GTX3576R .83AR too big?

[chiboy002]

getting ready to buy the final pieces for my build and my tuner suggested my turbo might be too laggy and I should step down, which has thrown my whole perspective off. Would like some advice from people with more experience

Build list:
CP 9:1 CR
Pauter Rods
Kelford 272
Supertech springs
OEM Valves
Lightly ported/polished head
T3 vband manifold

Goals:
~400-450 hp on pump
~500 on E85

I'm having trouble finding any solid builds with the GTX3576R, seems like only a few people have used it (which worries me) but I got a solid deal on it which is why I decided to go this route. I plan on mainly street driving the car/occasional drift - but I did used to road race and have been thinking about possibly going into time attack or similar events later on - so I would say my ideal powerband characteristic would be similar to a road-racing car

What can I expect from this turbo? Would it be super laggy? I figured with the 272s it would bring the powerband under 4000 and have enough breath to keep building power all the way to 7500rpm but now I am second guessing myself and if I should've gone with something like a G25-660/550 or even a GTX3071R

[Boosted90Hardbody]

A good rule of thumb for sizing a turbo for a street car is to use the smallest turbo that'll hit your max power goal (while still in a good efficiency zone for the compressor). That way you make the power you want while sacrificing the least amount of response possible.

The GTX3576 is rated for 750, which is a bit of an overshot. I would not expect much boost at all below 4500 rpm. An excellent choice for a corn fed drag missile, not so much for a drift/auto x/ street car that will see pump gas though.

I would agree with your tuner and step down to a GTX3071, GTX3076, G series 550/660 or, a favorite of mine and a handful of others here, the Borg S257sxe. I've got one on my single cam, and I'll be honest, I'd even consider dropping down to a S252sxe just for a little more response. I'm not even close to maxing this one out and I would kill to spool up a couple hundred rpm sooner. Just my 2 cents

[tuzzio]

Thats 3076 / s257sxe territory for sure.
a 3071 should do it as well on pump.