pookie025

so i have the infiniboost tune. the rpd boost gauge is not accurate at allllll. it jumps all over the place. in third gear ill hold 26psi then run it again and only hold 18 in the same gear. if i run it from 2nd gear un till mid 4th gear full out the boost gauge stops working and said data not avaliable with a no smoking type of sign with no boost numbers. then the numbers will appear back again. also my clutch is slipping now, and tires are extremlly bald 25k stock tires lmao. but whats up with the guage u guys think

mkriebs

MAP sensors can't read all the pressure. Car is fighting the tune... welcome to the world of high boost on the stock turbo.

09BlueBaltSS

Its not the turbo, its the map sensor. Your probly spiking out of range. If I spike 26psi or higher(rarley happens now) the my rpd says the same thing and will come back in like 30 seconds. Dont worry about it. If the ecu thinks its a problem it will either go into limp or throw code P0106

pookie025

should i get the clutch new tires and a new boost gauge. will this make a difference

but when it says 18 psi am i actually boosting more

09BlueBaltSS

I bet Vince rescaled your map sensor. Why are you goin past 24psi anyways? You would probly make the same power and it would be smoother

pookie025

i dont know what he did but he data logged it two time before upping the boost. to make sure it would be safe. he told be that my boost solinode was strong and he felt confident to up the boost. so to me it sounded like he was safe and sure about it. and whats rescaled map sensor mean?

Billsac

Don't feel bad mine does it too. It's not meant to really go that high for too long it freaks out when it sees a consistent high psi, mine usually does it when in 4th gear because the higher gear im pushing about 23.5

pookie025

so when the boost drops im really higher then what the gauage says

09BlueBaltSS

Maybe one our more experienced tuners can explain more correctly but I took it as this...the map sensor reads pressure as a voltage and is sent to the ecu. The ecu then reads the voltage converts it to a psi number makes it adjustments to the engine and displays what its seeing on the rpd. Well say .1 volt is equal to 1psi, if you are pushing 26psi the the map is sending 2.6v to the ecu, but the ecu cant read above 2.5v on that sensor. So now your gonna get fuel cut, limp mode or a code for the map goin out of range(the ecu cant tell how much boost your making) so it goes into overboost protection. Now if we rescale the map's conversion method to say 0.07v=1psi then 26psi would display as 18.2psi. Id assume that there is some rescaling of the other systems as well to sync everything back together.

If that was completely wrong I apologize. Input tuners?

SSlobalt

Sounds right to me. It's called a Look-up Table in my profession.

mkriebs

The MAP sensors are 2.5 bar sensors, which is 36 psi. BUT, this is MANIFOLD absolute pressure, this is not boost pressure. The computer reads boost as a formula comprised of a couple different sensors. I am not sure which ones to be completely honest... but i have a hunch it is the MAP, boost, and the BARO sensor. Boost is the MAP minus 14.7 for atmospheric pressure, so your computer only recognizes 23ish psi.

As for exactly why the gauge actually reads higher than that, I am unsure. There is a boost sensor on the car, that reads outright boost, and i think that basically runs the gauge. This is why I said the car is fighting the tune. I have an MBC on my HPT tuned car, and it did the same thing (with the 08 boost gauge). So, I have no doubts your boost is sporadic.

I am not the most experienced in tuning these cars, but I know a thing or 2 about it. This is mostly speculation and some educated guesses on my part, as I have been trying to figure out the same thing.

09BlueBaltSS

Hmm... Thought I read somewhere that our map's were like 2.8 bar which would read around 27psi. I know ive seen a 27psi spike before, may have had something to do with the weather at the time, now I spike at like 24-25

mkriebs

Well, really the only way to tell EXACTLY how much boost the car is running, is to install a mechanical boost gauge. Otherwise its all guesswork. Hence why my MBC got taken off, and I will maintain 22 psi til I get a stage kit and a big turbo.

