K&N filters vs. OEM & Conforti chips vs. Dinan

  • Mr. Castle and Mr. Conforti spend a day on the dyno

    As some of you may be aware, Jim Conforti recently tuned two 850i 6-speeds and two 850CSi's on a Dynojet 248h chassis dyno. (In Atlanta. PMB) A chassis dyno measures horsepower and torque at the rear wheels, not the crankshaft. And the chassis dyno doesn't lie or pretend - what you have is what is measured. And one other note regarding driveline loss. All four of the 850's measured a minimum of 22% or more driveline loss, with the lowest CSi loss being at just over 25%. Those are the facts.

    Let's take care of the easy stuff first.

    First one of the 850CSi's, after tuning, was tested initially with stock air filters and then again with K&N panel filters for the 850 application. The K&N filters produced between 1 and 2 LESS horsepower at the rear wheels throughout the entire RPM range. I sold mine over the Internet last Sunday since they measurably add no power and pass more dirt.

    Second, one of the 850CSi's was tested with Dinan's chips for the 850CSi and then Conforti's chips. The Conforti chips produced between 4 and 10 MORE horsepower than the Dinan chips at the rear wheels throughout the RPM range.

    With the easy stuff out of the way, I'd like to quantify the dyno results. The results of tuning the 850i were both outstanding and amazing. Horsepower gains at the rear wheels ranged from a low of 13.1 at 4,800 rpm to 40 (yes, 40) at 5,700 rpm, with gains of at least 25 horsepower or more from 5,200 RPM up to the redline. Torque gains were also outstanding, ranging from a low of 14.3 ft. lbs. at 4,800 RPM to 36.8 ft lbs. of torque at 5,700 rpm, at the rear wheels. Guys, these are measured results, with the four of us guinea pigs as witnesses. We'll all tell you the same thing about the results, because we were all there and personally witnessed the results as measured on the dyno.

    In stock tuning, the 850i's peak horsepower was achieved at 5,000 RPM, and then it's a rapid decline in performance from there onward. With the Conforti chips, however, the HP and torque both continue to climb until the rev limit. As Sean and Stephen will swear to, the transformation of the 850i's dynamics is both amazing and astounding. With the additional torque and power on tap, with no decrease in performance in the higher RPM band, the car is now even more of a sheer joy to drive. I'd highly recommend Jim Conforti's chips (available through Turner Motorsports)as the first and BEST mod you can do for your 850i. Buy 'em now and AMAZE yourself.

    We also had two 850CSi's to work with. One was bone stock, and the other had extrude-honed intake manifolds and a Supersprint exhaust system on it. Its base run was with the factory chips in DME's.

    The first conclusion reached concerns the power and torque advantage of the extrude-honed intake manifolds. In comparing the car with the extrude-honed intakes (EHI) with the "stock" car, AFTER JC TUNING, the car with the EHI, running factory chips, produced more horsepower and torque than the JC-tuned "stock" CSi between 3,900 rpm and 5,100 rpm. The effects of Jim C's chips were evident above 5,100 rpm and below 3,900 under this comparison. However, when the JC chips were installed on the EHI car, it produced more power and torque than the stock car throughout the entire RPM range, with a peak gain of 11 HP at the rear wheels and 14.4 ft. lbs. of torque.

    On an absolute basis, the car with EHI and JC chips produced 17 more HP and 22 ft. lbs of torque at the rear wheels than the stock CSi. These results were consistent with the expectation that Motorsport had already aggressively tuned the stock CSi engine. The EHI car simply has more power and torque on tap at all times, and it was very noticeable in actual driving of the two cars.

    One caveat: even though Jim C. was able to raise the 850's performance by substantial amount, it's ultimate performance still lags the all-mighty 850CSi by nearly 60HP at the rear wheels. Don't get cocky ;)

    It was great to have four beautiful 850's in one location, and all of the owner's were ecstatic with their "new" cars at the end of the weekend. We had an absolute blast, and for the four of us, it was this year's 850 gathering. We need to have a "real" one next year.

  • Dyno stats before and after Jim C. chip install


    For those who are interested in seeing the actual Dyno numbers here they are:


    Pages 1-2 is the baseline run.


    Pages 2-4 is the Jim C. modified run.


