bolt-on tuning - how much?
05-21-2005, 07:58 PM
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bolt-on tuning - how much? Hey all,
I'm planning on tuning soon to compensate for the bolt-on mods I have done since buying the car. I've been here quite frequently, although it doesn't show in my post count, reading most of the posts here in the tuning forum. A lot of the posts are about tuning for cams and more dramatic mods than I am able to pull off right now. I'm going to leave the internals stock for at least another 9 months, but I have the opportunity to tune now.
My question deals with the amount of change I'd be making to the VE tables and any other tables to compensate for the following bolt-ons on my 98 Z M6 (just the ones that might affect performance):
lid, SSRA, port/polish TB, LS6 intake, Pacesetter LT/ORY, Magnaflow, u/d pulley, 160* stat...
I know these mods are minor compared to internal work, and this is certainly not an exact science, but how much can I expect to be adjusting the tables in order to squeeze some performance out of what I have put on? I'm just looking for some ballpark numbers to use as an extra guideline when I go to tune the car. I've never really seen somebody post what all they had to change for just external mods before.
Also I've seen posts dealing with the 85mm MAF and people using the table from the 6.0L truck engine. Is that the thing to do? I've had an 85mm laying around for some time now and I hadn't put it on knowing it would throw my tune way out of whack. But now with the tuner I can change to compensate for the larger diameter...I can grab the table off one of the other posts, but I'm just wondering if this is the one most everybody uses. Thanks for any responses.
I'm planning on tuning soon to compensate for the bolt-on mods I have done since buying the car. I've been here quite frequently, although it doesn't show in my post count, reading most of the posts here in the tuning forum. A lot of the posts are about tuning for cams and more dramatic mods than I am able to pull off right now. I'm going to leave the internals stock for at least another 9 months, but I have the opportunity to tune now.
My question deals with the amount of change I'd be making to the VE tables and any other tables to compensate for the following bolt-ons on my 98 Z M6 (just the ones that might affect performance):
lid, SSRA, port/polish TB, LS6 intake, Pacesetter LT/ORY, Magnaflow, u/d pulley, 160* stat...
I know these mods are minor compared to internal work, and this is certainly not an exact science, but how much can I expect to be adjusting the tables in order to squeeze some performance out of what I have put on? I'm just looking for some ballpark numbers to use as an extra guideline when I go to tune the car. I've never really seen somebody post what all they had to change for just external mods before.
Also I've seen posts dealing with the 85mm MAF and people using the table from the 6.0L truck engine. Is that the thing to do? I've had an 85mm laying around for some time now and I hadn't put it on knowing it would throw my tune way out of whack. But now with the tuner I can change to compensate for the larger diameter...I can grab the table off one of the other posts, but I'm just wondering if this is the one most everybody uses. Thanks for any responses.
05-22-2005, 01:17 AM
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Good post man. I'm in exactly the same boat you are.. just threw on the pacesetters and TSP catted Y. After some scanning my LTFT's are screwed and showing anywhere from +12 to +20 on average.
I have a good idea of what I need to do, just posted another thread in this forum asking about some specifics.
Basically (and correct me if I'm wrong) people put the car into speed density mode by unpluging or tuning out the MAF sensor.. this makes the PCM go into fail-over and rely just on the VE tables. Then when you scan you can adjust the area's in the VE tables that are out of whack by + or - the relative numbers your scan returns to try and get everything between -2 and 0 or so. I also remember that when you put the car into speed density you have to copy either the primary VE over the secondary or the secondary over the primary.. memory is the ***** right now.. long weekend..
After all that stuff, you've got a dialed in VE table for speed density mode.. From my understanding you have to then either be a math wiz or you can use redhardsupra's correction excel spreadsheet that based on the included instructions will allow you to scan the correct settings, then scale them appropriately so you can throw the values back into your VE table and have a dialed in table for use WITH a MAF. After that you need to copy the (I'm guessing) stock secondary VE table overtop of your basterdized version and things should work out okay.
Obviously this post sucks because I'm so vague.. I've got the super basics and I've done this once only with a friend in his 99 Firehawk.. after we were all done it really made a difference part throttle.
Hopefully I haven't screwed up too many things (ducks) and my advice is at least somewhat helpful? Not sure what tuning package your using but there is a ton of info on the HPTuners forums!
Good luck man!
I have a good idea of what I need to do, just posted another thread in this forum asking about some specifics.