09BlueBaltSS

Ok. I was wondering, if you are using a MBC isnt the ecu having a conflict with the boost level not being maintained to the commanded level?

mkriebs

That is an interesting question. Like I said, I am still learning the tuning thing. I learn by doing it on my car, and thats why the MBC went on. I wanted to see the effects and stuff of it.

As far as I can tell, this is what happened on mine (with the MBC)... What an MBC does is reduce the amount of boost pressure the wastegate actuator sees. This in turn slows the response of the wastegate, which was giving me erratic boost, since the car was guessing what would happen next. It was not odd for me to see 30+ psi (scary, really). There are other ways of achieving this, and there are also other types of boost controllers. This is something I am still learning (got a book beside my bed right now, lol). Some other type of MBC may be better for the LNF, or there may not be a good one for the LNF.

But, I really don't know the answer to your question. I am sure Vince uses wastegate control on his tune, so the computer is still controlling it. I just don't know how reliable this is on the stock sensors yet. A local friend of mine has the infiniboost, and it seems to run well. I need to get back out and do some logs on his car, and compare them to mine again. I only got one log last time, and its not enough.

ecotecturbo

Quit running infiboost. Problem fixed.

Cpott

ahhh so glad i have a analog...

BYT*SS*TURBO

iTrader: (6)

You may have a code pending. When I first did the 25+ psi mod on my car, it would pull hard a couple times, then trigger a immature code and limit things. I disabled those codes and I get consistent high boost now. Im still running 25+ now, if I do a long 3rd or 4th gear pull and the RPD reads over 23psi for more then like 5-6 seconds, the data will blank out. Car still pulls hard, boosts right etc... Just no boost display on the RPD when it happens.

Not sure that this can really help you, this is just what I noticed when I did something similar to the infiniboost tune.

Gimpster

Its a code being set that causes the RPD to get stupid.

If you have the ability to log or pull codes, pull them next time you see NO DATA. I was running a restrictor pill on my car for awhile (ghetto infiniboost) and also saw this behavior from the RPD. P0161 and another one was setting on my car, I forget the other code (MAF over range ... something along those lines). I disabled whem w/HPT and my RPD stopped doing it.

All that being said, its ability to show you > 25/26psi is nill

So hopefully Vince can kill those codes for ya.

Terminator2

That was your overboost protection kicking in. The ECM closes the throttle blade to 48% throttle if you exceed 22.5 psi for more than 3 seconds continuous. I guess you turned the overboost off after that.
Mkribs: you need to make sure that 1. You have the overboost turned off. 2. the CELs for the Boost solenoid turned off. Otherwise you will go into limp mode.

pookie025

thanks for the helpful info. so... i have the rpd, nad i want to get the manual boost guage to read the correct boost im pushin out. where should i mount the new guage? above the rpd? any suggestions? and where should i but the guage

BYT*SS*TURBO

iTrader: (6)

Term - I did have the overboost set to 8K rpm, still got that tho. I disabled 0106 codes and 0234 for turbo over boost, since then Ive been boosting 25-26+ no prob!

mkriebs

Yeah, I had overboost and everythign turned off, never tripped limp mode or a CEL. IDK what the problem was, but my current tune is strong enough.

Stamina

My RPD does the same thing after you boost above 22.5. It does show above that though, and I've seen even 25.5 at least twice on it.

A part of it may be your clutch slipping. Mine's started to do the same thing and it lowers boost. Vince and I think that it may be the ECU watering things down in an effort to save the clutch after it notices slippage. This may also be the cause of an NLS bog-down that happens sometimes, where the car will "trip up" for about half a second and then get its footing and continue hauling again.

I rarily boost above 22 now, usually around 20 to 21. I did in the beginning, but as time has progressed and I've started using up the stock clutch it has started dropping. I'm thinking a better clutch may help this by the ECU not watering things down, not slipping too much during NLS, and also allowing for more engine load leading to that allowing more turbo spool.

pookie025

where should i mont up the maunal boost guage and where to buy it