Tuning a TBucket Dart 400 cuin Engine

With the SS header design above that I posted, does it make a difference in the
position of each cylinder in the collector? I've noticed that the SS headers above
are different in the position of each cylinder when compared to the headers I
have now?
 
Ive tested that in a couple cars, but came to the conclusion, that the over all header design, IE, the length & diameter of the primary tubes, their diameter and the collector length and diameter seem to have a greater effect, so short answer is I doubt youll see a difference,
and theres also the fact that collector design, and the cam timing and engine compression seem to have a noticeable influence on results, if you look over the KOOKS headers below it should be very obvious that rotating the 4 into 2 section of the collector 90 degrees pairs different cylinders which due to the un-evenly spaced cylinder firing order has, at least in theory a much greater potential effect, but I've yet to see any major advantage,,its generally the collector length, degree of back pressure , cam timing and engine compression and displacement that seems to effect results, and cams with tight LSA in the 104-108 range on the higher than about 10.5:1 compression engines seem to benefit most
its always Impressive, to see the amount of work required and the details of that work that was required to build custom components, especially engine and related components ,especially when you considered, that you need to work around the frame,suspension and engine to get headers to fit and still try to maintain semi-equal length tubes.
many guys would have tried to do that custom fabrication work and given up after a couple hours ,after realizing its not nearly as easy to do as it at first might appear to be, I think you did a really nice job for a first try!,Id point out that Ive seen many sets that looked far less well done, produced from supposed pro-muffler shops, whose main goal was making a profit , which is as I,m sure you know now an unlikely prospect once you start counting the time and materials required,to fabricate headers that fit a custom installation with suspension and frame components blocking the easy routes
if you get a chance, after those headers are installed, let us know your impression of both how the car sounds and how it runs and accelerates

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you might find re-reading the links useful here
http://garage.grumpysperformance.com/index.php?threads/x-or-h-pipe.1503/


http://garage.grumpysperformance.com/index.php?threads/calculating-header-design.185/

http://garage.grumpysperformance.com/index.php?threads/building-custom-headers.961/

http://garage.grumpysperformance.com/index.php?threads/is-backpressure-hurting-your-combo.495/

http://garage.grumpysperformance.com/index.php?threads/x-or-h-pipe.1503/
 
I had a brand new set of Champion RN12YC plugs. They have 30 miles prior to the test
and then about 10 miles after the test to get back home. The test was taking off with the
trans in 2nd gear. Launching was controlling wheel spin in 1st until the 1-2 shift (4000 rpm)
then full throttle up to and including some of 3rd gear. Top speed was 85 mph

FP02_SparkPlugOdd_6198_6199.jpg
FP02_SparkPlugEven_6200_6201.jpg

A better look down the inside to the bottom of the porcelain insulator.

FP02_SparkPlugSingle_6203.jpg

Do the plugs appear any different with the slower advance curve. That's the
only change so far.
 
yes they look marginally better, but Id strongly suggest you back off the total timing advance 2 degrees as the plugs indicate a bit too much total ignition advance, and combustion heat, and that might eventually cause damage, you appear to be running a bit lean, at WOT on the plugs coloring .
but your data shows your a bit f/a rich?
are you using ethanol laced gas?
I trust the plugs , indicate the combustion chamber condition so just as a test go for a bit larger secondary jet size as a test and lets see the result, you should get valuable info from the change for little effort and time spent making the change that should help narrow the issues source,yes I'm well aware I said try leaner earlier, your plugs indicate your running a bit rich, with that dark band on the outer plug threads, but the porcelain and ground strap show excess heat, the heat band on the plug ground tends to show a bit faster than ideal advance porcelain a bit lean.
read this
http://garage.grumpysperformance.com/index.php?threads/reading-plugs.5428/
timing%20indicator%20mark.jpg
 
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What octane gasoline are you using Rick ?
Is it 100 % pure gasoline ?
Have you fixed the fuel pressure & Volume issue ?
You must maintain 7 psi constant even to 160 mph WOT.

Unless you fixed the fuel supply problem all further tuning is MOOT, for nothing.
 
