AMS1000 operation for dummies

[Robert Wilson]

Very interesting. What turbo, wastegate and spring weight are you using? What pressure is your CO2 regulated to?

At that time, I was using a T64E p-trim turbo with a .63 A/R exhaust housing, 3" THDP with the stock style "flapper" valve, and a homemade dual port actuator with about 8lb. of spring pressure. This was my old stock block combo.
The C02 was supplied through a Biondo preset regulator at 80 psi. The 1st stage of the controller was set at 10psi which resulted in about 16lb of launch boost. The second stage of the controller was set at 34psi resulting in my 27 psi of boost. As you can see, in this case, boost did not go up one for one with the controller setting.

I have sinced switched a 274 stage 2 with a 76GTS turbo using a .96 A/R exhaust housing, Tial V44 gate, and a .2 bar (2.9lb.) spring. The CO2 supply is the same 80 psi.
With 4 psi on the first stage, I have 7lb. of boost. With 21 psi on the second stage, I have 23lb. of boost. I currently have the ramp rate set at 30psi/ second and it results in no spike.

I only have 9 passes on the current set up so far but I am very happy with how the controller is working.

 

[Alky V6]

At that time, I was using a T64E p-trim turbo with a .63 A/R exhaust housing, 3" THDP with the stock style "flapper" valve, and a homemade dual port actuator with about 8lb. of spring pressure. This was my old stock block combo.
The C02 was supplied through a Biondo preset regulator at 80 psi. The 1st stage of the controller was set at 10psi which resulted in about 16lb of launch boost. The second stage of the controller was set at 34psi resulting in my 27 psi of boost. As you can see, in this case, boost did not go up one for one with the controller setting.

I have sinced switched a 274 stage 2 with a 76GTS turbo using a .96 A/R exhaust housing, Tial V44 gate, and a .2 bar (2.9lb.) spring. The CO2 supply is the same 80 psi.
With 4 psi on the first stage, I have 7lb. of boost. With 21 psi on the second stage, I have 23lb. of boost. I currently have the ramp rate set at 30psi/ second and it results in no spike.

I only have 9 passes on the current set up so far but I am very happy with how the controller is working.

Now this is what is perplexing to me with the AMS system. How did you calculate what target pressure on the controller for each stage would result in your true target boost level? Or is it just how I think it is, a trial and error procedure that ends up being different with each combination?

 

[49-blues]

Thanks for all the info on this-its the best explanation of how boost controllers should be set up i ever heard.

 

[Alky V6]

From what I have gathered so far, it's best to use a regulated pressure supply that is around 10-15 psi above your highest manifold boost target level. The higher supply pressure will wear out the solenoids quicker. I was told a 60 psi system should be adequate for most users.

Is it really necessary to run such a light spring pressure? I'm sure it causes a quicker reaction of the w/g valve, but is there a level where it's overkill to go lighter than necessary? I had always thought that a spring that was 1/3 of your highest target level was OK. MSBC school of thought.

I hear that the CO2 lasts a long time as long as there are no leaks in your system. Is that true? I'm sure it's best to close the bottle valve after each run.

 

[Robert Wilson]

Now this is what is perplexing to me with the AMS system. How did you calculate what target pressure on the controller for each stage would result in your true target boost level? Or is it just how I think it is, a trial and error procedure that ends up being different with each combination?

I am sure you read at the bottom of the AMS instructions where it says: "The AMS ____ controls the pressure on the wastegate so the actual boost level obtained is a combination of the wastegate spring pressure and pressure applied by the controller".
Then when you go to a wastegate manufacture such as Tial where they say: The spring pressures are an approximation based on a intake and exhaust pressures being 1:1.

So yes, I believe it's trial and error dependant upon the combination.

I also think its a fairly quick and easy process. The last time I went to the track I put in the .2 bar spring changing from a .6 bar. I set the launch boost on the return road just bring the car up on the transbrake (not actually launching the car). Then I ran the car 1 low pressure pass to see what the second stage boost looked like and worked up from there. 2 passes later the car was running 9.70s.

