I went over to STS and Rick & Ben helped me analyze the different readings between my 1 bar and the new 2 bar they got me. Now I have total control over my spark timing (after changing about 6 tables with TunerCat)! I don't have to just go conservative in the last column of the Spark timing tables anymore, or rely on the KR sensor to pull timing when I get into full boost. I was a little nervous starting the car for the first time, but it still idles like stock and pulls like crazy when the boost builds! Thanks a ton to Rick and STS for providing tools and expertise to figure this stuff out.

Right now, I'm pulling about 8 degrees for 7 lbs of boost at 4000 RPM and higher. Think I need to pull a couple more degrees when I get into the boost at lower RPMs. Any recommendations from you tuner pros? I'm a stock motor, stock compression, etc. I'm spraying the STS methanol system at 5 lbs and higher. It increases the spray as the fuel injector duty cycle builds. A very nice setup.

Here's the equation that Excel helped me come up with after plotting some vacuum readings with both MAPs (sorry, I was too lazy to simplify).

1BarMapReading=-0.0344 *((2BarMapReading - 0.4819) / -0.0163) + 0.8886

So, when the 2 bar says I'm at 20 kPa, the 1 bar would say I'm at 42 kPa. 45 on the 2 bar is 94.84 on the 1 bar. So, the 2 bar does roughly read half of what the 1 bar reads. Both sensors kPa readings (as monitored through the car's computer with freescan) were linear and came up with easy equations when different vacuum levels were applied to them. I'm sure every sensor is going to be a little different. My 1 bar, after all, is 10 years old. But with the 2 bar, here's some of the boost equivalences I see in my spark tables.

A reading of 50 kPa on the 2 bar map is the equivalent of 1.02 lbs of boost (at my altitude and on a nice hot day!)

60 is 4.2 lbs of boost
70 is 7.34 lbs of boost
75 is 8.9 lbs.

What's really sweet is when I'm logging with freescan, I now have real boost numbers logged by my factory computer! --using this equation... boost=(2BarMapReading - .4658) / .0319. So looking in freescan, 1 atmosphere here in Utah is .4658 on my 2 bar map on the day I measured this stuff.

 

What map sensor are you using? what are the 5 or 6 tables you modified in Tuner cat? I want to do this too when I get a chance to bolt on my blower. So in dork talk basicly you scaled the tables that rely on the MAP by 50% and "built" the top half the tables according to what it needed under boost? More info please!!!!

 

This has been done before but not documented.. so Thanks for posting this... I will be doing this when my car comes out...

There is a guy that developed a real lt1 boost bin but doesn't want to release it... Since i have not heard of these people from a long time I dont know the deal with that... ANyways he supposedly removed the MAF limitation and added a few tables i think to accoutn for boost.

 

Yes, I pretty much just took the 50 table and moved it to 25, 60 to 30, and so on. Then built the remaining columns.

If you would like, I can email you my excel spreadheet with what I've done with my car. DISCLAIMER: I've only messed with my car. Every car's going to be a little different I'm sure, so study it and make sure you're happy with what you see! The tables I changed are:
Main Spark Advance vs. RPM vs. MAP
Extended Spark Advance vs. RPM vs. MAP
Spark Correction Vs. MAP vs. coolant temp
Max Spark retard vs. MAP
open loop afr vs. map
egr correction vs. vaccum
The low octane knock retard multiplier vs. map
the VE tables (not used in my MAF car--but just in case I fall back to speed density mode)

 

Oh, yeah. I'll get the part # for my MAP (nothing was printed on it--so must be some aftermarket part??). Rick at www.ststurbo.com sold me mine. He said he'll sell them for $72. He's not into selling little bits and pieces so much since he's focusing on creating turbo kits for more car applications.

BTW, I had to notch my wiring harness plug to get the unit to fit. You could've trimmed the MAP sensor as well. There's 2 additional little bumps on the sensor plug designed to keep an installer from plugging a 2 bar into a 1 bar car.

 

I'd like to look at the file (bin and excel). Can you email please?

jrbellas95z28@yahoo.com

 

I would like to see all thet you have also, mail me at mattdeckert@comcast.net If you could also I would like to take a look at the file you have on the car so If you would send that along too that would be cool!
(not that I would use it I would just like to see how exactly you scaled them)

 

send me your bin file... highlander@caribe.net

Thanks

 

can I get a copy of the Bin file as well. Evilz28@hotmail.com

 

Shoot me a copy of that when you get a chance. cechristian@tcu.edu

Thanks

 

Just order a 2 Bar Map (stock for the 87 Buick Grand National). As posted you'll have to grind a couple of the alignment tabs to plug in on the f-body harness.

 

or you can simply get the connector and use a tool to remove and install the connector w/o splicing any wires

 

not true.. i can exchange that connector in less than 10s

 

Sorry... i was exagerating.. make it 20s

 

I'd like to check out your file as well. smoknz@charter.net
I ran my car for a while with a 2 bar MAP and it still ran fine. I accidently had it in when converting back to the stock PCM from the FAST system.

Bill