Your not drag racing Rick.
But excess low end torque is kinda bad in a way.....You can never hookup no matter what you try unless you Bolt on Slicks on the street.

Comes down to how much $ do you have & how much do you want to spend ?
$4,000 - $10,000 can be be spent real fast.
 
Where did the 4-2-1 Header Idea come from anyhow Grumpy ?
4-2-1 Was a prominent feaute on many Factory. 1963 SD 421 Cars.
Was it Smokey Yunick's idea ?
 
The gas is 100% gas and 91 octane.

Ignition timing was changed from 35° to 33° total advance, with vacuum advance plugged.
 
The gas is 100% gas and 91 octane.

Ignition timing was changed from 35° to 33° total advance, with vacuum advance plugged.
Ok . Trying to tune on E10 gas ultra precise can be a PIA with a Carb.
E10 is not actually E10 always. Can vary by law .

It will be easier tune with Fuel pressure not dropping off anywhere once corrected right.

Also 2 ways to control excess wheelspin through rear diff gearing alone.
Gear Taller.
Or Granny Gear rear diff.
 
Ignition timing was changed from 35° to 33° total advance, with vacuum advance plugged.

ok, have you noticed any change in the cars acceleration or tip-in-power curve from the change in the ignition advance being a bit slower or the peak power changed any?
 
I just don't think I could tell something so minor as just 2° in ignition timing. But I did
another test run, but this time I did a GoPro video. Again I put the trans in 2nd gear tried
to control wheel spin initially and then nail it, shift into 3rd for a short time and then
shut down. I doubt that you can tell when the trans shift to 2nd gear, its so smooth, but
it's around 3500 rpm when the trans does the shifting.

This gives me the most consistent runs. This run was done with a 25-30 mph tail wind. Still
looks like I need to go one size smaller on the secondary jets like you suggested Grumpy, but
one change at a time.

I check my speedometer for top speed and it showed 108 MPH.


Grumpy_2015-09-13-1350.jpg
 
your printed data shows the fuel/air ratio plotted, in your graph's,
is closer to the ideal curve,than when you started out, but if you go back and look over the older printed graphs youll see several things improved but I suspect , looking at the at times inconsistent f/a ratio, that your fuel delivery systems trying hard to keep up with fuel demand.
. your spark plug pictures tend to show the engine combustion, operates significantly leaner on average than the graph indicates.
 
I definitely can see where that would be true. Cruising at 45 to 65 mph, the AFR meter
shows visually 14.5 to 15.0, but when I stand on the loud pedal, the carburetor goes to
12.0 to 12.5. Makes for good gas mileage and good acceleration performance. Just need
to lean it out about 1/2 point under hard acceleration and we will be there.

Maybe I need to cut back on the PVCR.... what do you think???

Yes I think you are right about the fuel delivery system has it problems, something which is
on my agenda for this winter.

http://garage.grumpysperformance.co...selection-design-for-500-hp-fuel-system.7787/
 
usually you should make only one change at a time and document results,
you can test swapping to a different power valve, but your obviously fairly close,
so you might want to go one step leaner on the primary jets as a quick test and leave the rest alone,
or go one step leaner on the primarys and one step richer on the secondaries,
remember the primary jets are always contributing fuel flow
 
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You have been saying one step leaner on the secondaries. I assumed this was to flatten
out the AFR curve slightly on the high RPM range under load. Now you are suggesting
the primaries....why??? Under cruise I'm running nearly 15:1.

I suggested the PVCR because that determines the AFR under load, the PV determines
the timing of the enrichment.

you should make only one change at a time and document results,

I think I've done a pretty good job of doing that, are you speaking to the others that might
read this thread???
 
