map sensor

[CRTD]

have a 98 k1500 s/c vortec 350 R engine. map maxes out at 105 kpa right away. so i am thinking i need a different map sensor. this thing should stay under 10-15 lbs boost. is there an oem sensor that should work. like say one from a s/c 3.8 perhaps?

then will the pcm accept it? or do i have to change something. i have the tuning guides from the tuning school. the info is pretty similair on the vortec compared to the ls engines. i try calling them however they rarely answer their phone. and never return a voice mail. so i am hoping to get some help here.

[turbo4.5]

are you going to tune it in speed density mode. if you do you will need a 2 bar map sensor and make the changes to the calibration

[CRTD]

thanks for the reply.

the vehicle has a maf on it. i guess that doesn't mean we have to use it. i am not sure how to go about it (changing to a different type map). or which way is better (sd or airflow). i can see the map is currently useless because it is getting maxed out right away. the thing idles at about 60-70 kpa in gear and about 45 in p-n.

what is involved in tuning sd vs airflow. do i just fail the maf? if i do airflow does it matter that the map gets maxed out?

[turbo4.5]

the map sensor graph is only used when the mass airflow has a problem and also to compare against. i think that you could do it in either fashion. you would have to change the airflow maf frequancy. then use your pe for WOT. the only thing is that your timing graph is MAP vs RPM so it might no be a bad idea to do a 2 bar map enhancement

[CRTD]

when i click on the "OS" button in the editor it opens a blank window. i am thinking it is not available for the 98 vortec 5.7 so it seems at this point that is not an option. so is there a way around the maxed out map? or is there a way to do it i am unaware of? or is it that big of a deal? if i can get the airflow corrected will that be enough?

there were alot of these kits sold. but i think they came with an add on controller that controlled a valve to restrict return fuel from getting back to the tank forcing it through the injectors.

this vehicle does not have the oem style injectors with poppet nozzles. instead it has a marine style manifold and bosch /delphi type injectors that equal almost 42#@58 psi according to the flow rate calculator.

[tokymon]

alot of people including me hace steped up to the 411 computer out of a 02 express van (they still ran the vortec ) this gives you a ls1 pcm and a vortec
most are using the other guys software but i can be done with hp tuners if youre not 4x4

[tokymon]

just lookled you are 4X4 only thing that suck is you will have a 4 low that does not want to shift right.
i dont have a 4l60 file so i cant just read mine out for you. i have 4l80
but that might not even work as you can not segment swap with hp tuners
i only use this (hp tuners) for ford and 4 banger gm

[edcmat-l1]

You have 2 choices.

1, tune it with the MAF and PE tables to get the fueling right under boost.

2, put a 2 bar MAP sensor in it, and cut the VE table in half. I've done that a few times on LT1 cars. It's more difficult and time consuming than just tuning it with the MAF.

[CRTD]

the main spark table on this thing is rpm vs map (not airmass). and when i try to do a histogram on maf vs output frequency it will not set up. maf reads in lbs/min only. i have tried to set up the histogram but no luck yet. is there another way to calibrate the airflow?

i also looked to see if i could do a s/d set up but it is apparently not available for this o/s. but the map needs to be referenced for spark so could i achieve a decent result with the limited spark table?

[CRTD]

trying to get this thing happy with the maf. but the maf airflow vs output frequency table maxes out at 400 g/sec

[CRTD]

You have 2 choices.

1, tune it with the MAF and PE tables to get the fueling right under boost.

2, put a 2 bar MAP sensor in it, and cut the VE table in half. I've done that a few times on LT1 cars. It's more difficult and time consuming than just tuning it with the MAF.

so how do we cut the ve table in half. is that possible on this os?

[CRTD]

based on all we have learned so far on this thing we have bailed out on the idea of tuning the oe vcm. we switched to the 12200411 pcm and the express van base tune to start over. so far, things are working a lot better.