3bar map sensor

[futuretgper]

it struck me that this sensor was found on a "tuner" site and the description also interested me

3 Bar map sensor for misc tuning use. Compatible with all engine management and tuning devices requiring the use of a "3 bar MAP sensor"

....although i doubt this is a useful part for us in stock form...i was wondering if anyone has come up with a way to program the computer to run a 3 bar sensor....how hard is it to achieve this? in the datamaster program there is an option that is available to change to a 3bar map sensor (if you had one equiped)so it just got me thinking about it... i know this is an old topic just wanted to bring it up cause it hasn't been openly discussed in awhile and i wanted to make sure this "gm 3bar map sensor" wasn't something we could use.

 

 

just for kicks i added a poll to this topic!!

[Guest TurboSedan]

from what i've seen from Mick's posts it would be extremely difficult to develop a 3-bar calibration. if i wanted over 15psi i'd use an adjustable zeiner diode and a 7th injector (or maybe bigger injectors & an AFPR + RRR), along with either EGT or WB02...and a bigger turbo of course, hell might as well throw in some lower compression pistons and 3x00 topend while you're at it

[god910]

Very difficult and involved changing the $8F to 3bar. Datamaster has the option so that it knows how to interpret the voltage coming from the map sensor. If anybody doubts the ability to make power w/ less than 14.7 psi. Just ask Curtis.

[Canada]

3 bar sensor........why? Oh.....I have over 30 psi (because thats all the more a 2 bar sensor is good for). In other words, if you where to have over 30 psi, you would (I'd hope anyways) be making over 400 hp.

 

So why buy it when a 2 bar sensor does the exact same thing.....plus you don't have to deal with the apparent issues other people had mentioned.

[Guest TurboSedan]

3 bar sensor........why? Oh.....I have over 30 psi (because thats all the more a 2 bar sensor is good for).

 

2-bar MAP is good for 14.7psi

[Prospeeder]

well, even if u did get more boost, would our engines be able to even handle it, its an old 3.1 MFI V6, if stock it had only 7 psi, u think they knew this thing couldnt handle much, they forged some stuff and a more powerful transsmission to take the beating, so pushing like 20+ Psi, shouldnt that like destroy the motor

[Guest TurboSedan]

well, even if u did get more boost, would our engines be able to even handle it, its an old 3.1 MFI V6, if stock it had only 7 psi, u think they knew this thing couldnt handle much, they forged some stuff and a more powerful transsmission to take the beating, so pushing like 20+ Psi, shouldnt that like destroy the motor

 

yeah, you'd obviously need supporting mods to run over 15psi. but like Jay mentioned, i think plenty of power can be made with less than 15psi, keeping the stock 2-bar MAP.

[Prospeeder]

yea. probably, look at what just 7 psi does for the motor, double that, 140hp-205hp, 185tq-225 tq, so what, with almost 15 u could be with 270hp and 275 tq, or more, some people iv read are pushing over 300+hp with just running 11psi, k&n, and some other mods, so im not sure, this is all at the crank though

[Canada]

3 bar sensor........why? Oh.....I have over 30 psi (because thats all the more a 2 bar sensor is good for).

 

2-bar MAP is good for 14.7psi

 

Yeah.....I'm an idiot.......I forgot the whole atmospheric pressure thing.

 

Still though......is there more than 5 people on this board with more than 15 psi?

 

If you want to get technical.........1 bar is 14.5 psi, not one atmosphere.

[futuretgper]

if i wanted over 15psi i'd use an adjustable zeiner diode and a 7th injector (or maybe bigger injectors & an AFPR + RRR)

 

can you explain how the zeiner diode and 7th injector would work/set up....also with the abreviations i asume afpr is: Adjustable Fuel Pressure Regulator, but im not sure what RRR stands for.

 

has anyone done the math on a turbo big enough to support 400hp+ build up....

