mike33

iTrader: (1)

I would like to share my personal results from doing several different common performance upgrades to my 2009 isf. The car was purchased in Oct 2018 with 80k miles in completely stock form, all upgrades and testing were done in Nov and Dec of 2018. The goal of my testing was to see what real world gains could be
achieved from various performance upgrades on the street. The testing consisted of using a Gtech performance meter to record timed runs through the 1/4 mile,
the meter also provides other timed intervals which will be listed. In my experience the Gtech meter is very accurate, but more importantly extremely consistent in its measurements... All testing took place on the same PRIVATE road in as similar temperature (DA) conditions as possible. The road is not prepped for launching from a stand still, like a drag strip would be, so these times are not representative of what may be achieved at a properly prepped track. I made between
30- 40 timed runs, and will list the best run for stock and each performance upgrade. I will also post pictures of the Gtech meter and various runs but it may
be difficult to read as each run is spread out over multiple screens.







Testing results: 2009 Lexus ISF odo 81k....all runs with 1/4 tank and no weight reduction

...................10/28/2018..............................11/16/2018.............................11/27/2018.............................12/5/2018.....................1/11/2019
...................baseline............................wider summer tires....................catback exhaust.......................engine ecu tune............actual drag strip
................w/ oe tire size..................... 245/35r19, 275/30r19............. Xforce w/varex mufflers........... RR racing 7200 rpm............. PBI Raceway
................Michelin a/s3+.......................Pirelli P1 plus.........
...............................................................................................valve closed......... valve open
60ft.................. 2.329.................................2.136......................... .2.082................. 2.085..................... 2.088.............................1.937
0-60 .................4.943..................................4.558......................... 4.628..................4.373.......................4.255..............................n/a
1/8....................8.833.................................8.472...........................8.505...................8.319.......................8.253............................8.109
mph..................87.22.................................88.09...........................88.21...................89.87.......................90.88...........................89.62
1/4....................13.37................................12.99...........................12.99...................12.72.......................12.612..........................12.464
mph.................109.30...............................109.30.........................110.51..................112.78......................113.78.........................112.03
temp................. 64*................................... 62*............................. 55*..................... 55*......................... 57*............................ 64*
DA................... 317.................................. 241............................ -214..................... -214....................... -325............................. 240
kclv................... 25.5................................ 25.5............................ 25.5..................... 25.5....................... 19.5............................ 23.9

(DA corrected.....13.33...............................12.96...........................13.02.....................12.75.......................12.65............................12.43
time)................109.65..............................109.56.........................110.28....................112.54.....................113.42..........................112.30


In conclusion; the xforce exhaust and rr racing tune added measurable performance gains on the street. The gains were also backed up when taken to the drag strip..
Also note that the ecu did not need to ''learn'' in order to see performance increase when doing the exhaust test, as I ran valve closed then valve open
in back to back runs and had immediate performance gains and I tried multiple runs in both configurations with similar results.







Best individual run:

Rossi

iTrader: (4)

MileHIFcar

Thanks Mike for putting these results together for everybody!! Your results posted have mirrored my non-scientific butt dyno results when doing my mods and the car is definitely quicker!!

You need to update your results with a pair of headers

cvt

Kenny88880

Excel sheet -> screenshot

Vervish

iTrader: (4)

Wow - Thanks for pulling this together. Great info..

mahcah

iTrader: (3)

How much work did you put into formatting that data? Looks like good work

Vervish

iTrader: (4)

Took 5 min - updated below.

cvt

Great data put together! There is a an improvement on the 60' thats skewing this a little but this layout is great. Thank you for the info!

Ram3n

I wonder how the quarter miles would differ when running the Hankook V12 summer tires

mike33

iTrader: (1)

Thanks, I wanted to be able to put real numbers to the modifications that many of us have done, so I am glad you found it useful... I am still debating whether or not to do headers, cost and noise are factors I need to consider. For now I am going to turn my attention to new poly bushings for the rear diff and then coilovers... btw, your posts on using e85, made me decide to use a 20-25% blend to increase kclv after installing the tune, even at sea level I could not get the number above 19.5, but since using e85 its up to 23.9.


Thank you for doing the spread sheet!!! It looks much better than what I did.

Yes, there are some variances with the runs, it was hard to lay down a consistent 60ft with out a good prepped track, but the xforce exhaust open/closed and the rr-racing tune best runs had almost identical 60ft and the xforce closed exhaust run was nearly identical to the stock exhaust best run even with the difference in 60ft... So I think the performance increase from the xforce exhaust open and tune are still evident.

Vervish

iTrader: (4)

lobuxracer

iTrader: (2)

ETs aren't the big indicators of change unless your goal is drag racing. MPH through the traps tells all for hp gain and isn't as driver dependent as ET is. It would be interesting to normalize the data for the DA and see how much was conditions and how much was actual power increase.

MileHIFcar

Awesome!! glad it has helped you out in that aspect

mike33

iTrader: (1)

I am considering gutting the primaries, but I'm hesitant because of not being able to return to stock if I do not like it for some reason... What is the noise level like with the gutted cats? Currently mine
sounds as quiet as stock when the varex valve is closed... If I do decide to gut them I will definitely test and post the results.