 

[Alky V6]

Electronic boost control

Let's finally get caught up to precision electronic boost control. This is what everyone wants to talk about. Me too.

We have our wastegate with ports above and below the w/g diaphragm. As before where the computer was controlling the pressure to the lower line to control boost, now we have a computer controlling the pressure to both above and below the w/g diaphragm.
With an adequate pressure to these lines and the computer programmed to vary the pressures above and below the diaphragm, you can make the w/g valve do anything you want. The more supply pressure you have, the quicker reacting the w/g will be and the more control you will have on the manifold boost rise rate and boost level. The w/g spring with this system basically is just in there to seat the valve when the system is at rest, or can be used to set the most basic mechanically controlled boost level. As I mentioned previously, the more supply pressure you have, the quicker the control, if you need it that quick. The higher pressures also wear your equipment quicker, and if you have a small leak in your system, the pressurized gas will be lost quicker.

 

[Robert Wilson]

From what I have gathered so far, it's best to use a regulated pressure supply that is around 10-15 psi above your highest manifold boost target level. The higher supply pressure will wear out the solenoids quicker. I was told a 60 psi system should be adequate for most users.

Is it really necessary to run such a light spring pressure? I'm sure it causes a quicker reaction of the w/g valve, but is there a level where it's overkill to go lighter than necessary? I had always thought that a spring that was 1/3 of your highest target level was OK. MSBC school of thought.

I hear that the CO2 lasts a long time as long as there are no leaks in your system. Is that true? I'm sure it's best to close the bottle valve after each run.

I talked to AMS and they said the 80psi I am running is no problem.
The only reason I run a light spring is I am not using a 2 step rev limiter to launch the car. I am using the low boost level to help control the launch.

With the CO2, the light spring works ok when spooling from stage 1 to stage 2. This is because you have enough pressure to close the gate when stage 2 is activated to allow the turbo to spool as fast as it can or as fast as you have the ramp rate set to.
I tried this without CO2 using only manifold pressure and the spool up is much slower because pressure wasn't available to quickly close the gate.

The C02 seems to last a long time. I have a 10oz. bottle and have been to the track 6 times between last fall and now (4 times with old combo and 2 times with new) and I still have enough to go a few more times. I do try to close it between passes but sometimes forget.

 

[Alky V6]

I am sure you read at the bottom of the AMS instructions where it says: "The AMS ____ controls the pressure on the wastegate so the actual boost level obtained is a combination of the wastegate spring pressure and pressure applied by the controller".
Then when you go to a wastegate manufacture such as Tial where they say: The spring pressures are an approximation based on a intake and exhaust pressures being 1:1.

So yes, I believe it's trial and error dependant upon the combination.

I also think its a fairly quick and easy process. The last time I went to the track I put in the .2 bar spring changing from a .6 bar. I set the launch boost on the return road just bring the car up on the transbrake (not actually launching the car). Then I ran the car 1 low pressure pass to see what the second stage boost looked like and worked up from there. 2 passes later the car was running 9.70s.

Thank you. You confirmed what I had already imagined. Your input has been invaluable.

 

[J-B Racing]

Trial and Error = Yes. WG Spring Pressure vs WG Hole size plays a key role.
I am sure that some who purchased a Boost Controller thought that they would get it on first Shot....WRONG unless you blessed!!

Norbs, I run a Hobbs Switch on my car to activate my Solenoids at 15 psi and I am off by less of pound on the Controller...

Donnie...Where do you find the time for this...

Please Continue..:biggrin:

 

[Alky V6]

I talked to AMS and they said the 80psi I am running is no problem.
The only reason I run a light spring is I am not using a 2 step rev limiter to launch the car. I am using the low boost level to help control the launch.

With the CO2, the light spring works ok when spooling from stage 1 to stage 2. This is because you have enough pressure to close the gate when stage 2 is activated to allow the turbo to spool as fast as it can or as fast as you have the ramp rate set to.
I tried this without CO2 using only manifold pressure and the spool up is much slower because pressure wasn't available to quickly close the gate.

