Need tuning advice for a turbo Lt1 impala
12-17-2010, 11:11 PM
#1
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Need tuning advice for a turbo Lt1 impala Wus up guys!
I just recently finished installing a 60mm turbo onto my 95 impala and I decided to do the tuning myself.
I am definitely new to tuning and I have already accepted that this will be a long and drawn out process. I have done a ton of searches hoping to find I guess some sort of a small guide to point me in the right direction for tuning a turbo car. With very little luck I started with the basics like, switch tables and constants. Then after reading some basic info on lt1 pcmtuning.com I started to mess around with the maf sensor tables. In return I was rewarded with the richer idle that I was looking for in closed loop.
I guess that I'm picking the concept slowly but surely but I have yet to find any basic info on tuning a turbo car. Is there such basic info out there? Or will I just have to pick things up as I go and by asking questions and such?
This site has already helped me out a lot.
I just recently finished installing a 60mm turbo onto my 95 impala and I decided to do the tuning myself.
I am definitely new to tuning and I have already accepted that this will be a long and drawn out process. I have done a ton of searches hoping to find I guess some sort of a small guide to point me in the right direction for tuning a turbo car. With very little luck I started with the basics like, switch tables and constants. Then after reading some basic info on lt1 pcmtuning.com I started to mess around with the maf sensor tables. In return I was rewarded with the richer idle that I was looking for in closed loop.
I guess that I'm picking the concept slowly but surely but I have yet to find any basic info on tuning a turbo car. Is there such basic info out there? Or will I just have to pick things up as I go and by asking questions and such?
This site has already helped me out a lot.
12-18-2010, 03:24 AM
#2
Teching In
iTrader: (1)
Join Date: Jul 2010
Location: Blacksburg VA
Posts: 49
Likes: 0
Received 0 Likes
on
0 Posts
Wus up guys!
I just recently finished installing a 60mm turbo onto my 95 impala and I decided to do the tuning myself.
I am definitely new to tuning and I have already accepted that this will be a long and drawn out process. I have done a ton of searches hoping to find I guess some sort of a small guide to point me in the right direction for tuning a turbo car. With very little luck I started with the basics like, switch tables and constants. Then after reading some basic info on lt1 pcmtuning.com I started to mess around with the maf sensor tables. In return I was rewarded with the richer idle that I was looking for in closed loop.
I guess that I'm picking the concept slowly but surely but I have yet to find any basic info on tuning a turbo car. Is there such basic info out there? Or will I just have to pick things up as I go and by asking questions and such?
This site has already helped me out a lot.
I just recently finished installing a 60mm turbo onto my 95 impala and I decided to do the tuning myself.
I am definitely new to tuning and I have already accepted that this will be a long and drawn out process. I have done a ton of searches hoping to find I guess some sort of a small guide to point me in the right direction for tuning a turbo car. With very little luck I started with the basics like, switch tables and constants. Then after reading some basic info on lt1 pcmtuning.com I started to mess around with the maf sensor tables. In return I was rewarded with the richer idle that I was looking for in closed loop.
I guess that I'm picking the concept slowly but surely but I have yet to find any basic info on tuning a turbo car. Is there such basic info out there? Or will I just have to pick things up as I go and by asking questions and such?
This site has already helped me out a lot.
Idk what software is sued for those cars but if there was any way you could post the tune you'd get a lot more feedback
12-18-2010, 07:31 AM
#3
Hmmm, how'd you end up with a richer idle in closed loop?
If it were me, I would not tune it using the MAF, I would go SD. But you being a newB to tuning, that's probably out of the question. It's difficult and time consuming for someone who's done a bunch of them.
If it were me, I would not tune it using the MAF, I would go SD. But you being a newB to tuning, that's probably out of the question. It's difficult and time consuming for someone who's done a bunch of them.
12-18-2010, 10:27 AM
#4
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Theres such a broad answer to this I'm not sure where to begin. Whats your AFR right now? Are you using a wideband? What Software? Assuming its in speed density correct?