 

i posted this on the netav site:

 

http://www.atpturbo.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=GRT-TBO-025&Category_Code=GRT

 

anyone know/have maps for this turbo...sounds like its a direct bolt in a with 450hp capability

 

 

i tried doing some math last night and came up with high ass pressure ratio's like 3.2 with 44lb/min flow for our engines to run 450hp. thats why i was interested in a the 3bar progress!!

im sure my numbers are off (wasn't sure of the rmp redline, so i used 5500?? and the effiency i used was for stock engine)...i found the volumetric effiency for the stock 3.1 n/a engine at 140hp was 60% according to these formulas. thats way too low there is no way that they are that ineficient...so i think i used 85% for my calculations.

so

heres the site with some walk through formulas, run your numbers through them and see what you come up with (dont be shy, simple math even if it looks moderately technical) http://www.teknett.com/pwp/drmayf/turbocal.htm

[Guest TurboSedan]

if i wanted over 15psi i'd use an adjustable zeiner diode and a 7th injector (or maybe bigger injectors & an AFPR + RRR)

 

can you explain how the zeiner diode and 7th injector would work/set up....also with the abreviations i asume afpr is: Adjustable Fuel Pressure Regulator' date=' but im not sure what RRR stands for.

[/quote']

 

an adjustable ziener diode only costs like $25 and can be installed in line with the MAP sensor voltage wire. it limits the voltage output of the MAP sensor so as to 'fool' the ECM into not seeing any higher voltage than say....4.65 volts or whatever voltage 14.7psi equals. IOW it will give you enough fuel up to 14.7psi, but also prevent the ECM into seeing an overboost condition, eliminating fuel/boost cut and letting you raise the boost past 14.7psi (or whatever fuel/boost cut level is on a stock TGP calibration).

 

HOWEVER, adding fuel past this point is up to you of course, since the ECM has no way of knowing how much boost you are running past 14.7psi. this can be done with a 7th (or even an 8th) injector set to turn on at a specific psi, or you can add bigger injectors, then turn down the base fuel pressure with an adjustable fuel pressure regulator and adding a Rising Rate Regulator (aka an FMU) so fuel pressure rises with boost pressure.

 

now, i haven't done any of this myself so i don't want to give the impression i have direct experience because i don't (yet). the Turbo Dodge guys are using these methods with their speed density 2-bar calibrations, i don't see why it wouldn't work on a TGP.

[GutlessSupreme]

Where exactly would a 7th or 8th injector go?

[futuretgper]

thanks for the clarifications!! yeah, where would the 7th or 8th injector(s) go, tap into the up intake or intake pipe?? like a nitrous tip would??

[Guest TurboSedan]

that's probably what i would try to do...in the upper intercooler pipe right before (and pointing at) the throttle body.

[Canada]

My friend with the turbocharged Probe GT (TPGT) had two addition injectors (big.....480) right before the throttle body. He had an extra injector controller (EIC) from Simple Digital Solutions (SDS). On 5-6 psu the ran 25% duty...even at that, they where rich.

 

From there he used a 12:1 FMU and a adjustable FPR....it was a bit excessive for his level of boost.

[god910]

I believe the biggest misconception in this thread can be solved w/ the "Straw" discussion. You will get high pressure by blowing through a straw w/ a small diameter. Open the diameter, you get a lower pressure, but a higher volume. This is why I say you can make more than enough power to get yourself into the 13's (which most of us have a goal of and haven't hit yet) Turn that straw into a garden hose. Then worry about how much pressure you have. Yes, there are other ways around it. But the only person on the boards w/ a monster number is in the 12's (yes he has wicked sick mods) but he can do it at a lower pressure (much lower at that) than all of us. He's spent the time and money making his engine breath (on both ends)

 

BTW Future, I think 85% is still a little low for your calcs. Maybe not for a 15 year old motor, but fresh it would be low.

[Canada]

I think 85% is high for a pushrod motor.....and remember......thats only at peak torque.....once you get into the high part of the rpm band it drops.....a lot.

[futuretgper]

i sent atp an email and they refered me to maps of the GT3071R becuase they don't have any for the GT3071R-WG, which is the one that interests me because its a high hp bolt in ... the guy said they are very similar (compressors have the same wheel size and trim, A/R is the same too) here are the links...could somebody with better knowledge of reading the maps explain why this turbo would or would not be a good choice for a high hp build up.

 

trubine: http://www.atpturbo.com/root/maps/gt3071rturbine.htm

 

compressor: http://www.atpturbo.com/root/maps/gt3071r.htm

 

the guy who emailed me back said "this would be a 'sweet' set up." jee whiz thanks for nothing...

 

the the flow numbers i got, that were neccessary to support 450 hp land nicely on the compressor map.... PR around 3.2 @ 44lbs/min

 

thats without figuring the gains of an intercooler and like i said im sure my numbers are off and if the engine could breath better im sure the pressure ratio would drop off...

