Tag Archives: PerformanceBox

Updated Baseline Cadillac STS-V 0-60 time

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This morning it was a fresh 91F out, so I ran some new baselines for the STS-V.  Just tickling the 5 sec line at 91F.

Weather: 91.4F; Baro 29.12 Hg. (14.3 psi); Humidity 10%.  Fuel: half-tank.  Altitude: 600 feet above sea level.

My Cadillac is a 2008 STS-V with a Spectre Intake.  This is a 4,233 lb sports luxury V-Series sedan with a 4.4L supercharged & intercooled V8.

Today in hot weather it ran a 0-60 time of 5.42 sec (0 feet-5,280 feet), or 4.98 sec including 1 foot of rollout as at a dragstrip, (1 foot-5280 feet).

The 60′ time for this run was 2.3 sec.

Previous measured times for my STS-V with me driving were 5.39 sec w/rollout and 5.29 sec w/rollout, so today’s time of 4.98 sec w/rollout is an improvement of 0.3 sec.  Between the runs I have changed the tires, added the Spectre intake, and changed the MAF.  Side by side, today’s run would have been 17 feet ahead of the previous run at 60 mph.

w/rollout
Speed(mph) Time 0.44 Dist(f)
10 1.01 0.57 6
20 1.75 1.31 23
30 2.46 2.02 49
40 3.31 2.87 93
50 4.30 3.86 159
60 5.42 4.98 248

Here is the graph:

Here is a view from HPTuners of the peak near 60 mph for this run showing that I am getting -3.2 degrees of advance due to the ambient and IAT2 / MAT temps at this point; it heads as low as -4 degrees.

IAT Advance at -3.6 degrees

I believe that because the boost is calculated from Manifold pressure and barometric pressure, that it reflects boost after the pressure drop across the Laminova intercooler tubes.  So some pressure going in, 9.4 psi getting to the engine in this snapshot.

Here was a video of the HP Tuner scan of the 0-60 run:

I captured a second run at 5.45 sec w/o rollout or 5.08 sec from 1 foot.

w/rollout
Speed(mph) Time 0.37 Dist(f)
10 1.06 0.69 6.2
20 1.87 1.50 22.58
30 2.61 2.24 48.61
40 3.41 3.04 92.88
50 4.38 4.01 158.55
60 5.45 5.08 248.34

My rollout is still a bit high — taking too long to get from 0-1 foot.  I would like to see rollout around 0.3 sec.

Summary

Today’s run shows a clear improvement from the previous mark.  I would like to see under 5 sec without rollout considered.

The IAT Advance is pulling timing from the engine based on the incoming air temp out of the supercharger.  Either running the car in cooler weather (!) or improving the intercooler cooling perhaps would help.  This is with the stock calibration; it may be possible to simply adjust the tune to be somewhat less aggressive on IAT Advance.  Adjusting shift times and possibly RPM may also reduce 0-60 times.

Improving a tenth at a time…

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100F out today here in Texas, but testing must go on.  Mostly because inquiring minds want to know and my interest is piqued about how this could be simpler and yet any more subtle in execution.

Speed vs Time (red) and Distance Travelled (gray)

 

And the table with comparison to last best run:

Today’s Test
Rollout Previous Test
Speed (mph) Time(s) Dist(f) 0.37 Speed (mph) Time(s) Dist(f)
10 0.93 6.33 0.56 10 0.71 7.13
20 1.71 23.73 1.34 20 1.45 23.53
30 2.53 53.59 2.16 30 2.23 51.94
40 3.43 100.4 3.06 40 3.09 96.6
50 4.45 168.07 4.08 50 4.21 170.2
60 5.66 265.64 5.29 60 5.39 265.8

Conditions: Weather: 95.6F baro 28.85 in Fuel: almost empty (car indicated 100F outside; 96F per the weather underground)

Today I wanted to try accelerating briskly until 20 mph or so then wide open throttle.  My goal was to get to 20 mph as rapidly as possible without wheelspin, figuring that even with full throttle there would be little wheel spin after 20 mph.  I was partially correct.

