Kiloalpha

iTrader: (1)

I know, I know.. not another one of these comparo theads.

But it looks like you can get a GT30 BB turbo that will bolt up to the stock manifold.
True or False?

How would a GT3071R or GT3076R compare to a HTA green; or Blouch Dominator. My preliminary research leads me to believe that the Garretts are capable of producting more HP, but how does the spool compare?

I'll be looking for around 370 awhp on the stock block and head. ~ 25 psi

** If your response is GT30 FTL or Green FTW, etc.. your input is not necessary. **

Lets hear it

Kiloalpha

iTrader: (1)

Looking at a Garrett set-up like this:
http://www.vividracing.com/catalog/g...i-p-63678.html

Sharkbite2000

iTrader: (21)

I was actually looking at that today.

1800bigk

Get the green it will meet your goals, spool similar to stock, costs hundreds less than the Garrett. The hp # quoted by Garrett are probably crankshaft hp not at the wheels.

Kiloalpha

iTrader: (1)

I've seen a couple FP turbo's failing for member's on this forum recently, maybe the Garrett will have better reliability. The BB versus journal is also a big selling point for me.

linjy2

iTrader: (4)

Maybe you can be one of the first to try out the revised Garrett 30r. I along with a few other with the rev 1 30r have switched to Ewg due to a faulty internal wastegate design. The 30r will also lag more then the green

Kiloalpha

iTrader: (1)

Why does it lag more?
*dont get too technical, as I'm kinda dumb

Wickedwhite8

iTrader: (9)

I went with a 3076 on my evo 8, I really wish I went HTA green. The spool does get me angry at times but only since I started autocross. I do love my 30r though. I will be going to fp or cbrd to do the hta conversion soon. It all depends on what you are going to do with the car. HSAX or road racing hta3076, autocross in parking lots hta green. Just my .02

CBRD

iTrader: (60)

the GT30R simply will not perform like any of the good stock housing turbos in regards to spool and overall powerband.

I have never been super impressed with the 30R.... its a nice turbo for low boost and large displacement... not small displacement and high boost, and the garrett engineers will even confirm this.

The other benefit you have with the stock housing turbos is the assymetric twinscroll volute which will allow for better part throttle and transient response regardless of which stock housing turbo you would use (unless its one of the big big ones hee he).

I usually tell people, if you want a 30R, you should just go 35R.. if youre going to deal with the lag, you should atleast get the peak power out of it.

cheers

cb

Kiloalpha

iTrader: (1)

Here's another piece of info regarding my goals.

I'm looking for a turbo that will efficiently run at ~26 psi; key word being efficient. I have zero aspirations to run 29+ psi on my stock block.

I'm guessing 25-26 psi is outside the efficiency envelope of the stock turbo; right or wrong?

So that being said, it sounds like a HTA green or BB-X is my best best.
(I know there have been numerous debates between the two of those)

spdracerut

iTrader: (2)

I would disagree with regards to the asymmetric volute shape. I've talked to the guys at Dent Sport Garage, and they installed a Evo X GT3076R on hill climb/time attack car replacing a FP Red. Though the 3076 spooled up later, as you would expect with a much larger turbine housing, it had significantly better transient response as compared to the Red.

The 3076 also made 20-30 lb-ft more torque from 4700rpm to 7500 rpm at the same boost level from the dyno chart they shared with me. Doing a quick bit of math, 20 lb-ft torque advantage at 7500 = ~30hp advantage at the same boost level.

As for why Mitsu would use the asymmetric volute shape? Same reason Borg Warner used it on the Ecotec, and Garrett on the new BMW 4.4L V8, for packaging reasons. They all use a v-band center housing to turbine housing joint. If the volute/divider wall were more more centered, you wouldn't be able to install the v-band.

Any turbo using the stock turbine housing and putting a bigger turbine wheel in it is a compromise. The turbine housing volute shape should be matched up to the turbine wheel. Just look at the Tomei and HKS Evo drop-in replacement turbos. Do you think they'd go through the trouble and costs of casting new turbine housings if it wasn't a benefit? And they're only using slightly larger than stock turbine wheels. I think the difference in transient response between the Red and 3076 is proof of that.

I'd be very surprised if any Garrett engineer said what you claim. GT30s seem to do very well on Evos with 2.0, 2.3L, STis with 2.0-2.5L, all manner of Honda B16-B20. If you look at the compressor map, at the high flow end of the GT3071 and GT3076 maps, they're in the meat of the map in the 2.5-3.0 pressure ratio range. That's basically 20-28psi range.

CBRD

iTrader: (60)

seeing as we did develop with Garret for the evo X turbo and went through the data with the combinations in the turbo, I can assure you.

I've had red's on evo X's here, BBX's, BBX lites, Red on a 2.3 liter Jun car...

the GT3076R in the supplied housings, was LAZY compared to the rest.. even a test 62lbs min turbo we tried and didnt like..

I have done enough testing here to say if you are going for quick response, and good transient.. i would recommend the HTA green over the 30R.... or something else

cb


also- if you are talking about a 3076R in a true garret housing...... i have multiple charts on th evo 8/9 too...... just overlayed our BBKB (58 lbs min) against an HTA3076R.... it was almost 1000 rpm difference... a turbo that is 1000rpm slower on initial response is simply not going to gain that back and then some, on transient once its building boost.

chkmgnt59

iTrader: (3)

shhh Chad. Don't educate the masses ;-)

spdracerut

iTrader: (2)

#1. If IIRC, you tested out the Garrett turbo when it was first released with the faulty wastegate arm and valve that leaked. Because it leaked, that would lead to a lazy response, wouldn't it? Also, what 62lb/min turbo are you talking about because the 3076 is certainly not a 62lb/min turbo.


#2. What Garrett engineer said the GT30s, "its a nice turbo for low boost and large displacement... not small displacement and high boost, and the garrett engineers will even confirm this." There are thousands of SR20s, B16-B20, WRXs, STIs, S2000s, and a few Evos even, running GT30 size turbos. Those are all small displacement and high boost.

In fact, if you look at the compressor maps comparing a GT3076 vs a GT3582, the 3582 is better at the lower pressure ratios than the 3076; the high efficiency islands on the map go to a lower pressure ratio.

#3. On the Evo 8/9, you're comparing a stock framed turbo using a small A/R with twin scroll vs. a GT30 in what turbine housing? If they're not in similar turbine housings and similar exhaust manifolds, it's not a valid comparison. Hell, using the exact same turbo and going from a log manifold to a tubular results in drastically different results; the S2000 guys have proved that.

#4. You said, "The other benefit you have with the stock housing turbos is the assymetric twinscroll volute which will allow for better part throttle and transient response regardless of which stock housing turbo you would use (unless its one of the big big ones hee he)."

Okay.... how does the assymetric twin scroll volute allow for better part throttle and transient? If you tell me how scientifically, I'll accept it. Until then, I can just as rightfully say, assymetric twinscroll volute makes for worse part throttle and transient.


I personally don't care what you say if you BACK IT UP with real data and real science.

Geoff Raicer

iTrader: (7)

that is not correct...