I have only owned the hta 71 and what I can say is that there is minimal lag for the power delivery up top. It is an amazing turbo for the street. Others have been surprised with the lag I the green, that is why I opted for the white and am very pleased with it.

With all of that being said, if you have a built motor, you will be able to gain torque sooner, spool faster, and be able to stretch either turbo to its limits. Having a 2.3 liter, my slightly uneducated opinion would be to strap the hta 73 to it. Because after all, you do have the opportunity to use it to its potential. For me, I would experience the lag and not have the benefits up top. You can basically max it out no problem. Buy an old 9 turbo, send it in for an upgrade. They do an amazing job.

 

If u are afraid of lag and the 73 hta is in the ballpark of 1400 for the upgrade I would rather get the bbk full upgrade. It spools insanely fast on a stock evo, Ive seen dyno vids of it on a 2.3 and there is no lag.

If I could afford and utilize the bbk I would get that over the 73hta any day.

I really want to know when the 71 hits full boost on a stock motor.

 

^^ what? The upgrade is like $850. ^^

Also this thread is for hta 71 vs hta 73. If you want to walk about bbk vs hta 73 there is a thread for that.

I need to get some time to post my graph and a video of a couple pulls.

 

You've made your choice now but possibly another one existed (I think) if you need boost now with a little more top end .

I think FP used to offer a 68HTA version of the 9 turbo on the standard turbine and the word from other Evom uses was that it gave about 10% more airflow than the standard 16g compressor wheel .
If you make the broad dirty assumption that 10% more air gets you 10% more rev potential it may just be enough . Only the user can judge how soon they get boost (torque really) vs how soon it falls off suits them .
The eternal problem with dyno tuning is that you create situations thatdon't exactly equate to what happens in the real world .

The great unevener with Evo engines is MiVec and everyone I've ever spoken to said you cannot match the width of the usefull power range of a 9 without it .

A .

 

I had the Fp white aka 68 and now the 71. Upgraded wastegate holds 26 to redline. FREIGHT train midrange ..

Lag gets tossed around pretty loosely

 

By "White" do you mean the 68HTA compressor or what was called the White Rabbit one ie their 5/5 bladed pre HTA wheel ?

For almost no additional lag and a really punchy mid range , what I think the OP wanted , it'd be interesting to see a back to back between a current 68 and 71 HTA Evo 9 based turbos .

I think once you go to non std turbines the turbo response has to suffer because of the extra inertia to overcome and what you gain exhaust flow wise higher up you lose down low spool wise .
It also owes you a new turbine and machining the housing to suit .

A .

 

I had a White Rabbit Im sorry. It was also clipped as part of the conversion. Robert was very shocked to see that turbo back at the shop citing "this is an early one". Said for 650 he could rebuild the White Rabbit, or for 600 dump me a 71 hta. 18months later im still stoked on this thing..

The FP white rabbit was supposed to be 10 % more flow than a std 9.

and my boost gauge is clearly off as it reads 25+-1 but my map sensor says 23ish. bastards.



very low timing in the low RPMS

 

I have the older hta 68 some of you are refrencing and here are some virtual dynos of stock ix turbo, then cosworth m2 cams then added the hta 68. Its a decent turbo no complaints best time with it is 11.3@120 on the stock nine gearing so crossing the traps over 8000 rpm.

 

Here's my graph.

Hardware Issues:
- Restrictive muffler (2.5")
- ****ty LICP
- Stock Manifolds

Made 383/352 on fftec's mustang dyno. There was more to be had but I wanted to wait until I fix the hardware before pushing the tune.

 

Hi this is Ron with the stock wingless Evo. We were hanging out at FFtec when you got dyno'd the first time on 91oct. Hey thats way better than the 315 from the first dyno day. Its interesting how the little details seem to make a difference. I'm sure with the changes you'll get past 400. Even with your 'geriatric' motor

 

Hey thanks Ron! Yeah my car apparently loves the e85 / turbo combo. Very pleased. Good luck with your calc final!

 

Bump for good info

So an oil return line is not needed for the hta 71?

 

Nyet! The FP oil feed line is only required equipment on the journal bearing FP Red, and the journal bearing FP Black.

 

I just want to rebuild my turbo with slightly more power..Bolt ons and for fuel only a walbro, so I'm guessing this would be the best route....

any failures?

 

Just got an fp green, can't wait to see how it runs against my friends 71hta, he has maybe 2 more mods than I do. Should be interesting.