The other thing to consider as Dave mentioned above is the ability to customize a tune versus a generic tune. Remote tuning via Durametric data logging and dyno tuning are both important aspects to consider.

 

One thing to notice is that 997t.1 compressor max flow is either 28 or 32 lb/min ( depending on source ). This means that, again depending on source, the hp output is from 232 to 266 crankhp ( 28 lb/min ) or from 264 to 304 hp ( 32 lb/min ).

Disclaimer: I haven't yet seen myself a 997t compressor map, but different tuners on this discussion board have claimed aforementioned flow numbers.
Again the hp produced by stated flow is dependent on BSFC, and that low hp is from a ( conservative ) calculator most likely based on 2-valve technology engine's BSFC. Higher number is based on one ( quite respected ) tuner's claim of Porsche's 4-valve engine's ability to produce 9.5 hp / 1 lb/min of airflow.

So 997t's max fwhp with just tune is from 532 to 608 hp...or from 425 to 486 rwhp... ( 20% drivertrain loss )

PS. Don't shoot the messenger if you're not happy with the message.

 

Good info! Thanks for sharing. My numbers vary a little from yours, but I could definitely be wrong.

Stock VTG: ~34lb/min @ 60% efficiency

As I understand it, the general rule for calculating a turbo's HP capability at 60% efficiency is flow X 9.5 (as you stated.)

With two turbos, that would be:

Stock VTG: 34 x 9.5 x 2 = 646hp

I asked a few years ago if anyone had a compressor map for the VTG turbochargers, but no one had one, or was willing to share.

 

Edit above.

Pete, I think your numbers are right. It appears that the flow numbers I posted are for the VTGs from the GT2/GT2RS and MK2 turbos:

5304 988 0060 & 61:
· Max compressor flow – 31-32 lbs/min
· Actual dimensions – O.D. – 56.1mm / Inducer – 43.3mm
· S&W dimensions – O.D. – 48mm / Exducer – 44.5mm

5304 988 0080 & 81:
· Max compressor flow – 34 lbs/min
· Actual dimensions – O.D. – 56.1mm / Inducer – 45.1mm
· S&W dimensions – O.D. – 48mm / Exducer – 44.5mm
· 15° clip

 

How about www.techtec.de ?

Does anybody of you know about this company ?

 

Never heard of them so can't comment.

 

Yes, and I heard from another well respected tuner that for a 997t it's more like 9.25 hp/lb/min.

 

^^^TTdude, most likely your number is the one I was trying to remember too...but got it wrong...I'm away from my own files, spending holidays at my parents'.
Then the max would be from 259 to 296 x2 @ crank. At optimum conditions, all restrictions removed.

BTW, to completely OT, or not...but it's nice to speculate after too many drinks.
Here's a compressor map of BW EFR6255 turbo...BW's state-of the-art tuner item. Most likely based on the same compressor wheel technology than those 63.5/65/68mm billet wheels tuners are using in their turbos for 997t.


49.6mm inducer / 61.4mm exducer = 65 trim





Here's the next bigger compressor from their line up ( EFR6758 ) :

53.9mm inducer/67mm exducer = 65 trim





In/ex ratios and the flow numbers makes me think this and that. Quote from tuner X's pages: " The factory VTG turbo has a 60mm exducer and 43.8mm inducer ( = 53 trim ) on the compressor side. Compressor wheel on the X turbos has been increased to 65mm (exducer) and 46.9mm (inducer) ( = 52 trim )"
IIRC GT2/997t.2 has 45mm in / 60mm ex = 56 trim compressor wheel.

More info about EFR's: http://www.turbodriven.com/en/perfor...urbos/efr.aspx

 

OT too but I was considering some EFR turbos for my set-up. Protomotive got some "mocked-up" EFR7076s and those things were huge. Too much fab work needed so it was out of reach for me and just went with bolt-on A3076s. Someone should try these out on our cars.

 

Todd's been peeking to the dark side... ...42lb/min of flow @ 1.5bar / 75% effiency...390hp each. And not even close to their max. (53 lb/min @ 1.5 bar )

 

I have softronic installed in my car, Great power feels like a differnt car. Easy to install and no taking out your ECU. Plus you can always go back to stock flash if needed. Very glad I went with this flash...

 

I mentioned these to him when they first came out and sent him the maps. For high boost applications, these would be ideal. Didn't have the coin to do the project. Maybe next project if I ever finish the one I'm working on.

 

If you consider to stay with just a flash and (maybe) an exhaust,APR is one way...there are two programms to switch with cruise control buttons and with good fuel and exhaust you will get above 600hp...where the limits of stock VTGs are.On the other hand APR does not support you with any other files for bigger turbos...But trust me,most of the cars with modified VTGs wont be faster than you until 200km...We measured 200-300 time with tip apr car with free exhaust and 100 octane fuel and it did at 13,5sec...That time is very hard to be beaten env with modified turbos...

 

^^^ Yes its hard to overlook the times set down by the greek guys madsex343 and skandalis447. So on that score it would certainly appear the APR tune is king of the heap. Tunes such as Protomotive and certain others are good if you intend going hard on further mods as these tuners offer re programming upgrades on top of their base tunes but as skand points out even so there isn't much in it over 200 anyway unless you go in very hard with big turbos etc etc etc. I guess what you need to consider is how often do you get to push over 200 these days?....unless you live in the less regulated (lucky) countries.

 

911tuning.com uses Todd's Protomotive flash/tune for an advertised 550/570hp

I really like it on my 996TT X50