Idk what software is sued for those cars but if there was any way you could post the tune you'd get a lot more feedback
Well my afr at first start up is 10.00 and then it leans out to 13.3-15.3 once it goes into closed loop. I'm using an AEM UEGO wideband controller, the software is tunercat and I'm actually tuning with the maf.
I"ll try and post up the tune that I currently have.
Idk what software is sued for those cars but if there was any way you could post the tune you'd get a lot more feedback
Well my afr at first start up is 10.00 and then it leans out to 13.3-15.3 once it goes into closed loop. I'm using an AEM UEGO wideband controller, the software is tunercat and I'm actually tuning with the maf.
I"ll try and post up the tune that I currently have.
12-18-2010, 10:56 AM
#5
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm, how'd you end up with a richer idle in closed loop?
If it were me, I would not tune it using the MAF, I would go SD. But you being a newB to tuning, that's probably out of the question. It's difficult and time consuming for someone who's done a bunch of them.
Well, I meant that my afr is richer than it was b4. It used to be 16.1 and up. Now I have it down to 13.3-15.3. I know that its not much, but now I can let the car idle longer without the afr's sky rocketing.
I am also still using the maf sensor. It was recomended for me to stay maf since my car will be a daily driver. I am open to learning speed density tuning also. Its recomened on lt1pcmtuning to tune in speed density also for extra assurance.
I think that I"ll give SD a try after I get the part throttle tuning together. Or should I do SD first?
If it were me, I would not tune it using the MAF, I would go SD. But you being a newB to tuning, that's probably out of the question. It's difficult and time consuming for someone who's done a bunch of them.
Well, I meant that my afr is richer than it was b4. It used to be 16.1 and up. Now I have it down to 13.3-15.3. I know that its not much, but now I can let the car idle longer without the afr's sky rocketing.
I am also still using the maf sensor. It was recomended for me to stay maf since my car will be a daily driver. I am open to learning speed density tuning also. Its recomened on lt1pcmtuning to tune in speed density also for extra assurance.
I think that I"ll give SD a try after I get the part throttle tuning together. Or should I do SD first?
12-18-2010, 02:00 PM
#6
Theres such a broad answer to this I'm not sure where to begin. Whats your AFR right now? Are you using a wideband? What Software? Assuming its in speed density correct?
Idk what software is sued for those cars but if there was any way you could post the tune you'd get a lot more feedback
Well my afr at first start up is 10.00 and then it leans out to 13.3-15.3 once it goes into closed loop. I'm using an AEM UEGO wideband controller, the software is tunercat and I'm actually tuning with the maf.
I"ll try and post up the tune that I currently have.
Idk what software is sued for those cars but if there was any way you could post the tune you'd get a lot more feedback
Well my afr at first start up is 10.00 and then it leans out to 13.3-15.3 once it goes into closed loop. I'm using an AEM UEGO wideband controller, the software is tunercat and I'm actually tuning with the maf.
I"ll try and post up the tune that I currently have.
Trending Topics
12-24-2010, 09:12 AM
#10
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
I hope these pics come up this time.
The turbo is a 60mm garret from hp performance. (those guys suck)
The intercooler is from SSautochrome.
Intercooler tubing is from Maxredline.
The turbo is a 60mm garret from hp performance. (those guys suck)
The intercooler is from SSautochrome.
Intercooler tubing is from Maxredline.
Last edited by GM PHASST; 12-24-2010 at 09:29 AM. Reason: wanted to comments
12-24-2010, 09:24 AM
#11
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Phasst is the name of the B-Body race car club that I am in.
The exhaust is a single 3" from the turbo down to dual 2 1/2".
The downpipe is wrapped in header wrap and I also added a heat shield blanket from summit.
TIAL 44MM WG.
The exhaust is a single 3" from the turbo down to dual 2 1/2".
The downpipe is wrapped in header wrap and I also added a heat shield blanket from summit.
TIAL 44MM WG.
12-24-2010, 09:44 AM
#12
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Update on the tuning. I went into the main spark vs rpm vs map table and put the timing back to the original settings. I wasn't happy with the way that the numbers were looking. (Inconsistant)
I took the car back out and did another log and then readjusted timing again. I couldn't log the new settings bcuz datamaster wouldn't make communication. I"ll try and post the tune next.
