1.3 bar throttle limiter !?!?!?!

[Speedkan]

Hi, i'm running a 996 TT with K24 turbos with a consistent 1.2 bar-1.3 spikes.

Now in Europe it's cold, around 0° Celsius (32° Fahrenheit) and the boost is increasing due to the cold air.

So what i'm experiencing now is, sometimes, the ECU closing the throttle just a little bit over 1.3 bar.

Do you know if is there a 1.3 bar throttle limiter as i have read in some topics in the 6speedliner forum ?

Or maybe is just the protection mode running when the pressure get close to 1.4 bar ?

Thank u guys

Bye

[Loren]

My understanding is that the DME controls max boost pressure based on a number of variables (like altitude, exhaust turbine speed, load, etc. etc.). One goal is not to allow the exhaust turbines to exceed 8,000 RPM - so I think max boost is variable depending on factors the DME sees at the time. At least that is how I understand the explanation in the Porsche TT Technik Book.

[Speedkan]

Hey Loren you say 8000 RPM for the exhaust turbine, but the k24 shouldn't be running at around 130000 RPM ?

Or maybe are u talking about something different ?

[Loren]

The Porsche Technik specifies the standard turbos - I don't know about the K24 (X50/GT2) turbos. I think the theory of operation is still the same - the DME limits boost based on the other variables.

I'll keep looking but there is not much documentation (that I have found) on the GT2/X50 turbos.

[Speedkan]

Thank u Loren.

[skandalis447]

Considering that the ECU is fine tuned on a dyno for boost pressure of 1.2 constant...Is it safe to run it at that pressure for engine internals?

[Loren]

I think the max boost is adjusted based on other engine variables including exhaust turbine speed. So it could lower or theoretically higher.

[Speedkan]

Well, considering that 1,2 bar should mean around 560-580 HP at the crank, the engine internals should be safe !

Somebody says that the connecting rods have a critical breaking point at 750 HP so i would stay away from that level and 560-580 looks to be enough safe!

[skandalis447]

Well, considering that 1,2 bar should mean around 560-580 HP at the crank, the engine internals should be safe !

Somebody says that the connecting rods have a critical breaking point at 750 HP so i would stay away from that level and 560-580 looks to be enough safe!

what about pistons,valves...etc...My goal is to produce about 580hp...Without opening the engine,reliable...So I am making a very careful consideration of what to buy in order to achieve it...If the engine internals are safe in that HP it is amazing...

[Speedkan]

what about pistons,valves...etc...My goal is to produce about 580hp...Without opening the engine,reliable...So I am making a very careful consideration of what to buy in order to achieve it...If the engine internals are safe in that HP it is amazing...

Your goal was my goal and i hope my experience with my car could be useful for you.

1) 100% stock engine internals (of course if i had the idea to change the internals i would do everything, crankshaft, pistons, valves, cammes...but 580 HP don't need internals change... as u say...really amazing !!!

2) Swap from k16 to k24 (but you can go Hybrids ... there's a lot of possibilities)

3) Ecu flash for sure

4) New Forge diverter valves

5) New k24 evoms headers (don't need to get more power, stock are perfect)

6) Stock exhaust modified with 100 cell cats

7) 5 bar fpr (probably don't need but better be sure with the fuel)

8) Blown six design larger intercoolers

9) Evoms wastegate boost kit set at 1,2 bar

10) Rev limiter to 7050 RPM

11) 350 mm front 996 gt3 cup brake discs with 6 pistons caliper (power needs brakes)

My Porsche is a 90000 km car (56000 miles) with the stock original doublemass flywheel and stock sachs clutch not slipping yet, and its reliability looks great after 1 year with that power.

12) Of course when the clutch will begin to slip i'm gonna change it with an upgraded one but not sure there is the need of it.

Bye

[skandalis447]

what about pistons,valves...etc...My goal is to produce about 580hp...Without opening the engine,reliable...So I am making a very careful consideration of what to buy in order to achieve it...If the engine internals are safe in that HP it is amazing...

Your goal was my goal and i hope my experience with my car could be useful for you.

1) 100% stock engine internals (of course if i had the idea to change the internals i would do everything, crankshaft, pistons, valves, cammes...but 580 HP don't need internals change... as u say...really amazing !!!

2) Swap from k16 to k24 (but you can go Hybrids ... there's a lot of possibilities)

3) Ecu flash for sure

4) New Forge diverter valves

5) New k24 evoms headers (don't need to get more power, stock are perfect)

6) Stock exhaust modified with 100 cell cats

7) 5 bar fpr (probably don't need but better be sure with the fuel)

8) Blown six design larger intercoolers

9) Evoms wastegate boost kit set at 1,2 bar

10) Rev limiter to 7050 RPM

11) 350 mm front 996 gt3 cup brake discs with 6 pistons caliper (power needs brakes)

My Porsche is a 90000 km car (56000 miles) with the stock original doublemass flywheel and stock sachs clutch not slipping yet, and its reliability looks great after 1 year with that power.

12) Of course when the clutch will begin to slip i'm gonna change it with an upgraded one but not sure there is the need of it.

Bye

Thank you for your reply...

Here are my comments...

2)I believe K24 is the best way to go for that goal...Porsche did it in GT2 also...

6)Stock exhaust modified....What kind of modification should I do with the stock muffler...I like the quiet interior of my car when cruising...Should I buy GT2 muffler?

What power did you dyno?What boost pressure?(1,2 constant?)

Thank you...

[Speedkan]

Yes, for what i know K24 is absolutely the best way and cheaper too (a couple of new K24 costs around 2500-3000$ without going with Hybrids just to have a little less lag... and swapping from k16 to k24 i haven't noticed so much difference in the lag!!!) to get 580 HP .

For sure this is their limit and there's no way to get more horse power with this configuration but it's not so bad, believe me!

The GT2 has 463 or 482 HP with the K24 but could reach this level power with the k16 too!

So the question is: Why do Porsche swap from K16 to K24 in the GT2 ? IMO is a pure marketing problem but not technical !

The only positive thing is that in this way GT2 has a higher starting point to get extra power!

About my exhaust it has been opened completely, removed the stock 400 cells cats and installed new 100 cells cats (in Italy there is the "Brainkat" that u can see at www.brainkat.net working great...think about that they work for Tubistyle and Supersprint, etc...) and removed some internal sheet to have a better flow that u can really feel.

The rumor is still quiet (maybe 5% more then stock) but the flow is more rapid !

So i wouldn't buy GT2 mufflers that i suppose they are the same of the TT but not sure 100% about this point!

No dyno because here around it's not easy to find a more then 500 HP 4WD Dyno but mathematically i can't be wrong about the approximate output power of my car (i know the maximum air flow of K24 and the power is directly chained with the flow...so that's way i can mistake my calculation by 10-20 HP but not more.

Boost now runs in this way:

1,3 bar 3000-4000 RPM

1,2 bar 4000-6300 RPM

1,3 bar 6300-Rev limiter

Bye