Changing The Wastegate Actuator

[RAP1D]

Whats that got to do with the cat?

Fix that issue then move on to the mod your planning.

I myself have not changed the accuator/wastegate, at my motors present level there is no need to... but there was a need to change the cat.

[AzMahoony]

Cat first ?????

The reason I ask is..............

Went to see Simon at XFT to get a custom tune. Had loaded generic tunes from the flash box with well, no results.......felt sh*t in otherwords. So here I am watching the dyno run at Simon hits the gas.....158kw......now here I am ( with my little known mechanical experience ) saying to myself, that's not right.....then Simon says those words you hate to hear... "You've got no boost"

Turns out the split pin (on the wastegate I think) has broken and fallen off causing the boost to flow out ( where I can't quite remember ) but as it's a warranty issue, Ford are going to fix it for me... =)

So if, and when Ford remove the Turbo, is there anything I need to do before they put it back in ????

Hey I saw you at Simons when your car was on the dyno

[Johnny G]

Agreed, rap1d. Forget the actuator; go for a cat and dump, injectors, in tank Walbro pump and limit your self to 14 - 12 psi with safe AFRs (from a good custom tuner) and your wish for 300 will be m o r e than upon you. SAFELY.

[bcl]

I think there are a few misconceptions in this thread.

A lot of people are changing the actuator spring when there is no need to do so. Some tuners will gladly take your money though. I run 600rwkw and am using a 10lb spring, and use maximum boost of around 24lb!

A stronger spring will help reduce boost creep, that is all. A good tuner can test the spring tension if required, or if too weak.

As stated in this thread, the spring tension controls the minimum boost that can be run.

I use a 10lb spring, so if I disconnect electronic boost control, and just rely on the spring alone then my car will run 10lb boost.

Don’t run a spring with a tension too close to the boost that you actually want to run, otherwise you can get a very jerky experience. Under such circumstance the valve will not be able to open fast enough, and you may get overboost with too strong a spring!

A stronger spring is not required to get more power.

As a guideline, once you reach 320rwkw it is best to get a bigger swing valve.

The basic reason for this is that the Garrett 3540 turbo that we use has a relatively larger compressor than exhaust; that is, it is designed for a large capacity engine running low boost. As you increase boost levels the excess exhaust gas that flows though the wastegate is too large for it’s capability … you then get a situation where you cannot control boost and it will overboost.

Again as a guide, if you want to go over 380rwkw it is advisable to get the exhaust housing ported, as the flow capability of the exhaust housing itself becomes a restriction.

Brian

[kilmo]

Hey I saw you at Simons when your car was on the dyno

Did I look like sh*t ???? Caus I only had 4 hours sleep....hahahaha.....I like your car mate......but did you know that your lights, the Altezza ones you have are starting to bubble a little bit from the heat of the globes ???? I happened to see it when I was admiring....lol

Anyway back on topic.....So my Turbo is getting fixed by Ford tomorrow......should there be anything I should do before it's slotted back in ??? Or should I just leave it and focus on other mods ????

Cheers,

Nick

Edited 19/08/07 10:53 AM by kilmo

[RAP1D]

Leave it... do the cat

[AzMahoony]

Did I look like sh*t ???? Caus I only had 4 hours sleep....hahahaha.....I like your car mate......but did you know that your lights, the Altezza ones you have are starting to bubble a little bit from the heat of the globes ???? I happened to see it when I was admiring....lol

I dont know what happened, the globe musnt have been sitting in correctly becuase it blew and I was left with a little bubble on the plastic, ahh well.

Doesnt do it anymore

[Headsex]

A lot of people are changing the actuator spring when there is no need to do so. Some tuners will gladly take your money though. I run 600rwkw and am using a 10lb spring, and use maximum boost of around 24lb!

Was it 24lb @ 3500rpm, or 24lb at 6000rpm, Needless to say this is comment is irrelavent to the standard xr6 turbo that ford fitted, as yours is a upsided turbo, and custom exhaust fitted with a external gate. The main difference being your boost to exhaust backpresure ratio is lower than the standard one. This comment isnt really comparing apples with apples.

A stronger spring will help reduce boost creep, that is all. A good tuner can test the spring tension if required, or if too weak.

As stated in this thread, the spring tension controls the minimum boost that can be run.

A stronger spring will not reduce boost creep alone. The main points in changing the actuator is It increases minimum commandable boost, giving you more commandable boost higher in the RPM and BETTER boost control.

Eliminating boost creep totally is done best electronically, Ie, requesting duty cycle of 1 (closed, so wastegate doesnt open as boost is building), forcing all exhaust gas to go into the turbine. (I have seen "bleed valves" which are spring rated eliminating creep, just not as well as it can be done electronically)

I use and recommend 12psi actuators. They give better accuracy when controlled electronically.. especially when Tuning using the PI Controler rather than straight Duty Cycle control. ie going from duty .5 to .55 is a small boost change with a 12psi , than what it is with a std, or 9psi actuator.

I use a 10lb spring, so if I disconnect electronic boost control, and just rely on the spring alone then my car will run 10lb boost.

Correct, If you disconnect electronic boost control, and still have a vac/boost refrence, the car will run 10lb boost.

