I would don't this so on the smog, as for maintaining the car, I don't expect any major differences as I didn't add any non Porsche parts to the car, just a software rewrite

So no before and after dyno charts? $1000 seems a bit expensive for a mail order tune. Now when you are saying 20hp you mean 20hp at the crank or rwhp? Im assuming at the crank because its super hard to gain 20rwhp without hardware (exhaust, intake etc.) Unless the car is already FI of course.

1000 is about on par for the majority of the mail order tunes I've seen. I've asked several questions to several vendors (GIAC, APR, Softronic, and now VF) - all of them are 900-1200 to buy. My sticking point is, will their mail order tune take into account the modifications that have already been done to my car? I know they do a TON of datalogging to produce a quality product, but how many Base 997s have been rebuilt with ported/polished heads, knife edged crank and then a full exhaust/intake setup put on them? my guess is not a whole lot. On my car, the extensive modifications have added a noticeable amount of hesitation between 5000-5200RPM, which i'd like to get rid of (that alone would make a tune worth it to me) Or, will a full blown Dyno tune be the only way to truly maximize? APR basically gave me ZERO sales pitch, and said it would be best to get a dyno tune, no matter what software I was considering.

APR advertises the highest overall HP gain for a base 997 C2 at (may be a number or two off, don't have their site in front of me right now) 24 crank hp, 27 tq or so, GIAC being the lowest, if my memory serves correctly, advertising only ~9-10 crank HP. The dyno shop near me that wants to do the tune says they'll start with the GIAC as it is the easiest for them to modify. IF APR/softronic/VF can push that 20-25hp limit, and have it work with the mods correctly, it most certainly would be worth it compared to GIAC with its meager 9hp gain, however, I assume the dyno shop will have much more customizable options, even if they start with the GIAC, which, theoretically could easily reach 20, 25, maybe even 30HP depending how it works with the current mods in place - especially since the dyno tune can custom tune the air-fuel ratio throughout the entire REV range, probably ending with a higher HP gain than the 9 from GIAC out of the box, probably safer (AFR can be specifically tuned for max power/efficiency), and in the end worth more overall to get than a mail order tune, even if the cost is greater. Also, it'll get pre/post dyno results.

I'm glad to hear the tune turned out well! nothing beats when something works as advertised, especially if it makes you enjoy your car more!

Yes glad the OP feels it was worth it but i would never do this myself. Dont trust anyone's butt dyno regardless of seat time. Would need solid ie dyno evidence that it worked or it would be returned

And without a dyno whether he thinks rwhp or crank is meaningless

Maybe there is some marginal improvement on stock cars but if you get an off the shelf tune you want it to work so you feel that it is working - just like the guys that add air filters and talk bout how the response is sooo much better and they can for sure feel the extra HP - its just human nature and everyone does it. True data is the only way to know and i dont trust the vendors data either. If they were all doing a tune on a stock engine and they all wanted to maximize results (so they can sell more product) then why would the performance improvement numbers be so different ie +/- 200%?

Agree with Milo that on engines that have been more modified, like mine, then i will go custom dyno tune

Cheers

Don't have to trust anyone's butt dyno since there is an easy way to get objective data. I recently play with the virtualdyno s/w since I want to compare my dynopack data with it and the result are consistence with each other. Just download virtualdyno (it's free) and do a log with the Torque Pro app on Android and/or IPhone via an OBDII dongle ($10 on Amazon) and you will have real data. Then we'll see whether the data are consistence with the OP's butt dyno.

Where did you send the questions to, and did they respond?

Interesting notes, thanks. How close was the data you got between a dynopack and the virtualdyno?

I sent to their technical service email. No response yet.

The dynopack and the virtualdyno runs were done in two different days, in different gear, with different operators under significantly different outside temp conditions which had a big impact on the output of my other turbo car, I was doing the comparison mainly to verify the shape of the curves (spool time & failing off at high rpm). Given that, the different between the WTQ and WHP numbers on the dynopack and the virtual dyno for my other car was within 7%. The log from my back-to-back runs under the same outside temp condition with the same operators were yielding WTQ and WHP numbers within 4% of each other.

So I'd suggest the OP log a few runs with the stock tune then switch over the VF's tune and do a few more runs to verify his butt dyno... taking averages of those runs should tell a story

Well who says he's getting any HP or how much? I am sure the tune improves something but without pre/post dynos on the same car, who knows?? And i have my doubts the differences are in how they report. If you were a vendor wouldnt you put the highest number possible?


Ok well thats cool. I am going to check that out, Thanks

I dont think that a company intentionally misleading customers on HP gains is something that happens a great deal at this level. All of VF's claims are dyno backed. I dont need the Dentist to send me an X-ray after they put in the filling to prove its there... All I can say is that I am a very happy customer that believes VF has the integrity to sell actual, provable updates...

Yeah, you'd want to post the highest numbers possible. But then people install it and if claims don't match reality, your reputation goes to hell and you get abused, on this forum in particular (see that climerepair thread for evidence.)

CW

Didnt say anyone was misleading customers. What i said was that without specific dyno results on your car you dont know what improvements you are getting. Dyno results can be very different on the same machine with different operators and different conditions. Vendors will always present the best case possible. Nothing misleading, its called marketing. And btw the dentist doesnt tell you that the fillin is made of titanium and therefore is good for an extra 10hp when you drive. You can just open your mouth and see its there!

I am glad you are happy with the results. I didnt pay for it so who cares what i think :thumbsup:

Well no one has actually dyno'd it so how is anyone to prove the claims match reality. I am sure they do but as someone said, trust but verify.....

I dont think the climarepair example is a good one. You can look at the switches (the early ones anyways) and objectively tell they were ****. No testing required.