Thread: Aem boost by gear?

Hello I have a question I have a 91 ser and I would like to do boost by gear my question is how do you get it too work if you are using a cable tranny .

AEM gets the Speed from the dash in the car. there is a wire going from the cluster to the ems or at least should be. you will have to calibrate the VS on the AEM since the base maps were done with electric speed sensor. you should look up on the AEM forum since there are a few threads on how to setup the gear calc etc.

Yeah, when I first tried to get a speed reading in mine it would just bounce back and forth from 0-255mph spiking any time the car moves. It basicly recieves the same type of signal but in a different fasion. You just need to go through and set up the VSS to get a stable signal by turning the two filters on because the reading from the cluster is so fine and sensitive and then making any other changes necessary to get a proper speed reading and thats just adjusting the cal for it.

I left mine alone because I didnt know this at the time but yeah because its not coming from an electronic speedo you need to turn the two filters on, one which is a course filter and the other which is a fine filter to get a stable speed reading from it.

i set it up on my car, im using a b15 speedo and its pretty dead on accurate no issues. its very very easy to set up the b15 speedo is only 2 wires and you you can wire it to a electronic speedo cluster and then straight to your aem, im sure you can go staight to aem and say screw the cluster if you wanted to

first determine how your solenoid is plumbed, i like to set mine up so that 0 is gate and 100psi is max boost

then, set your boost wg duty cycle map to 50% in all load zones

make sure boost wg out is ticked off as well as boost from load if your using a maf sensor

then go into the advance boost settings> boost target methods> boost by vss

set boost target speed table to a little over your wastegate spring, i am using a 7psi spring so i set my first target to 8.19 based on the "boost target comp table"

now the way this map works is that it will refer to the boost wg duty map, so because that map is set to 50% then 0 on the boost target comp table is 50% duty cycle on the boost wg duty map. therefore -50 would be wastegate and +50 would be max boost.

i pulled out about set mine to about -40 on the boost target comp map to get 8 psi your number obviously would be different. now work your way up to your max boost tuning each point after

8.15, 10.85, 13.51, 16.71 ect, all the way to your max boost ect (you can also skip every other parameter and use calculate to get the one inbetween, this is obviously faster)

each time you have to adjust the boost target speed table to w.e your tuning for.

when your done the aem will know what duty cycle refers to what psi. then you can set the boost target speed table to ramp up the boost via vss

once thats set you can do the boost error duty cycle, which basically helps the aem add or take away duty cycle to achieve the correct amount of boost similar to tuning your iac.

i hope i helped but this is the simpliest way to set it up. the manual has a good description as well as

this write up http://farnorthracing.com/DG_Guide_to_AEM_boost_control.pdf