[Canada]

Man.....I'm used to the old school compressor maps (mass flow on X, PR on Y, with efficeny circles)....at this point, I'm not quite sure how in the hell to read that map.

 

I can't seem to find any normal maps for that turbo.

 

Here is a good place for maps

http://not2fast.wryday.com/turbo/maps/

[TurboGTU]

That turbo is big for our stock engines. Boost will come on late to make good use of it. At lest the smaller turbine will get you something to use. Modded..well thats another story .

 

Here's some insite to his story (hope this is ok with the MODs)...

http://www.netavalanche.com/tgp/viewtopic.php?t=2524

 

Rising the VE on this engines gets verry expensive..so boost/density ratio becomes a big role in making HP. If we could raise the N/A VE easier than rasing boost..then we would be OK with "low" boost with a high lift long duration cams, exoctic head work, intake and exhaust pluming TO A POINT. Density ratio increases with BOOST. The displacement and rpm band of the engine will only see a given CFM. So even if we have 100% VE at 5000 rpm..the most we will only see is 273.4375cfm

MAX N/A theoretical CFM on our 3.1 (aka max VE)

 

2000 is 109.375

4500 is 246.09375

5000 is 273.4375

6000 is 328.125

7000 is 382.8125

 

As boost (Pressure ratio *PR*)increases the DR increases (assuming a great IC). DR is like a multiplier to cfm. SO at 14.7 PSI or PR2(14.7+14.7/ 14.7)on a GOOD turbo..we would get 546.875 absolute CFM. You cain't get anything beyond this at this DR/or PR. You must increse the PR. Up the boost past 14.7psi.

Also..PR is calculated from atmosphere and outlet pressure. What if you live on the mountins. 12psi of altmosphere then 14.7psi of boost. 12+14.7/14.7=1.8PR. 1.8 PR with a perfect DR is 1.8 DR. 1.8 and 2 is alot of HP/tq in difference. For the sake of simplicity I didn't include filter loss, IC loss, IC effectiveness, air temp, compressor effectivenss..ect and all other real world factors.

 

Of couse this is only for the Panchos out there that want to keep up with the sy/ty and GN guys . Who says we can't make 500 hp at 7K rpm on a 3.1 . :read:

OK im getting out of control .

 

Im going to try to figure out the turbine side sometime..DR/PR at max head flow. :shock: :?

 

As far as the 3bar..the sy/ty 3bar looks nice with an intergration of the DIS system...or if several people take care of sevral tables to make a 3bar setup out of the 8f code. I just keep looking at the code/tables and im overwhelmed at the task. Hell simple tunning takes time for one person. I've heard of the Mopar guys using those map trikery..but they also tune the ecm like a 3bar. Well 15in -0 vacume are left alone..and 2psi now looks like 1 , 10 is 5, 15 is 7.5,,,ect...even this takes alot of time.

[SleeperRed90TGp]

Good discussion. Unfortunately the 3.1 upper plenum is not conducive to distributing the air effectively to produce the HP numbers you would expect. You may be able to pump enough air in to overcome this problem but I was unable to. Or I just got tired of messing with it.

 

Cyl 6 being the worst and cyl 4 a close second. Putting the 7th injector in the charge pipe does nothing to alleviate the lean condition these 2 cyl have. They apparently get more air than the rest of the cyl and it’s a considerable amount. I found that I had to install the 7th and 8th injectors in the upper plenum directly over the 4 & 6 runners. This did help greatly but not enough. Next I put larger injectors in 4 & 6. This worked pretty well and I didn’t melt any more pistons. I suppose I could have eliminated the external injectors and just gone with extra large injectors in 4 & 6 but all this turned out to be a PIA. Constantly reading plugs, adjusting the Hobbs switch and adjusting the fuel pressure which ended up at 80# (scary).

 

Solution. Top end swap 30# injectors @ 55-60#. Broke into the 13’s out of the box. Well 4 or 5 passes.

 

If you boost the 3.1 your in for a lot of work. With the top end swap your in for a lot of fun.

 

Just thought I would let you guys know what your up aginst.

 

3 bar boost. I don't know if these motors will take it. When I'am pulling from the 1000' mark it's like I can feel every cyl firing and just praying it doesn't blow. I am going to try the 1/8 mile.

