So I'll be going the turbo route very very shortly and I've narrowed my turbo choices down to three:

GT3071R
GT3076R
GT3582R (I'm almost positive I don't need this)

My goals/predictions are 375 - 400 rwhp @ 14-16 psi boost pressure. That gives me a pressure ratio of just over 2 and a required mass flow rate of about 45 lbm/minute.

I've included the compressor and turbine maps from Garrett's website:

GT3071R



GT3076R

 

Looks like the two turbine maps are identical. I assume that the 3071 and 3076 use the same turbine?

On both compressor maps, if you trace a horizontal line along corresponding to about 1.9-2.1 pressure ratio, that will be my estimated performance line at full boost. Both lines pass through the meatiest portions of the maps, but it looks like the 3076 spends more time in the highest efficiency zones. 45 lbm/min looks like the absolute limit for the 3071 at a 2.0 pressure ratio, not to mention the efficiency at that point isn't ideal.

What do you think? I may have just answered my own question...

 

I myself am possibly going to be going to the T67 T3 flange turbo. I just can't justify putting a GT turbo on it when the journal bearing turbo's work great.

But I am also going for well over 400 whp.

 

Spoke to the guys at Inline and I chose the GT3076rb...basically a hybrid turbo with a B compressor cover (so it fits in the engine bay without frame cutting). Should suit these power goals perfectly.

 

post how things go when done please

 

i had a gt3076r and i liked how it spooled really fast but i changed to the gt35r for some future plans and i love my gt35r!!!

 

The GT3071R will make 400 whp with less lag. I have the GT3076R, but it's overkill for just 400 whp.

Tim

 

It will certainly make 400 whp with less lag, but its done at 400 whp. At least at a pressure ratio of 2. Look at the compressor map, it's pretty much maxed out. It operates much better at a higher pressure ratio, but I'll never go over 15-16 psi so I wouldnt reap those benefits. The GT3076 still has a little room to go after the 45 lbm/min mark at a PR of 2. The GT3071 looks to be dying off rapidly over 45 lbm/min.

Plus, down the road when I free up my exhaust system a bit, I'll be flowing considerably more air at the same boost levels. I think its a good choice.

 

yes but what AR do you go with? what does that effect?

I am going to get a GT0371R asap but i don't know about the AR

 

someone tell me the main difference between the gt3037r and the gt3071r or gt3076r