the first time i don’t know what happened to the catalyst but the car was only 1 month old from factory and i had check engine light. took it to dealer and they told me a catalyst was replaced. The second time (now car is 6 months old) the failure was so bad the car could not accelerate and you...
...I have an OBD2 reader which I monitor my fuel economy and other stats with and I always see the car running slightly rich with -20 to -30* ignition BTDC or 30* ATDC timing on startup. Also during full throttle it logs fuel ratios as rich as 11:1. From what I gathered from my research, the...
How lean is too lean for a modern (non-lean burn) car and how rich is too rich? Reason I'm asking is my new 4 cylinder Mazda 3 is going through catalytic converters like shit through goose. The dealer has been unable to solve this problem. Looking at the fuel mixture and its ECU, Its WOT fuel...
...have performed with stock ECU and VVT settings…but this car has EPA ratings of 18 city and 25mpg highway from factory. Average speed was 53mph which is very high as I did quite a bit of the way at 75+ mph. One thing I noticed however was water temperature was higher than usual by about 3*...
ok here is some info on car:
- it has a 3.5in diameter aluminum mandrel bent single air intake with heatshield with 2 path ways one through above radiator and another through the brake duct for cold air support. The intake is separated from rest of engine bay with steel shield. This tube is...
...is opened. This is what Toyota is employing as well on the Prius. No overlap on the intake stroke is a characteristic of Atkinson cycle. However 40* evo is still comparatively 'retarded'. On the small more fuel efficient BRZ/Impreza 2.0 DI engine the EVO is much more advanced at 70-50*. EGR...
hey the intake is painted red above and it is closing at 74* which is in between what you suggested. so my current timing is:
IVO 10* ATDC
IVC 74 ABDC
EVO 40 BBDC
EVC 8 ATDC
well what is happening now is the wideband in the exhaust has started to read too little fuel...aka i'm running lean...
...result. I ran this last night without issue on my drive home, about 30min of highway cruising. Car didn't feel any different but I am running 2* more ignition timing with this, though I feel as though there is less EGR compared to stock. The throttle response is more crisp. The intake can't...
this stock, not sure if it's accomplishing what you are suggesting:
This is what i was thinking of setting the VVT as:
am i getting this right? Is my exhaust too retarded/delayed?
...6 cylinder 3.6L Subaru engine. Currently the VVT settings are as such under loads experienced cruising @65mph.
advertised Intake duration 244*
ivo 15* btdc
ivc 49* abdc
intake cam can be advanced or retarded 25* from this
advertised Exhaust duration 228*
evo 24* bbdc
evc 24* atdc
exhaust...
@hemi i have been going to the dyno 2 times a week for the past month. So repeatability is high. So far I have come up with these tables, however it is still not fully done and yet to complete all combinations of cam and ignition timing and fuel ratios.
...dyno i found the stock intake valve timing to be best. however some minor tweaks to exhaust timing helped. for example retarding exhaust by just 5* added 3-5 horsepower at 4000-4600 rpm. however retarding the exhaust above 5k actually hurts performance. at low engine speed where factory...
sorry i'm a bit confused, why would 2000 rpm be a target for such high overlap then if it's targeted for hill climbing? Are you saying it has max overlap because it is the most used engine speed and this will reduce overall emissions or is it because it improves lower RPM efficiency AND torque...
so overlap from advanced intake and retarded exhaust is good for wide open throttle power? I have seen some discussions where the tuners increase overlap through out the rev range and add timing and lean out the fuel.
A 2013 Subaru Legacy 3.6 (H6) i'm tuning has dual VVT or Dual AVCS as subaru calls it. I can control both intake and exhaust timing (50*/40*) respectively. The cam specs seem to be very mild even though the car has no problem building torque up to 5200 RPM and power peaks at 6000 rpm at 260ps...
yes and the results were poor. it faired better with more ignition timing and higher cam lift and longer duration. AFR target is 14.7 at cruise and that seems to give best economy at this CAM setting
...timing and AFR which has made it both responsive and slightly more fuel efficient. For example I advanced part throttle ignition timing by about 3-8*.
recently i learned about its VVL system (valve lift) and i started tinkering with that. this engine does not have VVT or variable valve...
No not just idling. Im wondering to reduce cylinder head temprature do you retard (say from a reasonable base) or do you advance (assume no knock). With fueling is very simple. Richer mixture dramatically reduces cylinder head temprature.
Im getting xontradicting answers here. One person says mbt (when engine produces best torque and hence power) reduces temps but one person says heat is in sync with power. So should i detune timing for more colling (by reducing power) ot should i increase timing to cool?
I settled on 700 RPM, 10* BTDC timing and 14.4 AFR. That is 50 RPM increase, 5* of retard and .2 ratios of enrichment for idle compared to stock. Engine is dead silent now even with catted straight pipe exhaust. However my underhood temps still climb rather quickly at idle despite larger...