Basically (and correct me if I'm wrong) people put the car into speed density mode by unpluging or tuning out the MAF sensor.. this makes the PCM go into fail-over and rely just on the VE tables. Then when you scan you can adjust the area's in the VE tables that are out of whack by + or - the relative numbers your scan returns to try and get everything between -2 and 0 or so. I also remember that when you put the car into speed density you have to copy either the primary VE over the secondary or the secondary over the primary.. memory is the ***** right now.. long weekend..
After all that stuff, you've got a dialed in VE table for speed density mode.. From my understanding you have to then either be a math wiz or you can use redhardsupra's correction excel spreadsheet that based on the included instructions will allow you to scan the correct settings, then scale them appropriately so you can throw the values back into your VE table and have a dialed in table for use WITH a MAF. After that you need to copy the (I'm guessing) stock secondary VE table overtop of your basterdized version and things should work out okay.
Obviously this post sucks because I'm so vague.. I've got the super basics and I've done this once only with a friend in his 99 Firehawk.. after we were all done it really made a difference part throttle.
Hopefully I haven't screwed up too many things (ducks) and my advice is at least somewhat helpful? Not sure what tuning package your using but there is a ton of info on the HPTuners forums!
Good luck man!
05-22-2005, 07:16 PM
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The part about recorrecting the VE tables derived in SD mode for use with a MAF I don't think I have heard before; I'll have to research that a little more. My LTFT's are about the same as yours, Mat, my idle is around +17 which drops down to around +8 while under throttle. Plus I run rich and I'd like to do something about that.
I'm going to be using HPTuners to do the tuning. Can anyone give a guideline on how much I'd be changing these tables, or do the numbers come from adjusting the table by the amount of the LTFT's only?
I'm going to be using HPTuners to do the tuning. Can anyone give a guideline on how much I'd be changing these tables, or do the numbers come from adjusting the table by the amount of the LTFT's only?
05-23-2005, 12:22 PM
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When we were working on my buddies car with HPTuners we would log a bunch (he was using Last Value on the Histogram which now I'm thinking Average would have been quicker/more accurate) and then go in and scale the problematic area's of the primary VE table based on our scan data.. save it.. load the tune back into the PCM.. reset the fuel trim learn (so previous values don't screw up your new histogram) and then scan again.. we repeated that over and over until we got it to between -2 and 0 (or as close as possible to this.. some area's are hard to hit and scan accurately). After we completed that, we used redhardsupra's MAF calibration spreadsheet to calculate all the values correctly for use with a MAF. We copied those in, and coped every other cell to the secondary VE table (since we have 98/99 cars) and then copied the stock low octane table back (since we previously copied the high octane over the low octane).
It's about as clear as mud to me.
I'm learning as I go along with this stuff too.. it's starting to really sink in now though and I'm just about ready to start my own car.. sometimes I just figure I should take it down to ARE and let them tune it for me (as long as they don't lock tunes). I won't be able to do WOT anyways...
Check this link for all kinds of info:
https://ls1tech.com/forums/pcm-diagnostics-tuning/287094-read-me-first-tuning-docs-ve-maf-ses-lights-faqs-more-01-31-07-a.html
It's about as clear as mud to me.
I'm learning as I go along with this stuff too.. it's starting to really sink in now though and I'm just about ready to start my own car.. sometimes I just figure I should take it down to ARE and let them tune it for me (as long as they don't lock tunes). I won't be able to do WOT anyways...Check this link for all kinds of info:
https://ls1tech.com/forums/pcm-diagnostics-tuning/287094-read-me-first-tuning-docs-ve-maf-ses-lights-faqs-more-01-31-07-a.html
05-23-2005, 01:51 PM
#5
Originally Posted by Mat
After we completed that, we used redhardsupra's MAF calibration spreadsheet to calculate all the values correctly for use with a MAF.
05-23-2005, 04:03 PM
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It worked out great! 
Very nice job man! Super helpful and it made our job much much nicer then having to scale everything and correct it by hand!
The only thing that we got confused with is that the copy we downloaded had someone elses previous results in it and somehow the two were transposed or combined or something. Maybe a little message about clearing previous results first or something. This is what my buddy told me (it seemed to work without problem when I was there but the tune was a bit "off" until he figured out that was why. ).
I'm going to use it this week myself on my car and I'll be sure to give you any feedback!! (I bet it's all gonna be positive though!)
Since your here, VE tuning like this improves part throttle performance and throttle response right? When it comes to mods like the longtube headers I just threw on, will VE tuning help get rid of my false lean condition (thus having the PCM puke more fuel through the motor as it is now)?
