So last weekend we had a dynoday at Dynocomp. Since all i've done was an axleback TXS RFL & HKS BOV for the sound, I knew i wasn't expecting anything but a good baseline so when I reflash and finish the exhaust, i'd have some usable numbers to compare against. To their surprise, my car dyno'd way beyond what a stock STI should on a Dyno Dynamics. They said it should be around 220/220. They think the rear piece did help, but not the whole amount. They think i just got a strong car and that many are more powerful than Suby claims. I hope that trend continues when I finish my mods!!
:banana:

http://www.f20c.com/albums/ozysti/aax.sized.jpg

:eek:

Yup, looks like you got a great car.

Same thing with our 05 Sti. Totally stock, max 269.8HP and 275TQ on a dynapack with an average of 265/270 for ~20 runs.

Also, make sure that these #s are SAE corrected. I've seen in colder weather the cars make more HP, but once you SAE correct them for temp, they go down a bit.

-Tom

Yup, looks like you got a great car.

Same thing with our 05 Sti. Totally stock, max 269.8HP and 275TQ on a dynapack with an average of 265/270 for ~20 runs.

Also, make sure that these #s are SAE corrected. I've seen in colder weather the cars make more HP, but once you SAE correct them for temp, they go down a bit.

-Tom

I'd assume they were. When he started, he looked at his weather station and typed in a bunch of weather data.

Take off the BOV and get more HP with the stock BPV

An aftermarket BOV will not affect the car in any way during a 4th or 5th gear pull while WOT.

-Tom

Take off the BOV and get more HP with the stock BPV

Couch Mechanics Unite! :huh:

37% driveline loss??

wow, my figures have been way off on my car!

is this correct??

((and yes, it looks like a weds or thurs car indeed))

perhaps the 2004 flash you have is the older version (with noted pinging possible)

anyway, im not gonna discredit this at all;

great numbers!

ESE

Take off the BOV and get more HP with the stock BPV

You must have been hanging out with these guys.
http://asiatours.net/press/images/burma-smoking-people.jpg



The stock BOV has MANY merits over an after market bov, more hp is not one of them.

Great numbers!! Wish I had a wednesday motor.

so, is the 37% number a close value??

im making good numbers ifso!


ps- NST as a subaru/sti BOV. we use a BPV bro.....

37% aint even close ;)

-Tom

wednsday motor?? someone care to elaborate>?

cars built druing the week... its a joke. engineers get salckin on friday, want to get out of there quickly, start rushing... monday people are grumpy dont want to work, sloopy work. middle of the week, its back to normal, everyones happy, things get done right.

a freak motor is said to be built during the middle of the week. a slouch is a monday/friday motor. maybe someone can elaborate as to where this actually started.

yea i hear those robotic arms on the assembly line go out and get sloshed on thursday nights.

i have a saturday motor.

they were getting O.T. and were also hung over....

pleasing combo.

37% drivetrain loss????? holy jesus xmas. That cant be right.... I always thought it was more like 26%.

cool. ;)

There is nbo way to measure driveline loss short of dynoing the car and then pulling out the engine and putting it on an engine dyno, it is all just an estimate, there is no truth to it at all.

There numbers dont make sense at all unless they dyno stock STi's at 189whp.
300-0.37*300 = 189 whp

26% is more in the range that they even claimed when they said he should get 220/220. 300-0.26*300 = 222 whp

Even the numbers on the dynosheet dont match up. 346-0.37*346 = 218 whp.

They back calculate it using a 26-27% driveline loss. Which happens to be a 37% gain from whp to flywheel horsepower. This comes from
346-x*346 = 252 whp and x = 27% and is the driveline loss.
So they are still using the same driveline loss they always use, their terminology is simply off on the dynosheet. It should still say 27% driveline loss, not 37%.
Wow, I just ran through some numbers because I thought the gain percentage (the 37%) would change depending on what the car dynoed, but it doesnt.
So if you dyno 365 whp then 365*1.37 = 500 flywheel hp and the reverse way, 500-0.27*500 = 365 whp.
So once again there terminology is simply wrong. That 37% is the gain from whp to flywheel hp. But the associated driveline loss is still 27%.
I have heard that this is not exactly correct though, because the driveline loss is not linear. I thought it started off as linear in the region we are speaking off, but once you get to a point it starts to plateau, so the 365 whp example would not actually be a 500 flywheel hp car. I dont really know though.
Anyone know how it goes?

yea i hear those robotic arms on the assembly line go out and get sloshed on thursday nights.

sarcasm noted... the joke came before robotics assembeld everything. some are still built by hand, italians love their lil motors.

There is nbo way to measure driveline loss short of dynoing the car and then pulling out the engine and putting it on an engine dyno, it is all just an estimate, there is no truth to it at all.


Dyno dynamics removed the engine, dyno tested it and then dyno tested the engine in the car on the chassis dyno to come up with that figure. The company that designs the dyno uses that figure. If you dont like it dont use it but dont claim something you actualy dont know about on the net. It makes this forum filled lots of crap. :)

P.S. Thats an unreasonable strong near stock STI. Very skeptical.

Clark

the only issue i have is that i don't think drivetrain loss is a straight percentage: i think there's a flat loss involved. i can tell this by putting the car on a lift and turning wheels with my hands...

but yeah, v. strong car.

im not hating but you should get on another dyno to make sure. I read that AWD cars have difficulty showing true whp because the dynos have to calculate the front hp as well as the rear. Same thing happens on FWD cars but not as often. But impressive non the less

The dynocomp guys claim their dyno is down 10 hp on average compared to a dynojet. Good numbers.

