Speed Density tuning for the ZO6 LS7 E38 PCM...anyone done it?
02-04-2010, 10:16 PM
#1
Melting Slicks
Thread Starter
Speed Density tuning for the ZO6 LS7 E38 PCM...anyone done it?
I want to eliminate my MAF (hood clearance issues) and do a speed density tune with HPTuners....anyone performed this yet?
02-05-2010, 10:50 AM
#4
Former Vendor
02-05-2010, 10:58 AM
#5
02-05-2010, 03:43 PM
#6
Melting Slicks
Thread Starter
Awesome feedback guys! Can anyone share the process? I went to the HPT website and unfortunately their tutor video demo doesn't use an E38 PCM so it's very difficult to understand how many tables are impacted, where to start, etc. I have a plumbed in wide band so that I can collect the data necessary for refining the tune but really don't know where to start. I have a lumpy SR cam, ported heads, sheetmetal intake and 102mm TB.
Any help would more than be appreciated.
Any help would more than be appreciated.
02-05-2010, 08:20 PM
#7
Drifting
Awesome feedback guys! Can anyone share the process? I went to the HPT website and unfortunately their tutor video demo doesn't use an E38 PCM so it's very difficult to understand how many tables are impacted, where to start, etc. I have a plumbed in wide band so that I can collect the data necessary for refining the tune but really don't know where to start. I have a lumpy SR cam, ported heads, sheetmetal intake and 102mm TB.
Any help would more than be appreciated.
Any help would more than be appreciated.
02-08-2010, 07:03 PM
#9
Melting Slicks
Thread Starter
Check out my post's there. I wrote a program that is a "add-on" to HPTuners called EQ <> VE 3.5. That will help you with the process of tuning your VE equations.
Do you have an intake air temp sensor to replace the one built into your MAF?...
02-09-2010, 09:08 AM
#10
Safety Car
It will probably require you to change the calibration info for the sensor, then. I believe some of the IATs are set up with different scaling.
02-09-2010, 11:55 PM
#11
Melting Slicks
Thread Starter
It will probably require you to change the calibration info for the sensor, then. I believe some of the IATs are set up with different scaling.
03-14-2010, 04:46 PM
#13
did you improve your software? I tried to use it and it wouldn't work with the 2.5 BAR VE table that I have with the expanded resolution.
03-14-2010, 09:54 PM
#14
Drifting
04-10-2010, 12:05 PM
#16
You have to increase impact factor tables under fuel transients.
When you do a log do some fast shifting and watch how long it takes for the engine to richen up upon stomping the throttle.
It may take 1 full second or longer for afrs to reach commanded afrs this is because the e38 uses the MAF to work this out ie in g/s. from 0 to 256, problem is its disconnected so we only get a constant 0 g/s to work with lucky we can alter the other impact tables which can improve shifting and fueling under power enrichment by using a MAP signal. it takes some work. If you want some base settings shoot me a pm.
Basically fuel transients is an accelerator pump.
Its kind of like a delay or controlled ramp up of injector pulsewidth, watching how inj pw behaves in relation to afr and throttle is a good way to log this. This is very important with FI. If it takes to long to reach desired pw it will lean bog on shifts, its a horrible feeling and if it takes say 0.8 seconds to recover per gear change then its time off acceleration.
A good way to start is watch how afr behaves in logs on fast shifts(ie not flat change but fast throttle movements) with the MAF connected before building a ve table.
The ve table is very easy to build using STFT histograms and wot logs in a fixed gear for a desired commanded afr. Do this and get transients correct, once this is right I really recommend using the IAT sensor away from engine bay heat soak in NA applications because in WOT applications where the outside air is rushing in at ambient very quickly that is what the motor is seeing, A heat soaked sensor of 10 to 20 degrees higher will create a false reading and make the engine overly rich, esp this will be noticed in winter conditions and the engine can be accurately tuned then.
The best part is my tune is more stable in SD then MAF, I can say though that once the VE is spot on drivability is somewhat improved with the MAF basically due to what role the VE table plays behind the MAF.
We have found its more a battle of intakes then weather or not the maf is retained. A few tuners down under claim the maf is still better, I think they don't have transients sorted though. Some guys have very quick cars using the MAF with a decent OTR one in particular is the ramjet. With air intakes being sensitive on these engines it is possible that it may make more of an effect then weather the engine retains the maf or not. Switching intakes has required me to make changes of up to 20% in transients. I am not overly familiar with the corvette intakes. But one for the VE or G8 is named the ramjet and can utilise the MAF and has a large surface area to directly control the air from behind the grill. In this scenario a full tune of the VE maybe beneficial before then reinstalling the MAF. With this style of intake combined with the VE table being dialled in at lower vacuum and rpms especially and the MAF table being calibrated right the response will be as good if not better then an SD only tune.
