anyone have any experience with EPROM reading/ reprogramming? I am planning on copying the maps from the J30 and 300zx EPROM chips and comparing them, side by side. (see if the 20 HP the J30 comes up short is just due to intake and exhaust restrictions, or if its a subtle difference in the timing or fuel maps)
specifically, has anyone made their own EPROM reader / or burner? Just though i would collect advice before i forge ahead and make my own.
Next step is to socket the ECM board to accomodate some new engine management....
EPROM reader
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Or is it the fact that manufactures have a 5% window in specing power.......each engine is slightly different.
Seems like a time consumming project when you can just buy an optimized [some of factory built in safety removed] from JWT for either version of the 3 liter usually good for 10% more torque.
A lux car designed to last longer than the same engine in a 300zx might be slghtly more conservatively tuned or have more WOT safety built in.........just as one would expect of such a car.
All Nissan are super over rich [at WOT] to cool pistons, leaning always creates more power until things melt.
A single extra lb/ft at 6,000 rpm =1.1424 HP at 6400 the single lb/ft is 1.2185 HP.......[1.3328 @7,000]...one must be careful as to diffferences in rpm where peak is speced.
Seems like a time consumming project when you can just buy an optimized [some of factory built in safety removed] from JWT for either version of the 3 liter usually good for 10% more torque.
A lux car designed to last longer than the same engine in a 300zx might be slghtly more conservatively tuned or have more WOT safety built in.........just as one would expect of such a car.
All Nissan are super over rich [at WOT] to cool pistons, leaning always creates more power until things melt.
A single extra lb/ft at 6,000 rpm =1.1424 HP at 6400 the single lb/ft is 1.2185 HP.......[1.3328 @7,000]...one must be careful as to diffferences in rpm where peak is speced.
Nissans ARE super-rich at WOT, which means much power (quasi-reliably) can be gained by leaning these conditions out, more reliably and efficiently with a correctly tuned water injection system in combination with an intercooler and supercharger.
I as well have a feeling the J30 is more conservatively tuned up top, but i would like to find out myself...if just as a learning experience.
I could go ahead and get the JWT chip, but it doesnt afford much subsequent upgradeability for the money...
considering a Zemulator (same price as JWT chip) can change and save any engine parameter on the fly via a laptop (injector size, timing, fuel maps, rev limit..etc) It also includes the ability to trigger an external system (water injection) at a specified input sensor value (say, a specific RPM).
I will then be able to do a JWT-esque reduction of the OEM factory of safety, dyno the results for comparison later,
upgrade injectors, and add aforementioned systems one by one, tuning for each to the brink of detonation, and then backing off, say 5 percent.
tuning of course must be done with a bunch of runs on the dynojet with EGT and wideband AF.
I as well have a feeling the J30 is more conservatively tuned up top, but i would like to find out myself...if just as a learning experience.
I could go ahead and get the JWT chip, but it doesnt afford much subsequent upgradeability for the money...
considering a Zemulator (same price as JWT chip) can change and save any engine parameter on the fly via a laptop (injector size, timing, fuel maps, rev limit..etc) It also includes the ability to trigger an external system (water injection) at a specified input sensor value (say, a specific RPM).
I will then be able to do a JWT-esque reduction of the OEM factory of safety, dyno the results for comparison later,
upgrade injectors, and add aforementioned systems one by one, tuning for each to the brink of detonation, and then backing off, say 5 percent.
tuning of course must be done with a bunch of runs on the dynojet with EGT and wideband AF.
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
And real world driving conditions as the dyno is a fixed load device--- the weight of the drum and no wind resistance!!!!!
Generally you decrease the timing by 2-3 degrees from what ever optimum you get on a chassis dyno to survive summer in the mountains or a 90 mph WOT.
Notice that the coolant temp vs timing retard cell is self regulating.......every 5F above 194.999 [as read by ecu] decreases timing by 1 degree........for a 5 degree max retard.
Do knock sensors get more or less sensitive with age/heat cracks?
The problem is almost all engines run hotter than 195.000F in summer.............this is a critical place to look and tweak.
I found a 4F error [well within the sensor tolerance] in actual vs indicated coolant at 195F.[ every sensor resistance varies slightly as does the trim in ecu [how the ecu translates resistance to a value of temperature].........all these errors may stack up in different directions.
Very hard to find the balance between knock sensor sensitivity and base/expanded timing to fit every situation: fuel blend and temperature and load.
What is the load difference between a flat quarter mile and a slight up hill WOT pass from 55-80 mph. Can you visually tell if a road is flat or if 2% tilted up?