Yes youve done a great job!
as I'm fairly sure youve seen, I try hard to make these threads ,
at least some what, educational, damn near every time I post its ,
directed to anyone reading through the thread's later, and not directed only at a single problem.
most responses will be as general in nature as I can make them,
or anyone person, simply , because I know that these threads will be used as a reference many times.
your use of, and posting of those graphs and the sensor data is really helpful
hopefully to get anyone reading through the thread to think through the process.
theres no skill as necessary, to tuning as thinking through each potential problem, and its potential solutions
 
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Nothing is set in stone yet.
Correct the Fuel Pump fuel system issue.
The Wideband may be out of calibration slight.
It may need to be Free Air Calibrated.
We have to free air calibrate the Widebsnd O2 on the Mustang AWD Euro Chassis Dyno at work. Already have had 800 RWHP E85 Supercharged C6 Vettes on it since I started.
 
The LSU 4.9 sensor that I use does not require calibration like the LSU 4.2 sensor
that many aftermarket instruments use.

http://www.ecotrons.com/technology/bosch_lsu_49_is_superior_to_lsu_42_sensors/

Bosch LSU 4.9 is superior to LSU 4.2 sensors



LSU 4.9 is superior to LSU 4.2.

The major difference between LSU 4.9 and 4.2 is that LSU 4.9 uses the reference pumping-current, while LSU 4.2 uses the reference air. What does this mean? Let’s read this true story from the auto industries: when Bosch first designed a wideband oxygen sensor, a reference air cell was used to provide a reference of stoic AFR. The technology was to keep the pumping cell balanced with the reference air cell, by pumping the oxygen out of the pumping cell. The pumping current was the indication of the actual AFR in the exhaust gas. The bigger the pumping current, the more the oxygen in the exhaust, and vice versa. Therefore the reference air was vital to the accuracy of the sensor, because it was THE reference. It worked well in the lab, but not so good in the real life, because the environment around the sensor on a car was much worse. The reference air cell was susceptible to be contaminated by the surrounding pollution. Once the reference air was contaminated, the whole characteristics of the sensor were shifted to the lower side. It was called “Characteristic Shifted Down”, or CSD, in the industries. This was the biggest problem of LSU 4.2 that was used in some early OEM applications. And it caused the big quality issue to Bosch. To fix this problem, Bosch redesigned the LSU sensor, and came up with LSU 4.9 version. LSU 4.9 sensor completely got rid of the reference air. Instead, it used a reference pumping current which was equivalent to the stoic reference air, but without having any physical air in the cell. So the technology became: the actual pumping current was compared to the reference pumping current to maintain the balance. The actual pumping current was still the indication of the actual AFR, but the reference was a calibrated electrical signal, and stayed same all the time, all the situations.


This is the fundamental difference between the LSU 4.2 and LSU 4.9.








LSU 4.9 gets rid of the reference air, and therefore gets rid of the biggest failure mode. As a result, LSU 4.9 has a long life and can maintain the accuracy throughout the life. Only since then, Bosch LSU sensors have been used widely in the auto industries.

Nowadays, all OEMs who use Bosch O2 sensors are using LSU 4.9. GM, Ford, and Chrysler all use LSU 4.9 now. If you check out the O2 sensors on your recently bought vehicles, cars/SUVs/Pickups, (since 2007 or later), on the exhaust manifolds, you will find out that they are all exclusively LSU 4.9. No more 4.2 sensors can you find on OEM vehicles.


Most aftermarket wideband controllers are still using LSU 4.2, mainly for low cost reasons. Bosch sells the LSU 4.2 to the aftermarket at a much lower price than LSU 4.9. Plus, many of those companies do not want to or are not able to adapt the new LSU 4.9 sensors. There is a big mis-understanding that LSU 4.9 is only for diesel engines, because it can measure very lean AFRs. That’s not true. There is a diesel version of LSU 4.9, called LSU4.9D, mainly because of fuel and temperature difference. LSU 4.9 has been widely used with the gasoline engines. In fact, it is the most popular gasoline engine O2 sensor now, not only because it measures wide range of AFR, but also because it has the very good reliability, and high accuracy.


