Boost

[chadswe4]

How can you sence and record boost with Direct Scan?

Thanks
Chad

 

[ijames]

Buy the turbolink boost sensing harness and make up your own conversion table from "mat" to psi.

 

[chadswe4]

That sounds like a cool trick!
How do you do that?

Chad

 

[BoostKillsStres]

Just as Carl said, TL boost harness, 3 bar map sensor, the harness plugs into your MAT wire along with the TPS for power to the MAP. Then use a mitty pump or some regulated air pressure source and a good known gauge for accuracy and start adding pressure to the MAP sensor while building a table of MAT values reported in DS then after a run just reference your table to see what boost you were running based on the MAT DS reported.

Now this won't account for atmospheric condition changes like the TL setup will as it has a zeroing feature before you start the car. So you'd have to look at the MAT reading in DS before you started the car to see which way your table would be skewed for correct boost but we're not talking about a wole lot of change.

HTH

 

[Rayk]

Originally posted by BoostKillsStres
Just as Carl said, TL boost harness, 3 bar map sensor, the harness plugs into your MAT wire along with the TPS for power to the MAP. Then use a mitty pump or some regulated air pressure source and a good known gauge for accuracy and start adding pressure to the MAP sensor while building a table of MAT values reported in DS then after a run just reference your table to see what boost you were running based on the MAT DS reported.

Now this won't account for atmospheric condition changes like the TL setup will as it has a zeroing feature before you start the car. So you'd have to look at the MAT reading in DS before you started the car to see which way your table would be skewed for correct boost but we're not talking about a wole lot of change.

HTH

Along these same lines, if you already have Turbo Link, could you just hook the boost sensing cable to the 3 bar sensor and then leave the Turbo Link console in MAT? Then hook up an accurate boost source and gauge and see what Turbo Link reports the MAT as for a given boost reading on the gauge? Wouldn't Driect scan interpret MAT the same? Just a thought.

 

[BoostKillsStres]

I'm not sure I understand your exact thinking w/ TL and the MAT, why would you want to chart boost to MAT in TL when the TL software is already telling you the boost reading? Maybe your running mucho boost. But yes you could correlate boost to MAT in TL if you wanted you just again have to remember differing atmospheric conditions are going to give you incorrect readings using a MAT to boost lookup table because you have no zeroing feature like TL does w/ the boost reporting. And I'm pretty sure DS will report the same MAT readings as TL does since the electronics in the boost harness are controlling this. There also may or may not be some temperature issues related to conversion of the MAT signal so not having a zeroing feature could end up skewing readings also, you would just have to test and see what the MAT readings do w/ the harness at room temp vs. engine compartment operating temp to verify this possible skewing.

 

[ijames]

If you are saying to read mat in tl and then change tl to boost to get the equivalent number, to make up your conversion table to use with ds, then yes, you could do that but you will have to make very sure your "boost" pressure is stable. Any leaks and the readings will drift down while you get tl switched back and forth.

The mat reading will really be giving you the map, the manifold absolute pressure (and you can put this in bars or pounds per square inch absolute), while a boost gauge gives "psig", pounds per square inch gauge, which is always referenced to the local atmospheric pressure. That's why the map reading and boost gauge will differ on different days, when the weather has changed and the atmospheric pressure is higher or lower. However, your fueling really depends on the map, not the boost, so I think it's actually better this way . Yes, fueling really also depends on the temperature but using map at least gets one variable out of the way. The downside to this whole scheme, of course, is that you can't also move the mat to the uppipe or plenum and log the mat along with map to really get a handle on required fueling .