[blisstik]

So how does one find the "proper" delta between stock TT and the AR ST setup?

Dyno stock TT with corrected values then
Dyno AR ST with uncorrected value OR multiply this by some number

???

[07'335iAlpine]

So would it be safe to say that these single turbo AR numbers, are innaccurate?
If so, i've been fooled.

[andrew20195]

Originally Posted by dzenno

Why has everyone, up until today, been reporting STD dyno results? Why not uncorrected???

Because the STD correction usually returns higher numbers than SAE or uncorrected.

FWIW, I don't think AR is intentionally trying to mislead people. Hopefully we'll eventually see some trap speeds once the tuning is finished.

[OpenFlash]

Originally Posted by 07'335iAlpine

So would it be safe to say that these single turbo AR numbers, are innaccurate?
If so, i've been fooled.

Yes, the original numbers they presented (485whp) were inaccurate. But I wouldn't assume that AR tried to fool you or anyone else. However, they could have been less selective with the data they presented. Posting Actual uncorrected numbers as well as corrected, OR, mentioning that the 488whp run was with a 1.25 correction factor would have saved a lot of time/confusion.

Shiv

[stevetx77]

LMAO. "You Don't Shouldn't Use It!" Am I the only one that caught that?

[enrita]

what about DIN correction?

[BMWeber]

that makes a lot more sense. I understand bigger turbo more volume/flow at same psi but putting down more whp at less than 15psi as anyone has with 18-19 psi seemed a little off.

[dzenno]

Originally Posted by andrew20195

Because the STD correction usually returns higher numbers than SAE or uncorrected.

FWIW, I don't think AR is intentionally trying to mislead people. Hopefully we'll eventually see some trap speeds once the tuning is finished.

I wasn't implying they were at all...i was just bringing up something I didn't understand...i really like and appreciate the work AR is doing...its awesome..

[AltecBX]

Why doesn't Dynojet come up with a centralize formula. It should include (temp, altitude, etc) so no matter where in the world they dyno a vehicle, they can plug those surrounding elements in their dyno. This way, the result will be the same if I test a car at 60F at 50ft under seal level or 9500ft above seal level. We have sophisticated computers now-a-days, no reason there shouldn't be this in place. Should eliminate a lot of confusion in my opinion.

[marcel b]

Originally Posted by AltecBX

Why doesn't Dynojet come up with a centralize formula. It should include (temp, altitude, etc) so no matter where in the world they dyno a vehicle, they can plug those surrounding elements in their dyno. This way, the result will be the same if I test a car at 60F at 50ft under seal level or 9500ft above seal level. We have sophisticated computers now-a-days, no reason there shouldn't be this in place. Should eliminate a lot of confusion in my opinion.

how I understand the whole this discusion is that this is not possible, that is the whole point. There is no standard formula valid for all Turbo engines.

[mkPOTO]

i would really like to see AR with some more info, I mean the only thing that they showed of it actually working is a video and then all of these number came out of no where

[forza1976]

Originally Posted by mkPOTO

i would really like to see AR with some more info, I mean the only thing that they showed of it actually working is a video and then all of these number came out of no where

I've drven the car. It's 100% legit and I was impressed by it's power!

[Brey335i]

Originally Posted by vasillalov

Shiv, how does increasing the pressure at the manifold increase the O2 density in the air? No turbo can do that. All the DME and any tune can do is add more boost. Adding more boost won't magically oxygenate the air charge.

You need to read the OP again.

BTW, what is with your ride? You drive a 2008 335is sedan???

Originally Posted by blisstik

So how does one find the "proper" delta between stock TT and the AR ST setup?

Dyno stock TT with corrected values then
Dyno AR ST with uncorrected value OR multiply this by some number

???

This is how: Take both to sea level. Run both on the same dyno in the same conditions. Done. No correction factor.


This is my take on the matter. And I believe Shiv will agree with me.

AR should have posted up the uncorrected number and explained that this is what their turbo is making in Colorado at much higher than sea level. That way people would be talking about how great it is doing for being an uncorrected result at high altitude. Also, it would be acceptable to point out what uncorrected number a fully modded 335i with stock turbos makes on the same dyno there. That way AR could have presented a great setup that not only makes better power than the stock twins, but also has a distinct advantage at altitude.

See what I did there? All positive, great results... and no one can argue with them. Because they are all facts. You just have to be open about it. Why try to compare corrected numbers at all?

I understand AR wants to show what their setup can do at sea level... but to do that they should test it at sea level...

For individuals on here. The only reason you would have corrected numbers is to compare them to others for **** measuring competitions. At the end of the day, it doesn't matter what your car would make in Houston if you live in Denver.

My rather long 2 cents...

PS. This is not an attack on AR, but rather my idea for what to do to solve this and create a positive atmosphere around this project without bloated expectations or uneven measurements.

[enrita]

the only thing i am actually measuring right now and that tells me how fast my car is is PBox times. you cant be wrong with those.

[forza1976]

Originally Posted by Brey335i

BTW, what is with your ride? You drive a 2008 335is sedan???

I've always wondered that too... No such thing as a 335is in 2008 (sedan at that)

[klipseracer]

Originally Posted by Brey335i

You need to read the OP again.

BTW, what is with your ride? You drive a 2008 335is sedan???

Its pretty obvious that as of April 2010, he didn't know much about 335's let alone turbocharger efficiency. If you look at his garage, 4-23 he added a 2008 335is. No picture = he didn't even own one but was making a username on the forum. Then on 6-1, he adds a 2008 335i and never changed his, "what do you drive" comment in his profile. And suddenly he knows all about atmospheric pressure and oxygen density, oh wait! No offense to him or anything but you are speaking quite loudly in one of the bigger threads on this forum, immediately after they are desperately asking those who think they know a lot but really don't to just keep hush.

