Car looks great. I like this one above. Nice shot!

 

^^^Thanks Sambo.

 

Because there is linear relationship between engine speed (rpm) and road speed, it dawned on me that, assuming there is no slip, I could calculate how much faster the car is purely from my Durametric data (without VBox, which still is more desireable). So here it is, first documention of acceleration improvement using Durametric data :

GIAC Time Improvement
From 38.5 mph to 92.5 mph (2500 to 6000 rpm)
Stock Normal 6.07 seconds
Stock Sport 5.88 secs
GIAC Normal 5.73 secs
GIAC Sport 5.38 secs

The improvement from Stock Sport to GIAC Sport for example, is 5.88-5.38 = 0.5 second, a lifetime :-)! I really do encourage those on the fence to jump in. Even in my humble stage 2, meaning no hardware change other than my beloved Cargraphic exhaust, and therefore 100% safe, there is significant improvement both subjectively and, now, objectively, as calculated above with Durametric data.

It should be noted that the horsepower gain doesn't adequately reflect the huge improvement in torque at low and mid rpm as seen in my dyno curve (check first page of this thread - horsepower gain is simply a measurement at one point in time - at peak rpm, the torque curve is a better judge over the entire rpm), which leads to that saying "horsepower sells cars, torque wins races," something to that effect; it *is* important.
A stage 2 tune is therefore extremely highly recommended :-) - once you have it, it's a guarantee you will not tolerate stock mode again because the stock car feels very ponderous in comparison. GIAC has a 30 day money back guarantee and with S&P 500 at all time high, it's really a no brainer to try - possibly your best (self) Christmas gift ever.

 

Congrats on the new mods, great write up. Looking to do similar mods.
So overall where would you say your horsepower and torque is now compared to stock. Would you recommend an IPD Plenum?

-KD

 

Thanks. Objectively, the gain varies depend on rpm, as seen in the dyno I posted on page 1 of this thread. For example in my car in the mid band the gain is as much as 25% around 4200 rpm, and less at higher rpm. This is why to properly evaluate a tune, you would like to look at the curve and see the shape of the whole dyno curve and gain at all rpm's, and not just peak rpm gain that is frequently quoted. The mid band gain (say 3000-5000 rpm) is very important for a daily driver, because that's where you spend a majority of the time.
I have also tested time improvement with Durametric runs, and the result is posted above. Durametric testing is by me, so this is real number without manipulation by vendor, and not inaccurate advertised material. It is a modest gain because this is a modest stage 2 car - but that is all that I am looking for. To maintain 100% reliability, I prefer not to change any hardware other than exhaust.

Subjectively, as I have mentioned, there is simply no question about the gain. The tuned car feels completely different, transformed into something much less ponderous. It has nearly no lag with instant acceleration at lower rpm. At the max mode (GIAC Sport mode), it feels like it's going downhill all the times! :-)

Re. plenum, no I don't have it and don't have plan to add. Were I to add anything, it would be the intercooler because it is one of the 3 important improvements I remember mentioned by GIAC engineers: better exhaust, better intercooler, better fuel. Plenum hp gain by itself has been elusive to prove by third party and I would use it only if recommended by your tuner. I would love to see someone do Durametric testing pre and post plenum though - that would be a great test - anyone wants to take the challenge?

Together with Bilstein and Cargraphic exhaust, my Turbo has morphed into something that for me is less comfortable but VASTLY more fun and fantastic to drive, somewhere in between the stock Turbo and the GT2. I love it and very highly recommend these mods .

 

I have the plenum and I would recommend adding it because it does free up the air flow coming through the intake system and provides a nice extra "whoosh" sound to go along with it too.

 

BTW, not just ECU tune, but any components, header, IPD plenum, exhaust, intercooler, etc., anyone who is adding them, may I remind again if you do Durametric before and after, you could find out exactly how much power you've gained. Very easy to do and many people on this forum know a lot more than I do and we could all help you; just ask.

As I've demonstrated, it does NOT have to be a 60-130 mph run. A few very simple second-gear runs from 2000 rpm to 7000 rpm (99 mph) done safely on empty track would be more than enough. It would be nice to start getting more data!

 

Cannga, Your posts are great, you set the standard for communicating clear and useful information. It helps that your usage patterns and perspective are the same as mine, although my TT isn't a daily driver. In this post you've given me a great roadmap should I choose to mod the car, who am I kidding, it's only a matter of time…..

 

Hi Bryan, sorry didn't see this post. Anyway thanks and yes surely it's only a matter of time!