I really recommend to utilise the MAF, Use intake options that utilise it that are effective. Try and get the VE dialled in better aswell. Once the MAF is maxxed out or you are in an FI application then look at soley SD.
When you do a log do some fast shifting and watch how long it takes for the engine to richen up upon stomping the throttle.
It may take 1 full second or longer for afrs to reach commanded afrs this is because the e38 uses the MAF to work this out ie in g/s. from 0 to 256, problem is its disconnected so we only get a constant 0 g/s to work with lucky we can alter the other impact tables which can improve shifting and fueling under power enrichment by using a MAP signal. it takes some work. If you want some base settings shoot me a pm.
Basically fuel transients is an accelerator pump.
Its kind of like a delay or controlled ramp up of injector pulsewidth, watching how inj pw behaves in relation to afr and throttle is a good way to log this. This is very important with FI. If it takes to long to reach desired pw it will lean bog on shifts, its a horrible feeling and if it takes say 0.8 seconds to recover per gear change then its time off acceleration.
A good way to start is watch how afr behaves in logs on fast shifts(ie not flat change but fast throttle movements) with the MAF connected before building a ve table.
The ve table is very easy to build using STFT histograms and wot logs in a fixed gear for a desired commanded afr. Do this and get transients correct, once this is right I really recommend using the IAT sensor away from engine bay heat soak in NA applications because in WOT applications where the outside air is rushing in at ambient very quickly that is what the motor is seeing, A heat soaked sensor of 10 to 20 degrees higher will create a false reading and make the engine overly rich, esp this will be noticed in winter conditions and the engine can be accurately tuned then.
The best part is my tune is more stable in SD then MAF, I can say though that once the VE is spot on drivability is somewhat improved with the MAF basically due to what role the VE table plays behind the MAF.
We have found its more a battle of intakes then weather or not the maf is retained. A few tuners down under claim the maf is still better, I think they don't have transients sorted though. Some guys have very quick cars using the MAF with a decent OTR one in particular is the ramjet. With air intakes being sensitive on these engines it is possible that it may make more of an effect then weather the engine retains the maf or not. Switching intakes has required me to make changes of up to 20% in transients. I am not overly familiar with the corvette intakes. But one for the VE or G8 is named the ramjet and can utilise the MAF and has a large surface area to directly control the air from behind the grill. In this scenario a full tune of the VE maybe beneficial before then reinstalling the MAF. With this style of intake combined with the VE table being dialled in at lower vacuum and rpms especially and the MAF table being calibrated right the response will be as good if not better then an SD only tune.
I really recommend to utilise the MAF, Use intake options that utilise it that are effective. Try and get the VE dialled in better aswell. Once the MAF is maxxed out or you are in an FI application then look at soley SD.
04-10-2010, 03:18 PM
#17
Burning Brakes
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04-10-2010, 07:52 PM
#18
To build the ve on a NA engine, stick with 3000 around pk tq area. around 2000 75-100kpa 2000rpm region. around 1250 idle areas of 50kpa. Build an stft error histogram turn LTFTs off altogether. There are a lot of areas to become unstuck with SD tuning them. A lot of tuners think there right on the dyno but errors are exposed on the strip and street especially fuel transients which when right will make or break performance, just a matter of time to sort through it.
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Lee Howie (01-06-2016)
01-06-2016, 10:50 AM
#19
You have to increase impact factor tables under fuel transients.
When you do a log do some fast shifting and watch how long it takes for the engine to richen up upon stomping the throttle.
It may take 1 full second or longer for afrs to reach commanded afrs this is because the e38 uses the MAF to work this out ie in g/s. from 0 to 256, problem is its disconnected so we only get a constant 0 g/s to work with lucky we can alter the other impact tables which can improve shifting and fueling under power enrichment by using a MAP signal. it takes some work. If you want some base settings shoot me a pm.
Basically fuel transients is an accelerator pump.
Its kind of like a delay or controlled ramp up of injector pulsewidth, watching how inj pw behaves in relation to afr and throttle is a good way to log this. This is very important with FI. If it takes to long to reach desired pw it will lean bog on shifts, its a horrible feeling and if it takes say 0.8 seconds to recover per gear change then its time off acceleration.
