New turbo new tune?
 

So my car was dyno'd last weekend, and I was upset with the way my turbo spooled, it had a lot more lag than I thought it would, boost coming on at 4,000 not too sure where I made full boost, but it was over 5,000. But long story short I made 287 whp with 13 psi in my 1.6 with a T3/T61 non-BB turbo. The shop who tuned my car (Sound-Performance) known for there Supras said with a smaller turbo my car would make 300+ whp at 12 psi, if I where to get a new turbo would I have to re-tune the car, even at the same boost?

Here are the three turbos I can't decide on:

-GT2871R w/ T3 .63 exhaust housing
-GT2876R aka GT25/40R w/.63 exhaust housing
-GT3071R w/ .63 exhaust housing

I want a good spool, but make the most power. I know they'll all have different power bands, etc. but which is the best balanced turbo for 300+ whp?

Yes, you HAVE to retune. You have to retune your car whenever you make any changes in your setup. I'd get number 1 out of your list.

Is your motor built? Or at least does it have forged rods?

Definately NOT a turbo guy, but you retune it if you swap turbo's I would think. What are you using for engine management? MegaSquirt is popular on this forum.

I'm using AEM EMS with 750CC injectors, fully built motor with .20 overbore.

Engine specs

-Wiseco pistons
-Carrillo H-beam rods
-Balanced crank
-Blueprinted/O ringed block

Someone on this forum is selling a brand new GT2871R in different trim
https://www.miataturbo.net/miata-parts-sale-trade-5/f-s-new-garrett-gt2871r-0-64-r-14084/

yay, you defently have to re-tune. the new turbo with be flowing different, so the current tune could be close, but close can blow the motor too. are all of your hotside gaskets good?

You must retune. Your current maps will be close, so they won't be starting from scratch, but adjustments MUST be made.

Okay thanks, guys. Now I have to find a good tuner in the San Diego area, I know Bisimoto Race Engineering is close...

I've been thinking about replacing my T3/T4 with a GT3071R. I'm looking for similar power levels 300~350 whp. Please post back and let us know which turbo you end up with.

The 3071 will take you well beyond 400 whp. :)

Ok does any one esle think his 280-300 whp at 13 psi out of a 1.6 is alittle high. Even i think it is a little high. Sure y8's and airbrush did it on there NB's but who else has seen a 1.6 hit numbers like that before. Please jtothawhat post up a sheet on this i gotta see it if it is true i will most def look into a huge ass turbo. And try to figure out what you are doing right.

It's not a 1.6 more like a 1.7 lol, I will post the dyno sheet as soon as it's emailed to me.

I have around 250rwhp at 13psi. with a stock block. The 60-1 is highly efficient in that CFM range, I could see it possibly.

Hmm this gives me great hope for my 1.7 liter. :D Maybe i should step up to a bigger turbo next year. But still scot hayden etc took quite a few psi to hit 300 whp on his setup i think he made 320 or so at 20, jasono made 300 someodd at 16-17 psi. aswell i look forward to some more info bud.