Need help with pumping eff table and other tuning issues

[1966 dart wagon]

I've had issues getting my fueling tables correct and after read I've relized I need to adjust the pumping eff table.

I have a 2.5 stock intercooled s60 turbo, 3in turbo back exhaust stock intake, slight ported exh manifold and stock head/intake with 40+s.

I have the injectors set up in mptuner to be pumping around into the low 9s for afr and still getting mid 12s as far as WOT. While im driving, cruise, its going fine at 14.7, but when I let off the gas, and coast in gear especially its a little rich in the 12s untill I hit the gas again then its fine, what table adjusts this? All of my fueling tables at the moment are rich, very rich in the 12s for driving around at cruise and as well as baseline.

I've read in other threads about adjusting the Pumping eff. I was wondering if someone has a table I can use as a reference to get a close setup then fine tune from there.

I've read this, but prefer to have something close then fine tune:


The easiest way to tune the PE table is to drag the brakes to hold the RPM at a set point. Ride it for at least 10 seconds like that and then record your readings. If the AFR is higher numerically than what it should be according to the AFR line in MPT2, then up the PE table in that RPM spot. If it's lower numerically, then lower the PE table.

If you use that process in 500RPM increments you should have the PE table dialed in perfectly in no time at all.


So Brian...I'm assuming you want to do this at 0 lbs of boost and WOT to eliminate the turbo from the equation as much as possible?

If so, what is the best way of keeping boost out? I need to fine tune my pumping efficiency table and I was going to disconnect my intercooler piping from the throttle body, hook an air tank through a regulator to the wastegate can, putting about 30PSI against the can to keep the wastegate open (to reduce backpressure from the turbine wheel and keep the turbo wheel speed down). Then do some WOT runs dragging the brakes to log the AFRs at each 500 RPM point, and adjust the Pumping Efficiency table accordingly. Does this sound like a valid method, or am I off base somewhere?

Is this what everyone does, If Rob would chime in how does he go about making cals for people with this turbo since its send in your specs and go from there, does he use the tables from the MP computer for the s60 turbo???


Oh and another issue my fuel calculator for MPG is WAY OFF is this effected by the pumping eff.??? I says im getting 99 mpg all the time at cruise, I wish!

[Aries_Turbo]

set the FuelBaselineFromMap, FuelPartThrottle, and FuelFullThrottle back to stock 2.5L scaled for +40's and 3-bar.

set the boost as low as possible (hose straight from the turbo outlet to the wastegate can or even unhook the wastegate can arm) and do some WOT pulls against the brakes at various RPM points. adjust the pumpingEfficiency table at those RPM points.

if certain boost/vac areas give you trouble after that, then tune that area of the Map based fuel tables listed in the first sentence.

PumpingEfficiency is the key table to getting the fuel dialed in and should be addressed before any other table other than basic scaling for injectors and map.

even if warmup is crap, get the engine warm and get that pumping efficiency dialed in. it may fix the warmup issue.

Brian

[cordes]

set the FuelBaselineFromMap, FuelPartThrottle, and FuelFullThrottle back to stock 2.5L scaled for +40's and 3-bar.

set the boost as low as possible (hose straight from the turbo outlet to the wastegate can or even unhook the wastegate can arm) and do some WOT pulls against the brakes at various RPM points. adjust the pumpingEfficiency table at those RPM points.

if certain boost/vac areas give you trouble after that, then tune that area of the Map based fuel tables listed in the first sentence.

PumpingEfficiency is the key table to getting the fuel dialed in and should be addressed before any other table other than basic scaling for injectors and map.

even if warmup is crap, get the engine warm and get that pumping efficiency dialed in. it may fix the warmup issue.

Brian

This should be in the KC.

[turbovanman²]

Yep, adjust PE tables, also if using MP tuner, use the built in air fuel scaling tables, its pretty damn close.

Brian is right, I had a lean idle then lean to rich transition at 2000 rpm, tweaked the PE table, fixed.

Take notes at what RPM its rich/lean, then adjust accordingly, then if you need minor tweaks, use the appropriate part/wot tables next.

[1966 dart wagon]

set the FuelBaselineFromMap, FuelPartThrottle, and FuelFullThrottle back to stock 2.5L scaled for +40's and 3-bar.

set the boost as low as possible (hose straight from the turbo outlet to the wastegate can or even unhook the wastegate can arm) and do some WOT pulls against the brakes at various RPM points. adjust the pumpingEfficiency table at those RPM points.

if certain boost/vac areas give you trouble after that, then tune that area of the Map based fuel tables listed in the first sentence.

PumpingEfficiency is the key table to getting the fuel dialed in and should be addressed before any other table other than basic scaling for injectors and map.

even if warmup is crap, get the engine warm and get that pumping efficiency dialed in. it may fix the warmup issue.