A good way to start is watch how afr behaves in logs on fast shifts(ie not flat change but fast throttle movements) with the MAF connected before building a ve table.
The ve table is very easy to build using STFT histograms and wot logs in a fixed gear for a desired commanded afr. Do this and get transients correct, once this is right I really recommend using the IAT sensor away from engine bay heat soak in NA applications because in WOT applications where the outside air is rushing in at ambient very quickly that is what the motor is seeing, A heat soaked sensor of 10 to 20 degrees higher will create a false reading and make the engine overly rich, esp this will be noticed in winter conditions and the engine can be accurately tuned then.
The best part is my tune is more stable in SD then MAF, I can say though that once the VE is spot on drivability is somewhat improved with the MAF basically due to what role the VE table plays behind the MAF.
We have found its more a battle of intakes then weather or not the maf is retained. A few tuners down under claim the maf is still better, I think they don't have transients sorted though. Some guys have very quick cars using the MAF with a decent OTR one in particular is the ramjet. With air intakes being sensitive on these engines it is possible that it may make more of an effect then weather the engine retains the maf or not. Switching intakes has required me to make changes of up to 20% in transients. I am not overly familiar with the corvette intakes. But one for the VE or G8 is named the ramjet and can utilise the MAF and has a large surface area to directly control the air from behind the grill. In this scenario a full tune of the VE maybe beneficial before then reinstalling the MAF. With this style of intake combined with the VE table being dialled in at lower vacuum and rpms especially and the MAF table being calibrated right the response will be as good if not better then an SD only tune.
I really recommend to utilise the MAF, Use intake options that utilise it that are effective. Try and get the VE dialled in better aswell. Once the MAF is maxxed out or you are in an FI application then look at soley SD.
When you do a log do some fast shifting and watch how long it takes for the engine to richen up upon stomping the throttle.
It may take 1 full second or longer for afrs to reach commanded afrs this is because the e38 uses the MAF to work this out ie in g/s. from 0 to 256, problem is its disconnected so we only get a constant 0 g/s to work with lucky we can alter the other impact tables which can improve shifting and fueling under power enrichment by using a MAP signal. it takes some work. If you want some base settings shoot me a pm.
Basically fuel transients is an accelerator pump.
Its kind of like a delay or controlled ramp up of injector pulsewidth, watching how inj pw behaves in relation to afr and throttle is a good way to log this. This is very important with FI. If it takes to long to reach desired pw it will lean bog on shifts, its a horrible feeling and if it takes say 0.8 seconds to recover per gear change then its time off acceleration.
A good way to start is watch how afr behaves in logs on fast shifts(ie not flat change but fast throttle movements) with the MAF connected before building a ve table.
The ve table is very easy to build using STFT histograms and wot logs in a fixed gear for a desired commanded afr. Do this and get transients correct, once this is right I really recommend using the IAT sensor away from engine bay heat soak in NA applications because in WOT applications where the outside air is rushing in at ambient very quickly that is what the motor is seeing, A heat soaked sensor of 10 to 20 degrees higher will create a false reading and make the engine overly rich, esp this will be noticed in winter conditions and the engine can be accurately tuned then.
The best part is my tune is more stable in SD then MAF, I can say though that once the VE is spot on drivability is somewhat improved with the MAF basically due to what role the VE table plays behind the MAF.
We have found its more a battle of intakes then weather or not the maf is retained. A few tuners down under claim the maf is still better, I think they don't have transients sorted though. Some guys have very quick cars using the MAF with a decent OTR one in particular is the ramjet. With air intakes being sensitive on these engines it is possible that it may make more of an effect then weather the engine retains the maf or not. Switching intakes has required me to make changes of up to 20% in transients. I am not overly familiar with the corvette intakes. But one for the VE or G8 is named the ramjet and can utilise the MAF and has a large surface area to directly control the air from behind the grill. In this scenario a full tune of the VE maybe beneficial before then reinstalling the MAF. With this style of intake combined with the VE table being dialled in at lower vacuum and rpms especially and the MAF table being calibrated right the response will be as good if not better then an SD only tune.
I really recommend to utilise the MAF, Use intake options that utilise it that are effective. Try and get the VE dialled in better aswell. Once the MAF is maxxed out or you are in an FI application then look at soley SD.
01-06-2016, 10:52 AM
#20
Advanced
the whole point of a public forum is to share knowledge, because if you have a question, it probably means many others have a similar question.
just ask your questions here, we'll be glad to answer
just ask your questions here, we'll be glad to answer