So Cool
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
So Cool
i editted my hp tuners lastest bin to pull -20*. this is done but installing momentary switch that cuts the signal from my ait sensor. what this does is the hp tuners vcm will read lowset possible ait vrs timing and i pull -20*. well i tested in the driveway, didnt even have to leave home, and it works awesome! i saw 4.5 psi @2100 rpms!! when i was at the track i saw 1 to zero boost at the line. thinks thatll cut my 1.78 60ft to something lower 
scew getting bigger stall 
man i getting good with hp tuners sd 3 bar
special thanks to QUICKSILVER
scew getting bigger stall man i getting good with hp tuners sd 3 bar
special thanks to QUICKSILVER
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
Originally Posted by Skunkworks
Congrats Nick,
Glad to here it worked for you. Are going rich and pulling timing or just pulling timing?
Mike
Glad to here it worked for you. Are going rich and pulling timing or just pulling timing?
Mike
just timing ... my alchy doenst work anymore
with the ait table mike, it only controls timing not fuel.
check this out. since ill be pulling e brake i will be unable to push/hold button(switch). so what ill do is tap into my the e brake switch and use, run it to a relay which inturn will cut ait!!!
mike all other things being equal, if i cut 1.78 to something more respectable, 1.50 that gets my 9.9 run to...............?? what do you think????????? .26X1.5=.39 faster??? i'd say at least as the car left line soooooooooo soft.
drop the e brake and back to normal ait!!!!!
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
Originally Posted by NICK YOSKIN
just timing ... my alchy doenst work anymore
with the ait table mike, it only controls timing not fuel.
check this out. since ill be pulling e brake i will be unable to push/hold button(switch). so what ill do is tap into my the e brake switch and use, run it to a relay which inturn will cut ait!!!
mike all other things being equal, if i cut 1.78 to something more respectable, 1.50 that gets my 9.9 run to...............?? what do you think????????? .26X1.5=.39 faster??? i'd say at least as the car left line soooooooooo soft.
drop the e brake and back to normal ait!!!!!
with the ait table mike, it only controls timing not fuel.
check this out. since ill be pulling e brake i will be unable to push/hold button(switch). so what ill do is tap into my the e brake switch and use, run it to a relay which inturn will cut ait!!!
mike all other things being equal, if i cut 1.78 to something more respectable, 1.50 that gets my 9.9 run to...............?? what do you think????????? .26X1.5=.39 faster??? i'd say at least as the car left line soooooooooo soft.
drop the e brake and back to normal ait!!!!!
With speed density (SD) your IAT is factored into mass flow calculation so I would expect PCM richened your mixture. Dry shots work in a similar way (cooling MAF or IAT).
Like I mentioned before you can do window switch, but E-brake with relay will certainly do the job.
As far as how much 60 will improve it’s hard to say but if you can plant power .15+ is certainly not unreasonable. Guys with 1/4 mile experience will chime in. I’ve only run 1/4 on two wheels and that was twice. I’m more of a 180+ MPH person.
But just as a guess you should now be 9.75-9.6 second range based on your previous 9.9 run. With 4 plus pounds of boost now launch shouldn’t be so soft. Did you factor in air temps?One thing that may concern me is transition from open IAT circuit to normal operation. I doubt it’s going to be a problem, but look at how PCM recovers.
Oh, remember your exhaust gases are now very hot do to pulling timing and may actually have flames traveling down header.
Mike
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
thanks for chiming in!
i am not aware of any table were ait modify fuel.
180mph... i was ripping around last weekend at 186, and pulling hard!!!
id like to think that ill pull easy 1.5 and that going to get me 9.5 easly.
no problem on recovery.
i am not aware of any table were ait modify fuel.
180mph... i was ripping around last weekend at 186, and pulling hard!!!
id like to think that ill pull easy 1.5 and that going to get me 9.5 easly.
no problem on recovery.
Originally Posted by Skunkworks
Nick,
With speed density (SD) your IAT is factored into mass flow calculation so I would expect PCM richened your mixture. Dry shots work in a similar way (cooling MAF or IAT).
Like I mentioned before you can do window switch, but E-brake with relay will certainly do the job.
As far as how much 60 will improve it’s hard to say but if you can plant power .15+ is certainly not unreasonable. Guys with 1/4 mile experience will chime in. I’ve only run 1/4 on two wheels and that was twice. I’m more of a 180+ MPH person. But just as a guess you should now be 9.75-9.6 second range based on your previous 9.9 run. With 4 plus pounds of boost now launch shouldn’t be so soft. Did you factor in air temps?
One thing that may concern me is transition from open IAT circuit to normal operation. I doubt it’s going to be a problem, but look at how PCM recovers.
Oh, remember your exhaust gases are now very hot do to pulling timing and may actually have flames traveling down header.
