06blackg85ss

iTrader: (1)

yup are tranny's won't take 400wtq.... Don't tell mine that.

SynapseTurbo

Got a few cars on the dyno today, hopefully we can get the cobalt back on the dyno tonight for some more testing.

duke3323

are you really using Psykostevo to do your tuning and how do you go about picking tuners on here

SynapseTurbo

Up to this point we have done all our tuning in house, no one has touched our tune or car but us. We will spend alot of time on the dyno trying diffrent thiings and parts. If everything looks the way we want them, then no outside tuning will be done. Our goal was to provide the best and the most complete kit available, not something you slam-dunk together with no other proper supporting mods. When we are satisfied with the results then we will release it to the public, this was "initial testing" and up to this point we are happy with the results as we have been building the hardware for it the last 2 months.

psychophyr

Pleeeease get some vids of the tc dynos

krispy

is it just me or does it seems like how the torque curve was affected and how the HP curve would keep increasing past redline that this turbo is too big?

PimpLay2

you know me, have 2 subscribe

IonNinja

the dyno only reads to 6100 rpm

also they tend to rev it out a bit which is why they chose a bigger turbo

peachpuff

I agree, the gt2871r is a mid size turbo and should be treated as one. The turbine housing/wheel should be as small as possible for instant response but still be decently sized so it doesnt choke at the top.
Theres a dyno sheet on hptuners forum with a GT3582R on the lnf, its a much bigger turbo yet spools identically to the gt2871r.

08BlackSS/TC

I was going to post that dyno sheet but I said nahh

SynapseTurbo

I just tuned a 600hp 2.0l honda with a race motor today, gt3582r, and full boost at at 5500rpm, so I am going to have to disagree. This head has been flow tested at 305cfm.

But I will let you guys make your judgments when you see some street video, your not waiting for anything.

boostking

GT2871R - 743347- 2 with a 71mm, 56trim, .60 a/ FTW. would this turbo work with your components? I have some good friends that work for garrett so I will be buying the turbo direct from them. but wish to use many of your products. please pm me when I can start buying your parts! got cash in hand....

stage2

plz post a street vid .....thank you

Baldturbofreak

I have had the 2871 and 3071 on a few differnt cars 2.0,2.4. They seem to be a bit more sluggish than their slightly larger brothers. I beleive it's the ratio of turbine eff to the compressor it's turning.
Also the trim is pretty large on the back side, making the velocity across the turbine volute slower. THis was done for turbine flow at the cost of turbine efficincy.

Edit- I just double hecked, for sure the spooltime has to do with the turbine efficiency. that particular model's turbine map is only 66% efficient.
What this means is that it takes more pressure delta (mroe turbine inlet pressure) across the trubine to generate a given shaft torque. I.E. it takes more turbine pressure to make a certain intake boost when compared to some of the other offering where turbine efficinecy is in the low to mid 70's.

That being said they are great turbo's and flow very well for having an internal gate.


I'll ask again, what gear was the pulls made in?

boostking

I was looking at your pics and I see the car has not been map clamped. clamp that car throw some meth and full exhaust and you have 400whp+ easy!

Runnerdown

After cam tuning, our powerband was drastically increased, and with the help of our superior tubular manifold we are able to make singificant peak power. Baldheaded, all of our runs are done in third gear.

elecblue06

iTrader: (1)

holy **** .. overlay the new dyno with the stock one.. thats ******* crazy.. it has more power then 80% of cobalts by 4k

Runnerdown

Here you go...

1badBlueberrySC

Still falls on it's face after 5500 though...... hmmmmmm

boostking

rev that motor!!!!!!!!!!!

Runnerdown

I wish we could we are waiting on Hptuners software revision for that.

lewisb13

Yep, definately need to increase the compressor wheel size.

cakeeater

not really. Power is still increasing at redline. The drop in torque isn't significant enough to outweigh the higher rpm's. Looks like a great powerband for the street imo.

Runnerdown

Its not the compressor wheel, there is a graph of a gt35r in another thread that drops tq just as hard

06black

you don't know how power is calculated do you.......

horse power is a function or torque and RPM.

as you can see there, power climbs all the way to redline, with the curves both intersecting at 5252rpm as per expectations, and math.

the torque curves drops as rpm climbs because its inverse the RPM count.

quite simple my dear man.

EDIT-

inverse is the wrong word to use, basically as RPM climbs, torque past 5252 will always drop.

the rate and amount are dependent on the power the motor makes up top.