GM 2 Bar Map

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GM 2 Bar Map

Postby VSRaptor » Mon Jun 10, 2019 6:52 pm

I have been having issues with the unbranded GM 2 bar map sensors that is currently available for peanuts. I have a supercharged side mount ecotec VS. It twice threw fault codes 65 and 76. At first it was the fuel pressure regulator but the fault codes came back 5 days later, both the same. I opened up the bonnet and I noticed a electronic burning smell and it came from the map sensor. I swapped it over with another unbranded map sensor and the faults went away but the boost didn't feel very responsive and the car wouldn't rev past 4000 rpm.
I have read on PCM hacking forums about the LS may be the way to go.
I ordered a Raceworks LS 2 bar map with the piggy tail connector for $90. It's made in the USA so I'm hoping it's a far better quality.
WOW, what a difference it made, responsive, I get the full 10 psi boost and it easily revs to the 5500 rpm.

Anyone else had issues with the unbranded GM 2 bar maps?
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Re: GM 2 Bar Map

Postby delcowizzid » Mon Jun 10, 2019 8:04 pm

The gm style ones are no longer made genuine and the China ones are very hit or miss .the output changes big time for every 10 degrees of heat in the engine bay so your mapping is all ways changing
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem

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Re: GM 2 Bar Map

Postby VSRaptor » Mon Jun 10, 2019 9:16 pm

Raceworks has a GM 2 bar they state is made in USA and Repco is one of their retailers, $200 though. I think the LS 2 bar is the way to go as easy to get hold off and way cheaper. I see Delco has moved some of their stuff back to USA due to quality issues. I recently bought the orange neoprene lower manifold valley seals that has made in Detroit USA on the packaging dated 2017 Aug

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Re: GM 2 Bar Map

Postby delcowizzid » Mon Jun 10, 2019 9:36 pm

I found a good 3bar was aem brand replacement for there aem boost gauge .tested it with heat gun and rock solid compared to 3 Chinese ones
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem

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Re: GM 2 Bar Map

Postby OZ38 » Tue Jun 11, 2019 2:56 am

Funny about those delco style 2 bar map sensors. I recently took my VS L67 for its Kalmaker Map Tune & I had plumbed in a 2.5 bar delco style Map sensor. Little did I know it would not work with the Kalmaker as the Map sensor needed to be either a 2 bar or a 3 bar, but not a 2.5 bar. With engine off the 2.5 bar was reading 80kpa on the Kalmaker software & not the required 1 atmosphere. So the Tuner grabbed a LS 2 bar map sensor he had & we wired it in to complete the Tune. Later I bought a 2 bar delco style Map sensor off ebay for a round $90. I thought simply I would just unplug the LS map sensor & install the delco style 2 bar & it would all be fine. Well a quick spirited drive out the back blocks proved that not to be the case. It ran ok in most areas except when trying to get off the line hard. It just seem to died & choke. So the Tuner has not got his LS 2bar map sensor back as I quickly put it back on for now lol.

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Re: GM 2 Bar Map

Postby VSRaptor » Tue Jun 11, 2019 9:37 am

Who did your kalmaker tune?

I paid that price for a LS 2 bar with piggy tail plug. I have seen it going on Ebay for $30 delivered as I think word has caught on that these no brand are garbage. I remember them being $150 at one stage.

Stick to the LS 2 bar map. I had for years this issue where the car feels responsive and strong, other times it feels like the stock motor before I put the supercharger on and could not pin point it. I probably would have figured it out earlier if I had the Kalmaker software but I could not justify the cost at the time once the tune was done and thought I would never need it or use it again.

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Re: GM 2 Bar Map

Postby antus » Tue Jun 11, 2019 2:56 pm

The ebay sellers are always reading forums like this and trying to find out how to sell junk for money. If we say look for this or that, they can start saying their product is this or that. Its best to spend the $90 or so from a reputable non-ebay seller for things where low quality copies exist, otherwise it'll always be a risk. Even the reputable sellers get caught sometimes but at least they'll usually stand by their stock and their suppliers should too. Yes, no delco software can accept the 2.5 bar. As you noted, depending on the settings the code is interpreting the 0-5 volt value as 0-100, 0-200 or 0-300 depending on the sensor setting but 2.5 bar needs 0-250 range which nobody has written the software for.
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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Re: GM 2 Bar Map

Postby Holden202T » Tue Jun 11, 2019 4:25 pm

theres a few things i always buy from reputable place, wideband sensors, map sensors and bosch 044 pumps!

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Re: GM 2 Bar Map

Postby antus » Tue Jun 11, 2019 5:56 pm

Dont forget the dodgy MAF sensors out there too!
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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Re: GM 2 Bar Map

Postby VSRaptor » Wed Jun 12, 2019 12:08 am

I almost took the route of going back to the MAF setup until I read somewhere on this forum L67 Getrag had issues and delcowizzid mentioned the LS 2bar will work but the plug is different and everything else is the same. I still got my stock factory MAF so I would imagine there be unbranded cheap MAF out there too. I have the aldl and the nvram with the vs auto L67 on it and it would have been a good opportunity to have my 1st crack at learning.

What do most prefer, MAF or MAP?
I have read that most forced induction engines making over 500 HP require MAP

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