 

Jud

 

Edit changed 5 cyl to 4.

[futuretgper]

how did you come to find that the 5th and 6th cylinders were the ones with the lean condition?? jeff m is coming out with genII heads -->http://www.turbograndprix.com/new_page_2.htm eventually and they only bolt up to the 3.1 intake manifolds (w/out modification) so if what your saying about them cuasing this uneven distribution of air is true then is he going to have problems getting them off the shelf...or do you only experience this problem at higher boost than most run? how much different are the turbo heads compared to n/a?? are they any harder to get ahold of?

 

p.s. all this talk is making me anxtious to get my car out!!! damned winter bs!! :x :dammit:

[SleeperRed90TGp]

This is a Jeff type post ----Long. Unusually for me but were on a good subject.

 

First off let me edit the last post which I did It’s 4 & 6 not 5 & 6. It’s the 2 front left cyl. I get numbers mixed up in my yawing years. If you look at the direction that the TB is pointed it’s directly at

2, 4 & 6 and considering the extra long runners on 2,4,6 (12†verses 8â€Â) it’s understandable that the volume in those cyl is going to be greater. The ram effect has got to be grater It’s just not a good situation having half your cyl runners 50% longer. I have no idea how to correct this condition other (than make them bigger which is a little beyond our scope) than getting rid of it. :oops:

 

futuretgp'er wrote

how did you come to find that the 4th and 6th cylinders were the ones with the lean condition

 

Pretty simple when you melt pistons and bend rods on 4 & 6 and none of the other’s. All the others look good even when inspected on a tear down and they seem to hold up good while melting another on of 4 & 6. #2 cyl seam’s to be ok, although it’s a little leaner than the back cyl according to the plugs. You would think it would have problems also.

 

futuretgp'er wrote

Jeff M is coming out with genII heads --http://www.turbograndprix.com/new_page_2.htm eventually and they only bolt up to the 3.1 intake manifolds (w/out modification) so if what your saying about them causing this uneven distribution of air is true then is he going to have problems getting them off the shelf...or do you only experience this problem at higher boost than most run? how much different are the turbo heads compared to n/a?? are they any harder to get a hold of?

 

Lets get one thing straight. My personal opinion is that the gen II heads are as good as or better than the genIII. The ports are bigger. I used gen II heads that were ported almost to the max and there was a noticeable difference between the stock heads. The problem is the intake manifolds. The gen III don’t even come close to fitting and anybody that welded up gen II intakes to fit gen III is a pure gluten for punishment. Intact I would say with confidence that it’s never been done. In other words I would have to see it. The genIII have equal length runners(8†on both sides) that’s the difference. You can tune your motor with one adjustment that will effect all cyl. I would assume that the GM engineers that designed the 3.1 intake no longer works for GM . I wouldn’t keep them. I would have fired there asses.

 

The turbo heads are 2 CC’s larger than the N/A reducing the comp ratio by .2 and yesssss after scouring the j/y in Houston I couldn’t find any. Somebody on here said that 89 n/a had the same chamber configuration but I had moved on by then. I took a set of n/a ported heads out to 30 CC’s to keep my compression ratio about the same with a .040 bore.

 

As for Jeff’s set up that he’s working on I am sure it will be a safe setup. He knows what he is doing. He may send you different injectors for each of the front cyl and a chip to go along with it although his TG chip works well with any injector that I have put in. (22,24,26,28,30, well 40# didn’t work, damn I wanted to go realllllllly fast. Problem is It takes him to long. The trans kit is what 2 years in the making.

 

Yes I am at higher boost. 10=12 #. Which I would estimate is twice the output of the stock T25. I have the paultry GT28 which since I bought it there have been a slew of Gt’s. I bought this for 1k where there GT28RS were 1800. When I run out of boost I’ll upgrade. But I think I’ll learn how to master the boost of this turbo before I do.

 

Well I hope that helps your turbo aspirations. 3 bar, were along way from 3 bar applications.

Jud

[Jeff M]

Yep, a long way from a 3-bar, if its needed for most real money, and the very few talking is like any group buy........so ain’t gonna happen unless you do it yourself 8) !! If you z-diode or other tricks to fool the computer for more than 14.5 psig, just prepare to ask for more luck than hp gains .