Brian

Ok low boost and do some brake boosting, ok so say at 3k brake boosting WOT I'm lean, then what? what if im rich? adjust the table up down? sideways???? This topic should be in the KC I agree!

[turbovanman²]

Ok low boost and do some brake boosting, ok so say at 3k brake boosting WOT I'm lean, then what? what if im rich? adjust the table up down? sideways???? This topic should be in the KC I agree!

If rich, move it down, if lean, move it up, and yes, you can move it sideways but I've never had too.

[cordes]

Ok low boost and do some brake boosting, ok so say at 3k brake boosting WOT I'm lean, then what? what if im rich? adjust the table up down? sideways???? This topic should be in the KC I agree!

I would start out at a low RPM while doing this. If for some reason you have too much timing (not too likely at WG setting) you'll need to adjust that too.

[GLHNSLHT2]

set the FuelBaselineFromMap, FuelPartThrottle, and FuelFullThrottle back to stock 2.5L scaled for +40's and 3-bar.

set the boost as low as possible (hose straight from the turbo outlet to the wastegate can or even unhook the wastegate can arm) and do some WOT pulls against the brakes at various RPM points. adjust the pumpingEfficiency table at those RPM points.

if certain boost/vac areas give you trouble after that, then tune that area of the Map based fuel tables listed in the first sentence.

PumpingEfficiency is the key table to getting the fuel dialed in and should be addressed before any other table other than basic scaling for injectors and map.

even if warmup is crap, get the engine warm and get that pumping efficiency dialed in. it may fix the warmup issue.

Brian

I agree either unhook the WG or if you have an adjustable gate arm then set the arm so you get 0 boost. 0 boost will still use exhaust gas energy to spool through the turbo and get the compressor moving rather than just the sucking of air through the intake tract moving the compressor. Once set you should be able to forget about it unless you change something that will change your airflow.

[zin]

I think this has been the clearest explanation of how to tune for fuel that I've read to date.

If I'm reading this right, scale for map and ijectors, leave timing "stock" for moment, then loosen the wastegate (or remove if non-adjustable) to minimize or eliminate boost while maintaining some backpressure for better accuracy. Then drag the brakes to hold the rpm point to be adjusted, note indicated a/f on your wide-band, adjust pumping efficiency up or down as needed to bring the two into agreement.

Am I on Target here?

Assuming I am, would it be too aggressive to make 1000rpm steps, then go back to smooth out the steps?

I'll also assume that further tweaking would be required once ignition timing is adjusted?

Seems like an old an old set of rotors and some cheap pads would be a good idea!

Mike

[cordes]

I think this has been the clearest explanation of how to tune for fuel that I've read to date.

If I'm reading this right, scale for map and ijectors, leave timing "stock" for moment, then loosen the wastegate (or remove if non-adjustable) to minimize or eliminate boost while maintaining some backpressure for better accuracy. Then drag the brakes to hold the rpm point to be adjusted, note indicated a/f on your wide-band, adjust pumping efficiency up or down as needed to bring the two into agreement.

Am I on Target here?

Assuming I am, would it be too aggressive to make 1000rpm steps, then go back to smooth out the steps?

I'll also assume that further tweaking would be required once ignition timing is adjusted?

Seems like an old an old set of rotors and some cheap pads would be a good idea!

Mike

You've got it right. I go every 500RPM, but that doesn't mean you have to I guess. I don't notice any change in my AFR with what little timing changes I make.

[GLHNSLHT2]

I just datalog the a/f and rpm, go out hit the record button at 1000rpms in 3rd and run it till redline.

[Aries_Turbo]

I just datalog the a/f and rpm, go out hit the record button at 1000rpms in 3rd and run it till redline.

going slower and loading the engine harder with the brakes makes the tuning much more accurate and alot closer to what goes on in a factory dyno cell.

its essential for timing changes as you need to let the EGTs stabilize before you can figure out how much timing the setup can handle. it also loads it hard enough to simulate being in 4th and 5th gear so that you will be able to not knock in those gears once done.

current tuning methods where folks just rip through the RPM range on a dyno while datalogging and then making changes isnt ideal.

ive seen cars run great on the dyno and then get on the street and the tuning is all wrong and runs bad.

Brian

[cordes]

going slower and loading the engine harder with the brakes makes the tuning much more accurate and alot closer to what goes on in a factory dyno cell.

its essential for timing changes as you need to let the EGTs stabilize before you can figure out how much timing the setup can handle. it also loads it hard enough to simulate being in 4th and 5th gear so that you will be able to not knock in those gears once done.

current tuning methods where folks just rip through the RPM range on a dyno while datalogging and then making changes isnt ideal.

ive seen cars run great on the dyno and then get on the street and the tuning is all wrong and runs bad.

Brian

Preach on!

[zin]

I'm interested in doing the data logging, but know even less about that than the tuning, other than recognizing the value of being able to review at your leisure what just happened and make changes accordingly...

