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also thats what you use a trailer soo much! you make you weight as much as you can plus the drag means you have to be into the throttle.. but hows the mpgs like this??
Actually no, I only just built the trailer last year. Just in time to break the car a bunch and end up competing with it twice.
From 2004 and on I just packed everything in the car.
Believe it or not you don't notice the trailer. Has no effect on fuel economy. Same when I towed it with my friend's turbo Miata, fuel economy didn't change one bit. Was kinda neat doing full throttle blasts up onramps
I think you're crazy to go with that port configuration it's going to be so undriveable and chaotic I think it will cause a disruption in time and a black hole will mysteriously appear
So after much research, it appears the best way to achieve drivability on a PPort is through tuning, and via TPS / RPM based tuning.
Because the engine is forced induction, TPS / RPM is difficult / risky in boost as load can change from turbo, but TPS can remain the same.
The best method to tune a Pport Turbo engine is a combination of both.
Build a TPS / RPM table for vacuum to 0psi. This will allow a higher resolution for signaling load of the engine as the vacuum is erratic / low on such high overlap. Tune the car with the turbo off the engine, to get 0-100% throttle at all RPM's covered.
Next, come back with the turbocharger and add a "Boost Compensation" table, which the ECU will refer to as manifold pressure exceeds 0psi. This will introduce a MAP based table, adding fuel via new table, separate from the tps table.
Here's a screenshot of the new AEM computer, and the option for the correction table. In fact, this is silver6ports ECU, powering his monstrous 20b turbo car. He's likely going to experiment with this method:
Here's some comparable information from another party with a 20b PP turbo:
a friend of mine has an EVO with a huge cam. -5 inches of vacuum at idle. He tunes on TPS low load, as mentioned above, to precisely adjust timing/fuel in all areas of low load. This has eliminated much of the bucking.
For those that are using older technology, with timing / fuel that's not as adjustable, this may very well be the cure. I guess we will see with experimentation soon.
Just trying to search for new age solutions, other than avoiding pport. One this engine runs, I'll try my best to discover a solution to the maniacal bucking of the peripheral port, at least to the point that one can be driven sensibly on the interstate. Engine should arrive in the next few weeks! Thank you
I'll try my best to discover a solution to the maniacal bucking of the peripheral port, at least to the point that one can be driven sensibly on the interstate. Engine should arrive in the next few weeks! Thank you
lol, go watch the 787B in person, its like the pickup truck of race cars, i've seen em use it to haul tires around, it fires right up with something that is like a key. its competition, the silk cut Jag is like launching a space station, it takes a computer, and a team of people to even start, and then its slower.
it is cool that your engine is showing up, that is exciting!
So after much research, it appears the best way to achieve drivability on a PPort is through tuning, and via TPS / RPM based tuning.
Because the engine is forced induction, TPS / RPM is difficult / risky in boost as load can change from turbo, but TPS can remain the same.
The best method to tune a Pport Turbo engine is a combination of both.
Build a TPS / RPM table for vacuum to 0psi. This will allow a higher resolution for signaling load of the engine as the vacuum is erratic / low on such high overlap. Tune the car with the turbo off the engine, to get 0-100% throttle at all RPM's covered.
Next, come back with the turbocharger and add a "Boost Compensation" table, which the ECU will refer to as manifold pressure exceeds 0psi. This will introduce a MAP based table, adding fuel via new table, separate from the tps table.
Here's a screenshot of the new AEM computer, and the option for the correction table. In fact, this is silver6ports ECU, powering his monstrous 20b turbo car. He's likely going to experiment with this method:
Here's some comparable information from another party with a 20b PP turbo:
a friend of mine has an EVO with a huge cam. -5 inches of vacuum at idle. He tunes on TPS low load, as mentioned above, to precisely adjust timing/fuel in all areas of low load. This has eliminated much of the bucking.
For those that are using older technology, with timing / fuel that's not as adjustable, this may very well be the cure. I guess we will see with experimentation soon.
Just trying to search for new age solutions, other than avoiding pport. One this engine runs, I'll try my best to discover a solution to the maniacal bucking of the peripheral port, at least to the point that one can be driven sensibly on the interstate. Engine should arrive in the next few weeks! Thank you
Thanks for shedding more light on this!
i was also once told, or picked up the bit of information that you want an ecu advanced enough that you can edit the injector end time. piggy back fuel controllers and the rtek can't do this. i dont know about older e6k or e6x, or lt8..
i know the ps1000 CAN do tps VE tuning. but i don't know about the inj end time thing. same for your AEM I6..
i'd like to know how about the adaptronic as well.. gonna throw up a bat signal or something.
Tuning strategy isn't as important as simply how it is tuned. A lot of people just tune at full throttle and don't care about anything else as long as the engine doesn't actually stall while driving.
I use batch fire, not sequential fire, so if one injector is theoretically perfect then the other one is theoretically most imperfect. (Fuel only with a distributor, computer has no idea which rotor is where, it just pulses the injectors every other spark event) Excellent drivability with half bridge, full bridge, and peripheral port. Always used speed density tuning too, which the internet says is impossible. Sequential would mostly allow me to pull some fuel out of the map.
To be honest, I really want to try running a MAF one of these days. Once you have the MAF scaled properly, you just give the computer your injectors' characteristics and an air/fuel ratio table and it always gives the correct amount of fuel because it is measuring the air directly. This way you don't have to change the tune every time you put a different muffler on your car or something.
To be honest, I really want to try running a MAF one of these days. Once you have the MAF scaled properly, you just give the computer your injectors' characteristics and an air/fuel ratio table and it always gives the correct amount of fuel because it is measuring the air directly. This way you don't have to change the tune every time you put a different muffler on your car or something.
