Petrol RON 95 vs 100

[FreakensNL]

Hope this is the right sub.
I really want to know what is the difference in (ecu, tune) between 95 and let's say 100, is it just a bit of timing adjustment?


I run 95 cause 100 is super hard to find here, I want to boost to 1.0-1.2 bar
Can stock maps handle 95 @1bar? (With fmic, etc)

 

[JDM_virgin]

Yes they can, you will be right on the duty limit of the stock injectors at 1.2 bar

 

[FreakensNL]

But the fuel and timing map are safe in the stock ecu? (Just to be clear without a retune @ 1 bar)

Will get a nistune in a couple of months to fine tune the brain, but plan on run ron95 @1bar till then

 

[JDM_virgin]

I wouldn't increase the boost at all without a map as you'll just lean the fuel mix out- that is why you get a car mapped so it fuels more. You will also need a bigger fuel pump like 255 to increase the fuel flow when you map it.

 

[FreakensNL]

Got a wideband to monitor the fuel..
I just wonder about the timing, if it's not detonating with 1 bar and ron95
As long as it's not leaning or detonation it's should be safe
The retune is to get closer to ideal on the timing and fuel isn't it? (= more power)

 

[Rubix_Cube]

The issues with 95 and 99 RON are at the higher end of the scale, so if your doing a Vmax run and everything is nice and hot the 95 will pre detonate causing damage. The 99 is more stable.

I'd suggest until you get a map, you simply run 0.8 or 0.9 bar not 1Bar. That way it lessens the strain on things.

 

[TomK]

My car was run on a dyno at 1bar with stock map and 98ron fuel and was fine. Not sure i would want to run it on 95ron.

Edit: just for clarity, I don't run it at 1bar, it's on stock pressure 95% of the time and put up to 0.9bar on special occasions. It was just ran at 1bar on the dyno to see if the stock map could cope.

 

[Chriscooke]

I wouldn't run 1 bar on the stock map with 95ron fuel.

 

[FreakensNL]

You think the stock timing is to soon, or do you actually know?

 

[immy21]

JDM Spec R (with Walbro, decat, MBC) is marginal at 1 bar on high octane pump fuel, so no I don't think it will be ok on 95, your only hope is it det's within knock sense range and the ECU pulls timing/switches to knock maps. Not something I would suggest you mess with unless you have an after market knock sensor. They fuel very rich once boost is turned up so don't let you AFR gauge fool you into thinking it's safe.
What I found (on high octane) was after a pull or two on the street 14-15psi was enough to make it det. 13-14 psi with a couple of degrees retarded at the CAS kept det at bay on 97-99 octane until I got Nistune fitted.
So I would suggest 14psi on 95 is not recommended.

 

[FreakensNL]

Good to know, you don't got a FMIC and cooler spark plugs?
i got NissanDataScan so i can see if it goes into det map, so will put it on .8 bar for now
will order nistune asap to "try" and make it safe...

 

[immy21]

Good to know, you don't got a FMIC and cooler spark plugs?
i got NissanDataScan so i can see if it goes into det map, so will put it on .8 bar for now
will order nistune asap to "try" and make it safe...

NGK copper 7's but stock SMIC.

 

[FreakensNL]

Aaai SMIC, think that's more likely to be the reason it was detonating... after one run the side mount is fully heated..

http://www.ebay.nl/itm/NISSAN-200SX...763?pt=LH_DefaultDomain_3&hash=item51d1ff2ad3

here you go

 

[immy21]

Yeah I agree, however bear in mind the knock sensing only works up to about 3200rpm, if it det's before then the ECU can pull timing globally across the map but after 3200rpm knock sensing is disabled. So at the very least, check for det.

 

[FreakensNL]

if i am running stock boost and tune, .7bar is a A/F ratio of 13.1 (12.5-13.5) in mid range and 10-11ish near red limiter(6K+) normal?