In short, I'd love to know what would be the best way to log wide-band and engine parameters, not just what program to use, but the hardware, where to get it and how do you hook it up?...

Yeah, I'm looking to get spoon fed, but that will be the fastest way for anyone to get started... Would be even better if someone had the time to do a KC article.

Mike

[Aries_Turbo]

search for "ftdi" with the user name of "risen"

he wrote up all kinds of stuff

---------- Post added at 12:48 PM ---------- Previous post was at 12:46 PM ----------

http://www.turbo-mopar.com/forums/showthread.php?55769-The-USB-Device-datalog-guide&highlight=ftdi

http://www.turbo-mopar.com/forums/showthread.php?42191-Logworks-plugin-for-SMEC-SBEC-LM&highlight=ftdi

[ShelGame]

To the OP, if you're engine is all stock (stock cam, no porting), you shouldn't need to adjust the PEFTBL. I actually don't touch it for turbo changes only. Especially just an S60.

If you're going that rich on decel, though, a PEFTBL adjustment might work. First, I would measure your vacuum on decel and note the RPM/vac where it goes rich. Then, look at both the PEFTBL and base fuel table to see how much fuel is being called for. Chrysler setup the PEFTBL with a constant value below ~1500rpm IIRC. Which isn't at all accurate. But, I think they were counting on the idle routine to control the A/F in that range. Some of the cals also never go to 0 on the fuel tables. So, check that too.

The notes about tuning the PEFTBL are good, but in the case of decel and idle, won't really help much.

The SBEC cals have some added code specifically to turn the injectors off on decel until the MPH drops to where the idle control can take over. I'm looking at adding this to T-SMEC.

[1966 dart wagon]

I just find it so weird that before doing the turbo swap the fueling tables where pretty close, now I am telling the computer to dump into the 9's for afr and getting 12s while going WOT, just seems way to far off.

[1966 dart wagon]

also the car wont stop idling at around 1500-1600 how can I adjust this, will it automatically recalibrate with driving?

I also noticed while driving when I put it in neutral and go to coast it will hold around the same rpms as if it was in gear, and very very slowly drop, drops fast if I slow down, and if I slow down quickly, for a stop, it will drop down almost the same as the speedo, till i stop which it idles at 1500, its very annoying, thoughts on this?


I am just getting ready to burn a new chip and reset the full throttle tables its currently in the 7-6s for afr, maybe i'll do a fuel pump and fpr test.

[cordes]

It sounds like you have some mechanical issues going on. The idle will settle down once the computer learns a little, but if it keeps doing it after a while you've got other problems.

[turbovanman²]

Agreed with Cordes, I bet you've missed some vacuum lines or misrouted them, injectors or intake are leaking, etc.

[1966 dart wagon]

Well this morning the cars idle finally settled down to 1k. I still dont get why my fueling tables are so off since normally they are pretty close ill do some more research tonight and see if i did something wrong in mptune

[Force Fed Mopar]

To the OP, if you're engine is all stock (stock cam, no porting), you shouldn't need to adjust the PEFTBL. I actually don't touch it for turbo changes only. Especially just an S60.



I agree with this 100%. A stock head/intake engine does not need to have the PumpEff modified. I have had very good luck tuning my Daytona w/ the 3 fuel tables and never touched the PEFTBL. I even have a mild cam and 52mm TB. I figure Chrysler had thousands of hours in testing to get the original Pump Eff table right for stock heads, so why screw with it?

Also, I think some of the cals out there have incorrect tables for certain things. I tried using the MP Stg II cal to build off of, and it idled at nearly 3k when the engine was warm. Swap in a stock-based cal, normal idle. Went through it and there were changes to some tables that supposedly did not affect idle, but everything else in the cals were identical, so... :confused:

[Aries_Turbo]

I agree with this 100%. A stock head/intake engine does not need to have the PumpEff modified. I have had very good luck tuning my Daytona w/ the 3 fuel tables and never touched the PEFTBL. I even have a mild cam and 52mm TB. I figure Chrysler had thousands of hours in testing to get the original Pump Eff table right for stock heads, so why screw with it?

Also, I think some of the cals out there have incorrect tables for certain things. I tried using the MP Stg II cal to build off of, and it idled at nearly 3k when the engine was warm. Swap in a stock-based cal, normal idle. Went through it and there were changes to some tables that supposedly did not affect idle, but everything else in the cals were identical, so... :confused:

its not just the head that the peftbl is tuned for. cams effect it, exhaust effects it, intake effects it, turbine size effects it, wastegate flow effects it...

Brian

[zin]

Seems to me that pumpeff is another word for air flow, so if air flow is affected it would need to be adjusted to compensate for the added airflow ... correct me if I'm wrong.

Mike

[Aries_Turbo]

yeah thats about it.

[Force Fed Mopar]

I dunno man, I know what worked for me. And I have a cam, larger exhaust, bigger TB, ported exhaust manifold, etc. Stock head and 2-piece intake.