Very nice job man! Super helpful and it made our job much much nicer then having to scale everything and correct it by hand!The only thing that we got confused with is that the copy we downloaded had someone elses previous results in it and somehow the two were transposed or combined or something. Maybe a little message about clearing previous results first or something. This is what my buddy told me (it seemed to work without problem when I was there but the tune was a bit "off" until he figured out that was why.
).I'm going to use it this week myself on my car and I'll be sure to give you any feedback!! (I bet it's all gonna be positive though!)
Since your here, VE tuning like this improves part throttle performance and throttle response right? When it comes to mods like the longtube headers I just threw on, will VE tuning help get rid of my false lean condition (thus having the PCM puke more fuel through the motor as it is now)?
05-23-2005, 04:19 PM
#7
well...you can't quite tell people to clear it completely. the reason is that different cars get different ranges for which they're gonna get any useful data for. also, you might not hit all the 'bins' in your logging session. you don't wanna create a config for 2500-9500Hz, and clear out the rest, and then suddenly hit 10000Hz and have your PCM go crazy. you want values for it, preferably semi-resonable ones what i do (and it's a hack, but i'm yet to find a reason why it wouldn't work) is to take the points which you just got from the calibration, then graph a 3rd order polynomial trendline through it, and use the equation for that trendline to calculate the points which you didn't get through the empirical process. i've done it on few cars and it's been working fine.
what i do (and it's a hack, but i'm yet to find a reason why it wouldn't work) is to take the points which you just got from the calibration, then graph a 3rd order polynomial trendline through it, and use the equation for that trendline to calculate the points which you didn't get through the empirical process. i've done it on few cars and it's been working fine. Trending Topics
05-23-2005, 04:23 PM
#8
false lean comes from having a cam with large overlap. you can't do much about it unfortunatelly, or at least i don't know how to run around it. there's a really good thread on it in the tuning section, you'll get more out of that. i will find out about it more soon, as i'm going to be tuning a large H/C car, so if i figure anything out, i'll keep you posted.
05-23-2005, 04:40 PM
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Ahhh gotcha! That makes sense. Also makes sense how Mark got it all dialed in the second time too. Thanks for the tip on the trend-line!
My car only has a lid, longtubes, 3" catted Y and an exhaust on it. Ever since the headers she's been having a real pungent odour to the exhaust. I thought I remember reading somewhere that headers cause this because the PCM thinks the car is actually lean and thus adds fuel even though it doesn't need too. Not sure, I'm doing some searching on that right now.
Thanks again man!
My car only has a lid, longtubes, 3" catted Y and an exhaust on it. Ever since the headers she's been having a real pungent odour to the exhaust. I thought I remember reading somewhere that headers cause this because the PCM thinks the car is actually lean and thus adds fuel even though it doesn't need too. Not sure, I'm doing some searching on that right now.
Thanks again man!
05-23-2005, 06:34 PM
#10
the odor comes from not having cats usually..hmm...if you don't have a big cam, there's no reason to have false lean conditions either. adding headers makes it just normal lean, not false lean. less restriction==more flow==more air unaccounted for==not enough fuel==lean. so just do a regular VE retune and you're in business.
btw, sorry for a total hijack
btw, sorry for a total hijack
05-23-2005, 06:41 PM
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Originally Posted by RedHardSupra
btw, sorry for a total hijack
it's all good. Odd thing is though you guys are talking about headers making you go lean, and I think I'm running rich...I'm wondering if one of my sensors might be out though because Atap shows it hovering at 180mV or so rather than outputting a pseudo-sinusoid. Of course the damn thing isn't even running right now because I'm stuck in the middle of a swap to an LS6 intake and she won't start unless I pull the MAF and force it into SD...very strange...if anybody knows what might be the problem there feel free to reply to my thread in the external engine forum.
05-23-2005, 10:27 PM
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Originally Posted by RedHardSupra
the odor comes from not having cats usually..hmm...if you don't have a big cam, there's no reason to have false lean conditions either. adding headers makes it just normal lean, not false lean. less restriction==more flow==more air unaccounted for==not enough fuel==lean. so just do a regular VE retune and you're in business.
btw, sorry for a total hijack
btw, sorry for a total hijack
Finally some advice from somewhere. I was thinking along the same lines. I know the exhaust is more pungent now and the histograms show it's around +17 to +20 all over the board for the LTFT's.. I'll do some VE tuning just like you said and we'll see what happens! Thanks again man. I too am sorry for the hijack as I kindah started asking my own questions here! Sorry Rush!
