Lots of misinformation out there Justin. Several years ago I had carefully tracked my Type 1s and 2s via my logs on my 3.6.. With a 7200 rpm redline which was visited frequently as the car was predominantly track use, I recorded thousands Type 1s and only showed 16 Type 2s. In other words, zero Type 2s were recorded below the 7200rpm redline.

My current redline is at 7600 and I only see Type 2s being added above 7250. YMMV...

 

100% agree pwdrhound. My experience has been the same. Like others have said, Porsche realized how limited the tracking was with the 996 and made significant changes with the 997.

I think it should be assessed when buying a car, but unless the readings are excessive and / or RECENT, I would rely more on the PPI, how the car drives etc.

Just my opinion.

 

pwdrhound- I know I'm dragging this off subject but that is quite some engine you have built! I've got other toys and have resisted the temptation to do any serious mods to my GT2. [I'm old and will stick with this excuse]. Please, I know you're Motec now but when you were still 3.6 and logging, was that with a modded Factory ECU or ?? I realize it doesnt amount to a hill of beans but I'm very interested in how some engines aren't showing Type 2s with serious revs. [Actually, I love it as I've heard since my 356 days how you "should not modify Dr. Porsche's perfection" crap and it's rather gleeful to see people out there confusing the Correctness Police.]

 

I've always been on a stock ECU, on my 3.6, 3.8, and also my 4.0. I can log in the traditional sense via Durametric or Cobb AP which is what we used for engine tuning in conjunction with the data from Motec. I use a Motec dash for track analysis but it also datalogs around the clock through external sensors logging information that is not available on CANbus. Motec has inputs for the following external sensors:

Engine Oil Pressure
Engine Fuel Pressure
Engine Fuel Temp
Engine DHB Fuel control
Engine L&R Lambda sensors
Engine Manifold Pressure
Transmission Temp and operation
Brake Pressure

It also controls the fuel pump based on engine load and other parameters effectively making it a fuel system with minimal fuel return. Finally it controls the OEM transmission cooler instead of the ECU as on a stock GT2. By using Motec we can tailor the transmission oil cooler to operate on a different profile better suited for track use.

I have run two different OEM ECUs. I installed a brand new OEM ECU when my 3.8 was built and still run it in my 4.0. Regarding the Type 1 and Type 2 ignitions, as I stated previously, I only see Type 2s being recorded at roughly 7250 and beyond. I have just over 13K miles on the current ECU and interestingly Type 1s quit recording at 3240 several years ago and only Type 2s now get recorded. I have no idea what caused Type 1s to freeze and stop recording. Type 2s get recored at a pretty good clip as at the engine sees lots of high revs some in excess of 7800. Last I checked the ECU was approaching 55000 Type 2s with the Type 1s stuck at 3240. Go figure.

 

pwdrhound -All I can say about your build is WOW.

RETRACTION: What I stated about the stock ECU and Type 1 - Type 2s: Such a long time ago I accepted the 6750/6751 RPM data point. I was doing more research as well as digging through my Factory manuals. While looking I got a response about this chart. One of the top guys in the business kindly sent me a chart from one of his Porsche AfterSales documents. It has a plain verison of this exact chart!

This validates a lack of "funny stuff" on a 7251 RPM Type 2 that pwdrhound.mentions.

Having a factory verification eliminates any point in bothering to figure out what happened and when. I accept this but it's stunning to have such a difference from what I have understood so long. It's also reminding me how important it is to Keep Learning. That does it for me - I'm going to drag my poor 6-2 out of storage and make a point to use the poor thing again... and personally verify whatever I can.

SO 996tt and GT2: Type 1 = >6750 <7250 Type 2 = >7250

 

[QUOTE=john rice;4794547]pwdrhound -All I can say about your build is WOW.

Thanks, it's a fun toy...