hptuners noob looking for a good starting point on a previously tuned H/C/I/E swap..

[BMFIROC-Z]

As the title says,I'm a noob to hptuners..Long story short,I paid $500 to have my car tuned and was very unsatisfied with the results so I purchased hptuners to tune it myself,ive already corrected a lot of of the previous tuners mistakes already but now I believe ive come to the point where I need to start going over timing,fuelin ETC but being that its a pretty decently modified N/A car I'm not quite sure where to start..it runs decent at part throttle but wants to die occasionally when I push in the clutch when coming to a stop and its pretty quick but seems like it should be a little quicker for what it is..mods are as follows: *87' IROC,*T56,*370ci (LQ9),*milled/ported 243's (11.5:1 comp),*Lunati 231/239 .622/.629 111 LSA,*ported 96mm typhoon intake,*ported 90mm tb,*42lb/hr injectors,*85mm descreened maf,*true dual exhaust,*x pipe,*hawks budget swap LT headers,*classic chambered powerstick mufflers..i posted my current tune and my first decent log,if any more info is needed just lmk as this is my first time posting a tune etc..again,im just lookin for an experienced tuner to look over my info and give me some pointers on where to start,any pointers are greatly appreciated,TIA

[5FDP]

Just from that log, the fuel trims show a big problem with the airflow tables. Both VE and MAF are going to need a lot of work still.

Anytime you are off the throttle they peg the LTFT at +25% and your short terms at time are adding anywhere from 20-40% as well as removing the same amount at random.

Hopefully you have a wideband so you can watch real time air fuel ratio's, you are also going to need one anyway to properly tune the VE and MAF.

Me personally, I'd put the screen back on the MAF sensor. The screen serves an important function, it is design to straighten the airflow across the MAF sensor to give you the most accurate readings. If there is any turbulence in the airflow through the intake it can read wrong.

[BMFIROC-Z]

Just from that log, the fuel trims show a big problem with the airflow tables. Both VE and MAF are going to need a lot of work still.

Anytime you are off the throttle they peg the LTFT at +25% and your short terms at time are adding anywhere from 20-40% as well as removing the same amount at random.

Hopefully you have a wideband so you can watch real time air fuel ratio's, you are also going to need one anyway to properly tune the VE and MAF.

Me personally, I'd put the screen back on the MAF sensor. The screen serves an important function, it is design to straighten the airflow across the MAF sensor to give you the most accurate readings. If there is any turbulence in the airflow through the intake it can read wrong.

ok,thanks for the analysis..yes, I have a AEM UEGO wideband in the car,but the maf screen is long gone..where would be a good starting point to correct the issues you pointed out?

[BMFIROC-Z]

I apologize if it was already explained to me and I'm just not pickin it up (noob lol) but,should I start trying to dial in the main VE or MAF first? if so,which one should I start with? or are there other parameters I need to take a look at first such as injector data etc?

[BMFIROC-Z]

Anybody else got any input/suggestions?

[5FDP]

It doesn't matter what you start with, either VE or MAF can be done first.

You will need to include the wideband into your logs but somehow wiring it into your HP Tuners. If you have the PRO interface you can wire it through there or if you have the standard interface you can use the computers EGR circuit or AC circuit to wire it in. I've used the EGR circuit without issue.

https://www.youtube.com/watch?v=Ru_2M2uGSKs

[BMFIROC-Z]

It doesn't matter what you start with, either VE or MAF can be done first.

You will need to include the wideband into your logs but somehow wiring it into your HP Tuners. If you have the PRO interface you can wire it through there or if you have the standard interface you can use the computers EGR circuit or AC circuit to wire it in. I've used the EGR circuit without issue.

https://www.youtube.com/watch?v=Ru_2M2uGSKs

ok,thanks again for the help,much appreciated. I have the PRO interface with the inputs on the side..I just set up a channel through external input 1 for my uego 30-4110 via the preconfigured wideband's in hptuners scanner as outlined in this video: https://www.youtube.com/watch?v=jMalD15mOg4 ,with that being said, will I just need to connect the (white) 0-5v analog output wire from the wideband to pin 1 of the external inputs connector,connect the chassis ground the wideband uses to pin 5 and be good to go?

[Oleblu]

Yes that's the correct way to setup your wideband. I have noticed with my aem 4110 the scanner output is really erratic. Even with 250ms filter the polling rate is so fast it's hard get a good read on how accurate it's reading. If you feel like it's off more than a tenth, use the settings to apply a ground offset one way or the other until you feel it's as close as you can get it.