05-23-2005, 10:32 PM
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Originally Posted by Mat
Kick ***! Finally some advice from somewhere. I was thinking along the same lines. I know the exhaust is more pungent now and the histograms show it's around +17 to +20 all over the board for the LTFT's.. I'll do some VE tuning just like you said and we'll see what happens!
Thanks again man. I too am sorry for the hijack as I kindah started asking my own questions here! Sorry Rush!
Finally some advice from somewhere. I was thinking along the same lines. I know the exhaust is more pungent now and the histograms show it's around +17 to +20 all over the board for the LTFT's.. I'll do some VE tuning just like you said and we'll see what happens! Thanks again man. I too am sorry for the hijack as I kindah started asking my own questions here! Sorry Rush!
The more good advice the merrier.
05-25-2005, 01:59 PM
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I'm the guy Mat is referring to (just haven't got my name changed here yet but it is Mark99Hawk on the HPTuners board).
I've attached a screenshot of what the spreadsheet looks like with my MAF calibration. There are a couple of weird values there but I just smoothed it out when I put it into the HPTuners cells (just interpolated by hand up to the max - didn't leave a big dip in there like it had).
As you can see my MAF calibration is much higher than what it should be. I have no idea why this is the case. I have a stock MAF (screens and all), stock TB, and just an SLP lid as the only intake mod.
Let me know what you think. I've attached a screenshot before I removed the old values Mat referred to and a screenshot after (which is the one I used).
Mark
I've attached a screenshot of what the spreadsheet looks like with my MAF calibration. There are a couple of weird values there but I just smoothed it out when I put it into the HPTuners cells (just interpolated by hand up to the max - didn't leave a big dip in there like it had).
As you can see my MAF calibration is much higher than what it should be. I have no idea why this is the case. I have a stock MAF (screens and all), stock TB, and just an SLP lid as the only intake mod.
Let me know what you think. I've attached a screenshot before I removed the old values Mat referred to and a screenshot after (which is the one I used).
Mark
05-25-2005, 02:01 PM
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Sorry for the hijack (again) but I figured this was a good place to post this
Those screenshots above are AFTER doing the VE tuning and getting the LTFT's close to 0 (a little on the negative side). Figured I should clarify that
Thanks again for the spreadsheet redhardsupra!!!!!!!!
Mark
Those screenshots above are AFTER doing the VE tuning and getting the LTFT's close to 0 (a little on the negative side). Figured I should clarify that
Thanks again for the spreadsheet redhardsupra!!!!!!!!
Mark
05-25-2005, 02:10 PM
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that's pretty cool (graphs are always easier to understand then words!). I'm going to have to get this spreadsheet myself for when I begin to tune hopefully within a couple weeks. It looks to be very helpful. Your values sure are off from the stock calibration for mostly stock setup (all lid??). I got a feeling mine will be pretty far off as well once I get my trims back down and swap out to an 85mm MAF.
05-25-2005, 04:16 PM
#17
if you got dips like that, take a look at the 'calculations' sheet and you'll see the count of how many values you got for a given interval. if it's less then 20-30 i'd just ignore it.
or better yet, use the 'historical compounding' feature and keep gathering data till you have 100+ samples for each interval. that amount of samples is usually very resistant to bad data.
i don't quite understand how come you flow that much that early on, i guess it's gotta be that fresh canadian air care to email me some logs?
or better yet, use the 'historical compounding' feature and keep gathering data till you have 100+ samples for each interval. that amount of samples is usually very resistant to bad data.
i don't quite understand how come you flow that much that early on, i guess it's gotta be that fresh canadian air
care to email me some logs?
05-26-2005, 09:08 AM
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Originally Posted by RedHardSupra
if you got dips like that, take a look at the 'calculations' sheet and you'll see the count of how many values you got for a given interval. if it's less then 20-30 i'd just ignore it.
or better yet, use the 'historical compounding' feature and keep gathering data till you have 100+ samples for each interval. that amount of samples is usually very resistant to bad data.
i don't quite understand how come you flow that much that early on, i guess it's gotta be that fresh canadian air care to email me some logs?
or better yet, use the 'historical compounding' feature and keep gathering data till you have 100+ samples for each interval. that amount of samples is usually very resistant to bad data.
i don't quite understand how come you flow that much that early on, i guess it's gotta be that fresh canadian air
care to email me some logs? I also don't know why it flows that much
Which logs would you like me to email you? The spreadsheet with the logged values or the hp tuners log? Send me a PM with your email and I'd be happy to.
Mark