The C02 seems to last a long time. I have a 10oz. bottle and have been to the track 6 times between last fall and now (4 times with old combo and 2 times with new) and I still have enough to go a few more times. I do try to close it between passes but sometimes forget.

Yes, I understand the 80 psi will work with the system, but was also advised that if you don't need that high a pressure you'll save on the solenoids with a lower pressure.

So a heavier spring in the w/g when using only manifold pressure will help to close the valve quicker, or hold the valve down better against exhaust back pressure?

 

[Alky V6]

Trial and Error = Yes. WG Spring Pressure vs WG Hole size plays a key role.
I am sure that some who purchased a Boost Controller thought that they would get it on first Shot....WRONG unless you blessed!!

Norbs, I run a Hobbs Switch on my car to activate my Solenoids at 15 psi and I am off by less of pound on the Controller...

Donnie...Where do you find the time for this...

Please Continue..:biggrin:

I have always been puzzled that there are so many people using this controller, but in my opinion, there is a lack of information about how to use it. A controller that uses actual boost pressure in a feedback loop is obviously easy to setup. In a day and age where there is so much computer control and so much taken out of the hands of the tuner by computers, I was rather amazed that someone would have to go through a trial and error period to fine tune the ramp rate and boost level target. I'm sure there are others that are puzzled by the same thing and I just wanted to get confirmation and put out some info for others to use.

Besides, I'm waiting for parts and I'm bored.:biggrin: Lonnie, I need my parts.

 

[Louie L.]

Now this is what is perplexing to me with the AMS system. How did you calculate what target pressure on the controller for each stage would result in your true target boost level? Or is it just how I think it is, a trial and error procedure that ends up being different with each combination?

Exactly.

I ran my AMS 500 triger off the XFI. For non XFI users a TPS switch can work too.

 

[Robert Wilson]

Yes, I understand the 80 psi will work with the system, but was also advised that if you don't need that high a pressure you'll save on the solenoids with a lower pressure.

So a heavier spring in the w/g when using only manifold pressure will help to close the valve quicker, or hold the valve down better against exhaust back pressure?

I understand what you are saying on the pressure, but the Humphrey solenoids supplied with the AMS are industrial type solenoids rated for 125psi. I would think they will last quite sometime even at the 125 psi.

The stronger spring, in my case, did help the spool from the 1st stage to the second. I don't think it actually closed the valve, it was just easier to spool from 15 to 24 psi versus going from 5 to 24 psi.
The other problem with running manifold pressure was I could only go up to 24 psi no matter how much I turned the controller up to. I assume, for my combination, pressures had equalized on both sides of the wastegate at the 24 psi.
I even tried to add a solenoid activated bleed valve to the bottom side of the gate to raise the boost during the second stage but it didn't work.
The only thing that worked was switching to the C02. It cured all the issues with spool up and with maximum boost setting.

 

[Alky V6]

Maybe now we can discuss different launch and boost rise stradegies.

What sort of boosts are people using to launch on, and by the 1-2 shift point, how much boost are people finding to be the limit of traction for the shift? Please give a little info on your car such as hp level, ET/MPH performance, 60 foots, and tire size.

What is the quickest boost rise rate people are getting away with on the launch?

 

[Alky V6]

Maybe now we can discuss different launch and boost rise stradegies.

What sort of boosts are people using to launch on, and by the 1-2 shift point, how much boost are people finding to be the limit of traction for the shift? Please give a little info on your car such as hp level, ET/MPH performance, 60 foots, and tire size.

What is the quickest boost rise rate people are getting away with on the launch?

Hmmm. I expected such. We're delveing into closely held speed secrets territory. I understand completely.
Ok. I'll go it alone.

As many already realize, the launch boost level, the rate of boost climb, the limit of boost for first, second, and third, and any rate of climb during each gear and out the other end are all very specific to the car and its equipment.
The kind of variables that will dictate what rise rate and boost level you will get away with are:

1) First and foremost, the engine/turbos capacity to build boost as quick as you want, and as high as you want.

