AMS1000 operation for dummies

[charlief1]

I love your threads Donnie and I wish I was closer to you to tech stuff out some. Once again, subscribed.

 

[Alky V6]

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.

Good points Carl. Thanks.

 

[Alky V6]

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.

I brought this up because someone told me about this procedure being done by some other turbo racers.
Frankly, I don't see how this could actually work.
Anybody else have any thoughts on this?

 

[Chevota]

Sold my AMS, but in my experience CO2 lasts twice as long as Nitrogen/Air. Also turn off the unit when not in use/pits to keeps the solenoids from constantly regulating. It'll last a couple of events dependant on tank size. Don't forget, it's easy to refill a CO2 tank at the track too! N20 and CO2 operate at the same pressure/temp:wink:

 

[Chevota]

I brought this up because someone told me about this procedure being done by some other turbo racers.
Frankly, I don't see how this could actually work.
Anybody else have any thoughts on this?

Reverse your current wastegate strategy/thinking and relocate it on the intake side. Popular boost control method on supercharged apps but also used on turbocharged vehicles(eliminates intake B/P and allows turbo to freewheel to desired boost pressure) Risky method if you don't keep an eye on turbine speed.

 

[Alky V6]

Reverse your current wastegate strategy/thinking and relocate it on the intake side. Popular boost control method on supercharged apps but also used on turbocharged vehicles(eliminates intake B/P and allows turbo to freewheel to desired boost pressure) Risky method if you don't keep an eye on turbine speed.

I just logged back on to post because I just realized that the stradegy was for the BOV, not the w/g. Scott, you beat me to it and explained it perfectly. Thanks.

So a good use for one of them new fangled turbine speed sensors? Or just do some simple experiments to determine how much on-time with the system nets 'X' amount of boost when the BOV is clamped back down. Then work that time factor into your delay box.

Very interesting.

I have to ask, Scott. What was the reason for selling the AMS?

 

[Sam Colalillo]

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?

The AMS 1000 rocks!!! I spent about 30 minutes on the phone with Cal after I got it wired up. It took about three trips down the track and a couple more calls to Cal and I had it nailed down. Not sure why but my MSBC 1 would over shoot target boost by about 2 PSI then fall back down where it needed to be. THis was on launch when I needed it to be most accurate.


Donnie, I'll give you some info but not too much.

The 109 is making well over 700 horse to the wheel. 60 foot is in the low 1.3's, we are just a shade under 120 mph by the 1/8th.

I have found that running three stages makes the car run smoother and faster down the track.

1st stage Rate time in seconds 0-1.15 seconds We launch with very little CO^2 pressure then ramp the boost up to 75% of what we will run on the pass. (at 1.15 seond is when the front wheels start to come back down)

2nd stage Rate time in seconds from 1.15 to 1.40, boost goes from 75% up to 88% of what I will run on this pass. This boost is ramped in to help keep the front wheels from smashing back to the earth. It eliminated that little bounce I couldn't tune out with the shocks. (this helped ET)

3rd stage (At this point in time the car is settled in.) 1.40 to 1.60 seconds on out the back door to 100% boost level

As you know I program all this by setting up the stage time in seconds, rate psi per second, and the target CO^2 pressure. This controller has never over shot the taget boost.

No more questions on that, I have already told to much. It gets even more interesting if you have traction control in the XFI.

I use a 10 oz CO^2 bottle and so far I have never ran out of CO^2 at the track. I always get it refilled after about 7 runs even though I don't need to. I run a 10lb waste gate spring. I use the XFI TPS auxilery output to turn on the AMS (thanks Cal for that little tip). Some people just have an on off switch in the car. On the street I leave the bottle off and just run around on the 10 lb spring.

Good luck to you with the AMS 1000, it is one of the best things I have bought for our car.

 

[Chevota]

Don't get me wrong. The AMS controllers are great units. I still use both to tune 2 different cars, the 1000 on a 7sec drag radial camaro and the 500 on a 8sec 10.5 mustang. I sold mine 'cause I found something else that better suits my car/preference. :wink:

 

[Alky V6]

This brings up another question. When the AMS system is at rest or turned off, the lines from the wastegate to the solenoids are not open to atmosphere, correct?

The solenoids when off, block flow from the 'in' port to the 'out' and 'exh' ports?

The solenoids when at partial to full pw allow flow from the 'in' port to the 'out' and 'exh' port?

I realize that the 'exh' port is blocked on the 'increase' solenoid, so if the above is correct, there is trapped air in the lines when the system is off. Air is compressible so the wastegate would essentially be acting as a poppet valve with the base spring pressure determining the max boost level and rate.