But if you remove the bac/boost refrence to the actuator, you will find you will have more than 10lb boost. I believe ForcedXR6 saw his boost guage needle bouncing past 20psi when his line came off his actuator.

Don’t run a spring with a tension too close to the boost that you actually want to run, otherwise you can get a very jerky experience. Under such circumstance the valve will not be able to open fast enough, and you may get overboost with too strong a spring!

Jerky experiance?

When I had my Boost refrence line bypassing the boost solenoid, and connected directly to the actuator, I had a very smooth drive, although there was alot of boost creep as boost was building.

Ive also fitted a 11.8psi(12psi) actuator and tuned the car to 12psi no problem. Whilst eliminating boost creep whilst the PI controller was hanging onto duty cycle 1 as long as it could.

Being computer controlled it has wonderful thing build into the PI Controller called "Fuzzy logic". Another secnario where this is used is in a elevator, As its approaching a desired floor, it slows the travel speed down to give a comforting stop, rather than coming to that desired floor and locking the brakes on. Similar thing happens when boost is approching Desired Boost.

A stronger spring is not required to get more power.

The problem with the std actuator is it is rated at like 3-4psi. Early in the RPM, you can make it spike to the likes of 15psi at 4000rpm no problem. but they trail down to anywhere between 8psi, and 12psi @ 5500rpm even when commanding duty cycle of 1.

The only ones that hold are the ones with good intakes, and good exhausts (usually no cat)

As a guideline, once you reach 320rwkw it is best to get a bigger swing valve.

I somewhat disagree that the wastegate port is "power related" on when you should upgrade them. A few examples.

a car that came to me.. Had a aftermarket intercooler, a punched cat, and a Tune. With a duty cycle of 0, it was not possible to command any less than 12psi boost. Sure, with Injectors, its possible to push a car like that upto 15psi no problem to hide the fact it was overboosting. Was the Problem fixed? No, its still there. Was the boost nicely controlled? No. It varied during the day to a lower boost amount, and at night to a higher boost level.

Obviously this car needs its wastegate ported, and actuator recommended

Another car that came to me. Had Process west intercooler, Injectors, 12psi actuator, valve springs, tune, punched cat. was showing 17psi boost on the datalogger. The funny thing about this car inparticular was, during the day (ie, when a tuner shop would normally tune it), it was boosting to a nice 15.5psi nice and controlled, but later said it was pinging at night. When we datalogged it at night, when the air was colder and more dense, commanding a duty cycle of 0.1 still did not allow the boost to be brought down past 17psi... A overboost situation obviously.

This car also needs its wastegate ported (although its believed it has it done, although I suspect if it has, not enough)

When I fitted my nizpro gear plenum, cooler etc, My car at night would not go any lower than 17psi. I put a car back into my car, and it was somewhat controlled again. Since then I have redone my wastegate port (yes first time was not big enough) and now I can command anywhere from 12psi to 17psi+ without a CAT without overboosting

So as a Guide.. If you plan on Freeing up all the restrictions from yoru Intake and exhaust, THEN you need a bigger wastegate port and Swing valve.

The basic reason for this is that the Garrett 3540 turbo that we use has a relatively larger compressor than exhaust;

This is more the reason why you need a stronger sprung actuator, as the boost to exhaust backpresure ratio is higher than it normally would be, and in turn, the higher exhaust gases presure want to take the easiest option, and push on the wastegate port, hense why the STD actuator cant hold boost when you go onward of 4500rpm, and loosing boost.

When you free up the intake restrictions (A proper cooler, and a proper set of intake pipes), The turbo doesnt have to work as hard, and in turn, you go from having low boost top end due to actuator, to overboosting as you need to bypass more exhaust gases from the turbine.

it is designed for a large capacity engine running low boost. As you increase boost levels the excess exhaust gas that flows though the wastegate is too large for it’s capability … you then get a situation where you cannot control boost and it will overboost.

100% correct.

Again as a guide, if you want to go over 380rwkw it is advisable to get the exhaust housing ported, as the flow capability of the exhaust housing itself becomes a restriction.

Brian

You said 320rwkw before

One of the disadvantages Tuner shops have, is they can tune a car with perfect boost during the day. And later on a old winter night, the boost could drift(if not tuned in closed loop) or overboost without their knowledge, and in turn possibly pinging, and worst, resulting in engine failure.

At the end of the day, You need your wastegate ported and bigger swing valve fitted when you free up the intake and the exhaust. And you notice it overboosting situation(more so at night).

I would rather have the piece of mind knowing that if I tune a car, its not going to overboost at night and cause possible engine failure

Danny.

[Dannopower]

I might be a little uneducated in this area, but to get your 300 plus wouldnt it be better for the engine and the turbocharger to open up the air intake and exhaust system instead of cranking up the boost?

Unless your looking at 350 plus, your turbo wouldf thank you for running a more efficient system. There are a few guys on here that are getting 300rwkw with less than 12 psi of boost, just with a more efficient system.

[Headsex]

Yes, cracking up the boost ona restrictive intake or exhaust limits the amount of spark advance you can deliver. As a result, power.

You can make more power with less boost with bf based engines due to the change of the cams away from the ba's taxi profile