Is there anyone out there running this turbo? I installed one on my FC this week and I just wanted to hear what sort of results people are getting. Im not really a numbers guy (horsepower) but the response is not what I expected. Im getting little to no torque on the low end (2500 to 3500) compared to my (stock) hybrid. I get full boost around 3800rpm's. I have no complaints about the top end power as the car hasnt been dyno'd (currently street tuning).

GTX3576R .82 T4 undivided housing.
HKS Cast manifold (undivided)
Tial 46mm wastegate but soon to be HKS 60mm (the wastegate it should have).
S4 Block with Pineapple racing large street port and EP3A exhaust ports.
Corksport Intercooler.

I have a fairly on the conservative timing map and my fuelling is currently running around 10.5 when Im on it. Pulling 1 Bar of Boost. Honestly, in the cruising range my hybrid was a way better turbo and really pulled in the mid range compared to this one. Is this something I can tune out with timing?

 

Did you have the same intake ports with the old turbo? You are running pretty rich which will hurt spool and torque. That turbo would come on a lot better with a divided manifold and turbine housing too.

 

I have the map trimmed so it starts to fuel slightly rich at positive pressure and by the time it hits .6 bar its below 11.5.

The engine was ported with the old turbo. I didn't have a choice on divided or undivided. They only make one manifold lol.

I noticed an exhaust leak last night which I originally thought was the Vband off the back of the turbo but it sounds like a pinhole at the wastegate, which would be a huge contributing factor. Im switching over to my HKS wastegate soon, just waiting on a bigger spring.

 

You are losing a lot with the cast undivided manifold. A proper twin scroll manifold would help spool time. Also, the GTX turbos are intended for higher boost, and often actually make less power at lower boost levels than the same turbo with a GT wheel. Turn the boost up and tune to 20lbs plus (providing the motor is built for it and you have the supporting mods) and that turbo will scream.

 

So I thought I would follow up on this thread as I've made some developments.

I've installed my proper 50mm HKS racing wastegate and fixed a couple pre turbo exhaust leaks. Spool up is similar to stock with but there is pronounced lag in the lower gears. I believe this is my intercooler piping is restrictive on the cold side. The spring I have runs about .6 to .7 bar and with my Profec I run about 1 bar. The car pulls unbelievably hard. Spool up is good, response from the turbo is good. I've been playing with the timing maps a bit but nothing crazy until I get it on the dyno for a proper tune.

I wanted a GTX3582 but the GTX3576 seems to be a good choice so far for the 13BT (S4/S5) engine with some work.

I'm planning to dyno it maybe in a month or two, work and weather permitting.

So far the 725/1000 injector combo with series fuel system seems to be working fine.

 

So today I was able to get my car on the dyno to make 2 runs. The first at 10PSI (Wastegate spring pressure) and the next at 18PSI. The results were surprising, to me at least.

It made

345WHP and 268 lbs/ft of Torque at 10PSI

423WHP and 345 ft/lbs of Torque at 18PSI

Complete Engine Mod list is as follows:

S4 Block with S5 reinforced rear iron
S4 Rotors and Rotor Housings
Pineapple Racing Large Street Port and EP3A Exhaust Ports.
Stock Tension Bolts
ACT Prolite Flywheel
Corksport Intercooler Kit (and piping).
S5 Upper and Lower Manifolds
Aeromotive Stealth 340lph Fuel Pump
Stock Lines with stock series plumbing to rails
Aeromotive A1000 Regulator set to 43PSI base Pressure
725cc ID primaries and 1000cc ID secondaries
HKS Cast Manifold Undivided
HKS 50mm Racing Wastegate
Greddy Profec Spec B controller
Garret GTX3576R Turbo
3" Exhaust with a Racing Beat Resonator and an HKS muffler
MSD 6A Digital
Stock Spark Plugs (7's and 9's).
Koyo Rad, GM 150AMP Alternator and a Taurus 2 Speed Fan.

 

You can see above the two runs overlayed with each other. These represent an UNTUNED state. I am using the timing map from my hybrid, which is fairly agressive for a single turbo compared to other maps I have seen. The fueling is a little much but when street tuning I wanted to be safe. At 10PSI the AFR looks good. At 18PSI the AFR looks like ****. Power Drops after 7000rpm and we felt its the intercooler pipes causing the restriction (mainly at the throttle body inlet).

But I thought I would keep this thread going to sort of document the 3576 turbo in my instance. I will be returning to the dyno after some new intercooler pipes, throttle body inlet (greddy) to get some proper tuning done and to maximize the results. I don't believe I will be running anymore boost but we will see.

 

Forgot to Mention I am using a Power FC with a Banzai adapter for engine management. Fast acting AIT and GM 3 bar.

 

Torque seems kinda low for that power..