[BMFIROC-Z]

Yes that's the correct way to setup your wideband. I have noticed with my aem 4110 the scanner output is really erratic. Even with 250ms filter the polling rate is so fast it's hard get a good read on how accurate it's reading. If you feel like it's off more than a tenth, use the settings to apply a ground offset one way or the other until you feel it's as close as you can get it.

awesome,thanks for the heads up,ill play with it and try to get it dialed in the best I can

[BMFIROC-Z]

Ok,got the wideband hooked up and working,posted a log file of a test ride I took after setting the wideband up..everything look ok? do I need to add any channels or parameters to my scanner layout before my next log? and whats my next step? obviously I need to go do another data log with the wideband hooked up,but do I need to disable the maf and pull some timing etc beforehand? or just log it as is? again..sorry about my noobieness,just trying to learn,TIA

[BMFIROC-Z]

Just need someone to confirm my next step and ill quit buggin as im pretty sure ill have it from that point...do i start logging LTFT'S in speed density mode for VE tuning next?..as outlined in this tuning guide: http://www.ls2.com/boggs/ls1edit/ls1...ing%20info.htm ..would really appreciate it if somebody would answer my question..TIA

[5FDP]

I've seen lots of guides out there but I wouldn't use that one.

If you have a wideband, do not use fuel trims.

The wideband is your tuning tool. Enable fuel trims once you are doing tuning both VE/MAF and see how they behave.

I used this guide and still do it pretty much the same way.

Disregard some of the settings it talks about, no need to multiply the VE by 15% as you already have the engine running and going. Set the MAF fail high to 0hz and the 3 MAF dtc's must be set to MIL on first error.

http://michigansnowmobiler.com/hptuners/SD%20VE%20and%20MAF%20Tuning%20Instructions%20rev2 .pdf

[5FDP]

Also because you are new you really need to invest your time into some books or a course on tuning. You will just run yourself in circles otherwise. Choosing something so modded to start with is always a bad choice too, it's makes things 5x harder because you have to learn everything while knowing nothing of how a stock vehicle may act.

Engine management advanced tuning by greg banish is a good book on understand how things work.

Look into ERM performance's website, they offer a course for new users on how to use this software and general tuning tips. The course if not a lot money for the knowledge you get.

[BMFIROC-Z]

I've seen lots of guides out there but I wouldn't use that one.

If you have a wideband, do not use fuel trims.

The wideband is your tuning tool. Enable fuel trims once you are doing tuning both VE/MAF and see how they behave.

I used this guide and still do it pretty much the same way.

Disregard some of the settings it talks about, no need to multiply the VE by 15% as you already have the engine running and going. Set the MAF fail high to 0hz and the 3 MAF dtc's must be set to MIL on first error.

http://michigansnowmobiler.com/hptuners/SD%20VE%20and%20MAF%20Tuning%20Instructions%20rev2 .pdf







thank you very much,that thread looks like its going to help out tremendously..n yeah I'm about to break down and buy a book or attend a course or something..i thought I had a pretty good grasp on things but like you said,with my first tune being on such a modified car its hard to get the basics down..in the mean time,ill try out that tuning guide you posted and see how much trouble I can get my self into lol..thanks again

[BMFIROC-Z]

Well, did some data logging in speed density/VE tuning today as outlined in the tuning guide 5FDP provided,and I figured id just post the reults here since ive already stated/posted all my info/setup here..with that said,it don't run great but runs decent enough to drive around without much issue but I can tell it still aint right powerwise.. I also noticed the values toward the center of my main VE graph seem way higher (well over 100) than other cammed LS cars I compared mine to.. am I missing something? or does this indicate I have another issue? I attached my current tune file with the main VE modifications I did today.. I also attached my 2 data logs I recorded today..if anybody has any suggestions or sees anything I'm overlooking please let me know..TIA

[SultanHassanMasTuning]

what brand injectors are you running, if you want a decent idle/cruise/wot

you need decent injectors

[BMFIROC-Z]

what brand injectors are you running, if you want a decent idle/cruise/wot

you need decent injectors

They are Bosch 42lb injectors..mind elaborating a little?..

[BMFIROC-Z]

Just from that log, the fuel trims show a big problem with the airflow tables. Both VE and MAF are going to need a lot of work still.

Anytime you are off the throttle they peg the LTFT at +25% and your short terms at time are adding anywhere from 20-40% as well as removing the same amount at random.

Hopefully you have a wideband so you can watch real time air fuel ratio's, you are also going to need one anyway to properly tune the VE and MAF.

Me personally, I'd put the screen back on the MAF sensor. The screen serves an important function, it is design to straighten the airflow across the MAF sensor to give you the most accurate readings. If there is any turbulence in the airflow through the intake it can read wrong.

just got an email back from the previous tuner and this is all he said after reviewing the first log I posted:

"where are you having problems at? I do not see anything that is
really way off. You will not register anything accurate for
fuel trims until after 1200rpm as the cam and headers will
not allow it to properly adjust so that area is tuned to be
open loop."

does this explain the problems pointed out in this post?

[smokestack]

If you really paid 500 for that tune you got yanked on... Just be honest around here. We all started somewhere. And i still make mistakes. It's human nature.