Q@EvoPowerMods

iTrader: (23)

Any O2 Housing will creep when you have a Big Turbo and only run it at 50%....again who wants to get a Red and only run 15-18lbs...?....

sparky

iTrader: (1)

So true. The Green and even more so the Red have larger than stock turbine wheels stuffed into relatively small A/R turbine housings with restrictive turbine bypass ports and are more prone to creep especially at the lower boost levels 19-22#.

This propensity to creep becomes even more pronounced at higher wastegate preload levels. If you want it to spoolup fast then you need to keep the wastegate puck on the seat longer, but as you increase preload you increase seat pressure and reduce the ability of the small diameter WG puck and the ill flowing bypass port to bleed off the flow from the turbine inlet area.

Too bad that there isn't a larger diameter wastegate puck option available from FP for the 10.5 single flapper housing. PT&E makes a larger wastegate puck available as an option for the Garrett T04 turbine housings. This was helpful as then the bypass port's internal diameter could be enlarged when running a higher flowing, larger diameter H2 turbine wheel.

deuce329

iTrader: (2)

^^^^^That is a very good explanation. The car is only set to 20psi b/c it creeps to 26psi. It cannot be set to 24-25psi on 93 oct b/c it will creep even higher (This is only on 93oct pump gas). The car is using brand new OEM gaskets.

Q@EvoPowerMods

iTrader: (23)

Could be the Turbine side tube on the (QTP) is so small that it makes the Turbo less efficient.which leads to backpressure...just a thought as I am no fluid dynamics engineer or turbo designer. I know our (EPM O2 Dump) has yet to see any of these issues, even at lower boost levels.

sparky

iTrader: (1)

Deuce are you running the FP HD wastegate actuator? You may want to swap on a stock IX actuator just for comparison's sake. This may or may not help, but it is worth a try. Since the FP HD actuator is an 18# minimum WGA it is best at controlling boost at levels above 23-24 PSI.

There are a couple of other things that you can try to reduce creep. Have PPI port your Red's turbine housing thoroughly in the turbine inlet and bypass port turnin radius area, as well as the turbine outlet area.

By porting the turbine outlet area of the housing you reduce internal backpressure within the scroll area because the Red's larger diameter turbine exducer is excessively shrouded in an unported housing.

In another thread 9sec9 recently talked about the extra power obtainable from turbine housing porting. A lot of that power comes from opening up the turbine outlet area. This reduces back pressure within the housing which should also help reduce boost creep.

sparky

iTrader: (1)

Q, I am convinced that the larger diameter of your turbine outlet tube design should be a sigificant improvement in helping to reduce backpressure over any other design on the market, including stock or aftermarket cast or tubular.

The heavily shrouded turbine outlet on the Green's turbine housing accounts for 3-4 PSI of exhaust backpressure. I copied 9sec9's porting from photos and got my Green to drop down to 13 PSI base wastegate pressure with the FP HD actuator which is an 18 PSI actuator.

So, turbine oulet porting of the turbine housing along with your excellent dump design should be the least restrictive combination possible, at least from my point of view.

EVO8LTW

iTrader: (41)

How is that possible? If it's an 18 psi actuator, then the wastegate should be shut until there is 18 psi of pressure applied to the actuator. And if the pressure is under 18 psi, then the wastegate should close and boost pressure should rise until it hits 18 psi. The flow of the turbine housing and O2 housing shouldn't affect wastegate pressure, should it? Do I have a misunderstanding of how the actuator and wastegate work?

Craig King

iTrader: (11)

Is 25psi about as high as you want to go on a Red with 93octane?

shivaswrath

iTrader: (9)

dicey. . . I was thinking of running a red on 93 OCT, but am wondering now. . ..

Sean@Iveytune

iTrader: (14)

The red is great and the boost creep issues can be worked out easily, give it some time.

Sean

shivaswrath

iTrader: (9)

Sean - is this on the stock WA, the FP WA, or another one?

Maybe the FP WA would be best, it's a little "tighter", right?

EE

iTrader: (9)

Boost creap is due because of the fp wastegate actuator imo.
When the target boost is close to the wga pressure (say 5 psi, ie: 23 psi in our case), that could cause boost creap. That's why on 100 oct you are not facing the issue, because your boost is much higher. Turn up the boost a bit on the 93 oct and your boost creep issue should go. O'wise, put a stock wga (11 psi).


Rgds
Elie

ForcedPerformance

iTrader: (6)

Nice tuning Sean! Looks like that car is running VERY well

Boost creep is because the boost is too low. J/K. Mine runs a flat 20psi (to 8200rpm limit, stock mota) on my heavily preloaded HP actuator when I run straight boost pressure and no boost controller. I use a Works 3" O2 housing and DP. Go figure.

deuce329

iTrader: (2)

The car runs great still and the turbo spools with minimal lag. The boost creep is honestly not that big of a deal. It is still hitting 25psi just later in the rpm's. Its more gradual instead of a big spike. You can see by the dyno graph its at 300lbs tq by 3800rpms on 93. Thanks Sean Ivey for a great tune!!! Car is beast on 100oct and 30+psi!!!

k2boarder3187

iTrader: (17)

No boost creep here and im running a green