Exactly! this is why if you look at the progression of oem technology you have the use of the AFM first.. then to speed density and or alpha-N( tps based) tuning, and then hotwire MASS sensors came along.. now you can find a complicated mixture of alpha-n and speed density AND MAF doing a major correction on top of it all, and doing it this way started around 2002-2004.. along with the use of widebandO2s. im not sure how complicated something like a GTR ecu is...
Tuning strategy isn't as important as simply how it is tuned. A lot of people just tune at full throttle and don't care about anything else as long as the engine doesn't actually stall while driving.
I use batch fire, not sequential fire, so if one injector is theoretically perfect then the other one is theoretically most imperfect. (Fuel only with a distributor, computer has no idea which rotor is where, it just pulses the injectors every other spark event) Excellent drivability with half bridge, full bridge, and peripheral port. Always used speed density tuning too, which the internet says is impossible. Sequential would mostly allow me to pull some fuel out of the map.
To be honest, I really want to try running a MAF one of these days. Once you have the MAF scaled properly, you just give the computer your injectors' characteristics and an air/fuel ratio table and it always gives the correct amount of fuel because it is measuring the air directly. This way you don't have to change the tune every time you put a different muffler on your car or something.
i think running sequential would make a big difference, you can actually hear the difference at low rpm in a stock port, and the big ports are more picky, obviously i haven't tried it, i'm happy with the carb, it runs way better than i would have thought possible
Exactly! this is why if you look at the progression of oem technology you have the use of the AFM first.. then to speed density and or alpha-N( tps based) tuning, and then hotwire MASS sensors came along.. now you can find a complicated mixture of alpha-n and speed density AND MAF doing a major correction on top of it all, and doing it this way started around 2002-2004.. along with the use of widebandO2s. im not sure how complicated something like a GTR ecu is...
the progression is an odd one, but we don't know what we don't know, its easy to look back and think that the progression looks weird.
Mercedes was using mechanical injection (into the cylinder) in the 30's, they were also running superchargers, not sure how it measured load, probably just throttle position. Porsche used a newer, but similar system in the 917/30, its just Alpha-N, mechanical injection, with a turbo. and hey, if porsche can do a 1000hp turbo engine, cooled by a fan and running alpha-N, i dont see why the rotary can't work
then there is the Bosch D jet (i'm skipping the GM system, i don't know a lot about it), which is a Map sensor based system, and uses points to trigger the injector openings. on a v8 its batch fire, on a 4 cylinder it could be sequential i suppose.
then bosch has the K-jet, its meant to be cheap, so its hydraulic, and not electrical.
then there is the L-jetronic, like we see in the FC's, where it has an AFM, and measures the airflow, which then proceeds to have a hotwire airflow sensor.
the current modern cars basically run this same architecture, but the computer has gotten WAY bigger, and they run fairly abstract things like calculating torque, and such. the GTR, which has a couple of SAE papers, is able to run 14.7:1 afrs up to a certain power level, so where your FC has an rpm/load limit, the GTR has a torque limit. or the other example is the Rx8, apparently the ECU has something like 300 maps/tables in it, which is a LOT
Bosch D-jet looks like a development of the Chrysler/Bendix electronic (analog) fuel injection from 1958.
So really the first fuel injection was mechanical alpha-N, then mechanical volume air (Rochester, anyone? This system became K-jet) electronic speed-density (Bendix which begat D-jet), then air flow meters (L-jet) and then hot wire MAF systems (LH-jet).
the progression is an odd one, but we don't know what we don't know, its easy to look back and think that the progression looks weird.
or the other example is the Rx8, apparently the ECU has something like 300 maps/tables in it, which is a LOT
I had the cobb AP for my first rx8, i know the number of maps.l.. yes with the mazdaedit there are even more over 130 correction maps.
and it's from 2004!
Get the free copy of HPTuners and see if you can get a tune for a 5.3/6.0 truck engine and have a peek inside. Those are probably the most hacked of the GM computers.
There's probably 30 maps just for fuel injector characteristics alone... and when it gets to the actual engine, my brain signed out at the maps for calculated engine drag from oil viscosity vs. engine temperature.
When your operating strategy is torque based, you need to know how much torque EVERYTHING uses... and if that torque is variable (A/C torque vs. A/C high side pressure) then you need a sensor on that variable (or GOOD math to approximate it - oil temp is inferred) and there will be a map to define what to do with it.
As an owner of a 4 rotor and have driven it on the road. It's fun, but it's a pita. Why? Because og what ppl say. It needs acceleration to work. And it will not drive good under 3800 rpm. At least mine did not. It would have the pp gargled sound under that. Trying to maintain same rpm and load over time does not work well. It will start to buckle.
Mine is na and tuned on tps/rpm and it was not easy to drive under 50% tps. Best thing about it is pulling into a gass station to fill up. Ppl are looking for a f1 v12 driving in :P
I did get quite alot of questions about what F1 engine was i. The car
I drove my 4-rotor PP car on the road for a week or so. It would buckle back and forth without load. By the time it was loading enough to run smoothly I was going around 60mph. What helped was clearing up the exhaust as much as possible. I had stuffed DB killers in the mufflers, which killed drivability. Completely straight through open was the best. I also retarded the timing during cruise so I could open the throttle more, which helped. Leaning it out or richening it up didn't do much. Whenever the intake pressure is low, and / or the exhaust pressure is high it buckles because of the exhaust gas dillution.
02-12-16, 04:44 PM
