i'm trying to see what map sensors people are using, any issues run into as far as drivability, life of sensor, what program their using to tune, and what boost level's do their sensors see. i see alot of different type's (bar levels used) and brands/mfg's making them. i will need one that works good with my setup, i run an aem and plan to use 15psi street and 25psi max on track. i know one bar is 14.7psi, so why do people use 4 bars on 20psi setups, resolution quality? i don't want to spend all that money on an aem unit when there may be something cheaper and better. thanks for all feedback, yes i've searched but didn't fine any detailed compo of all sensors.

 

They all work fairly well...

Motorola 2.5 & 4 bar sensors
AEM map sensors
GM 3 bars

We have yet to have any isssues with any of the common sensors on the market.
Best bang for the buck is probably a gm 3 bar.

 

i was leaning towards a gm 3 bar cause i get them from my work (dealer) with harness, i just wanted to see if the idle or low load/rpm is better with any others as far as tuning goes. thanks for some input, any others?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosstboy &raquo;</TD></TR><TR><TD CLASS="quote"> i was leaning towards a gm 3 bar cause i get them from my work (dealer) with harness, i just wanted to see if the idle or low load/rpm is better with any others as far as tuning goes. thanks for some input, any others? </TD></TR></TABLE>

You shouldn't have any issues with a gm 3 bar with idle or partial throttle.
We have ran tons of cars on gm 3 bars without issues on aem ems, hondata, crome etc.

 

thanks , im worried cause im running ferrea roller rockers with stage 2's, so idle lol, not sure if you can call it that. those are going to be a new tuning experience for me.

 

The one crucial thing to understand about Map sensors is that the sensor is rated with 1 bar factored in as the standard Atmospheric Pressure. A stock Honda map is a 1.8 bar map. Since 1 bar is atmosperic pressure, the map reads .8bar (11.6 bar). The GM 3bar map reads 29 psi and the AEM 5 bar reads 58 psi

 

i know about atmospheric pressure being calculated in with the sensor, but was wondering why run a 4 or 5 bar on a 20 or 25psi set up? wouldn't map resolution be lost due to the wide range of those sensors pressure used within the 5v ref signal. example: -14.7 to 58.8psi for a 5 bar vs. -14.7 to 29.4 for a 3 bar would you not see more tunable load points with a closer calculated map sensor to your setup?

 

Thats a good point, but as with most things, people find that they must go with parts that are larger than necessary. For example, how many people run turbos like the GT30r, SC61 and 60-1 on bone stock engines at 8-10psi? Its a matter of having something "cool" that can make/take a lot of power.

Bigger is Better Mentality FTL

 

lol, but the girl's said...... i guess i'm just letting myself get confused over other people's bad/different choices of map setup's. thanks for input.

 

IMO, go with the 3bar. It has been tried and true on many many setups. If you need to run more than 30psi, then you'd be better of talking to your tuner and seeing what he/she recommends...

 

We have some map sensors that are good to 100 psi. If you are looking to run over 30 psi lol .

 

just give me a turbo to match, sold

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosstboy &raquo;</TD></TR><TR><TD CLASS="quote">just give me a turbo to match, sold </TD></TR></TABLE>
So far the most boost I have seen on a single set up is 88 psi and that was one of our S478's.

 

what was the hp, 4000?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbodano &raquo;</TD></TR><TR><TD CLASS="quote">
So far the most boost I have seen on a single set up is 88 psi and that was one of our S478's.
</TD></TR></TABLE>

What does a turbo that large at 88psi sound like? I was talking to Mac (theshodan) one day last summer about a Failure test at BW or Garret or somewhere....anyway, as you know, they take a turbo and spool it until it blows up. I think the one he told me about failed around 2xx,xxx rpms at like 190psi....i cant even imagine the shrill death song that turbo would have been singing...What are those S4xx series able to handle?? I know that Mac doesn't recommend more than 22psi on a 57 trim

Does BW over-engineer things a wee bit??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosstboy &raquo;</TD></TR><TR><TD CLASS="quote">what was the hp, 4000?</TD></TR></TABLE>

It was only a 78mm turbo so it made around 1200whp. Making big boost doesn't always mean making big power. A lot of the power depends on what the back pressure is.

 

lol, i was being sarcastic, but nice numbers. iv'e been thinking of getting a s366 in place of my current turbo.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schister66 &raquo;</TD></TR><TR><TD CLASS="quote">

What does a turbo that large at 88psi sound like? I was talking to Mac (theshodan) one day last summer about a Failure test at BW or Garret or somewhere....anyway, as you know, they take a turbo and spool it until it blows up. I think the one he told me about failed around 2xx,xxx rpms at like 190psi....i cant even imagine the shrill death song that turbo would have been singing...What are those S4xx series able to handle?? I know that Mac doesn't recommend more than 22psi on a 57 trim

Does BW over-engineer things a wee bit?? </TD></TR></TABLE>

As a rule our turbos are over engineered by 40%.

When a compressor is tested it is designed to go atleast 40% past the service speed then it is burst for containment/saftey.

So far we have made 1600bhp on the S486's with the 96mm turbine wheel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbodano &raquo;</TD></TR><TR><TD CLASS="quote"> So far we have made 1600bhp on the S486's with the 96mm turbine wheel. </TD></TR></TABLE>

On a Honda too i'm sure

 

I've seen GM 3BAR sensors get very non-linear above 15 PSI, they work fine, but the voltage rise rate becomes non-linear with the boost rise rate. It's annoying if I'm datalogging or using the ECU as a boost controller (which you can do with your EMS). I'm guessing that GM doesn't calibrate them that high because none of their vehicles actually run 30 PSI of boost. Any more I use an AEM sensor, they are calibrated and linear throughout their rated range.

AEM EMS
23 PSI

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rmcdaniels &raquo;</TD></TR><TR><TD CLASS="quote">I've seen GM 3BAR sensors get very non-linear above 15 PSI, they work fine, but the voltage rise rate becomes non-linear with the boost rise rate.</TD></TR></TABLE>

Thats the prob people have had with it on both sides, low and high pressures. When you change injectors and go with a 3bar GM, then rescale the fuel maps, you really have to retune everything.

Sensors and gauges in general do this, you'll find the way gauges are classified is how accurate they are in the middle 2/3's of their range. One thats w/i 1% in that range can be off 2.5% before/beyond that range. As far as I've seen, as well as the datasheets show, Freescale (motorola) sensors are designed to be linear regarding voltage vs pressure.

BTW Freescale also has a 3bar sensor - MPXH6300AC6U. Digikey has them, and this is the $14 ported sensor. They best way to use the large sensors is to set your 2nd to last map column to the psi just over what you think will be the most your engine will see. Then dump a ton of fuel and reduced timing in those last two, so they will act like simple overboost protection.

 

very good info guys, and merry x mas. this was the info i was needing about how the different sensors react on the maps to seeing boost pressure. sounds like the aem and motarola have better voltage graph's. have any of you compared the difference between the two? cause there is a big price difference between them.