Mike
With speed density (SD) your IAT is factored into mass flow calculation so I would expect PCM richened your mixture. Dry shots work in a similar way (cooling MAF or IAT).
Like I mentioned before you can do window switch, but E-brake with relay will certainly do the job.
As far as how much 60 will improve it’s hard to say but if you can plant power .15+ is certainly not unreasonable. Guys with 1/4 mile experience will chime in. I’ve only run 1/4 on two wheels and that was twice. I’m more of a 180+ MPH person.
But just as a guess you should now be 9.75-9.6 second range based on your previous 9.9 run. With 4 plus pounds of boost now launch shouldn’t be so soft. Did you factor in air temps?One thing that may concern me is transition from open IAT circuit to normal operation. I doubt it’s going to be a problem, but look at how PCM recovers.
Oh, remember your exhaust gases are now very hot do to pulling timing and may actually have flames traveling down header.
Mike
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
mike 1.78 to 1.50 will get me more then .15 
,
,
Originally Posted by Skunkworks
Nick,
With speed density (SD) your IAT is factored into mass flow calculation so I would expect PCM richened your mixture. Dry shots work in a similar way (cooling MAF or IAT).
Like I mentioned before you can do window switch, but E-brake with relay will certainly do the job.
As far as how much 60 will improve it’s hard to say but if you can plant power .15+ is certainly not unreasonable. Guys with 1/4 mile experience will chime in. I’ve only run 1/4 on two wheels and that was twice. I’m more of a 180+ MPH person. But just as a guess you should now be 9.75-9.6 second range based on your previous 9.9 run. With 4 plus pounds of boost now launch shouldn’t be so soft. Did you factor in air temps?
One thing that may concern me is transition from open IAT circuit to normal operation. I doubt it’s going to be a problem, but look at how PCM recovers.
Oh, remember your exhaust gases are now very hot do to pulling timing and may actually have flames traveling down header.
Mike
With speed density (SD) your IAT is factored into mass flow calculation so I would expect PCM richened your mixture. Dry shots work in a similar way (cooling MAF or IAT).
Like I mentioned before you can do window switch, but E-brake with relay will certainly do the job.
As far as how much 60 will improve it’s hard to say but if you can plant power .15+ is certainly not unreasonable. Guys with 1/4 mile experience will chime in. I’ve only run 1/4 on two wheels and that was twice. I’m more of a 180+ MPH person.
But just as a guess you should now be 9.75-9.6 second range based on your previous 9.9 run. With 4 plus pounds of boost now launch shouldn’t be so soft. Did you factor in air temps?One thing that may concern me is transition from open IAT circuit to normal operation. I doubt it’s going to be a problem, but look at how PCM recovers.
Oh, remember your exhaust gases are now very hot do to pulling timing and may actually have flames traveling down header.
Mike
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Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
Originally Posted by NICK YOSKIN
mike 1.78 to 1.50 will get me more then .15 ,
,Try a couple test runs in driveway. Tell the significant other you had to from R&D standpoint.
Mike
Melting Slicks
Joined: Mar 2002
Posts: 2,931
Likes: 2
From: Tx
Originally Posted by NICK YOSKIN
thanks for chiming in!
i am not aware of any table were ait modify fuel.
180mph... i was ripping around last weekend at 186, and pulling hard!!!
id like to think that ill pull easy 1.5 and that going to get me 9.5 easly.
no problem on recovery.
i am not aware of any table were ait modify fuel.
180mph... i was ripping around last weekend at 186, and pulling hard!!!
id like to think that ill pull easy 1.5 and that going to get me 9.5 easly.
no problem on recovery.
I think a switch on the IAT sensor would do exactly what you want on a car running SD.
Interrupting the IAT signal will make the PCM think the IAT is -37*. This will cause a car running SD to go way rich (I've done this and seen the impact). You would then be able to go into the spark iat table and subtract a bunch of timing at the lowest iat point in that general area of load. You can pull up to 20*.
This would result in no impact under normal conditions and very low timing with a very rich af when the switch is on. I'm not sure how rich it would make it, but here is a quick example.
Given:
MAP = 135kpa
RPM = 3000
VE in % = 90
temp = 70
the pcm would calc: 204 g/sec or 1.01 g/cyl
change the temp to -37
the pcm would calc: 255 g/sec or 1.3 g/cyl
~ a 20% impact.
That should drop af about 2 - 3 pts.
You could easily rig up a button that would interrupt the IAT signal. Just hold the button on the line and let go just before launch. You could even do a micro switch behind the brake and then put an activation switch somewhere else in the car.
I think it is definitely worth a try.
Interrupting the IAT signal will make the PCM think the IAT is -37*. This will cause a car running SD to go way rich (I've done this and seen the impact). You would then be able to go into the spark iat table and subtract a bunch of timing at the lowest iat point in that general area of load. You can pull up to 20*.
