Quote:

Originally Posted by 997 GT3 RS/TT

and why you are running stock gt2 ?<V</V<?xml:namespace prefix = v ns = "urn:schemas-microsoft-com:vml" /><v:shape style="WIDTH: 12pt; HEIGHT: 15.6pt; VISIBILITY: visible; mso-wrap-style: square" id=Picture_x0020_1 alt="http://images-2.ibsrv.net/ibsrv/res/src:www.6speedonline.com/get/forums/images/smilies/confused.gif" o:spid="_x0000_i1025" type="#_x0000_t75"><v:imagedata src="file:///C:\Users\Jean\AppData\Local\Temp\msohtmlclip1\01\c lip_image001.gif" o:title="confused"></v:imagedata></v:shape>

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Good question I guess because I already have this one that is a bit modified. 100-200kph in 5.2s. (Good opportunity to show it off )
Also the roads here are definitely not appropriate for a modified Porsche.<O</O

 

Karol,

I think this new dyno graph also confirms that max. torque at 1.4 bar on these engines is limited < 650lbs.ft. While max. HP seems to be limited by the size of the turbos on this latest run.

 

how about amount of air? my present turbo produce more kilo of air than big vtg's on same boost level.

 

Every turbo will blow the amount of air that the ENGINE takes at a given pressure, if they don't choke of course.

 

Karol

The size of the turbo will not make a difference in the peak torque being delivered at the same boost level, it is driven by the engine capacity to absorb air, since both turbos are not flowing near their maximum capacity at those RPM levels. The torque peak will move to the right of the scale with the bigger turbo if it takes longer to spool to 1.4 bar. This is the same rationale as to why restrictors on turbos for race cars only limit maximum HP and max. torque is not impacted.

As emadelta rightly said, provided none of them chokes, also, the larger turbo "might" give slightly more torque in case the smaller turbo is driving higher intake air temperatures, but this is unlikely unless it is a very mismatched map with the engine needs.

 

Jean the value i got for "Pressure Ahead of Throttle plate" when the car is stationary is 1000 , and maximum was 2550 accelerating in 3rd does this mean the car is boosting 1.55 bar ??

 

if it show 2.55 than correct.


btw how to post here data log? it's long...

 

4th gear 100-200km/h

 

...no way to read it, so how should I post it?

 

Yes this is the way to do it. Theoretically it should be 980 I believe but if your idle pressure is 1000 that will be right.

Can you please post your highest mass airflow reading with the corresponding RPM and load reading?

Karol, if you hide a number of these rows (like 10 at a time for example) it should be more readable.?

 

I sent logs to you....

 

I would like to motioned again, I'm running without maf's so no way to measure kilograms of air?

btw. how many kilograms of air I need to produce 750PS?

 

Around 2200 roughly.

 

you think my turbos will produce this amount of air @1,2 bar boost?

please leave official feedback of the logs I sent you

 

"bit modified" 100-200 in 5,2sec.
you can't call this bit