There are a few wideband controller companies in the aftermarket using LSU 4.9. But that does not mean all controllers using LSU 4.9 are equal. Even with the same LSU 4.9 sensor, the controller can make a big difference. Some wideband controllers are designed for AFR display only, and they are named as “wideband AFR gauges” instead of controllers. You can imagine that those wideband gauges do not have good accuracy and fast response rate because they are not designed for those purposes. Those gauges are more for good looking than for engine tuning purposes. For engine controls, the accuracy and response rate are the most critical characteristics of a wideband controller. One way to tell whether a wideband controller is good or not, is to see whether it can be used as a feedback device for the ECU. A feedback device must provide a real-time signal in the fast rate and high accuracy, even under dynamic situations. The requirements for a feedback device are much, much more than those for a gauge.


Even with a LSU 4.2, the controller makes a big difference. Bosch sensors are not easy to fail even with a LSU 4.2, if controlled appropriately. Especially, LSU 4.9 is designed for more than 10 year life because it has to, for the vehicle life. It should not fail in short time, like a couple of years. Many OEM cars have been running with LSU 4.9 for years and we have not heard any recalls because of LSU4.9 sensors. Why do so many aftermarket wideband systems have failed LSU sensors? Because many of them don’t have a good heating control strategy.
The number 1 failure mode of a LSU sensor is being heated up too fast or too earlier. O2 sensors are made of ceramic materials, which can be damaged by severe thermal shocks, like condensations, liquid residuals, or just high heating power when it’s still cold. A very carefully designed heating strategy to detect the dew point and a close-loop sensor temperature control are vital for the life of the sensors. That’s why the LSU sensor must be controlled in the context of engine controls. You may say, only those who know engine controls can design a good wideband controller.


Furthermore, the accuracy of LSU sensors is highly dependent on the operating temperature of the sensing element. The sensor reading can be very different if the temperature of the sensing element is different. LSU sensors must work at the vicinity of certain temperatures for the good accuracy. LSU4.9 sensor must be maintained at 780 degrees Celsius precisely.


Bosch CJ125 chip is designed for this task. The heating strategy is a close loop control based on the measured sensor temperature. PLus, LSU 4.9 has a much higher sensor temperature resolution because of the resistance characteristics, so the heater controls are much better than LSU 4.2. As a result, 4.9 has a longer life and better accuracy.


In every Bosch LSU sensor data sheet (4.2, 4.9 or ADV), it is clearly stated:”The wide band sensor LSU operates only in combination with a special LSU control unit (CJ125 ASIC). The functional characteristics given in this document are only valid for operation with the CJ125 according to module specification and with recommended operational parameters.” Bosch means it. Anybody who tried to design a cheaper circuit and claimed it better ended up with a less quality one! Because Bosch simply had done that to the extreme. The cost in auto industry is everything. If there would have been a way to save another penny in the sensor control circuit, Bosch would have done it with the CJ125 chip. If some after-market vendors could design a better control circuit to control the LSU sensor and it would be cheaper, they could sell that “invention” to Bosch.


Instead of re-inventing the wheel, Ecotrons use CJ125 in every ALM controller. Because we are from the auto industry and we have the professional experience of LSU sensor controls, we know how to utilize every bit of the advantages of the genuine CJ125 chip.


In short, not only the sensor LSU 4.9 is superior to 4.2; but also the controller with a CJ125 chip makes it an OE equivalent system.


If you are still not sure, you can use an oscilloscope to actually measure the analog outputs of different wideband controllers if you really want to see the difference. Data do not lie.
Don’t forget, when you use a scope, you better set the time scale in 10ms or smaller. If you have a time scale of 100ms or more, then there could be no difference for any controllers.


More info on LSU4.9 vs. LSU4.2


What makes LSU 4.9 superior to LSU 4.2 is not only because LSU 4.9 uses an electrical reference signal, and LSU 4.2 uses the reference air, but also because Bosch significantly improved every aspect of the LSU sensor in the 4.9 version, and made it a mass production level, with superior reliability and quality. Once again, with LSU 4.9, Bosch has dominated the oxygen sensor market in the automotive industry as it did before. Below are some of major improvements of LSU 4.9:


1) Thinner sensing element. All LSU sensors use thick-film technology, which means the whole sensing element is composed of a bunch of thin layers made of different materials. LSU 4.2 has a total thickness of the sensing element as 1.5mm (1 mm = 0.04 inches), while LSU 4.9 is only half of that. How significant is this? Think about this: there are about 10 layers of materials in the sensing element, you squeeze them into 1.5mm thickness. Already hard to imagine? then you have to cut it to half for LSU 4.9. This is the most significant reason that why LSU 4.9 is more expensive than LSU 4.2. Because everything that is used to manufacture the LSU 4.2 sensors has to theoretically double the precision to make LSU 4.9! What are the benefits? more accurate measurements and faster response! Even common sense tells you, when the electronics become smaller and smaller, they tend to be more sensitive and respond faster!