Dyno dynamics removed the engine, dyno tested it and then dyno tested the engine in the car on the chassis dyno to come up with that figure. The company that designs the dyno uses that figure. Is that how they have a shootout mode? The guys I go to say that mode is pretty accurate.

An aftermarket BOV will not affect the car in any way during a 4th or 5th gear pull while WOT.

-Tom

an aftermarket bov may not affect the hp, but it makes the car SLOWER. When I go to the 1/8 mile track I run 8.2 @82.5mph with a worx bov set at 25/75, the next run at factory setting with worx bov and run 8.0 at 85.5mph.

I have done this several times, aftermarket bov's will yield slower times and mph in both the 1/8 and 1/4.

an aftermarket bov may not affect the hp, but it makes the car SLOWER. When I go to the 1/8 mile track I run 8.2 @82.5mph with a worx bov set at 25/75, the next run at factory setting with worx bov and run 8.0 at 85.5mph.

I have done this several times, aftermarket bov's will yield slower times and mph in both the 1/8 and 1/4.
What you have said there, does not make my statement false.

It was in response to
Take off the BOV and get more HP with the stock BPV
;)

-Tom

What you have said there, does not make my statement false.

It was in response to

;)

-Tom

You are correct, no loss in hp, but the car will be SLOWER. ;)

it won't be slower if it doesn't "blow off."

flat foot shifting is the great equalizer... ;)

it won't be slower if it doesn't "blow off."

flat foot shifting is the great equalizer... ;)

whatever dude. go to the track and make a run with and without the bov, you'll understand then, regardless of how you shift.

ok pick one:

a) you have no idea what flat foot shifting is, or what it means,

or

b) you're just plain stupid.

ok pick one:

a) you have no idea what flat foot shifting is, or what it means,

or

b) you're just plain stupid.

i am A & B.....

can you explain A, because im B about it....

((really, id like to know.))

ok pick one:

a) you have no idea what flat foot shifting is, or what it means,

or

b) you're just plain stupid.

you're a tool. I can rip off 1.6 60 ft's everytime, so don't talk to me about shifting. You are simply in denial that your magic shifting will compensate for the LOSS in power that aftermarket bov's create. FACT, aftermarket bov's create lower et's and mph. I'm not hating on them, I have a worx bov and love it, but when it's time to go to the track I set it back on factory setting.

i am A & B.....

can you explain A, because im B about it....

((really, id like to know.))

Flat foot shifting means you never let of the throttle when you shift. If you don't let off the throttle the BOV never blows off.

you're a tool. I can rip off 1.6 60 ft's everytime, so don't talk to me about shifting. You are simply in denial that your magic shifting will compensate for the LOSS in power that aftermarket bov's create. FACT, aftermarket bov's create lower et's and mph. I'm not hating on them, I have a worx bov and love it, but when it's time to go to the track I set it back on factory setting.

i'm a tool?

you, my dear friend, just picked b).

have a nice day.

i have also tested with aftermarket BOV's and the stock BPV. No significant difference can be inferred from ANY of the data I have gathered. Hundreds of passes, 4 aftermaket BOVs (GFB (in both 50/50 and 100% modes), Forge, Blitz and TXS RFL).

As long as I launched well, the BOV didn't make a difference. The times were all within a statistically reasonable range.

Flatshifting, BTW, completely removes the BOV from the equation. You might as well not run one at all... it doesn'y do ANYTHING when flatshifting through the quartermile.

The biggest problem with aftermarket BOV's is people not adjusting them right... which in turn lets them leak... thus hurting performance when they are closed.

def

There numbers dont make sense at all unless they dyno stock STi's at 189whp.
300-0.37*300 = 189 whp

26% is more in the range that they even claimed when they said he should get 220/220. 300-0.26*300 = 222 whp

Even the numbers on the dynosheet dont match up. 346-0.37*346 = 218 whp.

They back calculate it using a 26-27% driveline loss. Which happens to be a 37% gain from whp to flywheel horsepower. This comes from
346-x*346 = 252 whp and x = 27% and is the driveline loss.
So they are still using the same driveline loss they always use, their terminology is simply off on the dynosheet. It should still say 27% driveline loss, not 37%.
Wow, I just ran through some numbers because I thought the gain percentage (the 37%) would change depending on what the car dynoed, but it doesnt.
So if you dyno 365 whp then 365*1.37 = 500 flywheel hp and the reverse way, 500-0.27*500 = 365 whp.
So once again there terminology is simply wrong. That 37% is the gain from whp to flywheel hp. But the associated driveline loss is still 27%.
I have heard that this is not exactly correct though, because the driveline loss is not linear. I thought it started off as linear in the region we are speaking off, but once you get to a point it starts to plateau, so the 365 whp example would not actually be a 500 flywheel hp car. I dont really know though.
Anyone know how it goes?

All I know is that they said multiply the # by 1.37 to get flywheel hp & tq.

Dyno dynamics removed the engine, dyno tested it and then dyno tested the engine in the car on the chassis dyno to come up with that figure. The company that designs the dyno uses that figure. If you dont like it dont use it but dont claim something you actualy dont know about on the net. It makes this forum filled lots of crap. :)

P.S. Thats an unreasonable strong near stock STI. Very skeptical.

Clark

Skeptical? I swear to god my car is stock except for the following:

HKS SSQBOV
TurboXS Axle Back Titanium RFL piece.

Thats it! They ran it like 6 times and each time the lines just overlayed each other. The guys at Dynocomp were surprised too. I'm running normal 91 gas and have not begun to mod it at all yet.