Mr Bian

Now forgive me if I am slightly confused !!!

I read this thread

mutant_matt

Most people will tell you that you are not imagining it!!!! (including me!! )

SUL should make the car run smoother particularly at the bottom end. If the summer ever arrives and we get some heat, SUL should make more of a diff then as the higher the rating, the less likely det is...

Matt

Andy W

Mr B,
Stick to the SUL, it does make a difference and with a full de-cat definitely a good idea, any improvement in the airflow could (in theory anyway) risk your car running lean. SUL would therefore be safer for your motor.(IMHO)

Andy

schuey

I run a MY99 on SUL and octane booster.
No need to reset the ecu, it "learns" after a couple of tanks.
Noticable difference in performance, though not spectacular.

Jon

nmyeti

This sounds a bit strange to me, but then again, i am an american and we just got the WRX. My question is why if the engine is suffering from detonation do you guys not fit larger injectors and a better fuel pump to flow a bit more fuel to keep it on the safe side?

On this side of the pond, it is rare for us to consider an booster when the real problem seems to be a lack of fuel.

Also along these lines, do any of you guys run Redline's wetter water in your cooling system? There are several tests on their site that show it to be quite good a cooling an engine in a mixture of water and 20% antifreeze... much better than a straight 50/50 mix. In any case this would help keep the detonation down and keep the spark advance up.

-Nathan
Albuquerque, NM USA
02 WRX

mutant_matt

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by nmyeti:
<B>My question is why if the engine is suffering from detonation do you guys not fit larger injectors and a better fuel pump to flow a bit more fuel to keep it on the safe side? [/quote]

Because fitting larger injectors is
a)not an insignificant cost
b)will blow the warranty away
c)wouldn't you then also need a new/programmable ECU to control them properly?
d)with my limited understanding of the issue, I don't think flowing more fuel is really the fix - I thought that the problem is charge temp - higher octane just = less det for a given charge temp? If this *is* the case then lowering the charge temp is surley the way forward - hence the Larger Intercooler/Front Mounted Intercooler/Water Spary Kits/Scoop Splitter/Water Injection threads....

Now of course, all of the above together should bring some pretty nice gains??!!

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR><B>
On this side of the pond, it is rare for us to consider an booster when the real problem seems to be a lack of fuel.[/quote]

What Octane is US fuel then? We use 95RON as "standard" and 97RON as Super. If we could get 100RON like the Jap imports are designed for then det would probably not be as much the issue as it is....

Matt

nmyeti

Your right that injectors and a pump are not exactly the cheep way to go, but then again a years worth of Octane boost may pay for a pretty nice fuel setup.

There really may be 2 issues going on here... the turbo may be flowing too much HOT air, as it might be out of its range, and 2 i think that there might not be enough fuel getting into the mix, thus leading to hotter temps.

What sort of power numbers are you guys hitting when the detonation starts to come on?

-Nathan

&lt;edit&gt;
I just noticed the question about our octane here in the states.

We use a combined scale It averages the RON number with something else. The highest we get is about 93, but if i remember right this is like RON 98...

[This message has been edited by nmyeti (edited 02 April 2001).]

Nate-old

I have found several BP service stations in my area now sell SUL at 98 RON

Nate

Andy W

Nate,
as far as I know SUL is 97 RON if it is badged as 98 it is probably incorrectly labelled (a hangover from the good old days of 98 RON)

Andy

mutant_matt

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Nate:
<B>I have found several BP service stations in my area now sell SUL at 98 RON[/quote]

There's been quite a lot of discussion about this on previous threads but any pump advertising 98RON is wrong - all SUL is now 97RON....

Matt.

Nate-old

So what you are all saying , is that BP are selling a product under the wrong description , I will phone BP and find out .

Nate

Chris L

I've just started using SUL in my MY00 after a year of using NUL (absolutely nothing to do with my company giving me a petrol card...no.. ). It has taken just over a tank to adjust itself (wanted to see how long it would take, rather than do an ECU reset) and I'm impressed with the difference.

It is much smoother under acceleration and it certainly picks up better. To be honest, I am pleasantly surprised by the results, I didn't think that there would be such a noticable difference.

I used to find that when accelerating hard through the gears, there used to be a slight lag between changes - almost like you were dragging the clutch. Using SUL this has gone and the car now pulls cleanly through all the gears. Just waiting to see if there is any improvement in fuel consumption which would be an added bonus.

Chris

Nate-old

I filled my tank again yesterday at BP , it is 98 RON , it is a fairly new service station (was recently converted to the Safeway/BP combination) , and the stickers are definately new looking , have not had much joy on BP's website or customer info lines about the 98 RON , but I will find out for sure .

Nate.

Alex Clydesdale

Just want to quote the latter part of page 35 of the year 2000 United Kingdom Shell Bikers Bible.

RON: Research octane number - this determines the knock resistance of a fuel in a CFR test engine with preheating at at 600 rpm. If the RON is low, accelaration knocks will occur. (usually audible)

MON: Motor octane number - this determines the knock resistance of a fuel in a CFR test engine without preheating at 900 rpm. If the MON is low, high speed knocks will occur. (usually inaudible due to engine sound)

SON: Street (or road) octane number - This determines the knock resistance of the fuel in a series production engine. The SON states the octane requirement of the vehicle.

Its worth mentioning as it goes on to state how high the octane ratings must be according to DIN standards.

Regular petrol:Atleast 91 RON and 82.5 MON
Super petrol:At least 95 RON and 85 MON
Super plus petrol:At least 98 RON and 88 MON

If you go to sites like vpracingfuels.com youll see that Americans prefer to label a fuel useing the 'mean' of its RON + MON, rather than just stating the higher RON number that fuel companies do here.

Nate-old

Had phone call back from BP , they no longer sell 97 RON and have not bothered to change the label .

Andy you were correct.

Nate

Doc

I run my UK MY98 on super and get around 27mpg when commuting (less at weekends ) On 95 Ron I used to get 23mpg so the extra cost at the pump is more than compensated for by decreased consumption.

PaulMc

I'm with you on that one Doc!

52 litre SUL fillup and a steady commute from Manchester to London got me about 325 miles before another fillup.

slimshady

paul,
325 mls from only 52 litres ! wow ! is this a scoobynet record ? anyway i am only jealous coz i only get about 260 mls .
i use sul also , but did not notice any difference when i reset the ecu and stopped using normal ul (neither smoother or more eager after reset )

Mr Bian

Blimey I can't remember the last time I got more than 200 miles out of a tank of petrol!! Obviously driving to hard

I've ordered up a bucket load of Millers Octane Booster so will report back on the findings when in.

[This message has been edited by Mr Bian (edited 05 April 2001).]

PaulMc

Guys, that was not counting what was already in the tank. Should really have filled her up again and seen how much fuel I burnt against exact miles from previous fillup and done some sums etc... On SUL I always seem to get at least 300+ miles out of 'a tank' when cruising between 75 and 80 mph on motorways. Even a quick bit of fun doesn't alter the MPG by much. However, town/city driving kills any of that ecomomy.

Car is a UK MY97 with SS backbox. Had the car just over 3 years and 95% been run on SUL. I really notice the MPG difference when I go back to NUL.