Grumpy,
Please open this up to all readers if you would as I'm not sure how to add all members to the thread.
I'm planning to make a run to the local chassis dyno next week since I feel like I have all the bugs worked out of the Camaro.
The use of a dyno is new to me so I have a few questions.
Since I'm using EFI it is trivial to change AFR and am looking for input.
I plan to build 3 POWER tunes (12.5, 13.0 & 13.5 AFR) and try them all.
I know that higher AFR will help keep heat down but at some point I presume it looses its value. That is my KEY question...
how rich is too rich?
I am looking to make north of 500hp and torque. Based on reading detailed on your site, tools from Comp Cams and others I feel this is conservatively reasonable. I expect my torque to come in at~ 2300 and hold to 5000 or so and my peak HP to be around 5500-6000 RPM.
My oil temp stays at ~ 200° on long drives and and coolant stays below that so I'm not really worried about temps. I'm running pump gas (91 octane) without detonation and here is the build.
========================
10.3:1 CR 496
Mahle Pistons and 4340 crank , H beam rods & 7/16 rod bolts.
Ignition:
38° total mechanical advance all in at 2500RPM
- Pertronix III multi spark
- RN12YC Plugs
Intake:
- Low rise dual plane that has been port matched.
Heads:
- Brodix (2061003sscc) 115cc aluminum heads with CNC chambers (115 cc)
Exhaust:
Stainless Works CANV679 2" headers with 3.5" collectors.
Pypes - 3" stainless exhaust & mufflers
OILING:
- Moroso 7qt pan with windage tray
- Milling M77-HV oil pump
- Stewart Warner oil temp sensor
- Canton remote oil filter
- 2qt WIX 20 micron filter
Comp Cam components:
- Cam (XR294HR)
.540/.560 & 294/300 w/110 lobe separation (installed straight up).
- Short travel rollers (15854-16)
- Ultra Pro Magnum XD (1820-16)
Induction/Fuel :
- Fitech MeanStreet fuel injection
- RobbMcPerformance PowerSurge fuel supply.
Transmission:
- Tremec TKO600 (.82 5th)
Cheers and thanks for any guidance.
that sounds like it will be a fun to drive 496 BBC engine combo
you did not mention tire diam. or rear gear ratio.?
below you'll find a good base line starting point,
and Id suggest you monitor coolant and oil temps,
try hard to keep coolant temp under 200F and oil temp under 220F
verify your fuel delivery pressure is consistent over the whole rpm range
take the time to graph out and verify your ignition advance curve!
a good IR temp gun
infrared thermometers are a very useful tool to track down issues with tuning, or mal functioning sensors , without verified facts your guessing.
this is the most consistently accurate I.R temp gun I've used for testing[/img]
http://www.testequipmentdepot.com/e...1100200223789&utm_content=All Extech Products
INFRARED TEMP GUN
Wide temperature range from -58 to 1832°F (-50 to 1000°C)
to use on the header primary tubes helps locate fuel/air ratio inconsistency's
GENERALLY your fuel/air ratio should be in these ranges
Idle- up too about 2500 rpm try for 14.7:1-15:1 f/a ratio,
too get max mileage and prevent spark plug fouling
from about 2500 rpm- too about 4500 rpm,
try to smoothly and predictably transition the fuel/air ratio mix richer to about 13.5:1
for good power and less chance of detonation
from about 4500 rpm- too about 6500 rpm and higher
,try to smoothly and predictably transition the fuel/air ratio mix richer to about 12.5:1,
for good peak power and less chance of detonation.
this is only a well proven starting point on the tune,
but it generally gets you in the ball park ,
and tends to reduce the chances of the engine reaching detonation conditions.
the ignition advance curve needs to be checked, the chart below is a very good starting point to work from, and USE OF A RICHER FUEL/AIR MIX, WILL AT TIMES BE REQUIRED IN THE OFF IDLE TO 3500 rpm range,
btw what does a compression check show your cylinder pressure to be?
try to get the dyno test info too include your ignition advance curve and your fuel/air ratio every 500 rpm?
try to get the dyno operator to verify and show and plot out you your header collector exhaust back pressure in the collectors, and intake plenum vacuum, every 500 rpm, ?
knowing detailed info like that can be rather helpful.
but the idea here is to keep the lower rpm and lower stress operations running at efficient fuel/air ratios to reduce plug fouling and improve mileage as youll generally spend 90% of the cars operational life on the street at under 4500 rpm.
set the plug gaps at about .045, make sure the valves are adjusted correctly
In-Line Spark Checker
In-Line Spark Checkerwww.harborfreight.com
Fuel Injection Pump Tester
Fuel Injection Pump Testerwww.harborfreight.com
Noid Light and IAC Tester Set 11 Pc
Amazing deals on this Noid Light And Iac Tester Set 11Pc at Harbor Freight. Quality tools & low prices.www.harborfreight.com
14 Function Digital Multimeter with Sound Level and Luminosity
Amazing deals on this 14 Function Digital Multimeter, Sound at Harbor Freight. Quality tools & low prices.www.harborfreight.com
ZR13S OBD2 Code Reader with ABS/SRS/FixAssist®
ZR13S OBD2 Code Reader with ABS/SRS/FixAssist®www.harborfreight.com
related threads
http://garage.grumpysperformance.com/index.php?threads/dyno-tune-or-not.9250/#post-51804
http://garage.grumpysperformance.com/index.php?threads/dyno-hp-loss-rates.782/#post-43454
http://garage.grumpysperformance.co...n-engine-combo-and-dyno-slip.5074/#post-14421
Last edited: