Here is a very long read, but well worth every minute you spend reading or re-reading it.
via:
http://www.8thcivic.com/forums/hondata/ ... uning.html
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Hondata: A Guide to Tuning
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This is an edited set of notes from Conrad H. Blickenstorfer on a K-Pro seminar that Hondata presented back in 2004. I found this to be a very useful and informative guide to the basics of Honda ECU functionality and the tuning methods of Hondata. Much of the information presented here was originally for the K-Pro and RSX Type-S, but the FlashPro and Civic Si functions in a similar manner, so I felt that posting it can still be useful to the community. It should be noted that there certain aftermarket parts and their effects on the RSX Type-S are mentioned (Jackson Racing's supercharger, Greedy's turbo kit, etc.) but do not necessarily yield the same results on their Civic Si counterparts. To Hondata, I understand that the some of the information on here may not be completely accurate as the Civic Si and the RSX Type-S, although similar, are still different. Any corrections or additional information you'd be willing to include will be greatly appreciated.
Hondata: A Guide to Tuning
General Tuning Issues
Goals of tuning:
- The overall goal should be having educated customers: they should know what to expect from tuning and not have unrealistic expectations
- Reliability is important: always know what is safe and what isn’t, depending on the project
- Repeatability of runs (know all the factors that affect it; synthetic gear oil, for example, takes longer to warm up, water temp, air temp, etc.)
- Maximum power is really only “marketing power.” A complete tuning package also includes easy starting, steady idling and good drivability.
- Road tuning is just as important as dyno tuning; the dyno only tells part of the story and real world conditions are very different.
- Part throttle is very hard to tune (and also to sell as it takes much longer!)
- Tuning for economy/emissions. It IS possible to have BOTH power AND economy. Same for emissions.
Some points to consider:
- A road car is at WOT (Wide Open Throttle) only 0.1% of the time and part throttle 99.9% of the time.
- Part throttle tuning takes much longer (and costs a lot more), but done right makes for much better responsiveness and fuel economy. Some of the replacement chips out there only go for WOT top power. Some of those chips are very specialized, offer no ignition control, and generate error codes. Simply switching those codes off is not a good thing.
- Psychology of VTEC: The VTEC “kick” really shouldn’t be there if the engine is well tuned. Then the curve should be totally smooth. Interestingly, some people think the car with the VTEC “kick” has more power when, in fact, it has less.
Does more peak power always mean faster?
No! Acceleration depends on the power under the dyno curve. Higher peak power can actually generate less acceleration than a car with less peak power. Torque matters! More power between 3,000 and 6,000 is extremely important. The only time when that may be different and peak power becomes an issue is in drag racing.
Reliability:
- How high do people rev? Some said as high as 10,500. This is hardly ever needed as power drops off with most cams well below that. Hondata usually sets the rev limit about 500 rpm past the power peak. That way when you shift you drop back to a good high rev point, but one with lots of power left. How high should you rev? That depends on the strength of the rods and pistons. And valve bounce can damage pistons.
- Don't set the rev limiter any higher than 8600 rpm on a stock engine.
- Running rich/lean? Proper rich/lean tuning is extremely important. An interesting point: the Mugen thermostat and similar do not let engine ever warm up all the way so that tuning gets harder because the engine keeps adding fuel.
- Ignition advance knock: If the spark is fired too soon, the piston is still coming up and the flame front bops into the piston. That can mean broken rods, worn bearings, or blown head gaskets. Sacrificing the last 5 or 10 hp in a highly tuned engine will greatly increase longevity.
- Knock: one problem is that knock sensor reporting to the computer is not very good and the computer isn’t well equipped to accommodate. The knock sensor is actually a microphone; you can put headphones on and hear the knocking and which cylinder knocks.
- Altitude: table columns 1-10 must be tuned for higher altitude operation
- Fuel pressure: Some people think higher fuel pressure is better. That is not always so. Low pressure means cooler fuel, pump and injectors. Some pumps actually move lower volume at higher pressure. Basically, higher fuel pressure does not appear what Hondata recommends. 50-60 psi is the max Hondata recommends.
Dyno repeatability
- Water temperature should be 180-195 degrees
- Use datalogging during dyno runs
- Gearbox must be warmed up, especially when you use synthetic oil
- Keep the intake temperature as consistent as possible or else the dyno results will be distorted
- The intake manifold is aluminum and heats up when it really should be cool. The intake manifold is NOT a heat sink and the gasket does NOT hurt. Bypassing the heating on the throttle body (really only needed in colder climates) amounts to perhaps 20% of the lowered temperature and the Hondata intake gasket 80%.
- Do not switch off the knock sensor nor primary O2 when tuning the Civic Si.
Tuning for torque
- Rough rule: 10% fuel change = 1 Air/Fuel point
- At peak torque engine needs most fuel and is least sensitive (to what?)
- The fuel curve is shaped very much like the torque curve
- After the torque peak, remove fuel
- Don't tune an endurance engine rich
- 2D curves must be smooth over the rpm range (lines in the graph should be parallel and have no sharp drops and rises). Load lines should never cross each other
Tuning for max power
- Use the 2D view extensively to get it right
Stock Honda fuel maps
- They are loaded in the software and you can pull them up
- Study them: The lines are nice and smooth and parallel
Optimize starting and idling
- Cranking ignition does not use the ignition tables
- Idling control opens or closes the IAC
- For bigger injectors increase the target idle
- Advance ignition and lean via emulator
- 750-1000 rpm’s and columns 3-4 are the idle section
- Best idle around 830
Road tuning
- Dyno is different from road and different dynos load the engine differently
- Underhood airflow is different between dyno and road tuning
- WOT air/fuel seems richer on a dyno than on the road, up to a full AF point
- Don’t forget to switch back to enabling closed loop after tuning!
Knock
- The knock sensor is a tuned microphone. You can build one from a speaker amp ($30).
- The Civic Si ECU will not advance / retard on knock
- Knock sounds like a sharp ticking
- The knock counter resets every time the engine is started
Economy and emissions
- Part throttle ignition advance is optimized for economy, best not to change. Also, do NOT lean out the part throttle and run in open loop for economy.
- Doug mentioned examples of cars that failed to pass with the stock ECU but passed without problems with Hondata
Injectors
- Use saturated injectors (12 ohms) like the new 440 and 550’s from RC Engineering
- Stock Civic Si has 310 cc injectors
- 550 cc injectors at 50 psi fuel pressure can handle approximately 320-350 whp
- The Honda stock fuel pump is good for 250-290 whp
What does Datalogging do?
- Records a large number of sensor values from the car’s ECU and stores the data in a connected laptop computer
- Can be used to adjust fuel to get to proper Lambda values
- Measures intake system efficiency with the MAP sensor that senses air pressure or vacuum in the intake manifold (the ECU uses MAP input as an indication of engine load when adjusting air/fuel mixture and spark timing)
- Shows short and long term fuel trim (computer adjusts short term according to Oxygen sensor readings to a long term fuel trim value over a period of time, days, weeks) Watch for bad Oxygen sensors! Resetting the ECU sets the long term fuel trim back to zero.
- Shows intake air temperature compared to outside
- Shows injector duty cycle (should be under 90%). 100% means the injectors always open and cannot supply as much fuel as is needed.
Tuning with A/F ratio
General hints:
- Use a COLD AIR INTAKE! Something like the T1R Intake has better flow and is better than the stock airbox, but does not perform as well as a CAI.
- Use the Hondata heatshield gasket to keep the manifold from heating up and also to help it cool down quicker.
- Insulate/wrap your intake to keep air as cool as possible
- A CAI can provide an additional 0.3-0.7 psi more boost. Hot air costs boost pressure.
- The JRSC needs very little ignition timing retard vs. stock
- Turbo retard 18-20 degrees from 12 psi up
*Erick’s Racing 9.99 second ¼-mile Civic that has 300+ wheel hp on a 2.2 liter engine with the stock ignition and 10,500 rpm limit.
What did Hondata find when they analyzed the ECU?
- The stock Civic Si ECU does not run rich at high rpm
- The Civic Si stock ignition timing is not conversative
- It is VERY sensitive to the knock sensor
- Once tuned, there is more power, yet the same or better emission, and better economy.
Basics: What makes power?
- The motor is really an air pump
- Put in as much air as possible
- Add proper fuel and ignite it at the right time
- Make sure exhaust doesn’t restrict
- Simple as that!
The iVTEC system of the Civic Si is a combination of VTEC and VTC. VTEC basically creates one camshaft profile for good low end drivability, torque and fuel economy, and a second more aggressive “wild” camshaft profile for high end power (the “low speed” and “high speed”). VTC rotates the camshaft by a total of 50 degrees which results in different valve opening overlaps by changing the relative timing between the intake and exhaust valves. Both VTC and VTEC use oil pressure systems controlled by the ECU. The combination of VTEC and VTC enhances the effectiveness of VTEC and offers great tuning opportunities, especially smoothing the midrange and adding power there.
VTEC = Variable Valve Timing Electronic Lift Control
- VTEC is a system that changes valve lift, timing and duration; it’s like having a low rpm and a high rpm camshaft
- A hydraulically operated rod either engages or disengages on both intake and exhaust valves in the Civic Si
- Engaged means the car opens and closes both valves fully (with higher lift via more aggressive lobe), allowing much better breathing (and power)
- The “VTEC Point” can be set at a certain rpm, or it can be set between two rpm points depending on vacuum. The engagement then moves linearly between the two points.
- (Interesting factoid: overhead cams were created to eliminate rocker arms; yet Honda uses a rocker in an overhead cam to facilitate VTEC)
VTC = Variable Timing Control (rotating cam)
- VTC is a system that continually changes intake camshaft timing by a total of 50 degrees
- Why? Because different cam angles provide different power at different revs; switching angles can make for an optimized composite curve
- VTC enhances the effectiveness of VTEC
- What VTC varies by changing the angle is the intake valve opening overlap
- There is a VTC actuator controlled by the ECU that monitors cam position, ignition timing, throttle position and then advances or retards cam over a 50 degree range
- There are advance and retard chambers in the actuator wheel that cause a wheel inside the cam pulley to turn and thus turn the cam
- The idea is to have different cam settings for maximum power and/or lowest emissions; in general: the higher the advance the better the breathing
- Cam is almost fully retarded (no overlap) at idle. This makes for a smooth idle
- Cam angle is advancing as rpm rises, thus opening intake valve sooner to allow additional overlap for better fuel economy due to less pumping losses
- There are 5 fuel & ignition tables for low cam & 5 for high cam (0, 15, 30, 40 and 50 degrees respectively)
- The VTC Control valve and actuator engage and disengage a lock pin
- It takes about 0.1 seconds for the cam to turn by 10 degrees
- Exhaust cam is not under computer control. There may be benefits to adjusting the exhaust cam.
FlashPro Manager software
Properly setting and manipulating the cam angles is the most important aspect of tuning the K-Series engine. Basically, what Hondata does dyno runs with the cam angles fixed and see what cam angle produces the highest power at each rpm range. Then they built a composite cam map where the cam is at the angle that produces the highest power at each point of the rpm curve.
The FlashPro Manager software has datalogging built-in.Some of the handy “Parameters” settings of the FlashPro Manager software are:
- For tuning, turn off closed loop because you want to be in open loop so that ECU doesn’t constantly compensate
- Knock: “K. Count” is in the Sensors list and shows how often computer felt the engine knocked. Knock is a stored value, long-term. You can go see where the knocks occur and then see if the AF ratio is okay. If so, then check ignition advance. There can be dozens or hundreds of knock counts in a second (zoom in to see closely).
While the variable cam timing is terrific for tuning, having a constantly moving cam also means that it takes a longer time to tune all this. Doug has explained that when tuning a car and developing the optimal calibrations, they actually do dyno’s at each angle then see what cam angle is best for maximum power at each rpm. Doug has shown high-speed WOT dyno graphs for each cam angle. In general, between 3000 and 6000 rpm, the larger the angle the better the power. However, between 1500 and 3000 different angles produce best power, and at high rpms also.
General procedure for from-scratch tuning of the K-Series engines
- Set ignition timing to stock
- Set VTEC high (6500-7000 rpm) to tune low speed cam
1. Set both cam angle tables all to zero degrees and dyno tune ignition and fuel tables
2. Repeat dyno tuning of ignition and fuel tables with both cam tables all set to 15, 20, 30, 40, 50 degrees
3. Analyze dyno curves, then set cam angle table at each rpm to angle with best power
4. Dyno again with new composite curve (you may want to “bracket” by a few degrees up and down to see if optimal)
- Set VTEC low (2000-3000 rpm) to tune high speed cam, and repeat above procedure
- Set the VTEC crossover RPM
- Part throttle also needs to be tuned (part throttle = columns 7 and lower)
1. At part throttle/cruising (columns 2-7, 1500-4500 rpm) cam angle should be around 30 degrees. This will use EGR effect to reduce emissions and improve fuel economy
2. At higher rpms in part throttle, set angle to same as full load so that cam angle won’t go down during shifts.
3. 500-8100 rpm’s and columns 1-2 are the deceleration sections of the map and prefer lower cam angles (cam lobe centers are separated, valve overlap is minimal and there is little contamination of intake fuel going into the exhaust system).
Proper tuning at the VTEC point and setting the VTEC point
Getting the VTEC point right, and setting the cam angles at the cross-over right, is very important and one of the most difficult tuning tasks. If not done right, the curve is bumpy and performance suffers. This can happen when the low speed cam angle at the switch-over is far apart from the high speed cam angle, so that the cam needs to rotate by a lot. This can result in a power dip for a few hundred rpm after VTEC while the cam rotates into proper position. As for where to set the VTC point, it should be at the intersection of the low speed and the high speed torque curve.
- Cam takes 0.1 seconds to rotate 10 degrees, so you have to start rotating the cam angle before VTEC so that the low cam and high cam angles are not far apart at the VTEC Point
- Done right, the VTEC switch noise is greatly reduced; the difference in noise is because when VTEC engages you’re really running a different engine
- It’s better to sacrifice a bit of power before the VTEC point to gain it back and more after VTEC
- Getting the VTEC Point right is hardest to do on turbo motors (they generally want a high VTEC point)!
For NA engine tuning:
- Cam advance should be biggest (50 degrees) right after VTEC Point and then all the way up to 6500-7000 rpm
- After 7000 rpm, gradually take cam angle back to 25 degrees at redline.
- In general, with high backpressure you should retard the cam angles and raise the VTEC point, with low backpressure the opposite
- Use variable VTEC window, with lower boundary at point of highest power (intersection of low-speed and high-speed torque curves) at 90 kPa and upper boundary at 5,800 at 25kPa.
- The longer the primary and secondary runners on a header the lower the VTEC point.
- Air/fuel ratio that makes best power at WOT under full load is 13-13.5
For turbo VTEC tuning:
- If your cam angle is ever 0 at 8000 rpm, you have a major exhaust restriction which needs to be looked at.
- Retarding the cam can mean picking up 40 horsepower at high RPM.
- Use a fixed VTEC point. Since the crossover is high, the VTEC point should be high, around 6,000.
- However, a tubular turbo manifold setup may need a VTEC point of 4000-4500 rpm.
In general, with high backpressure you should retard the cam angles and raise the VTEC point, with low backpressure the opposite
For extreme cams, add lots of timing at low end for impressive torque gains, raise idle speed, reduce overlap in part throttle.
Supercharged engines:
- Tuning is really similar to larger NA motor.
- Supercharged engines love overlap (high cam advance)
- High cam set to 50 degrees throughout most of rev range, then down to 40 from 7000 rpm on up
- Low cam VTC 45-50 degrees
- Cam angle actually affects boost in manifold
- Don't set the WOT closed loop higher than 90 kPa.