Takes years of actual engineering experience and 1,000 of hours of testing to determine how much from optimum to back off the parameters...........more people will use the passing than will take the car to a drag strip.........knocking during a pass can KILL you as the semi approches..........a few tenths slower in the quarter may hurt your feelings.
Almost impossible to exceed 75 lb/ft per liter [NA] so 225 and 5% back off would be 212.
Today computer simulations are so accurate that 98% of software is written by machine and just checked by humans......who almost always chose the wrong parameter to tweek.
FACTORY Engines are so well modeled with pressure sensors under each spark plug and individual O2 per cylinder and 5 gas analyser on each cylinder that a dyno tune is almost always counter productive in any area other than WOT.
As too specs you can chose [and publish] the average of the 3 best engines tested, the average of a 1,000 or the worst case engine tested ............there could easily be a 5-8% variance in the numbers on the same engines.
Generally you decrease the timing by 2-3 degrees from what ever optimum you get on a chassis dyno to survive summer in the mountains or a 90 mph WOT.
Notice that the coolant temp vs timing retard cell is self regulating.......every 5F above 194.999 [as read by ecu] decreases timing by 1 degree........for a 5 degree max retard.
Do knock sensors get more or less sensitive with age/heat cracks?
The problem is almost all engines run hotter than 195.000F in summer.............this is a critical place to look and tweak.
I found a 4F error [well within the sensor tolerance] in actual vs indicated coolant at 195F.[ every sensor resistance varies slightly as does the trim in ecu [how the ecu translates resistance to a value of temperature].........all these errors may stack up in different directions.
Very hard to find the balance between knock sensor sensitivity and base/expanded timing to fit every situation: fuel blend and temperature and load.
What is the load difference between a flat quarter mile and a slight up hill WOT pass from 55-80 mph. Can you visually tell if a road is flat or if 2% tilted up?
Takes years of actual engineering experience and 1,000 of hours of testing to determine how much from optimum to back off the parameters...........more people will use the passing than will take the car to a drag strip.........knocking during a pass can KILL you as the semi approches..........a few tenths slower in the quarter may hurt your feelings.
Almost impossible to exceed 75 lb/ft per liter [NA] so 225 and 5% back off would be 212.
Today computer simulations are so accurate that 98% of software is written by machine and just checked by humans......who almost always chose the wrong parameter to tweek.
FACTORY Engines are so well modeled with pressure sensors under each spark plug and individual O2 per cylinder and 5 gas analyser on each cylinder that a dyno tune is almost always counter productive in any area other than WOT.
As too specs you can chose [and publish] the average of the 3 best engines tested, the average of a 1,000 or the worst case engine tested ............there could easily be a 5-8% variance in the numbers on the same engines.
i agree completely with everything you said, although if the engine ISNT restricted to being an NA, then the possibilties arent any where near as limited.
my ultimate intention here is to use forced induction, and tune the ECU accordingly.
since the knock sensor is most likely a piezoelectric device, heat cracks and age would definitely decrease its sensitivity. hence, the need for EGT and AF readings on each side during tuning.
my ultimate intention here is to use forced induction, and tune the ECU accordingly.
since the knock sensor is most likely a piezoelectric device, heat cracks and age would definitely decrease its sensitivity. hence, the need for EGT and AF readings on each side during tuning.
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Somewhat off topic but looking for a place to store this good info.
Basic block learn info:http://www.autoshop101.com/forms/h46.pd ... ms/h42.pdf
Basic block learn info:http://www.autoshop101.com/forms/h46.pd ... ms/h42.pdf
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Lots of these things show up once on Google but I found the others by substituting different numbers for hxx.pdf......common trick I must have 5,000 similiar pages.
As you can see the Toyota stuff is close just the names changed to be different.
You take a Consult and monitor the bidirectional data line and record the words and ecu response.
Most of us find it easier to not reinvent the wheel........we just purchased a $4,000 UNIVERSAL scan tool......works on almost everything [my mom's 88 Chev, my Q, Ford even MB but it doesn't do close to the things the Consult does.
I just can't see how you can do more or better than JWT accomplished.
Consider developing a variable remote control fuel pressure regulator to replace oem as 34-60 psi would allow a dynamic fuel range of 28% [ -11% to +17%].........not having 43.4 at WOT vs 34 would lean the fuel by 11%........roughly what JWT does above 5500 rpm............taking the 11:1 AF [stock] to 12.35 AF........store an 16-18" vacuum in a canister and switch the fuel pressure vacuum line with a common vacuum solenoid.......you could use the VVT signal [voltage cutoff][4600 rpm] to control the solenoid and oneway valve [like what's in the brake booster line to alway get and maintain the idle vacuum to the cannister.