2) New design of protection tubes. The sensing element is protected by a double layer tube. LSU 4.9 has a new design of the inner tube. It has a sophisticated structure to create gas rotations around the sensing element, and it also blocks the liquid droplets reaching the sensing element. What are the benefits? improved gas flow, faster dynamic response and significantly reduced thermal shock risk. Especially the latter one, that thermal shock has been the number one enemy of the oxygen sensor all the time. By fixing this problem, Bosch fundamentally made LSU 4.9 sensors to the mass production level for auto industries. In auto industries, all parts must be designed for at least 10 year life. The LSU sensor is the most important emission control device. It must sustain the harsh environment for 10 years or more. Since 2007, many GM, Ford and other OEM vehicles have been equipped with LSU 4.9 sensors to meet the recent stringent emission requirements. Most likely your vehicle has one LSU 4.9 at least, some have 2 or more. And most likely none of them has been broken. Otherwise you will see the “check engine” light ON on the dash the first thing.

Next time, if your vendor asks you to buy spare LSU sensors with their wideband controller, tell him: “I have been driving my truck for 5 years which has a LSU sensor and it is still working fine. Why would I have to plan to change the sensor soon with your controller?”


3) Measuring the internal resistance and close loop control of the sensor temperature. This is done with the CJ125 chip. We know the temperature of the LSU sensor has big impact on the accuracy and response speed. In fact, LSU sensor only works well at the vicinity of certain temperature. For LSU 4.9, it is 780 Celsius. Bosch factory calibration and sensor characteristic data are done based on this temperature. If your controller can not maintain the sensor temperature around 780 C, the sensor reading can be significantly skewed. With a CJ125 chip, you can measure the internal resistance of the sensor, which is the direct reflection of the sensor temperature, and use it as the feedback to control the sensor temperature in a close-loop manner. Only by controlling the sensor temperature in the close-loop mode can you make the LSU sensor accurate. Next time, when you buy a wideband controller, ask your vendor: “can your controller do close-loop control of the sensor temperature? Can your controller show the real-time sensor temperature so I can see it?”


There are many other advantages of LSU 4.9 sensors over 4.2 ones. But not all people are interested in too much technical detail. You can use common sense then. Why GM, Ford and other car manufacturers all use LSU 4.9, not LSU 4.2? If LSU 4.2 were very close to 4.9 and it is much cheaper, why wouldn’t they just use 4.2? It would generate a lot more profits. If LSU 4.2 were able to do the same job, why Bosch would even bother to spend a lot of money to develop new ones? In the auto industry, ETAS lambda meters are the widely used professional wideband controller. They are used exclusively with LSU 4.9 sensors, though they do support 4.2. But nobody would use an ETAS lambda meter with a LSU 4.2. By the way, ETAS is majority-owned by Bosch.


LSU 4.9 has become a mass production auto part. It is not a luxury part any more. It is available to aftermarket already. Yes, it is more expensive than LSU 4.2, but the benefits of 4.9 worth much more than the price difference. For engine tuning, every bit of the accuracy gain of the sensor can save you tons of hours of tuning time.


A little more on ALM


Besides air/fuel ratio measurement, ALM provides some supplemental functions which make your measurement or tuning more convenient: linear analog output to your ECU or gauge; LED digital display; engine RPM probe, other analog sensor inputs like MAP and/or exhaust gas temperature (EGT); data logging with a serial communication to a PC, etc


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You have a Low 13 second - high 12 second car from the You Tube Go Camera Vid Rick.

More work required if you want to go there.
 
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