- The higher the RPM, the higher the boost. (Greddy turbo actually got less boost at higher RPM)
- In the fuel tables, boost curves should be very flat and smooth
- However, more boost does not necessarily mean more power
- Ideal A/F ratio at WOT under full throttle is lower than NA, 11.5-12.5
- Use variable VTEC window like on stock engine but with two exceptions: you can set the lower boundary lower, down to 3,000, but set both the lower and higher point to occur at full engine load pressure. That way there won’t be a linear line. Under load it goes into VTEC, under part load it goes out of VTEC once revs fall below the upper boundary.
Nitrous:
Doug said the use of nitrous was much safer with the FlashPro. He recommended a dry system. Wet nitrous system are not a very happy match with Civic Si because at redline, the Civic Si cuts off fuel whereas nitrous continues, instantly leaning things to catastrophic levels. Nitrous works quite well with boosted engines. They get higher boost (by about 0.5 psi) and the supercharger acts as a nitrous mixer. Hondata tried a JRSC with 7 PSI and N2O. The nitrous dry system added boost but they found the belt slipping at high RPM (Doug runs DC twin canister exhaust and 7psi on his car). Ignition should be retarded, the system needs larger injectors, and nitrous should be shot off before redline. With turbo engines, nitrous can reduce turbo lag by spooling up the turbine more quickly.
Tuning for intakes:
For tuning purposes it is important to know the resonance point (the rpm where the intake makes that extra sound as if you were blowing on a bottle) of a CAI. For example, the AEM CAI on an RSX-S has a resonance point of 5200, the short ram AEM V2’s is at about 5900. Longer pipes have lower resonance points. There is a torque peak (and often a lean spot because an untuned motor doesn’t get enough fuel) at the resonance point. You can tune for different intakes. Doug has mentioned that pressurized intakes can really make a difference. Build a box around it to force air into it.
Intake manifolds:
Doug has shown some dyno runs of stock Type-S versus the Integra Type R intake manifold which has slightly fatter runners, and so should do better. However, the horsepower difference is primarily at the high end where the Type R peaks at higher rpm.
Fuel cooling and such:
Theoretical contemplation on injector positioning: They should be at the top of the runner. This would be bad for emissions but good for power. Doug has spoken of the power benefits of cooling fuel. 20 degree Celsius difference means 1% more power.
A variety of tuning pitfalls:
- Valve spring pressure too high is bad news as there isn’t enough lubrication.
- Cams can be installed incorrectly.
- TPS and MAP sensor can be reversed.
- The MAP was not relocated in a supercharger installation. (It must be AFTER the compressor.
- The supercharger belt can be slipping
Effects of various mods:
A stock K20A2 engine makes between 160 and 175 wheel hp. That is quite a big difference in a modern precision engine and it could be because of different sensitivity in knock sensor. Doug went on to show dyno sheets of a variety of mods they added to a stock motor.
A Hondata reflash added almost 20 hp on top (the primary benefit is the mid range power), an AEM CAI another 10 to about 190. A Greddy catback exhaust added a bit and ITR cams another 15 hp. Raceheaders from Comptech added an impressive 15 up to almost 230. A ITR manifold boosted the high-end a bit and placed peak power more into the 8000s. Titanium exhaust and pulleys added a few hp but not much. Finally they installed a ported big valve head with Toda cams, for a result of almost 250 all-motor whp. Hytech exhaust, 12:1 pistons, cams and intake raised that figure up to 270.
Another project (Hasport/Jackson Racing Civic Type R) replaced the K20A2 bottom with a K24 CRV bottom. This brought 40 pounds extra torque, but power dropped off quicker at the high end. Initial peak power was 210 whp. They added an 8psi JRSC and got torque of over 230 foot-pounds and over 290 whp.
K-Series Bang-for the buck list of mods (least to most expensive):
- Intake Gasket
- CAI
- ECU Reflash
- Header/Exhaust
- FlashPro and tuning
- Cams
- Nitrous and boost
- K24 bottom end swap
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Last edited by jdizzle37; 11-16-2009 at 05:19 PM. Reason: Updated information