Or one of those shop tool hand held vacuum pumps used to test sensors.Not very elegant but it would show you what an enleanment might accomplish.
Most factory programming doesn't lean the fuel after the HP peak rpm [which is already too lean]........so the AF just gets another 10-12% richer as the VE falls off towards redline.
Same with ignition advance it should increase a few degees the rule of thumb of 1 per 500 rpm after 4,500 says 5-6 more at 7,000......... but this may be too much for a 12.3 AF.
An washer type accelorometer under the spark plug [measure the force trying to push the plug out to measure peak BMEP vs crankangle [adjust advance for peak BMEP at 16 degs ATDC at each rpm/load] will tell you everything you need to know.................formula cars have these on every plug since they adjust each cylinders timing and AF to perfectly balance the power...........much more accurate than measuring individual EG temperature [the thermocouple is slow to react].
By the way the power scatters as the fuel/air is not perfectly homogenous from cycle to cycle so getting thing [where the peak BMEP falls] within an average of +-1.0 degree is excellant and even 2.0 degrees is twice as good as OEM.
They make V8 black boxes which intercept the injector signal and allow a +10% variation in closing time usually 1,2,3% is enough as the smallest Nissan ECU resolution . 0.1 millliseconds or 1% of max WOT open time.
As you can see the Toyota stuff is close just the names changed to be different.
You take a Consult and monitor the bidirectional data line and record the words and ecu response.
Most of us find it easier to not reinvent the wheel........we just purchased a $4,000 UNIVERSAL scan tool......works on almost everything [my mom's 88 Chev, my Q, Ford even MB but it doesn't do close to the things the Consult does.
I just can't see how you can do more or better than JWT accomplished.
Consider developing a variable remote control fuel pressure regulator to replace oem as 34-60 psi would allow a dynamic fuel range of 28% [ -11% to +17%].........not having 43.4 at WOT vs 34 would lean the fuel by 11%........roughly what JWT does above 5500 rpm............taking the 11:1 AF [stock] to 12.35 AF........store an 16-18" vacuum in a canister and switch the fuel pressure vacuum line with a common vacuum solenoid.......you could use the VVT signal [voltage cutoff][4600 rpm] to control the solenoid and oneway valve [like what's in the brake booster line to alway get and maintain the idle vacuum to the cannister.
Or one of those shop tool hand held vacuum pumps used to test sensors.Not very elegant but it would show you what an enleanment might accomplish.
Most factory programming doesn't lean the fuel after the HP peak rpm [which is already too lean]........so the AF just gets another 10-12% richer as the VE falls off towards redline.
Same with ignition advance it should increase a few degees the rule of thumb of 1 per 500 rpm after 4,500 says 5-6 more at 7,000......... but this may be too much for a 12.3 AF.
An washer type accelorometer under the spark plug [measure the force trying to push the plug out to measure peak BMEP vs crankangle [adjust advance for peak BMEP at 16 degs ATDC at each rpm/load] will tell you everything you need to know.................formula cars have these on every plug since they adjust each cylinders timing and AF to perfectly balance the power...........much more accurate than measuring individual EG temperature [the thermocouple is slow to react].
By the way the power scatters as the fuel/air is not perfectly homogenous from cycle to cycle so getting thing [where the peak BMEP falls] within an average of +-1.0 degree is excellant and even 2.0 degrees is twice as good as OEM.
They make V8 black boxes which intercept the injector signal and allow a +10% variation in closing time usually 1,2,3% is enough as the smallest Nissan ECU resolution . 0.1 millliseconds or 1% of max WOT open time.
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The problem is one of diminshing returns; a JWT ecu mod good for 9-10% [$600] and spending another $2,000 to gain 3-4-5% more.When your racing and have someone else paying spending $1,000 per each additional HP may make sense.
Personally I like each one to cost way less and $30 each for a JWT is a bargain.
Personally I like each one to cost way less and $30 each for a JWT is a bargain.
Q45tech wrote:The problem is one of diminshing returns; a JWT ecu mod good for 9-10% [$600] and spending another $2,000 to gain 3-4-5% more.
If the numbers you just threw out were accurate, i would completely agree with you, but the simple fact is that they are not.
first: price of zemulator and JWT chip are equivalent, at $600
the zemulator comes not only with a set of maps superior to the JWT (about 10 more HP from reduced factor of safety), but also complete ability to change all mapped engine parameters.