I took the car back out and did another log and then readjusted timing again. I couldn't log the new settings bcuz datamaster wouldn't make communication. I"ll try and post the tune next.
12-24-2010, 10:43 PM
#14
Staging Lane
iTrader: (1)
Join Date: Dec 2001
Location: Detroit MI
Posts: 92
Likes: 0
Received 0 Likes
on
0 Posts
where is the MAF located, I don't see it in the pics.
Have you upgraded the fuel pump?
Is the engine stock? What mods have been done to the engine?
What fuel do you plan to run?
You absolutely need to watch the knock on that engine or you will break parts.
You need to run Datamaster a lot when tuning it, or use some other sort of data monitor.
Bob
Have you upgraded the fuel pump?
Is the engine stock? What mods have been done to the engine?
What fuel do you plan to run?
You absolutely need to watch the knock on that engine or you will break parts.
You need to run Datamaster a lot when tuning it, or use some other sort of data monitor.
Bob
12-25-2010, 01:29 AM
#15
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
where is the MAF located, I don't see it in the pics.
Have you upgraded the fuel pump?
Is the engine stock? What mods have been done to the engine?
What fuel do you plan to run?
You absolutely need to watch the knock on that engine or you will break parts.
You need to run Datamaster a lot when tuning it, or use some other sort of data monitor.
Bob
Have you upgraded the fuel pump?
Is the engine stock? What mods have been done to the engine?
What fuel do you plan to run?
You absolutely need to watch the knock on that engine or you will break parts.
You need to run Datamaster a lot when tuning it, or use some other sort of data monitor.
Bob
These pics were taken during the mock up stage. The maf is now mounted right before the throttle bodie.
I did upgrade the fuel pump to a racetronix/walboro 255 with hotwire.
The engine is .030 over, has 96 aluminum camaro heads, manley tool steel springs, stock cam, forged coated skirt speedpro pistons (9.7:1), forged eagle i-beam rods, h-series bearings and stock polished crank.
It also has ARP head and mainstuds and comectic head gaskets.
My usb cable is falling apart and its brand new. I contacted tunercat and they told me to just send it back and they would repair or replace as necessary. Looks like I wont be logging anything til next week.
12-25-2010, 03:03 AM
#16
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
I've been reading up on how to adjust my fueling at closed throttle and part throttle. So far, one site says to adjust the fueling by scaling the maf tables when using maf and to use the ve tables when tuning in sd. Another site says to adjust fueling by changing the fuel injector constants. Increase the constant to make the pcm think that the injector is bigger so that pulse width is shortened (decrease fueling), and to decrease the injector constant to get more pulse width. (increase fueling)
Which one of these theories is correct, or are they both correct?
Which one of these theories is correct, or are they both correct?
12-25-2010, 10:31 AM
#17
Staging Lane
iTrader: (1)
Join Date: Dec 2001
Location: Detroit MI
Posts: 92
Likes: 0
Received 0 Likes
on
0 Posts
the 'correct' way to do it is to match the injector constant to the injectors.
But there are advantages to each method.
What MAF are you using?
On my impala I always ran the MAF. To run SD with the turbo you need a 2 bar MAP sensor and PCM software modified to match it. SD / VE table tuning is an involved process, I would save it for later.
Bob
But there are advantages to each method.
What MAF are you using?
On my impala I always ran the MAF. To run SD with the turbo you need a 2 bar MAP sensor and PCM software modified to match it. SD / VE table tuning is an involved process, I would save it for later.
Bob
12-25-2010, 11:44 AM
#18
On The Tree
Thread Starter
Join Date: Apr 2010
Location: Philly
Posts: 162
Likes: 0
Received 0 Likes
on
0 Posts
Im using the stock impala maf rite now. I will be getting a granatelli from a friend next week.
I really need to get a better understanding of how the maf is tuned. So far, all i know is that when u increase the numbers in the table u get a richer mixture and when u decrease them u get a leaner mixture.
