i hear i could use a gm map sensor off of a grand national??? is this true??? if not which map sensor would u recomend...goin for about 300 hp...on a stock b20

 

do you see that red search button up top? just wondering....because i do.

 

They'd be refering to the GM 3bar MAP sensor. Its used on a couple of GM models, but you can buy it new for $50-70. THere's also the "plug & play" Hondata/Omni 4bar for over $100. The cheapest route is a Freescale 2.5bar sensor, although it doesn't coem with normal connectors/wires.

You can make 300whp with 14.5psi on most Honda motors with a decent turbo, so anything over a 2bar sensor will work fine. FYI getting too 'large' of a MAP sensor will mean it will have less resolution, as in can't meter the fuel as well as with a 'smaller' sensor.

 

Omni 4bar map sensor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by omniman &raquo;</TD></TR><TR><TD CLASS="quote"> [img]https://i103.photobucket.com/albums/m160/omnipowerusa/Omni_Map.jpg[img] </TD></TR></TABLE>

Too bad it isn't 3 bar, or I'd buy one right now.

Seems weird that you'd go 4 bar to begin with. I can't imagine more than 5% of your customer base needs more than a 3 bar. As stated, the higher pressure rating simply means less resolution on the software side during tuning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote"> FYI getting too 'large' of a MAP sensor will mean it will have less resolution, as in can't meter the fuel as well as with a 'smaller' sensor.</TD></TR></TABLE>

Yes, in theory, this holds some ground. The reality of it is that you will not be able to tell the difference in anything between a stock map sensor and the Omni 4 bar sensor.

You've gotta remember, the computer interpolates between cells in the maps. You can have a 16 x 16 map that goes to 10psi or a 16 x 16 map that goes to 50psi. If you have a decent computer, the car will run the same either way.

The Omni 4 bar sensor was made as a 4 bar rather than a 3 bar because you can easily use a bigger map sensor than you need, you can't use a smaller one than you need. By going 4 bar instead of 3 bar, this sensor applies to 98% of the honda community instead of 80%.

 

i run into a car a week that has a 3 bar map sensor that needs a 4 bar. hondata and omnipower made the right decision going with the 4 bar

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Yes, in theory, this holds some ground. The reality of it is that you will not be able to tell the difference in anything between a stock map sensor and the Omni 4 bar sensor.</TD></TR></TABLE>

I'm aware, I'm just a perfectionist in that sense. The electrical system on a car is far from ideal, and given everything that affects a pressre sensor, I wouldn't run a 4bar if I was doing 15psi max. I say that more for the 'baller 3bar' people running 10psi, but having crappy vacuum readings because some GM 3bars aren't that great at reading vacuum.

One thing I was going to add for the OP, when using a 4bar on a mild setup, you can help with resolution by making the 2nd to last column a little above your max PSI, that way you at least don't have the ecu interpolating between two distance values.

 

what about the AEM/ZEITRONIX 3.5 bar MAP/BOOST sensor?
I've chosen that one because the ability to use it also for my wideband boost signal. any opinions on this one?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rudebwoy &raquo;</TD></TR><TR><TD CLASS="quote">what about the AEM/ZEITRONIX 3.5 bar MAP/BOOST sensor?
I've chosen that one because the ability to use it also for my wideband boost signal. any opinions on this one?</TD></TR></TABLE>

Electronically speaking, best sensor on the market.

 

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


One thing I was going to add for the OP, when using a 4bar on a mild setup, you can help with resolution by making the 2nd to last column a little above your max PSI, that way you at least don't have the ecu interpolating between two distance values.

</TD></TR></TABLE>

Do you have any idea how fine the interpolation is on the honda ecu?

For what it's worth, i can map my motec up to 40x40. I map it every 50kpa. For the most part, there is a pretty linear interpolation as manifold pressure increases. It's not like you'll have 1 value at 10 and one at 20, and 15 won't need to be almost exactly in the middle of those two. Having more data points that way doesn't do you any good. The important part of the resolution doesn't change by moving the cells, you're still only going less than halfway up the 5v scale running low boost.

Really, lets assume using a big map sensor on a low boost setup did lose a bit of resolution. What's the result? A few tenths of a point of a/f ratio change?

 

Buy one, two screws, plug it in & be happy

 

If you plan on getting a GM map sensor, make sure you use the right part number.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">...</TD></TR></TABLE>

Well your arguments aside, uberdata still doesn't support 4 bar sensors, so I'm still left high and dry

I know, I know, I should get with the times.