So, at initial purchase, the zemulator is superior.
The real gains come when you decide to add some sort of forced induction, whether it be turbocharging or supercharging. Either way, the EPROM doesnt need to be sent back to JWT to change the injector size, or again to change the fuel maps, or again to change the timing.
The fact is that 340 RWHP can be attained from the NA block and forced induction, with no detonation. i posted dyno charts on this previously. backing this off to say 320 would provide an adequate factor of safety, and still provide for 45% increase in power. granted, another $2000 investment in forced induction hardware, put the point is future UPGRADEABILITY.
the JWT affords virtually no future upgradeability as it costs 600 dollars if you want to change the value of one bit on the EPROM.
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
What does that have to do with anything.........given the air pressure and charge temperature, the fuel map will be the same whether turboed or supercharged.........sure there will be more back pressure turbo charged and more parasitic [super charger drive power] loss.
One would start with a Nissan TT ecu [and all sensors/intercoolers and 370 cc injectors] for a turbo 300zx and then have it tweaked since the supercharger only produces 6-8 psi...........that way when off boost the programming would be close for idle and part throttle.
Obviously the extra compression ratio [J30] would need to be addressed by limiting the part throttle advance from 40 to 35-33???].
Back in the mid 90's there were kits [Stillen??] to supercharge the NA 300zx..........same problem.
The JWT at least installs a socket so the prom can be replaced as they offer future reprograms at a discount.
But I agree with you that a tunable ecu map is better if the price is the same but most don't understand the physics to tune properly so a simple swap is hard enough for us to sell.
My Dinan Q ecu [no longer in the ecu business] progressively reduces the AF ratio above the 6,000 rpm HP peak from 10.8 millisecs to 9.7 millisecs at 7,000 rpm while increasing advance by 2>4 degrees vs the oem ecu which can hit 11.2 millisecs and locks from 6,000 to 6900......4%....>13% leaner.
http://ashleypowers.com/Na-TTC...o.htm
One would start with a Nissan TT ecu [and all sensors/intercoolers and 370 cc injectors] for a turbo 300zx and then have it tweaked since the supercharger only produces 6-8 psi...........that way when off boost the programming would be close for idle and part throttle.
Obviously the extra compression ratio [J30] would need to be addressed by limiting the part throttle advance from 40 to 35-33???].
Back in the mid 90's there were kits [Stillen??] to supercharge the NA 300zx..........same problem.
The JWT at least installs a socket so the prom can be replaced as they offer future reprograms at a discount.
But I agree with you that a tunable ecu map is better if the price is the same but most don't understand the physics to tune properly so a simple swap is hard enough for us to sell.
My Dinan Q ecu [no longer in the ecu business] progressively reduces the AF ratio above the 6,000 rpm HP peak from 10.8 millisecs to 9.7 millisecs at 7,000 rpm while increasing advance by 2>4 degrees vs the oem ecu which can hit 11.2 millisecs and locks from 6,000 to 6900......4%....>13% leaner.
http://ashleypowers.com/Na-TTC...o.htm
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
"Pistons & Oil Jets: The under piston oil jets are different between the two models. The NA jets aim toward the center/bottom of the piston whereas the TT jets aim toward the side/bottom of the piston. They actually shoot oil right into one of the holes that leads to a galley just under the piston crown for cooling purposes. See picture above of pistons for a better idea of this. If you use aftermarket forged pistons, it is adviseable to use the NA squirters as none of the aftermarket pistons have the cooling channel and the TT jets will unevenly cool the piston. This could be an issue with forged pistons as they expand/contract much more because of their higher grain density. Variations in temperatures across the piston crowns will cause the piston to become oddly shaped and cause cylinder/piston wear or even worse, the ring lands will pinch the rings and you'll lose compression and the engine will quit.""Fuel Pump: The fuel pumps are different between the two different models. They appear the same from the outside, however, the pump mechanism in the TT has a higher capacity than the NA. The only way to tell the difference between the two is the fact that the NA has a number "14" cast into the backplate whereas the TT has a "16" in it. This definately needs to be replaced when you convert your Z. The NA pump will be able to keep up with the demand up to a certain point, but I found that was short lived and the pump could not maintain proper pressure as the fuel demand rose with RPM.
