quote. Edmunds explain some interesting points about dynoing a GT2 RS here
Also stock dyno graph with and without an akpro system
The 997GT2RS compressor wheels are great. Here is a dyno of 3.8 Mezger in a 996 with a conservative 91 octane race tune. 7GT2RS compressor is mated to a K16 hot side. Running 1.25 bar. Interestingly both the Edmunds 7GT2RS dyno and mine are on a 248 dynojet and 91 octane which makes it a good apples to apples comparison.
Torque is 672 ft.lb (912 Nm) at 4000 rpm. When you look at the overlaid dyno charts, torque and hp rise initially mirrors that of the 7GT2RS dyno except that Porsche caps theirs at 500 ft.lb through tuning while in my application it continues to rise. Midrange (3500-5500) is noticeably stronger on the 3.8. Ported heads and better valve train allow the 3.8 to pull strong to 7500. I would imagine with a raised redline the 7GT2 RS would be similar up top. Interestingly the 3.8 intake y-pipe and throttle body (68mm Boxster part) and plastic intake manifold are stock 996TT/GT2 parts which leads me to believe there is not a huge improvement to be had there, contrary to popular belief. The post Maf manifold and turbo intake pipes are quite a bit larger than stock on the 3.8
Yes. That's correct. They are NON VTG K16 hot sides mated to the 7GT2RS compressors. The housing is ported on both sides to increase the amount of air funneled to the turbine and compressor thus increasing the efficiency of the turbo as a whole. In addition, the compressor housing uses a zero clearance coating to minimize any compressor blow by further improving efficiency. The result is a simple non VTG turbocharger that rivals the VTG turbo in spool while having significantly greater midrange punch and the ability to maintain power high in the rpm range.
I have two years of hard track use on these turbos running them in +100F temps and +8000' density altitudes. They have performed flawlessly in these harsh conditions all the while having lower compressor outlet temps than a stock VTG turbo, about 30-40F lower based on direct comparison of logs.
One thing to note is that these turbos will flow 1.6 bar while we are running them at 1.25 which is maintained all the way to the 7500 redline.
Here is some timing info on UK 98 fuel, 1.2 bar on std 997.1 turbos.
545bhp and 585ftlb. Totally stock hardware. Car makes 477bhp stock.
When comparing power, you need to take into account the country and Dyno. Most in the US use Dynojets which while useful for comparing against others, are pure fiction for the rest of us. Dyno Dynamics, properly calibrated Maha etc will read roughly what Porsche quote as standard.
Because on the engine Dyno it is done steady state.
It is held at full load at a particular RPM point and the maximum torque measured. Most turbo plots are done on Dynojet inertia dyno's which are over in a few seconds. No time to spool.
I have acheived similar on my Dyno by loading it right up. But in reality it doesn't mean a great deal as on the road the car is accelerating too quickly and by the time it has spooled the RPM has increased. Two different things - turbo lag and boost threshold.
Here is some timing info on UK 98 fuel, 1.2 bar on std 997.1 turbos.
Maybe you can show revs up to nmax? ZWOUT and ZWGRU is not the actual timing you get - but giving the data you have access to I assume you know that
On these cars the engine control really gets interesting on high boost and and high revs.
Totally agree on the engine dyno stuff and I never understood why the US dynos are that much different to ours and even between them there are huge differences. After all they are measuring a physical value and there is only one way to do this: correct.
zwout is the final ignition angle sent to out, it's zwgru that is output from base ignition maps which may then have torque intervention timing or knock retard applied to result in zwout.
The American Dyno readings are historic. It comes from when Dynojet measured a vehicle which did not make correct power, so they eventually fudged the reading. Turns out that the Dyno was reading right all along and the vehicle wasn't actually putting out the manufacturer claimed power - but it was too late by then as many dynos were in the wild!
Correct, but still not the ignition angle that will ignite the fuel. zwout contains phase corrections and thus is bigger than the actual ignition angle.
it's zwgru that is output from base ignition maps which may then have torque intervention timing or knock retard applied to result in zwout.
Almost
The American Dyno readings are historic. It comes from when Dynojet measured a vehicle which did not make correct power, so they eventually fudged the reading. Turns out that the Dyno was reading right all along and the vehicle wasn't actually putting out the manufacturer claimed power - but it was too late by then as many dynos were in the wild!
10-23-2016, 09:46 PM