How do u know where to scale the maf?
I just scaled all four tables in tunercat and logged the car to see if the afr's got any richer.
I really need to get a better understanding of how the maf is tuned. So far, all i know is that when u increase the numbers in the table u get a richer mixture and when u decrease them u get a leaner mixture.
How do u know where to scale the maf?
I just scaled all four tables in tunercat and logged the car to see if the afr's got any richer.
12-25-2010, 12:09 PM
#19
Staging Lane
iTrader: (1)
Join Date: Dec 2001
Location: Detroit MI
Posts: 92
Likes: 0
Received 0 Likes
on
0 Posts
Are you looking at the AFRs at part throttle or WOT?
(I would NOT run this car at high boost until you get it sorted out)
At part throttle, assuming the O2 sensors are active, the PCM will correct the mixture back to 14.7 .
The PCM makes a quick correction using the integrator, and then adjusts the long term corrections to try to bring the integrator back to to 'zero' (zero correction is when the integrators and blocklearns are at 128)
On the Block Learns, there is a group of them arranged like a grid. The PCM chooses which one to use based on airflow and RPM.
Anyway, are you using Datamaster for logging?
For curving the MAF, I would set the block learn enable temperature to something that will not activate. This way they will not learn anything. Then the integrators will adjust to bring your mixture back to 14.7 (assuming closed loop)
So, for example, there is a MAF table entry of 20 grams/sec.
drive at 20 grams/second for a few seconds and see where the integrators settle. E.g. the integrators settle to 120 (the PCM is reducing fuel).
now go back into the MAF table and adjust the 20 grams/sec entry to 20 * (120/128). or 18.75 grams/sec
The idea is to get the curve dialed in so that the PCM has to make very little correction.
Now, with the Granatelli MAF, you will need to start with a new set of tables.
Does this all make sense?
Bob
(I would NOT run this car at high boost until you get it sorted out)
At part throttle, assuming the O2 sensors are active, the PCM will correct the mixture back to 14.7 .
The PCM makes a quick correction using the integrator, and then adjusts the long term corrections to try to bring the integrator back to to 'zero' (zero correction is when the integrators and blocklearns are at 128)
On the Block Learns, there is a group of them arranged like a grid. The PCM chooses which one to use based on airflow and RPM.
Anyway, are you using Datamaster for logging?
For curving the MAF, I would set the block learn enable temperature to something that will not activate. This way they will not learn anything. Then the integrators will adjust to bring your mixture back to 14.7 (assuming closed loop)
So, for example, there is a MAF table entry of 20 grams/sec.
drive at 20 grams/second for a few seconds and see where the integrators settle. E.g. the integrators settle to 120 (the PCM is reducing fuel).
now go back into the MAF table and adjust the 20 grams/sec entry to 20 * (120/128). or 18.75 grams/sec
The idea is to get the curve dialed in so that the PCM has to make very little correction.
Now, with the Granatelli MAF, you will need to start with a new set of tables.
Does this all make sense?
Bob
12-25-2010, 12:13 PM
#20
Staging Lane
iTrader: (1)
Join Date: Dec 2001
Location: Detroit MI
Posts: 92
Likes: 0
Received 0 Likes
on
0 Posts
A couple quick details.
The PCM delivers fuel depending on how much air it thinks is in the cylinder.
It knows how much air got into the cylinder by one of 2 ways.
MAF (grams/sec) / RPM = air in the cylinder (basically)
or
Manifold pressure * VE = air in the cylinder. (basically)
So by increasing the number in the MAF table (or VE table) you essentially tell the PCM that more air is in the cyinder, so the PCM injects more fuel.
Bob
The PCM delivers fuel depending on how much air it thinks is in the cylinder.
It knows how much air got into the cylinder by one of 2 ways.
MAF (grams/sec) / RPM = air in the cylinder (basically)
or
Manifold pressure * VE = air in the cylinder. (basically)
So by increasing the number in the MAF table (or VE table) you essentially tell the PCM that more air is in the cyinder, so the PCM injects more fuel.
Bob