[Brey335i]

Originally Posted by klipseracer

Its pretty obvious that as of April 2010, he didn't know much about 335's let alone turbocharger efficiency. If you look at his garage, 4-23 he added a 2008 335is. No picture = he didn't even own one but was making a username on the forum. Then on 6-1, he adds a 2008 335i and never changed his, "what do you drive" comment in his profile. And suddenly he knows all about atmospheric pressure and oxygen density, oh wait! No offense to him or anything but you are speaking quite loudly in one of the bigger threads on this forum, immediately after they are desperately asking those who think they know a lot but really don't to just keep hush.

Well, I'm not saying I know any more than he knows. I don't know what he knows... I just know that I don't know very much haha.

The difference is... I try not to post things I don't know about... and if there is something I don't understand, I'll either ask a question or post my best understanding of the concept... but let people know that this is not an expert opinion

I simply think that those who obviously do know a lot (Shiv is an example that might come to mind... couldn't imagine why :P after all, he's only been around here for several years... and been doing this a good while longer) should be allowed to voice their opinions and takes on things without being edited out. What's in the closet that they don't want out there if they won't let anyone ask a question or pose a problem...?

[335iPSI]

$100 says they crank up the boost/timing to Jesus-H-my-pistons-are-going-to-melt levels and go dyno it at sea level at an attempt to prove Shiv wrong.

I'm not denying the cool-factor of the single-turbo... I love it. Why don't they hook up with Shiv and slap a damn V4 on it and let it ride! The wheel has been invented and perfected by Shiv... why bother?

[Joshboody]

Maybe I can confirm CFM and PSI here. The other thread was confusing replying to me "incorrect" when i stated at 14psi CFM is equal.

if pipe diameter at MAP sensor is equal and PSI is equal then CFM is equal correct? I understand that temps and air quality would be different.

In the first results thread 444hp was stated with no mention of altitude, and it kinda seemed to allude to 15psi with their turbo creating vastly improved results over stock turbos. The difference would only be based on temps right... what could that temp difference be at 15psi? IAT with a good IC are <20deg above ambient right... they can't get below ambient without meth.

unless you are going for 20psi, single turbo is not worth the expense. even then you can upgrade stockers. I think you would need to rebuild the motor and increase redline to greatly benefit.

[Joshboody]

on the standback... i think the flexibility is great and many options, BUT you would need to continually tune depending on environment conditions. Not sure how it works with timing... alters CPS like v4? but I know you have to adjust tables. it would be like the old days tuning conservatively for hot weather and not being able to take full advantage of the cooler weather, better gas, etc.

they shouldn't poopoo Shiv. The ability to autotune (based on revised maps for more top end torque of course) would be great. I'm sure they have just modified the factory wastegate concept to one turbo. And I'm sure Shiv could offer an option, apart from AR, if this kit takes off.

[adrian@vishnu]

Hi Guys,

I have written altitude compensation algorithms before for ECUs. Shiv is totally right, but there is also another part that he neglected. Assuming that a turbo is sifficiently large to supply the required flow at altitude and stay within reasonable efficiency on its compressor map, the the effect of running at higher altitude is probably a small loss in efficiency resulting in more heat output as Shiv stated, and a increase in shaft speed to pump more volume resulting in a higher exhuast back pressure. What Shiv did not mention is that the exhaust outlet of the vehicle is actually at lower ambient pressure. With a large turbo, the increase in back pressure at higher altitude is probably lower than the reduction in back pressure due to the exhaust outlet being at lower pressure. Therefore there is no loss in performance due to increase in exhaust back pressure, because it is probably actually reduced (depending on the turbo size).

Most people only concentrate on the atmospheric pressure effects on the intake, but engines have two openings to atmospheric pressure.... the intake and ALSO the exhaust.

But Shiv's theory is correct. If a turbo is large enough such that the turbo can remain efficient (there are obviously limits here) at the shaft speeds and pressure ratios of the higher altitude, then the outright power will not suffer much if at all.

One thing to note though.... at higher RPM, once the wastegate is open, the turbo can maintain the shaft speed required for the boost setpoint. At lower RPM when the shaft speed is limitted by RPM, then the result will be less boost than at sea level. This basically means that at altitude, all turbos will have more lag. At a given shaft speed, they are flowing less air, so the result is that it will need more shaft speed (RPM) to get to the boost target.

Vasillov.... you really need to learn to do your research before posting. Not the first time I have seen you get aggressive in a thread with bad data to base your post on. Maybe ask questions before arguing about something you know little about.

Cheers,

Adrian

[cn555ic]

Originally Posted by Joshboody

on the standback... i think the flexibility is great and many options, BUT you would need to continually tune depending on environment conditions. Not sure how it works with timing... alters CPS like v4? but I know you have to adjust tables. it would be like the old days tuning conservatively for hot weather and not being able to take full advantage of the cooler weather, better gas, etc.

they shouldn't poopoo Shiv. The ability to autotune (based on revised maps for more top end torque of course) would be great. I'm sure they have just modified the factory wastegate concept to one turbo. And I'm sure Shiv could offer an option, apart from AR, if this kit takes off.

Standback is for the extreme enthusiast and if you dont know how to tune it, alot can go wrong...Alot of members here are enthusiast to some point but going with a tune like the standback is asking for trouble.