jbrown

iTrader: (17)

Are these the same guys that told me a 3071 would make the same power as a 3076, but would spool up a hell of a lot faster? Because that turned out to be a big fat sack of bullsh!t

And FYI, backpressure CAN be affected by the compressor because the resistance against the compressor CAUSES additional backpressure. If you make it easier to spin the compressor by choosing a wheel that is a better match for the application, then it completely makes sense that backpressure would drop.

Is it not unreasonable for the shaft speed to be higher at a given engine speed since the the compressor was building boost sooner? Wouldn't that mean the turbine was spinning faster? Wouldn't that reduce backpressure?

Then STFU and leave the thread. It's already sad that you are attacking Dave for simply testing and providing results for a product from FP. If you want to beat up someone, call Robert at FP and give him ****.

All Dave did was test a damn turbo and share the results with us FOR THE BENEFIT OF EVERYONE ON THE FORUM. Anyone can buy this turbo without sending Dave a dime. He is not peddling some proprietary black magic doo-dad. He is taking an off-the-shelf part, swapping it for another off-the-shelf part, and sharing the results with us. He is at the mercy of his test equipment. Whether the results make sense to your Google Gods or not, they are what he found.

robertrinaustin

iTrader: (5)

240Z, Let me begin by saying I am not a fan of Dave's, nor the way he handles certain things and I am probably not one of his favorites either. I also agree that the more we know, the better off we are. However, I recognize Dave has the option of providing or not providing any information he chooses, though I find it a bit absurd that anyone would start a thread in the technical section and then get pissy when people ask technical questions.

Here is the problem I have. You claim to be after the truth, but you seem to have formed your conclusion at the outset and then set out to "prove" this conclusion. Now, I have no problem if you prove this via empirical testing, but you have done absolutely no testing. A couple of phone calls and some internet research does not prove anything and thinking you've done so only makes you look foolish.

I won't pretend to be an expert, though I took some engineering classes at one of the most respected Universitys in the world (Go Bears!) some 20 years ago, but wouldn't a more effecient compressor reduce back pressure? The compressor provides resistance and a better/ more effecient designed compressor would reduce this resistance. I going back to my Fluids classes way back when, but it seems fairly intuitive. A more efficient design could flow the same amount of air more efficiently and provide less back pressure.

Finally, I would be willing to put a small wager on who is right in this regard, say $500. We would have an independant shop do the testing. So what do you say, willing to put some cash behind that analysis you've done? I am.

sparky

iTrader: (1)

[quote=240Z TwinTurbo;3978883]....... called the head engineer at Garrett and explained the scenario as well as read your response. They were at a loss to explain how you could have decreased backpressure without changing a single thing on the turbine side. Backpressure is created by the restriction on the turbine side..........

It is easy to see how upgrades on the exhaust side, such as an improved turbine blade or turbine housing design, going to a freer flowing exhaust manifold or catback system, can reduce engine backpressure. What is not so clear however, is how intake upgrades such as a less restrictive air induction kit, a more efficient intercooler, compressor wheel or compressor housing design might have the same effect.

The key to understanding here, is to comprehend how turbochargers translate flow restriction in the intake system into backpressure. Turbochargers create an increase in pressure between their compressor intake and output. Likewise, they create a corresponding increase in backpressure on the exhaust side. These two pressure differences are related.

If the turbocharger needs to create a pressure increase of 14 P.S.I. on the intake side, it will increase the backpressure on the exhaust side by a multiple of that number. It may seem reasonable to assume that 14 P.S.I. of boost pressure will produce 14 P.S.I. of backpressure, but the different geometries of the compressor and turbine sections, as well as other factors, make this not the case.

So it follows that not only improving compressor wheel and housing design, but also reducing bearing friction, or improving the overall efficiency of the turbocharger will reduce exhaust backpressure as well. Here we applied a somewhat broader definition of backpressure as being any restriction of airflow which causes reversion within the system.

discopotato03

Flow restriction in the inlet side - different . The way I see it it the flow restrictions here are the reason we get any positive pressure at all , without flow losses no significant pressure would exist .

