This area will feature the FASTEST FIVE SATURN CARS in their respective categories. Think your car is fast enough to be featured in the Fastest V? Send your information and mods to poc301 to have your car listed here.

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.

Deciphering Compressor Maps - Page 2

by: Titan

Engine airflow

In order to determine the proper turbo size you will need to estimate the engine airflow requirements. This can be accomplished with the basic equation:

(CID x RPM) / 3456 = CFM

Variables
CID = engine displacement (116)
RPM = maximum rpm (6000)
CFM = cubic feet per minute

The CID for the 1.9 liter engine will be a constant value of 116 unless the engine's cylinders have been bored larger. I have chosen to use 6000rpms as the maximum rpm value simply because the power curve drops off quickly after that.

Substituting Saturn's 1.9 liter engine numbers into the equation we get:

(116 x 6000) / 3456 = 201.39 CFM

The 1.9 liter engine will flow 201.39 CFM of air assuming 100% volumetric efficiency (VE). Since most street engines have a VE between 80-90% the equation will have to be altered to reflect this lower VE. Splitting the difference we will assume the 1.9 liter engine possesses a VE of 85%.

201.39 x 0.85 = 171.18 CFM

Calculating for 85% VE shows that the engine actually flows 171.18 CFM. To compare the airflow requirement against the compressor map you will need to convert CFM to lbs/min by multiplying the corrected CFM by 0.069

171.18 x 0.069 = 11.81 lbs/min

11.81 lbs/min represents your x-axis value at 6000rpms..

Common displacements

Liter	CID	6000 rpm	85% VE	lbs/min
1.9	116.00	201.39	171.18	11.81
2.0	122.11	212.00	180.20	12.43
2.2	134.32	233.19	198.22	13.68

To properly determine which turbo housing best suits your application you will need to plot several data points on the compressor map. I would suggest using the following rpms 2000, 3000, 4000, 5000, and 6000. Substituting the rpm values into the formula produces the following table.

1.9 liter engine

RPM	lbs/min
2000	3.94
3000	5.91
4000	7.87
5000	9.84
6000	11.81

As an interesting side note, whenever you solve for the engine airflow requirements you can move the decimal over to the right one place you end up with the engine's horsepower. In our example moving the decimal one place to the right yields 118.1 horsepower for the stock engine, which is a pretty close estimate of the factory's horsepower claim.

Pressure Ratio

Now that we know the amount of airflow through the engine we need to calculate the desired pressure ratio (P2/P1). This can be easily accomplished with the following formula:

(P1 + P2) / P2 = Pressure Ratio

Variables
P1 = Desired boost pressure in psi
P2 = ambient atmospheric pressure (14.7psi)

Plugging in a desired boost of 7psi we get:

(7 + 14.7) / 14.7 = 1.48

This will give you a y-axis value of 1.48 for 7psi of boost.
Common pressure ratios

Psi	Ratio
5	1.34
7	1.48
10	1.68
12	1.82
15	2.02
18	2.22

Now we just need to compensate for the turbo's increased airflow and plot the data on the compressor map.

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.

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.