Get the actuator only if you plan to run over 24lbs....this actuator is infamous for the boost hump that it creates on lower boost settings (i.e. 20-21 lbs)...

 

that boost hump is what's most likely going to help slow down his taper...

 

yeah, but if his gas cant resist detonation at that level then timing will have to be pulled and he wont be making peak power either...

with the 18lbs spring my car would boost 23lbs @ 37xx creep up on to 25lbs @ 55xx and taper to 17lbs @ 70xx (average)...can you see why this is bad on pump gas now??? This is why the actuator is advertised for meth/race gas applications only on the FP site...

with the OEM actuator it goes from 23lbs @ 37xx to 20.5lbs @ 70xx (average)...

Has the pre-load been checked on the actuator? Maybe that will help with the boost taper too?

 

[quote=Ami;4454766]Ok guys. Some update on this...So there is a lesson to be learnt, if your stroking your engine, get the HD actuator as you wont be able to run even 20psi due to the extra exhaust coming from the higher capacity engine. Ill let you guys know what happens once the actuator is installed and car is re-tuned. If you think it could be something else let me know! But right now my money is on the actuator as boost is dropping after 5k./quote]



I tend to diverge from your line of reasoning. The way I see it, the larger swept cylinder area of your stroked motor should produce higher volumes of spent gases than a 2-Liter would. Given the same turbine wheel inside the same turbine housing, this higher volume of exhaust gases will exert higher rotational force on the turbine wheel. More heat, more volume, higher flow, and more energy acting on same trim turbine wheel inside same turbine housing equals higher rotational force, equals more boost, not, as you suggest, less boost. Maybe I´m wrong, if so please enlighten me.

 

Anyone try an external wastegate with the Green yet? I wonder if that would help on the stroked car.

 

The unported EvoGreen is a smallish turbo for a stroker and to a certain extent I think that it, along with the unported stock O2 housing, unported stock cast manifold, and a restrictive catalytic convertor might be creating excessive backpressure to the point where it is acting as a bottleneck and not allowing for adequate scavenging on the exhaust stroke.

Get rid of the stock O2 housing, and substitute a SSAC tubular, welded O2 housing in its stead, at least port the factory exhaust manifold, or better yet substitute a tubular header, replace the cat with a test pipe and finally port the turbine exducer outlet of your Green´s 10.5 housing and boost should rise 4-5 PSI easily. What goes in, must come out.

 

Yeah, ideal might be a dual WG setup since I don´t think that there is a non-gated turbine housing for the 16G. Have Full Race make a flanged header for the Green and run the integral 16G WG backed up by a remote(external) 38 mm Tial WG.

Ami´s case is wierd because, you´d think that given the increased displacement and smallish turbine housing he should be experiencing severe overboost and uncontrollable spiking instead of taper.

 

When you increase the engines demand for air, you'll find that the smaller turbos that once maxed out at 30psi can no longer keep that pressure up.

Also, pressure isn't indicative of power necessarily. A car with stock heads, cams, displacement might need 30psi to make 500awhp whereas a car with upgraded heads, cams, and more displacement might make 500awhp at only 25psi simply because it's moving more air through the engine.

boost is just a measurement of pressure that's backed up in the intake.. what's important is how much is moving through the engine.

 

This is what I was trying to say or should have said, but you said it better.

 

So basically am I wasting my time and money with this turbo on a 2.2lt? Should I cut my losses now as getting close to 400whp will not be achievable with pump gas?

And just save up for a bigger turbo like a 35R?

(by the way: the fp green i got has had the ported option included)

My standard extractors (exhaust manifold) has also been ported.

 

Fp´s porting option is limited to a gasket match of the turbine´s dual inlet to the turbo/exhaust manifold gasket. It consists of a five minute, $80, gasket match. You get what you pay for. They don´t touch the turbine housing outlet which leaves the LT´s larger exducer heavily shrouded within the casting and creates about 3 PSI of backpressure.

If it was me, and I had the money, I might go for a bit larger turbo if I had that 2.2 Liter mill. It depends on the type of driving you want the car for which´ll define your working RPM range. I hate to admit it but I might go with an AMS 50Trim kit. But it´s not my money and talk is cheap.

If I had already purchased the Green, I might tinker around with it some before discarding it though. I´d order a 4" inlet compressor housing for it from TurboDynamics in Britain or from Evo400. These are relatively inexpensive and if you are running a standalone, you could extend the 4" induction piping straight through to a cone filter with a 4" outlet. This might let it breathe a bit better. With the right camshafts and a 3.5" turboback exhaust along with a less restrictive O2 housing and proper turbine housing porting, you might get it to breathe.

 

You get the right parts in there, and you will get to 400 hp on the 2.2L.
Pump & 25 psi. with good tuning/parts = ~ 400 hp, .

 

Along with ported exhaust manifold and soon to be HD actuator.

I have the parts above, after this actuator goes in im hoping it will hold boost after 5000rpm and see what power i get. My aim is a reliable 400whp on pump fuel.

 

Guys here is the dyno graph, car is loosing boost after 5k.

 

Do you have a boost plot as well?