I think the crux of the matter is rotating group (turbine/compressor) and turbine revs/exhaust gas velocity vs power demands of compressor/airflow .

Anyhow theorising can go on forever . I think we basically want to know which compressor and comp housing have they used . If those in the know don't want to talk about it then its a case of who will buy and let the cat out .

Cheers Adrian .

240Z TwinTurbo

iTrader: (25)

A quote from your fearless leader....I guess you missed this weeks alignment session.

yellowEVO21

iTrader: (24)

That quote doesn't answer his complaint about same power output of a 3071 and 3076, all things being equal....i think everyone can agree that a 3076 will spool slower.

freshevo8

iTrader: (16)

wow, this thread went downhill fast. 240z, you dont contribute anything NEAR what dave has to this community. he goes outta his way to post USEFUL knowledge from the tests he does on his own time. last i checked, your not a vendor here so why are you on here trying to ONE UP someone who has proven himself over and over? when you make a name for yourself, contribute what dave has to this community and pay a vendors fee then maybe someone will listen to what you have to say. until then, noone cares who you are or what you've fabricated, etc. your a straight up A S S C L O W N and i'm sure the rest of us would appreciate if you would stop trolling this thread. take your "steve erkel"
s hit somewhere else you ****in geek. pm me your response to this and quit posting useless crap.

now, can we get back on topic? i'd actually like to know whats going on with this turbo. somewhere along the lines of how much its going to cost and when it'll be available.

240Z TwinTurbo

iTrader: (25)

Well said, nice to see some additional profanity in this thread. BTW, don't you have to be a vendor and pay fees to use profanity? I think you are correct, I have made my point and the Buschur minions will only continue to cry if I debate this further.

High_PSI

iTrader: (50)

Die....

Migsubishi

iTrader: (38)

Okay Okay, I just want to know when will this new turbo be available for testing on my own vehicle

jbrown

iTrader: (17)

My fearless leader? Alignment?

The only "alignment sessions" I have are with Robispec, and they don't involve brainwashing.

And I never said a 3071 didn't spool quickly, my point was that it makes nowhere near the same power. That has been shown by just about every vendor on this forum.

I don't need to be a fan of Dave Buschur to see that you're a d!ck and you have no clue what you are talking about.

David Buschur

iTrader: (53)

This turbo is still under testing. The turbo surged as it came into boost more than a standard GT35R. When we tested the turbo it had a standard non ported shroud compressor cover on it. I've pulled the turbo off and sent it back to FP to have the shroud ported, hoping to eliminate or reduce the surging. Not sure when they will actually be ready for sale.

Also, 240, you missed what jbrown was saying. His quote about the 3071 and 306 were referencing your boys at Garrett, not anything I have ever said. The 3076 is a turd. The 3071 isn't a prize for making power but atleast you don't have to wait around a month for the power it does make to come to you.

As for this arguement, I don't care enough to argue with you or your red toy in your car port. Wanna race that red thing against my EVO?

I'm going to ask Robert to post the backpressure testing I did. I think he has converted it from volts (sensor outputs volts) to PSI. If he isn't to busy we can just end this rediculous discussion on why that fast redneck from Ohio is wrong and go back to why that fastest redneck from Ohio is fast......

Contacting Robert now.

JKav

iTrader: (8)

240Z, who did you talk to at Garrett?

In engineer-speak, improving compressor efficiency (at some given compressor mass flow / pressure ratio operating condition) reduces the compressor's power requirement. This in turn reduces the power required by the turbine, changing the match point. The new match point is at a lower turbine expansion ratio. Lower expansion ratio means the turbine inlet pressure is reduced. Bingo, less backpressure.

In layman-speak, the compressor doesn't have to work as hard, and so neither does the turbine.

RSGuy

iTrader: (12)

HAHAHAHA!!! He don't want none, Dave.....

High_PSI

iTrader: (50)

Why would is it a Turd? I thought it spooled quite fast in comparison to the GT35R and the same spool as a 50 Trim.