Oil Pump: The oil pumps used on the NA engine ARE different than on the TT. The TT pump is significantly larger to prodive ample pressure/flow for the turbos and oil cooler system. I built my TT engine from an NA engine and did not change the oil pump out because I was under the impression that the pumps were actually the same.. I pulled the engine the weekend of 8/24/02 to change the oil pump and connectoing rod bearings. Oil pressure before the change was ~50-60psi max and now the needle comes up to 90psi at high RPM. It is definately at least 10psi per 1000RPM, and better than that on the top end.
Cooling: The electric fan on the TT is a two speed unit and the NA is a single speed unit. This really can be overlooked. But, the radiators are different. The TT radiator mounts are different than the NA mounts and there are no holes with nice welded nuts to just make this a "bolt on" conversion.. You will have to drill holes to make this work. Same goes with the AC condenser. These are two of the easiest parts of the conversion though. The intake plumbing also has mounting points which will need to be fabricated. As parts are being installed, sheetmetal and a torch will come in handy.
ECU: Well folks, breaking news here, the NA and TT ECU are essentially interchangeable. You cannot use a 5pseed ECU in an automatic application, but you can go the other way. The NA ECU is missing a few resistors and transistors which are used to complete the circuitry for the boost control solenoids. What this means is that you either need to use a boost controller or connect pin 25 to pin 50 of the ECU (ground). A stage 3 TT ECU can be used with the NA harness as well but it will lack this function. I have on a few occasions soldered in these additional circuits and was able to convert a 5 speed to automatic and an NA ECU to TT spec."from the site listed and posted above
Oil Pump: The oil pumps used on the NA engine ARE different than on the TT. The TT pump is significantly larger to prodive ample pressure/flow for the turbos and oil cooler system. I built my TT engine from an NA engine and did not change the oil pump out because I was under the impression that the pumps were actually the same.. I pulled the engine the weekend of 8/24/02 to change the oil pump and connectoing rod bearings. Oil pressure before the change was ~50-60psi max and now the needle comes up to 90psi at high RPM. It is definately at least 10psi per 1000RPM, and better than that on the top end.
Cooling: The electric fan on the TT is a two speed unit and the NA is a single speed unit. This really can be overlooked. But, the radiators are different. The TT radiator mounts are different than the NA mounts and there are no holes with nice welded nuts to just make this a "bolt on" conversion.. You will have to drill holes to make this work. Same goes with the AC condenser. These are two of the easiest parts of the conversion though. The intake plumbing also has mounting points which will need to be fabricated. As parts are being installed, sheetmetal and a torch will come in handy.
ECU: Well folks, breaking news here, the NA and TT ECU are essentially interchangeable. You cannot use a 5pseed ECU in an automatic application, but you can go the other way. The NA ECU is missing a few resistors and transistors which are used to complete the circuitry for the boost control solenoids. What this means is that you either need to use a boost controller or connect pin 25 to pin 50 of the ECU (ground). A stage 3 TT ECU can be used with the NA harness as well but it will lack this function. I have on a few occasions soldered in these additional circuits and was able to convert a 5 speed to automatic and an NA ECU to TT spec."from the site listed and posted above
Q45tech wrote:Back in the mid 90's there were kits [Stillen??] to supercharge the NA 300zx..........same problem.
there have never been any comercially available supercharger kits for the Z32, (as far as i can tell, and i have done extensive research on the subject).
the issues you mentioned must definitely be addressed, and all the better with a reprogrammable datalogging engine management system.
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Again I like things to last 200,000 miles so a 42% NET power increase would be enough for me.
10 psi out of supercharger, air to chilled water intercoolers plus water mist before and after supercharger to optimize delta temp. +8 psi as air passes injector in lower runner.
At 10 psi you have 120-150F extra heat to lose somewhere some how.
10 psi out of supercharger, air to chilled water intercoolers plus water mist before and after supercharger to optimize delta temp. +8 psi as air passes injector in lower runner.
At 10 psi you have 120-150F extra heat to lose somewhere some how.
exactly, were agreed then on about +8 psi in the intake runners. the supercharger will of course have to put out more due to flow losses from Y junctions in the plumbing, and of course a 1-2 psi drop over the intercooler itself, thus the required 10psi at compressor outlet.
A nice bridge of the efficeincy gap between air/air and air/water intercoolers would be a water mister on the front of the air/air intercooler, possibly triggered at WOT conditions...
A nice bridge of the efficeincy gap between air/air and air/water intercoolers would be a water mister on the front of the air/air intercooler, possibly triggered at WOT conditions...
-
Mayhem_J30
- Posts: 2643
- Joined: Tue Apr 30, 2002 2:00 am
- Car: Ummm...My Car
- Location: Louisville, KY