Holley Dominator boost controller question
Thread Starter
Joined: Nov 2004
Posts: 998
Likes: 19
From: Rotterdam, New York
Awesome car BTW. I watched a few of your videos. We are trying to get my buddy's 71 Camaro with a single 84mm down the track. He has Cal-Tracs like you and a small tire. Still trying to figure out the setup. Best so far is a 1.40 9.37@147 so far on 17 pounds on his old 80mm.
Ah ok. Can you see any benefit to running a 5 bar at under 30 pounds of boost?
Awesome car BTW. I watched a few of your videos. We are trying to get my buddy's 71 Camaro with a single 84mm down the track. He has Cal-Tracs like you and a small tire. Still trying to figure out the setup. Best so far is a 1.40 9.37@147 so far on 17 pounds on his old 80mm.
Awesome car BTW. I watched a few of your videos. We are trying to get my buddy's 71 Camaro with a single 84mm down the track. He has Cal-Tracs like you and a small tire. Still trying to figure out the setup. Best so far is a 1.40 9.37@147 so far on 17 pounds on his old 80mm.
As I said earlier I started off just using a 3 bar and never applied more than 17-18 psi to the gate. When i switched to twins I added a 2nd gate and changed to the 5bar, but I just looked at my last data log and I was applying 17.5 psi on the gates to get 21 in the motor.
Thread Starter
Joined: Nov 2004
Posts: 998
Likes: 19
From: Rotterdam, New York
I understand now. I am new to the fuel injection/turbo thing. I thought it had to be over the amount of boost you were running. I didn't realize it was a factor in how many pounds of pressure you needed to apply.
you can use a feed directly from the turbo/supercharger, but its very inefficient and slow to react....its ALWAYS better with CO2 (typically most people find best results in the 40-60 psi range from the regulator to the solenoids)
if you already have a spring in there of 10lbs... then you dont need as much as if you just had a 1lb spring
so to get to 21psi he really needed a total of 27.5 psi on the top of the dome of the wastegate
total Dome pressure is always going to be higher than your desired boost level
I have used both the AMS and the Holley...both work well
but if you already have the holley, there is no need for the AMS
also, you want the lowest presure sensor you can handle in your setup for maximum Fuel/Spark table resolution
if you are only going to make 12psi, there no need to go bigger than a 2 bar
if you are only going to make 20 psi, there is no need to go bigger than a 3 bar
get the drift?
in the tune, you can always scale the tables to fit your needs...you can make it any values you want, they dont have to follow the minimum and maximum values of the sensor you are using
but you cant change the sensor to make it more accurate, so the closer it is to your desired boost levels, the more accurate it will read.
its only 0v-5v.... thats a pretty small range, so keep your sensor as small of a range as possible as well
I have the hp system and a ams. I feel they are very close, but I feel like the holley is a little better just because it's built in.
I'd suggest the 5 bar in the dome, and mount it directly in the dome it's self for the fastest readings.
I'd suggest the 5 bar in the dome, and mount it directly in the dome it's self for the fastest readings.
spring pressure will take care of the first bit..
so lets say you put a 7lb spring in and you want to make 20 psi.....
from personal experience and tuning a bunch of these...
you need anywhere from 20-25 psi on top of the dome to get to 20 psi with a 7 lb spring
so you would only need a 2 bar pressure sensor for the dome in this case...
a 5 bar dome pressure sensor would only be necessary if you were making 72.5 psi of dome pressure...which would mean you were likely close to 60-70 psi boost pressure.....
dome pressure is not a linear control...but its usually slightly more than 1 psi dome pressure per extra PSI...
depending on the wastegate size and spring inside, some need close to 1:1, others need 3:2, or 5:3 to get to desired boost...
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Verdad Gallardo Electronic boost control like the holly has or the ams always responds faster with the sensor directly in the wastegate. Any other sensor you need to keep away due to heat and the sensors being plastic.