I also discovered that there is a cusp wherein the 6speed automatic will shift from 1 to 2 early in the low 20s if you are not at wide open throttle, which is bad for acceleration.  Manually shifting the automatic is right out because the redline at 1st comes up too fast for the manual shift to be effective.

Good news is a slightly faster best time, at 5.29 sec 0-60 with rollout.  Remember our goal is 4.9 sec 0-60 with rollout.  Low on fuel so 84 lbs lighter this run, which can also cause this difference in 0-60 times vs the earlier test.  The hotter temps act against acceleration, and 20F hotter is significant.

This simple method did improve my 1 foot acceleration time from 0.59 to 0.37 so there is that.  Also my 60′ time from a dismal 2.8 to 2.66 sec.  A reasonable 60′ time for street car on street tires is under 2.2 sec, so I am off in the first 60 ft and its me not the V.

I do think that this will be a matter of defining an exact technique to get the last few 0.1’s out however — brisk but not tire screeching acceleration up to 18-20 mph then full throttle before the transmission can decide to downshift to 2nd or similar.

In the real world it doesn’t matter much, but learning to drive the car can’t but help.

Intake update: the Spectre intakes are due from Streetsideauto.com in the next week or two, and then we’ll get before and after dyno tests run at True Street Motorsports in McKinney Texas per my  Project Cadillac Tuning Plan

Cadillac STS-V First PerformanceBox Test

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I have a RaceLogic PerformanceBox which can be used to measure vehicle performance in a variety of tests.  The Performancebox is a GPS based meter and data logger.

Unfortunately, I don’t get to use it all the time, so when I do there is a short period of re-familiarization.  For my first tests, no data got written to the memory card.  After I changed the setup to “yes, please write data” things improved dramatically.

Here was the best run written to the card today:

MPH vs Distance shows challenge getting off the line

 

Accel results
Speed(mph)     Time(s)
0-60                   05.4

With 1 ft roll-out details:

Speed(mph) Time(s) Dist(f)
0 0.00 0
10 0.71 7.13
20 1.45 23.53
30 2.23 51.94
40 3.09 96.6
50 4.21 170.2
60 5.39 265.8

Roll-out is a determination for ‘when’ the test time begins.  At a drag strip, there is up to 1 foot of roll-out before the timing lights are tripped, hence the term.  In other words, due to surface quality and wheel-spin it took me 0.59 sec to get 1 foot forward, but at the track that time would not have been included in the results and is not included above.

Weather Conditions: 87F; barometric pressure 29.69 in; humidity 64%.  Fuel: Full

Not sparkling time for the Cadillac STS-V, which Cadillac measured at 4.9 sec 0-60 mph with roll-out.  Most magazine tests ran high 4.x to low 5.x sec.  Road & Track measured 4.7 sec 0-60 mph for the STS-V.

I feel the 2008 STS-V is capable of a better time.  Getting the STS-V off the line involves a great threat of wheel-spin to be avoided.  Of course, my test area is not a sticky well prepared launch spot like at the drag-strip, but it does closely model real world circumstances.

On the bright side, this is a new ‘best’ for my personal vehicle measurements; my previous best was 0-60 in 5.95 sec in my modified CTS 3.6L and was measured on the AP-22 meter in more favorable circumstances.

Stock
STS-V


Mod CTS 3.6L
Speed (mph) Time(s) Dist(f) Time(s) Dist(f)
10 0.71 7.13 0.68 4
20 1.45 23.53 1.40 21
30 2.23 51.94 2.33 55
40 3.09 96.6 3.31 105
50 4.21 170.2 4.55 187
60 5.39 265.8 5.95 301

A line by line comparison — albeit of apples and oranges since different days, different gadgets — echoes the same issue — get the STS-V off the line faster and it would have much better times, and at 60 mph is 35 feet ahead of the CTS.