GIAC chip worth it in CA on an S4?

[B6_Rakete]

Given that California only offers 91 octane pump gas, does it even make sense to upgrade the ECU with a GIAC payload? I see nice dyno gains on various sites, but they never mention which octane level they're running in the car. If gains are only possible with 93 or higher, should I even bother?

http://www.awe-tuning.com/media/dyno...b6_s4_chip.jpg


http://www.awe-tuning.com/pages/shar...6s4flashloader

[ChronicTeutonic]

You can get race gas in cali at the pump. 100 octane. Look at this page: http://personal.linkline.com/dbarton..._in_SoCal.html

It's $$$$ though, you can probably "blend" in your tank to get 93 and save a few dollars.

[tomlafS4]

Most, if not all, tuners out here in California have their chips programmed to work with 91 octane since we're screwed with cheap piss gas.

Do yourself a favor and get your ECU loaded with the 91 program and the race gas file. Get the flashloader so you're able to switch back and forth between programs.

Even though we only have 91, after getting my car GIAC'd by EuroSport down here in Orange County, the gains made over stock were incredible. I definitely say you should go for it.

[FastB7S4]

Even though we only have 91, after getting my car GIAC'd by EuroSport down here in Orange County, the gains made over stock were incredible. I definitely say you should go for it.

Keep in mind gains made in a chipped biturbo B5 will me more "incredible" over the NA B6. Maybe someone in Cali with a chipped B6/B7 can chime in with their impressions.

[Tek4ever]

I had my B6/S4 flased w/ GIAC about 6 weeks ago. Far from, "wow!" was/is my experience; I do feel a slight improvement in the higher RPM range. I'm in Chicago and 93 octane is available here. The pump gas file was also optimized for 93 octane as well. If it doesn't rain all day tomorrow, I'll have a chance to try the race file w/ 102 octane and give another report. If you didn't know already - you have 30 days to decide whether or not you want to keep the GIAC program.

[tomlafS4]

I know...just trying to relay the fact that a chip running on 91 octane will still show an improvement over stock.

[lowbee]

I had my B6/S4 flased w/ GIAC about 6 weeks ago. Far from, "wow!" was/is my experience; I do feel a slight improvement in the higher RPM range. I'm in Chicago and 93 octane is available here. The pump gas file was also optimized for 93 octane as well. If it doesn't rain all day tomorrow, I'll have a chance to try the race file w/ 102 octane and give another report. If you didn't know already - you have 30 days to decide whether or not you want to keep the GIAC program.

Do you have any other mods or is the "wow" refer only to the effect of the GIAC chip on your V8 ?

[Tek4ever]

Yup, "wow" refers only to the GIAC flash. I have a snub mount also /flex!

[RAudi Driver]

here it is in a nutshell for me. Ca. car, had Giac installed, felt lousy. Went back to torque Factory and had it removed. I lost that getting pushed into the back of your seat feeling with the chip. then my full Milltek arrived in the mail. Took it to FI and had it installed. went back to Torque Factor and had Jeff reinstall it and purchased a flashloader (now for sale) to go along with it.

Well after the exhaust, the chip worked much better especially in the upper rpm band. The car still didn't have the feeling of being pushed back into the seat like it did when it was stock but it made up for it up top and pretty much anywhere after 4,500 rpm..

Would I do it over? Only after I got an exhaust and K&N panel filter installed. It slowed the car down too much in stock form.

[bhvrdr]

The gains on chips at 91 octane on an S4 have yet to be proven. A group of us just dynod 5 audi s4 cars and the one with the GIAC chip on 93 octane and full exhaust dynoed less torque then a car with no chip and a catback. If the gains are there, they arent very significant. Save your cash. What people are feeling is likely the increased throttle sensitivity. You can do this via vag-com tweaking for free.

cheers! Mike

[Jrunr]

Ok. It is K&N Filter and a CB for me!

[ChronicTeutonic]

Heres my $.02

If you want more HP you're going to have to go at it the same way Audi does; compression ratio. There are two basic ways to effectively increase your CR. 1) Decrease the size of the squish area in the cylinder maintaing the same volume of A/F mix. 2) Increase the volume of A/F mix going into the cylinder while maintaining the volume of the cylinder.

Since our V8s are normally aspirated we are (sort of) limited to option one. Option one requires actual mechanical work which means labor, which means money.

So how did Audi do it? Compare the S4 and RS4 engines. The V8 MPI engine features 11:1 CR while the V8 FSI has 12.5:1; a pretty significant increase. I'd venture to guess that just by getting your CR up to 12.5:1 you'll be close to 400hp out of this motor. On the bottom end bore and stroke sizes are same in both motors with the most significant changes being careful crank balancing and closer tolerances at the bearing surfaces. The FSI system is just the push over the cliff ("our amps go to 11") it is basically keeping the A/F mixture optimal at all times and saving you gas when you aren't giving it the boot.

Option two involves turbos or superchargers. Chipping these types of engines always has a "wow" factor since the factory generally stays conservative to increase the reliability of these engines for the average consumer. So for $20K more you will either get and RS4 or a superchaged MTM S4, pick your poison...

So why does freeing up the exhaust flow reduce the torque? Well you've basically changed the A/F mixture and the ECM isn't compensating or the injectors are maxed out and can't add more fuel to the larger amount of air that can now flow into the cylinder. In the case of the guy above with the GIAC 93 program I'd wonder just how good the chip program really is? Maybe it hadn't been driven enough to adapt yet? Dunno, but raises some interesting questions.

If you really want to get some insight into the V8 FSI engine (and to a lesser degree the V8 MPI) I'd recommend subscribing to eBahn and reviewing the Self-Study Programs in the S4 manual. Good stuff! I even learned what that flapper valve in the bottom of the air filter housing is for.

[B6_Rakete]

Heh, APR's chip shows a nice +0HP & +0ft/lbs torque increase on 91 Octane gas:

http://getapr.com/audi-b6-s4.html

I guess that answers my question, not worth it in CA unless I drive around with $10/gal race gas!