crcain

For kicks a while back I emailed this company which does gasoline testing among other things:

http://www.intertek-cb.com/petrotest...etesting.shtml

The quote they gave me was this:

R+M (Antiknock index) includes tests D2699+D2700 Average: $726

So you would get the RON and the MON octane rating and with that you could get the PON which is what USA pumps label the fuel as: RON + MON / 2

Driven Innovations

iTrader: (3)

Here are some of the projects I worked on in the past and current pictures of Evo Intake manifolds!

http://s249.photobucket.com/albums/g...enInnovations/

U2SLO

Thanks for the pics tom,it was really nice seeing your Manifolds in person.

David Buschur

iTrader: (53)

Shell, BP and Sunoco all seem to be very good gas and consistent.

itzwolf

iTrader: (9)

100% agree. While i don't have anywhere near the experience you have, I have logged my car with several different setups time and time again and those 3 give the best results and make the engine happy. I wont run anything else in my car, period.

C6C6CH3vo

iTrader: (9)

CAFB gas suck's - probably cut with JP8

03whitegsr

iTrader: (8)

I've noticed that some gas seems to want a different tune then other gas. Once tuned for that brand of fuel, you can often make very similar power and the tune will be consistent though. Change to a different brand of fuel from what you tuned on though and the car may detonate or be down on power.

For this reason, I try to fill up at the same gas station when ever possible.

From 2002-2005 I ran my '99 GS-T with a GT2871R on 91 octane at 25-27 PSI everyday on my 80 mile commute. It was enough power to run 113mph traps with stock cams. For those three years, I ran with the knock sensor disabled without issue. I'm not easy on cars...I broke 5 transmissions in this time frame. I also had the wastegate line come off twice in that time period (both times in the same day) that managed to max out the 2 kg/cm boost gage. Still nothing bad happened. I never came across any "bad gas," just different gas that liked different tunes. But I avoided small stations like the plaque and almost always bought from the station down the street from my house.

However, I had one night of some below 0 F pulls on the freeway. Half way through 3rd I happened to notice a puff of smoke out the back right around the time I heard a hard detonation event. The air density was just too much for the tune I had put on it. It didn't seriously damage the motor, but it was enough to make the motor push coolant every once in a while until I got around to replacing the head gasket 6 months later. Using a knock sensor may have prevented this.

I choose to run without the knock sensor for a reason though. While tuning, I was looking at raw knock sensor voltages and noticed some trends. These trends lead me to believe that the ECU could not accurately differentiate between knock and detonation under certain conditions even on a stock motor. With the "right" tune, you could get heavy detonation and the ECU never even saw a thing. The knock levels used in the ECU seem to be adaptive and if you "trick" the ECU into thinking the motor is just loud on average, it is very possible to have the ecu ignore a lot of knock events.

Granted, it was not on an EVO, but I wouldn't be surprised if the EVO knock sensor setup is at least based on the same type of setup and it may be possible to do something similar on an EVO.

warp9

iTrader: (35)

this leads me to wonder the ill effect of having an open wastegate dump. The ecu can't like when that machine gun sounds underneath the motor. I am saving up for a BR gt35 setup and hope he can make an exception and reroute the WG dump into the exhaust.

crcain

I always thought the term "knock" when used normally meant detonation. AFAIK there is only detonation and pre-ignition correct?

gamebred26

iTrader: (19)

Well after a certain point you have to consider a standalone..the sotck ECU can only take you so far..

Mellon Racing

iTrader: (38)

how far?

crcain

Mellon was there ever a point you thought the stock ECU was not perfect in it's knock detection? Either it would pick up false knock or it would not pick up knock when it was there?

gamebred26

iTrader: (19)

Depends if your budget allows you..but I will bet you will get a better tune with a standalone in the right tuners hands then with a flash. AEM , V-Pro..

I am no expert and am new to the Evo but I have talked to Ivey and consider him one. Sat with Yo-Solo and watched him tune many cars..mostly K-Pro and AEM..on Hondas...N/A and boosted..

I also see the issues my close friend is having with his car...running 30+ lbs. of boost with meth on 35r...on a flash..

I see my car getting false knock from the stock ECU SES light comes on..and I am still on a stock turbo..pump gas..

I think there is def a reason behind going to a standalone and being able to tune every apsect of the car...and have complete control..

Personaly when I upgrade my turbo I will prob go to a standalone EMS..either AEM and take it out to Buschur or V-Pro with Ivey not sure yet..

xiaoni420

iTrader: (32)

Exactly, gotta love the stock ECU.

gamebred26

iTrader: (19)

Put the Cosworth cams in your car..you will have false knock in a day..