    You can print this email out and compare the baseline run to the modified run by holding page 1 to 3 and 2 to 4.


    Quite a difference.


    This should take care of the questions about low end power changes etc.


    Again I want to thank everyone who attended the "Ultimate Tuning Session"


    I concur with Mr. Castle in that we should have an annual 8 Series "Gathering" for both the East Coast and the West Coast.


    OK, you will see that we started the dyno after 4200 RPM and the 850i has a rev limiter set for 5700 RPM where it drops off and we stopped the dyno (it's really cool to look down and see your car going 176MPH even if it is on the dyno without wind resistance!!)


    You will also notice that the chart shows a baseline maximum at 240.4 HP and a modified maximum at 257.5 HP. The actual chart graph shows 242.4 HP and 259.5 HP due to the 100 RPM interval that the run-time chart (below) shows.


    Here are the numbers:


    CALL DYNOLAB, INC (678)560 C Page 1 13 November 1999
    Name: SEAN.002
    Title: 92 850i
    Run Date and Time: 11/13/99 5:32:26 PM
    Acceleration from 3000 to 6000 RPM, interval = 100 RPM
    Absolute barometric pressure : 29.05 in.Hg.
    Vapor pressure : 0.37in.Hg.
    Intake air temperature . 77.O F
    Gear Ratio : 35.73 RPM/MPH
    Correction Factor : 1.02 SAE


    Column Max 240.4 269.4


    RPM POWER TORQUE
    3000 N/A N/A
    3100 N/A N/A
    3200 N/A N/A
    3300 N/A N/A
    3400 N/A N/A
    3500 N/A N/A
    3600 N/A N/A
    3700 N/A N/A
    3800 N/A N/A
    3900 N/A N/A
    4000 N/A N/A
    4100 N/A N/A
    4200 214.6 268.4
    4300 219.2 267.8
    4400 221.7 264.7
    4500 230.8 269.4
    4600 232.6 265.6
    4700 234.5 262.1
    4800 238.9 261.4
    4900 240.4 257.7
    5000 238.7 250.8
    5100 237.0 244.0
    5200 231.7 234.1
    5300 229.6 227.5
    5400 219.9 213.9
    5500 216.5 206.7
    5600 215.2 201.9
    5700 126.4 116.5
    5800 N/A N/A
    5900 N/A N/A
    6000 N/A N/A



    CALL DYNOLAB, INC (678) 560 C Page 2 13 November 1999
    Column Mm
    126.4 116.5
    Column Average
    221.7 238.3




    CALL DYNOLAB, INC (678) 560 C Page 3


    13 November 1999


    Name: SEAN.007
    Title: 92 850i
    Run Date and Time: 11/13/99 6:37:30 PM
    Acceleration from 3000 to 6000 RPM, interval = 100 RPM
    Absolute barometric pressure : 29.06 in.Hg.
    Vapor pressure : 0.37in.Hg.
    Intake air temperature . 75.OF
    Gear Ratio : 35.89 RPM/MPH
    Correction Factor : 1.02 SAE



    RPM POWER TORQUE
    3000 N/A N/A
    3100 N/A N/A
    3200 163.3 268.0
    3300 171.1 272.3
    3400 178.5 275.8
    3500 180.3 270.6
    3600 183.4 267.5
    3700 189.3 268.6
    3800 196.9 272.1
    3900 205.1 276.2
    4000 214.0 280.9
    4100 223.0 285.7
    4200 231.4 289.4
    4300 236.2 288.5
    4400 240.0 286.5
    4500 244.3 285.2
    4600 246.1 281.0
    4700 249.4 278.7
    4800 252.0 275.7
    4900 254.1 272.3
    5000 254.9 267.7
    5100 256.5 264.1
    5200 257.5 260.1
    5300 255.5 253.2
    5400 253.5 246.6
    5500 253.0 241.6
    5600 253.8 238.1
    5700 166.4 153.3
    5800 N/A N/A
    5900 N/A N/A
    6000 N/A N/A


    Column Max
    257.5 289.4



    CALL DYNOLAB, INC (678) 560 C Page 4 13 November1999


    Column Mm
    163.3 153.3
    Column Average
    223.4 266.1


    Sean Drury

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