I know I could test this, but if someone already knows, that would be nice.

 

[Alky V6]

Don't get me wrong. The AMS controllers are great units. I still use both to tune 2 different cars, the 1000 on a 7sec drag radial camaro and the 500 on a 8sec 10.5 mustang. I sold mine 'cause I found something else that better suits my car/preference. :wink:

Well, when you unvail your car, you're going to have a lot of people peaking around then.

 

[Alky V6]

Very nice of you to share Sam. It confirms a lot.

The overall boost ramp up is totally dependant on the available traction at each stage of the pass and the desired attitude of the car during the very critical launch and first 60 feet or so. If someone had good traction and wanted to extend out a wheelie, they would adjust the boost ramp rate and level to accomplish it. That would not necessarily mean the quickest ET though. I like how you use the controller to adjust the landing. Nice. That's how you get those Pro Stock looking launches.

So the first critical decision is how much boost to have at the launch. I would think the answer would be the highest that traction and your chassis setup will allow without getting the car too high in the front. From what I understand, quicker ETs result by keeping the launch as flat as possible, putting more energy into forward movement of the car.

I really don't see why people are so secretive about their particular boost controller setup. Each car is different, so each boost controller setup will be unique. Maybe close, but I'm sure there would still need to be subtle differences. I don't think there is anyone running the same equipment as another. It's why I have no problem posting my fuel table. I understand it's especially unique to everyone elses. Besides, if someone wanted to build an alcohol engine, I wouldn't hesitate to help them out anyway I could. But that's me, and I do completely understand why some are so bent on keeping things hush hush. Especially class racers.

It's like, what jets do you run in your carb? No fool would just throw in the same jets that someone else was using. Too, too many variables are involved.

 

[Alky V6]

Pretending that the engine has unlimited boost potential, the rate of boost ramp up and level is going to be totally dependent on what the chassis and tires can handle. Mmmm, maybe what the driver can handle would be involved too.:redface:

Torque being multiplied by the transmission in the different ranges (gears) would also play a part in how much boost you could get away with in each range.

And, let's not forget about the torque multiplication factor at the launch provided by the torque converter. That torque assistance waning away very quickly as the car starts to move. That also happens to be another important launch tuning tool in itself, the amount of torque multiplication that is built into a particular T/C component combination.

Boost control during the shift points...
There are a few ways to accomplish traction control through a shift in a situation where traction is marginal.

 

[Alky V6]

Couldn't the 'aux' channel on the ams1000 be used to control the BOV?

 

[turbobuick]

Well Donnie here is my WG strategy in a nutshell. I too sold my AMS1000 and stuck with the MSBC I've had on the car. I run it in manifold mode with CO2. WG mode is probably more accurate but the seleniods will run continuously in wg mode due to the pressure from the CO2 and would need an activation switch in this setup and I just don't want to add one more thing to remember to do when racing the car.

I too have a 2.5# boost spike. The problem with the boost spike, as I see it, is that it causes the AFR to be all screwed up as the WBO2 swings to correct for the transient fueling. I have tried ramping the boost and it'll shorten the spike but will ultimately slow the car down in the 1/8 and hurt ET.

What I did was take the ramp out of the boost controller and use the Accel NOS controls to remove 3 degree of timing for .5 seconds or the time that the boost spike occurs and while the boost is rising. With the Gen 7 we can also shut the WBO2 off during this time so we don't have wild swings in AFR from correction during this transient phase. IMO we can take timing out and put it back in WAY faster than we can change the rpm of the turbine. I would rather get the turbine speed up as fast as possible and remove timing where and when needed. With the GEN 7 we can also control EXACTLY how long we do this for and we can even adjust the timing and AFR maps to whatever we want during this period. I am still testing this theory but it seems to work well so far and the car went 1.27 60' on drag radials the other night.

 

[charlief1]

You guys are putting some good info on the table here. I for 1 apreciate it since I'm just starting to get to the point of needing some of it. Thanks.

 

[Alky V6]

Boost spikes

Thanks Chris. Boost control can obviously become extremely varied from one chassis/engine/converter/ECM/boost control system(s) combination to the next.

Boost spikes on initial spool up is not necessarily a bad thing. For instance, if you have an engine that can ultimately handle 40+ psi of boost by the top end of the track, and the chassis/tires will only allow a 25-30 psi boost level at around the 60 foot mark, and the boost controller is set to a 25-30 psi level until sometime after the 60' mark, then a 2 to 3 psi spike can be safely tolerated, unless the spike causes a loss of traction.