2) The capability of the chassis to put the power to the ground without getting out of shape, or lighting the tires up.

3) The capability of the chassis to take a gear shift under high power without getting out of shape, or lighting the tires up.

4) The capability of the tires to maintain traction under high power.

Every car will have different boost rise rates and levels that it can get away with. Dialing in a controller for the first time is a trial and error exercise.

I plan on sharing my experience dialing in my controller. My first hurdle being number one on the previous list.

 

[Alky V6]

Boost building tricks using the wastegate

My 224 cid engine and 91mm turbo have been a big challenge for me. I'm up to a 300(150 w/alky) shot of nitrous, and I'm upgrading my trans with Lonnie's boost builder feature. This will allow the converter stall to increase at the line to supply more exhaust mass to the turbine housing which should result in a quicker spoolup of the turbo.

This is a wastegate trick that I've heard of, but have not had the opportunity of testing yet. There are those on the track that are using the controller to hold the wastgate wide open during staging and then slamming it shut for the launch. The reasoning that I heard is, you have less exhaust back pressure working against the engine, so the engine can gain more rpm and increase exhaust flow energy. Sometime before the time to launch, the w/g is shut closed and the increased exhaust energy causes a increased rate of boost climb. Not exactly sure how that will work with my combination (nitrous and boost builder), but it sounds like an interesting trick to try out.
With a trick like this, I can see an advantage of using as light a spring in the w/g as possible. Although, as long as the spring is not too heavy so as to prevent complete opening of the valve, a heavier spring would assist the switching control pressure in shutting down the valve quicker.

 

[Alky V6]

Initial controller setup

Since I have such a problem with initial spooling of the turbo, I'll be setting up the controller to a boost limit of 30 psi throughout. From launch to finish. I'll have the CO2 plumbed by then, so there won't be any cracking of the wastegate during the boost climb. It should give me a true picture of the ability of the engine and other systems to spool the 91mm. I'll then plot out the boost climb rate from the datalog for future comparisons. Any timing, fuel changes or other boost building tricks will be judged against this boost rise rate plot. If I come across something that increases the boost rise rate, then that plot will be the new one to compare against. My little track dyno.

 

[Alky V6]

Here's my initial map trace.

This was with a wild guess boost ramp up from 8 psi to a 30 psi limit. The w/g spring setup for 22 psi and manifold pressure being used as the control pressure. The nitrous was also shut down a little too early. That's evidenced by the nitrous retard trace.
The next controller setup will be as described in the previous post and the nitrous will be left on a tad longer.
The drop in map at the top of second gear was caused by my pedal foot. It got a little scared. I have since had a little talk with my foot.

http://www.turbobuick.com/forums/al...advancement-fuel-delivery-12.html#post2233022

 

[Alky V6]

Optional pressurized control gases

Some people use pressurized nitrogen gas instead of CO2. Availability, and/or cost is usually the reason.

 

[ijames]

Some people use pressurized nitrogen gas instead of CO2. Availability, and/or cost is usually the reason.

The big advantage of CO2 is capacity - since it's a liquid in the cylinder the same size cylinder holds a lot more than if it were a pressurized gas like nitrogen (ballpark 500-1000x more at the same pressure, although a full nitrogen cylinder will have a pressure of about 4x the CO2 tank). I highly recommend having a spare CO2 cylinder at the track, as nothing is more frustrating than finding out you forgot to close the tank valve after your last run the last time out and now you have to pack up and go home without making a pass . Or having a fitting or hose come loose and run the tank down before you catch it. You can get the small bottles refilled at paintball stores or welding supply places, or you can get a 10 lb bottle and transfer line and fill them yourself.

A comment on one of your earlier posts: you started with both wg ports opened and then listed the effects of adding manifold pressure to the bottom port. An additional effect is that the wg will open much faster since the diaphraghm area is usually a good bit bigger than the wg puck area so the same change in applied pressure will result in a greater difference in force on the puck and thus more travel against the same spring constant.