 

As for the heads, Jud covered it, If you spend the time and money and are lucky as I was to meet with the guys that made these heads and the Gen I and Gen III and the intakes, and does work for guys like John Force, you can make the Gen IIs flow great (more details when the time comes, besides don’t like getting people excited till they are closer to for-sale). I have Gen III heads on my one TGP that had to have the lower TGP intake welded up to matched the raised runner of the Gen III heads, just a test for me, intake flows a bit more than a Gen II but the critical Exhaust Side is damn close to each other (Gen II and Gen III), at least after all the work was done to them. Only thing left to say is, and 8) sorry Jud…..the runner lengths are the same, don’t forget the length of the upper AND lower, and once you do you will find the lengths are the same front to back. As for lean in any cylinders, somewhere I posted the flow of the intakes and it was not that far off, what you probably had was running a little too lean for a turbo setup on the front bank, maybe the grounds or something related to that side only. When I was done doing the TopGun and all those other chips, I finished things up by trying to destroy my engines, basically find out what was weak and what it took to break it, guess its up to me to find those areas so I can warn others and/or find parts to address those areas, I am such a nice fucking guy . So I kept raising the boost and timing up and up till things gave up , first was a few collapsed spark plugs, then some spark plugs with missing parts, then blew pistons, on number 5 on one engine then number 4 on another (weeeeee), then a head gasket, lots of fun but no bent crank, no bent rods, though if I kept hammering it beyond the broke parts I got, I might have been able to do more damage, too high of rpms will do much more damage than what I was running with :!: :!: :!: :!: :!: , but the tests showed the TGP can handle a lot of punishment!!! Before I forget, back to the topic and using different size injectors and just to clear that one up FYI, if you do have a big (small not as important) mismatch of air flow and use different size injectors to achieve proper A/F then you are going to break, if one cylinder is making say 50 hp and another is only making 40 to 45 hp and since both are spinning the same crank, one is going to fight the other resulting in the crank being twisted not in a good way, and each defeating the power since they are not agreeing with each other (for a lack of better words). I have seen Sequential Systems added to give individual cylinder fuel control and the resulting gains were small, only were worth it for really big hp engine and pro racers needing any extra tenth or hundredth of a second.

 

As for the limits of power/boost CFM (yeee haaa, people are getting too damn smart :shock: 8) ) and all, the stock heads will flow up to a point for sure, but once you go into Mach speed (literally, somewhere around 300 fps, to busy to go dig up the info) you will not flow any more air no matter how hard you blow/boost, but if you just roughly and I mean roughly assume an average flow of a stock head I know we can flow some good numbers stock with a better turbo for sure, and with a lot less backpressure it would be worth the efforts (that I am doing as it sounds others are working towards). Worked heads will be better but with some oddly rigged tests I did with stock heads and mod’d turbo, there was a huge gain from 3800 rpms to shift point/5,200 rpms, and THAT IS THE RPMS we run between once past 1st gear :read:

 

 

Well, board posting these days is nothing as it once was, long time ago me and only a few others could talk higher levels of engine fun/tech, now we have lots of avid guys and that sure makes it easier for us old guys, I will humbly bow-out as I need to get caught back up as always, but a week vacation has be backed up badly, vacation pay-back is hell!!!

 

Jeff M

[futuretgper]

thanks sleeper and jeff!!

good to know that jeff is still keepin an eye on us underlings

steps in when we need him!

 

shift point/5,200 rpms, and THAT IS THE RPMS we run between once past 1st gear

 

 

wow i guess with my tach reading the wrong numbers i didnt know we were governed at such a low rpm...so are there any gains (more power to be had) @ higher rpm...with stock stroke and internals??

anyone playing with the revlimiter settings ??

 

oh and with the 3bar issue...i haven't really done any work to my car so i haven't started tuning or anything, but for those of you who do...how usefull/important is the 3bar MAP?? its got to be done some time!! sounds like it would be much less of a problem, if we had 3bars, when running bigger turbos in the future!! heck lets all throw money at it (research and develpment incentives) !! i'd throw money at this problem...if i were convinced that a good complete product would come from my contributions!! how many TGP guys do we have? what if everyone gave like 15 or 20 bucks to the person who could comeup with the answers?? something like that!!! lets start funding the people with the skills and get some of our problems nipped as a group/team baby!!