For those that are running the engine at tuning limits during the initial spool up of the turbo, then boost spikes over your target level do become a concern that needs to be dealt with.

Chris. I would think that it wouldn't be that difficult to deal with that spike with the practically infinite adjustability of the ramps with the AMS. Am I wrong, Cal? Are there some boost spike situations where even the AMS isn't enough and engine tuning cutback has to be employed along with the controller?

 

[Sam Colalillo]

Boost spikes on initial spool up is not necessarily a bad thing. For instance, if you have an engine that can ultimately handle 40+ psi of boost by the top end of the track, and the chassis/tires will only allow a 25-30 psi boost level at around the 60 foot mark, and the boost controller is set to a 25-30 psi level until sometime after the 60' mark, then a 2 to 3 psi spike can be safely tolerated, unless the spike causes a loss of traction.

QUOTE]

For me it did not cause a loss of traction it caused the car to Head up toward the sky instead of down the track.

When it would do a big wheelie I knew when I looked at the log the target boost was going to be over shot!! The travel limiters helped but with the instant center of gravity where it was to get maximum traction There was nothing I could when the car decided to throw more horsepower at the rear wheels than I anticipated. It just got frustating trying to out guess the boost controller. The problem was the MSBC 1 was not consistant


The big wheelies actually slow the car down. Like you said. The main goal is to keep accelerating forward down the track as fast as possible. This issue is now gone with the AMS 1000!

 

[turbobuick]

Donnie,
In my situation I want to use a boost controller for just that controlling boost. If I want 25 psi and I program it to run 25 psi that is what I want it to do. The boost spike on the initial ramp up is something you will see no matter what controller you use and IMO tuning it out by slowing down the turbine will affect ET greater than killing timing to compensate for it. There are several ways to skin a cat this is just the way I see it and what I think'll work. I would rather overshoot and come back down than slow it down to reach peak boost levels. Again, I am still messing with the idea and only started when going to the drag radials. With slicks the boost spike was never an issue and I never ramped it in either. The only problem I saw with the spike was the crazy things it did to fueling trying to keep the WBO2 correction on which would cause swings in AFR well into 2nd gear.

I don't think the amount of boost you run or the power you make should make a difference in the discussion. A 2 psi spike in first gear shouldn't hurt anything in the motor as it isn't under a significant load at that point so I don't see how that should make a difference.

Sam,
You are still killing power whether you lower launch boost, open the WG, kill timing etc you are still killing power to keep the nose down and your not accelerating the car and probably leaving some ET on the table. Also, that boost spike is likely occurring half to a full second into the 60' so your car is probably well into the air at that point.

If my car saw 8 inches of air under the tires Friday that would've been a lot. I'm waiting to see the pic on Milan's website when they get them up. I saw the flash so I'm pretty sure they took one.

I agree if you are going to use the boost controller as a traction/wheelie device the AMS is a MUCH better at it than the MSBC. Like I said I just want it to control a steady boost level I program it for and the MSBC does that just fine.

Good discussion BTW.

 

[HighPSI]

Chris. I would think that it wouldn't be that difficult to deal with that spike with the practically infinite adjustability of the ramps with the AMS. Am I wrong, Cal? Are there some boost spike situations where even the AMS isn't enough and engine tuning cutback has to be employed along with the controller?

You are correct, Donnie. When set up correctly, the AMS wil not have any boost spikes.

 

[Alky V6]

Boost spikes on initial spool up is not necessarily a bad thing. For instance, if you have an engine that can ultimately handle 40+ psi of boost by the top end of the track, and the chassis/tires will only allow a 25-30 psi boost level at around the 60 foot mark, and the boost controller is set to a 25-30 psi level until sometime after the 60' mark, then a 2 to 3 psi spike can be safely tolerated, unless the spike causes a loss of traction.

QUOTE]

For me it did not cause a loss of traction it caused the car to Head up toward the sky instead of down the track.

When it would do a big wheelie I knew when I looked at the log the target boost was going to be over shot!! The travel limiters helped but with the instant center of gravity where it was to get maximum traction There was nothing I could when the car decided to throw more horsepower at the rear wheels than I anticipated. It just got frustating trying to out guess the boost controller. The problem was the MSBC 1 was not consistant


The big wheelies actually slow the car down. Like you said. The main goal is to keep accelerating forward down the track as fast as possible. This issue is now gone with the AMS 1000!

Could you give us some idea of what the value of the boost spike was that was causing the out of control wheelie? Thanks.