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GASCO123

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Posts posted by GASCO123

    Got Over 400kw Atw?

    in Forced Induction Performance

    Posted

    No gear ratio will only change the tractive effort or the actual load through the load cell. In a perfect world the gear ratio shouldn't make a difference in measured hp or only be slightly different due to the differing thrust loading through the gearbox.

    In reality even the good dynos show a slight difference between say 3rd and 4th gear probly due to unaccounted for acceleration rates.

    The ramp rate is really the only thing that should influence how a turbocharged cars power delivery is plotted. Slower ramp rate gives the turbocharger longer to spool hence moving the graph to the left.

    In my opinion, exactly.

    Dyno's are set up to give a fixed road speed increase with time, e.g. 12 kph/sec.

    If you use a taller gear the dyno stills holds the wheel speed to 12 kph/sec, giving the dyno sweep longer time from start to red line.

    This then gives the turbo's more time to spool. Should give a quicker spool up , not by time but by road speed, which is what the reads.

    I prefer dyno runs in rpm not road speed. This shows what the motor is doing more acurately than the unknown gearing of the car.

    People on this thread do not even knowin what gear Ben's run was done.To me it seems 5th with a 4.1:1 diff. Only way to get 230 kph at 8000rpm.

    He does use 4th sometimes,and 5th soetimes. He tuned my R32 GTR many years ago, great job too.

    Got Over 400kw Atw?

    in Forced Induction Performance

    Posted

    How do you work that out exactly? :huh:

    You - 175km/h @ 7000rpm (4th)

    RPMGTR - 230km/h @ 8000rpm (4th)

    You are doing 150km/h @ 6k, 175km/h @ 7k... So roughly 200km/h you are 8k

    Meaning yours is the shorter ratio... So of course yours appears more responsive.

    Ben's dyno using 5th, mines 4th gear.

    Ben's getting 28.7 km/1000rpm. Std is 33.5 5th and 25.5 4th. Half way between.

    Ben tends to use 5th gear as it give less gear box loss, 5th is 1:1 ratio.

    Unusual he starts the dyno at 3000 rpm

    Rb29 Wow!

    in Forced Induction Performance

    Posted

    It's a bad comparison.

    Clearly he came here to big note himself (why else would you thread dig)...

    Read the 400kw thread for more details if you really wanna get into it.

    Please read the thread in 400 kW.

    I posted the link to get a reaction. Was not expecting a bad one.

    I have no axe to grind, just want to share my experience on the best GTR forum in the world.

    I guess the comparison I can make is I spent about $14,500, all work done by others.

    I now have close to a brand new motor, new turbos. Surely this is valuable to others.

    Got Over 400kw Atw?

    in Forced Induction Performance

    Posted

    post-73885-0-09323800-1332557482_thumb.jpgGTR R34 RB30 conversion

    RB30 block rebuild by Pro engines, inc forged pistons, rods.

    Nitto oil pump

    Garret -5 new turbos

    Aftermarket injtrs,manifolds, cams, detail not known

    Reconditioned GTR head

    Drives like a V8

    On boost above 2500 rpm, smooth as, with progressive boost increase.

    Torque tapers off above 5500 rpm, but still 77% max torque at 7000rpm

    Interesting to compare this with Racepace Ben's WOW 2.9

    Low rpm torque better than Ben's up to 5000 rpm, then Ben's better revability takes over.

    Worth mentioning this dyno done on 4WD. Ben's on 2WD. 4% difference maybe?

    Also note, Ben's diff is very short, 230 kph at 8000rpm

    With RB30 bottom end, rpm limited to 7200.

    Max torque at 3500rpm and comes up nicely from 2500 rpm.

    Estimated air flow 32 lb/min at 21 psi each turbo. Equates to about 10.5 FWHP per lb/min air.

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