This would result in no impact under normal conditions and very low timing with a very rich af when the switch is on. I'm not sure how rich it would make it, but here is a quick example.
Given:
MAP = 135kpa
RPM = 3000
VE in % = 90
temp = 70
the pcm would calc: 204 g/sec or 1.01 g/cyl
change the temp to -37
the pcm would calc: 255 g/sec or 1.3 g/cyl
~ a 20% impact.
That should drop af about 2 - 3 pts.
You could easily rig up a button that would interrupt the IAT signal. Just hold the button on the line and let go just before launch. You could even do a micro switch behind the brake and then put an activation switch somewhere else in the car.
I think it is definitely worth a try.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
Originally Posted by QuickSilver2002
Nick, the IAT input is part of the base airflow calculation so you should be seeing a very rich AFR. Here is the post I made in the orginal thread.
gotcha...
hp tuners doesnt go into the caculations of the iat and base airflow. there is no table that shows that, unless i missed it.
Melting Slicks
Joined: Mar 2002
Posts: 2,931
Likes: 2
From: Tx
Originally Posted by NICK YOSKIN
gotcha...
hp tuners doesnt go into the caculations of the iat and base airflow. there is no table that shows that, unless i missed it.
hp tuners doesnt go into the caculations of the iat and base airflow. there is no table that shows that, unless i missed it.
I think HP tuners uses the VE% format in the ve table display. If so, use this formula to calculate predicted airflow.
Code:
g/cyl = ((VE% * 178.33 * 0.708 * Kpa)/(IAT+273)/5120) g/sec = "g/cyl" / (15/RPM) VE% - is from the table in the tool Kpa - is from the table IAT- is in Celsius and you just have to pick one or use logged data .708 - is the displacement in liters of one cyl on 346 ci motor RPM - is from the table
Code:
g/cyl = (VE value) * Map/(IAT + 273)
In this particular case, the low IAT is doing exactly what you want. Causing the PCM to add fuel and run a very rich mixture to help with spool.
Last edited by QuickSilver2002; Nov 28, 2005 at 02:16 PM.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
excellent info!
i need to save this post in my desktop
i also need to relocate ait sensor as its after alchy.
QUOTE=QuickSilver2002]Right, there is no table that shows it. It is just at the core of the PCM SD/VE calcs. You can look at any value in your VE table (which is really not a VE table, it is a Massflow table) and determine what the PCM will calculate the predicted airflow to be. More predicted airflow = longer pulse widths and more fule.
I think HP tuners uses the VE% format in the ve table display. If so, use this formula to calculate predicted airflow.
If it displays VE in the native format (g*k/kPa), then use this formula
The bottom line is that IAT has a pretty major impact on the VE calcs. This is why I tell people to not spray the IAT sensor with alky when running SD. It does the exact opposite of what you want, since the PCM will just add more fuel (which is the opposite of what you want when spraying alky).
In this particular case, the low IAT is doing exactly what you want. Causing the PCM to add fuel and run a very rich mixture to help with spool.[/QUOTE]
i need to save this post in my desktop
i also need to relocate ait sensor as its after alchy.
QUOTE=QuickSilver2002]Right, there is no table that shows it. It is just at the core of the PCM SD/VE calcs. You can look at any value in your VE table (which is really not a VE table, it is a Massflow table) and determine what the PCM will calculate the predicted airflow to be. More predicted airflow = longer pulse widths and more fule.
I think HP tuners uses the VE% format in the ve table display. If so, use this formula to calculate predicted airflow.
Code:
g/cyl = ((VE% * 178.33 * 0.708 * Kpa)/(IAT+273)/5120) g/sec = "g/cyl" / (15/RPM) VE% - is from the table in the tool Kpa - is from the table IAT- is in Celsius and you just have to pick one or use logged data .708 - is the displacement in liters of one cyl on 346 ci motor RPM - is from the table
Code:
g/cyl = (VE value) * Map/(IAT + 273)
In this particular case, the low IAT is doing exactly what you want. Causing the PCM to add fuel and run a very rich mixture to help with spool.[/QUOTE]
Safety Car
Joined: Apr 2004
Posts: 4,097
Likes: 10
From: East Coast
Originally Posted by NICK YOSKIN
i editted my hp tuners lastest bin to pull -20*. this is done but installing momentary switch that cuts the signal from my ait sensor. what this does is the hp tuners vcm will read lowset possible ait vrs timing and i pull -20*. well i tested in the driveway, didnt even have to leave home, and it works awesome! i saw 4.5 psi @2100 rpms!! when i was at the track i saw 1 to zero boost at the line. thinks thatll cut my 1.78 60ft to something lower scew getting bigger stall
man i getting good with hp tuners sd 3 bar
special thanks to QUICKSILVER
scew getting bigger stall man i getting good with hp tuners sd 3 bar
special thanks to QUICKSILVER