In case of the ECU tune, don't wait too long because it really does transform the car to the point that it feels like a different car. As you are from Southern Cal, I would think it's a no brainer to check out GIAC and see if they could give you a custom tune on their chassis dyno (PM austin@GIAC for example).

A stage 2 custom tune (exhaust only, without any other hardware change) has near 100% reliability so there is little reason to wait. GIAC tune also doesn't require spark plug change so that helps to lower the overall cost of the tune. Good luck and have fun.

 

Good post.... Cannga

Bryan


A few things I wanted to add to this as we see a lot of Turbo's in the So Cal for maintenance and performance tuning as well as race prep.

As GIAC authorized tuning partner for 10 years now we have worked with GIAC on standard flashes and development of upgrade specific tunes.

We also have a Mustang 4wd 500se Chassis dyno with a proper test cell for unsurpassed reliability and repeat-ability.


One thing to consider is mileage of the car when the question of spark plugs needing replacement with a tune comes up.

Although it is not technically necessary to replace plugs when you have a car flashed this assumption is solely based on a good low mileage properly functioning car.

Keep in mind that when these tunes are developed they are developed on cars that are verified in good running condition.. Furthermore a lot of this software has been on the market and in development since the car was introduced in 2007. We had one of the first 997TT's in So Cal and it went to GIAC with less than 400 miles on it for development of a tune to compliment our exhaust system. The car was NEW back then today the car is considered old.

We are seeing more and more used 997 Turbos with mileage in the 15k + range needing spark plug replacement with a tune. The root of this is most likely age and our poor grade 91 octane fuels we have here in Ca.


Over the years we have flashed hundred of turbos with GIAC tunes and they have been bullet proof and very reliable.

There are several variations of the 997TT tune, if your car has minimal upgrades ( exhaust etc) one of the standard tunes is more than enough.
There would be NO reason in my opinion to try and squeeze out every possibly once of hp and incur the additional cost of a custom tune. Not to mention the fact that GIAC is currently backed up with projects.

We do work with GIAC directly and if you would like could log the car for you and send the files back to GIAC to see which file would best suit your car.



Feel free to stop by the shop our give us a call if you have any further questions I would be happy to help in anyway I can.

On any given day we have several Turbo's in the shop in various stages of tune so there is always an opportunity to see the hardware up close and personal.


Cannga your posts are always a blast to read. Its interesting to hear your perspective as an enthusiast..

 

Fabryce, Thanks for your insights, I'm going to try to stop by to visit with you soon, Bryan

 

^^^
Hi Fabryce, thanks. My car still has the GMG bar that I bought 5-6 years ago, and the GIAC tune bought through GMG. Still perfect and without any problem.

Hi Bryan, good luck and have fun. You might want to check my comment on first page of this thread (item 2a) regarding custom vs. non-custom tune. A generic tune is fine, but if you want a custom tune, I am sure Fabryce could arrange it for you - GMG and GIAC do work together closely, being practically neighbors.

 

http://s214.photobucket.com/user/can...d27a4.jpg.html

God your dyno looks exactly like my old Giac tune with AWE GT2 exhaust....

I also got that weird little dip in the power then big boom after 6000 rpms, this is also confirmed by my Eurodyne datalogging...... the old GIAC tune added so much oomph my car goes way over 100% DC and pulls timing at 3500-4800 rpm

Id be interested to see your Durametric injection times vs rpms etc to see if your car does the same... my AFRs were going very rich sub 10 at 3500 rpm to peak torque

This is my newer tune still showing a boost drop then a blip up which tracks the power like on your dyno curve

http://datazap.me/u/groupamerica/eur...-9-14-16-19-20

 

I am still on original clutch and it slips at WOT. I've been told (not by GIAC) that the power dip at high rpm could be because the clutch is slipping. A friend had a similar curve that normalized after the clutch was changed. I am really not into super high power tune so don't plan to test this theory any time soon (my car will stay a simple stage 2, stock intercooler, car). AFR and timing were fine at the time of dyno at GIAC (4th gear pull). The car accelerates smoothly and potently.

Have you done acceleration times with Durametric (see below) - that's a lot of fun.

>>>>>>
GIAC Time Improvement
From 38.5 mph to 92.5 mph (2500 to 6000 rpm)
Stock Normal 6.07 seconds
Stock Sport 5.88 secs
GIAC Normal 5.73 secs
GIAC Sport 5.38 secs

 

Yes, great thread!