Street Class
1) UnderdogSDA 13.3 (Nitrous)
2) S.Bretz 13.35 (Turbo)
3) Poc301 13.50 (Nitrous)
4) BoostedSL2 13.56 (Turbo)
5) Yardbird 13.59 (Nitrous)

Unlimited Class
1) Nefarious 12.26 (Nitrous)
2) LowSC2 12.4 (Nitrous)
3) 92saturnSS 13.33 (Nitrous)

DOHC
1) UnderdogSDA 14.21
2) Green Monstah 14.5
3) DonBaker 14.71
4) Applebit 14.8
5)SaturnMotorsportsOfCary14.84

SOHC
1) ProjectPhase1 16.61
2) Sh1FT 16.90
3) Wraith 16.98
4) jhsl1 17.2
5) SL_Sled 17.96

Ion
1) JGreen 15.48
2) schzzo97sc2 15.60
3) Chris 15.79
4) rascon11 16.06
5) IonJon 16.27

Updated 1/05

For the most recent list of the fastest five cars click here.

Programing the A'PEXi AVC-R

by:Titan

Duty cycle
Before we can start programming the AVC-R we need to understand what the duty cycle does. Without going into the theory behind wastgate operation here is basically everything you need to know about setting the duty cycle.

Increasing duty cycle increases the length of time that the wastegate remains closed. If you are exceeding your desired boost level than reduce the duty cycle. If you are not achieving your desired boost level or boost falls off after reaching the set point than increase the duty cycle.

The AVC-R's duty cycle is a very powerful tool. You can actually increase spool up with this boost controller.

Setting desired boost levels
Using 3rd gear set the boost level to .68 (10psi) and the duty cycle low about 30%. Slowly increase the duty cycle percent by 5% until the desired boost level of .68 is reached. Once your desired boost level is attained the duty cycle will be set. Now you can set the final boost level. Double check the boost level matches the final desired level by using third gear and punching it from about 3000rpms to redline. If it overshoots or undershoots by a lot make slight adjustments to the duty cycle as necessary. Small variation is acceptable don't spend all day trying to get it exact.

Once desired boost levels are attained put stars in the duty screen to begin self learning. I recommend that you use the self learning mode for duty cycle because it will create a custom duty cycle curve that will decrease turbo spool up time. It should only take a few runs for the AVC-R to learn but double check by looking at the duty cycle screen.

The AVC-R MUST be set on rpms and NOT injector duty cycle or it will not learn.

Gear based boost
In order for the AVC-R to identify gears, a gear judge value must be entered for each gear. These numbers can be set by:
Having the gear judge setting screen displayed
Driving the car at 3000rpms in first gear
Once you reach a steady 3000rpms push the > key to set the value
Repeat for gears 2-5

My values for a DOHC transmission:
1st) 196
2nd) 121
3rd) 84
4th) 62
5th) 43

The numbers are not as important as the actual relationship between them. This is how the AVC-R judges gears.

Make sure that all of the start duty numbers are set to 0% for all gears/rpms otherwise the AVC-R will not go into self learning mode.

Once all the settings are entered and you have allowed the AVC-R to create a custom duty cycle based on your turbo setup you can adjust the start duty.

Start duty
Here is where the magic begins. The manual states, "Higher start values will make the boost pressure levels higher." Translated into understandable English, a positive start duty value will increase boost while negative numbers will subtract from your desired set boost. If you desired boost level is 10psi and you set the start duty cycle to -30% in first gear than your maximum boost will be reduced to 7psi in first gear only. To help with traction in first and second gear subtract start duty from those two gears, the rest of the gears you can leave alone.

Below are some settings that you shouldn't need to adjust.

NE
The manual states that you can set the engine RPM point to control post pressure. This feature doesn't interest me since I want to control boost by gear. I'm not going to adjust this setting.

F/B Speed
Again the manual states "If unstable boost or boost drop occurs during boost control, the feedback speed setting may be necessary." I'm not going to use this setting either since adjusting the duty cycle is a more precise method of adjusting boost control.

Conversions

1atm = 14.206

1psi = .9664Kg/cm^2

Author's note

The AVC-R is overkill for any Saturn running less than 275whp. This electronic boost controller is used primarliy to reduce boost/power in the first two gears of a traction limited FWD car. If you are not interested in building a 300whp+ Saturn than stick with a manual boost controller.

The turbosaturns.net forum has become one of the best resources for Saturn performance on the net. Our members are constantly pushing their cars to new performance levels. So, log in, share your ideas, and help push your car’s performance to the next level.

• Apexi Safc Install
• Turbo Tuning
• Cams 101
• Wastegate 101
• HP vs Torque
• Ian's Turbo F.A.Q.
• Oxygen Sensors
• DIY Fuel Regulator
• Taming Detonation
• Walbro Install
• Fuel Injectors
• Techedge Wideband
• OEM Fuel Pump Limits
• AVC-R Programming
• Dynosoft
• 220whp or Bust

Archived Articles

HERE

August 2005 TSN will be holding its first ever meet in Chardon, Ohio. Some of the fastest Saturns in the country will be attending. Activities will include drag racing, dyno, tech session, and BBQ. Look for the latest information in the forums.

Different Racing

Jeff and his team Different Racing have big plans on breaking into some really low quarter mile times this year. Last year he posted a 12.40 on a pretty healthy nitrous shot. This year he has a new turbo setup and some serious determination. Visit his website for the latest news and information. I expect we'll be seeing some low 12's from him by the end of the year.