Just like Voltage calls the tune as to fuel pump output, higher Voltage to the coil greatly multiplies ignition efficacy. Three factors convinced me to rune the Boost A Spark:
Higher Voltage to the coils only in boost when you need it. no fried coils
Voltage is adjustable, i am at 16 V. IGN-1A/Smart coils have an internal voltage limiter at 17 volts.
Kenne Bell build and engineering quality. (i have run a Kenne Bell Boost A Pump since 2003)
Here's my current timing map.
I decided to do another run and hold timing level. The effect was to lower timing from 11 to 8.6 throughout the run. AFRs were virtually the same at 10.9 V 10.8 and boost was identical at 18.1 psi. Knock disappeared from 110 to 20! BTW, hp rose with the absence of knock from 483 to 489. ( see "No Dyno? No Problem" section so you can also determine power from your log).
These two logs show the importance of having excellent knock data as well as the importance of timing. The cause of the knock was a combination of winter gas and that it had probably been a long time since it was refined as it was a very low volume station. Julio Don, proprietor of Alkycontrol (my AI system) currently runs in a pump gas only drag class in Florida. He has a 1200 rwhp fox body Mustang and has always run only pump gas. ( he also is one smart guy) ... He told me that gasoline loses a little over one octane each month after being refined.
Buy your gas from a high volume station.
The following year (2018) , after finishing my evaluation of the Borg Warner S 300 SXE62 with the .91 and 1.0 hotside i switched to my Borg Warner EFR 9180. During the year i had ramped up my timing back to original levels as summer gas arrived. I also switched to a high volume Mobil outlet.
Here's a log at 585 rwhp on 93 pump and 1000 CC of meth as AI. No knock.
The second challenge is as CCP rises so does CCH and with it the chances for dreaded knock. While more malleable apex seals have greatly reduced breakage, and the attendant carnage, chances are excellent that the corner seal springs will de-arch and you will be looking at a 20/30% compression loss. The motor will have to come apart.
Correct timing is the key. A proper knock system is essential. (See Tuning/ Hardware for details). Knock data is the primary factor when building a timing map. There are numerous variables that effect timing and knock. Actual hardware is one. Fuel is another. (see Tuning/ Fuel section). The key to fuel is that it normally is not a constant. In many parts of the country we have summer and winter gas. Further effecting octane levels is the fact that fuel loses over one octane per month after being refined. Buy your gas from a high volume outlet.
I encountered a modest but significant amount of knock doing some road tuning on December 6, 2017. I was burning Mobil 93 octane and 1000 cc of methanol.
The fix was a switch from .030 to .023. This occurred before i switched to inductive ignition which would have allowed a wider gap. i have since added another killer ignition component:
Kenne Bell Boost A Spark
From the Kenne Bell site:
"At last… an ignition system designed specifically for “coil” engines
So much energy it may have to be dialed back.
Activates only at boost or wide open throttle where the engine really needs it!
Recommended for high cylinder pressure (turbocharged, supercharged, nitrous). The ignition system market has changed. The new domestic and import engines no longer use a distributor with one coil. Instead, there are multiple coils – one (1) for each cylinder. Some engines even have a coil mounted on the individual spark plugs. CD ignitions use the high voltage “short spark” principle whereas the BOOST-A-SPARK™ incorporates the preferred higher energy “long spark” (2500 microseconds vs. 200 for CD’s.
Kenne Bell, The Innovators, has done it again! The FIRST high energy non CD system designed specifically for the new 4, 6, 8, 10 and 12 cylinder engines. And it’s cockpit adjustable from 0-50% to handle any boost or rpm. You are in total control. The revolutionary adjustable Kenne Bell BOOST-A-SPARK™ merely taps in on one (1) wire and supplies all the energy your engine needs. All stock modern day engines have great ignition systems for start up, idle, part throttle, fuel economy etc. It’s at WIDE OPEN THROTTLE where they’re marginal. We activate our hot ignition only where it’s really needed – at wide open throttle or in boost. In fact, it produces so much energy you may have to turn it down if the plug wires aren’t in good shape. And it works equally well on ALL engines, not just the “coil” engines.
Forget the rhetoric and magazine ads and let’s tell it like it really is. Never buy an ignition system for your late model “coil” vehicle because you think it will make more HP, help start ups, increase throttle response or improve fuel economy. It will not. You add an ignition system to guarantee it wll fire at higher rpm or boost levels. The Cobra’s ignition (see below) was not igniting all the fuel mixture at 8 psi above 2500 rpm. We activated the ™at 3 psi and made 50HP.
FEATURES THAT MAKE BOOST-A-SPARK™ SUPERIOR TO ALL OTHER IGNITIONS
• Increases spark energy – ALL 12 VOLT IGNITION SYSTEMS. Highest voltage of any ignition system concept.
• New Kenne Bell “Long Spark” Technology increases AND regulates voltage. NOT a CD with an inherently “short spark.”
• More energy than CD systems. Over 2 amps at the plug (10 times more than OEM and 4 times more than other aftermarket ignition systems).
• Eliminates engine misfire under boost or high load.
• Ideal for supercharged, turbocharged and nitrous applications.
• Will fire spark plugs with up to .100″ gap and 30 psi boost. 2500 microseconds vs. 200 for CD’s.
• Regulates ignition voltage within .1 volt, regardless of battery voltage.
• Allows wider plug gaps for MORE POWER. Other ignition systems must run closer plug gaps.
• Automatically adjusts spark energy to meet engine requirements i.e. rich, lean, supercharged, high compression etc.
• Two (2) models. Supercharged / Turbocharged or Normally Aspirated. Pressure or vacuum switch included.
• Attractive red anodized extruded aluminum weatherproof case.
• Developed on the Kenne Bell Dyno.
• Easy to install. Just connect to primary coil wire."
The ignition map is the backbone of the tune. Just like fuel, it is extremely important to get ignition right. All turbo'd rotary engines make tremendous amounts of Combustion Chamber Pressure (CCP) and Combustion Chamber Heat (CCH).
CCP and CCH create two key challenges:
The CCP level creates a challenge to the spark's journey from the center electrode to the ground strap of the spark plug. Think of it as trying to drive a nail into a granite counter top. You better have a BIG HAMMER and that would be powerful ignition coils ( four IGN 1-A, also rebadged by AEM as Smart Coils), exceptionally good ignition wires with tight spark plug boots (Magnecor 8.5 custom wires my pick- visit the site to find out why https://www.magnecor.com/magnecor1/main.htm ), correct spark plugs (NGK R7420 in a 10 to 11 heat range or Denso 5721 IRE01-32.) and gap. See spark plug part numbers/heat ranges below. Kenne Bell after exhaustive boosted testing states..."Iridium plugs will fire under much higher cylinder pressure than any other plug we ever tested."
MSD offers an excellent wire separator kit. It is important to keep the wires at least an inch apart. Spark cross-fires can break motors.
I tuned with Luke Stubbs at Beyond Redline on 93 pump and methanol quite successfully from 2003 thru 2008 and had a well developed timing map. I detoured to E85 from 2009 thru 2014 and then switched back to gas. My car was idle for a while and when i finally had my ducks in a row i downloaded my trusted timing map from gas days into my ViPEC V88.
And it knocked!
The knock was unapparent during the run and only surfaced as i looked at the log before another run.
My motors make peak torque around 6450 and that is the area where knock is most likely to surface as peak torque is:
Maximum combustion chamber fill
Maximum combustion chamber pressure
Porting generally determines peak fill. If you look at a well tuned map you will see max fuel and minimal timing at peak torque. After peak torque you need less fuel and can use slightly more timing since as RPM rises less fill time is available.
I initially looked thru all my data trying to figure out if some setting was awry. Nope. The only item that offered possible relief was that my timing was modestly rising thru the knock period.
Of course my present map is presented as what works for me and may very well not work for you. As i have shown, the quality of fuel alone can disqualify this map. This is why it is essential to run a proper active knock system. Start very conservative, monitor knock readings and time accordingly. I am able to find 93 octane, maybe it is unavailable to you. I run 100% methanol as AI which brings my Intake Air Temps from over 300 F coming out of the turbo to under ambient... I have an excellent intercooler. There are so many variables and only a knock system can net them out and provide proper guidance. The good news is that we now have the hardware and software to manage detonation.
If you are wanting to run into the 500 rwhp area and are unable to find 93 octane i strongly suggest you use 100% methanol as AI injectant and/or add a modest amount of the newer octane enhancers such as Boostane.
Another item worth consideration is misfires. Misfires are not able to be recognized from the driver's seat and they are not detonation but they do cause power loss. The only way i know how to I D them is looking at a dyno power plot on ZERO SMOOTHING. Misfires show up as tiny wiggles. The cure is a smaller spark plug gap ( .023) works for me, more coil dwell, better plug wires. Here's a run showing misfires:
Split or Trail Timing is zero in vacuum and 11 in boost with an important smoothing transition between the two.
recommended Spark Plug part numbers
Denso Iridium NGK Iridium
5720 IRE01-31 10 heat range 5501 R 7420 10 heat range
5721 IRE01-32 10.5 4857 R 7420 10.5
5722 IRE01-34 11 7756 R 7756 11
5741 IRE01-35 11.5