Right, some interesting test results.

Using Shaggy's scoob and a knocklink.

3 full tanks of Optimax.
The car started to det, we figured the injectors just aren't up to the engine, as you can live map the fueling to cope.

At 1.3bar the car dets at 6000rpm on Optimax
with 10% more fuel and a 58% duty cycle.

Decided to try Esso SUL, just to make sure it wasn't poor petrol.

Decreased to fuel back to the original map,
<B>no</B> det at 1.5 bar @ 7800rpm at a 58% duty cycle. So we increase it till it did.

1.7 bar @ 7500rpm with a 70% duty cycle.

Det detected using the knocklink.

Just goes to show, allthough this petrol might have a higher RON, it has loads of other stuff into to aid cleaning etc, maybe this is making the petrol performance worse than normal SUL.

It might make the car feel better to, but unless you got any warning like the knocklink, how do you know what it is doing inside the engine.

Shaggy's car flew at 1.7 bar...... very impressive.


Food for thought, as i aint a scientist, well not in this field http://bbs.scoobynet.co.uk/wink.gif

So Dingy, would you continue to use Optimax?

cem

Nope.

Are you ?

i agree optimax is not very good.......

i would sooner use good quality SUL anf a certain amazing octane booster *cough* NF *cough* http://bbs.scoobynet.co.uk/wink.gif

My MY99 with PPP seemed to run worse on Optimax so have gone back to Esso SUL.

Mmm interesting, i have had a couple of dodgy tanks of Optimax and generaly not been that impressed(especially after 3 or 4 days)

maybe its back to BP to see if there is any difference.

Scott

optimax is after all 98 ron.anyway while im here can any one tell me if i disconnect the battery for say 45 miutes and connect it again will it affect the ecu? [its a ppp ecu] 1999 model.or affect anything else for that matter.also out of interest ive just fitted the barrierlock on my gearbox any thing i should know about it?.CHEERS

Hmmm. Haven't used the Optimax much in the Scoob yet - haven't used the Scoob much the last couple of weeks at all as I've bee working as a motorcycle courier.

BUT I have used it in my bike (couriering on a Blade!). This has been tuned such that the compression ration dictates SUL/LRP petrol. Tried Optimax for several tanks. But the mpg seemed lower than it should - even for blasting around London. Tried various other SUL/LRP petrols and get better mpg from it. No difference in performance.

Is this another Shell cock up...???

Dave

I don't want to jump on the Optimax pants bandwagon but IMHE I have not found any downside in the RA, but in my 620ti Optimax makes it run like a dog!

SJD

That's 'cos your 620 is a tuned performance car and your RA isn't http://bbs.scoobynet.co.uk/tongue.gif http://bbs.scoobynet.co.uk/wink.gif

Got to say on my third tank of optimax and IMHO its sh1te,car ran better amd pulled a lot harder on ESSO super so when this tank is finished its back to ESSO,thats in MY01 WRX http://bbs.scoobynet.co.uk/biggrin.gif

Sorry for my ignorance in this matter but a lot of you are talking about noticing "det". I assume this means detonation but how can you feel this when driving?

If you can hear the det from the car, the engine is already screwed / about to be screwed (mine went bang 1 - 2 seconds later)

The guys that are talking about det have special sensors (knocklink etc) - ie sensitive microphones - which can hear det when it is just starting, so giving you time to back off (I haven't got / tried one, this is AFAIK).

- edit, oh yeah or they are using det cans on a rolling road.

[This message has been edited by Gary Foster (edited 11 October 2001).]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by pwebb:
<B>

I am monitoring the ECU's own knock sensor activity via the techtom and it has never shown any activity at

Paul W[/quote]

I thought the whole point of the Knocklink was the sensor is more sensitive than the OE unit....?

More generally, I would be interested in the engine spec which allows you to run 1.7 bar - I take it the pistons, rods, fuel pump etc have been uprated...?

The other thing is I don't hear any mention of det cans which I thought was the only proper way of telling if an engine is detting....?

Thanks

Gavin

[This message has been edited by GavinP (edited 11 October 2001).]

Ive found one benefit with Optimax - my car actually starts first time now from cold - its been OK since I got it (2 months) when its been in the garage - but if its been in the car park at work for the day and its been cold - it wouldnt turn over properly and would only start the second time i turned the key - now - with optimax and millers (approx 101 octane) - it starts perfectly all the time

On my basically standard UK00, the car *seems* to be running smoother and pulls harder and I'm getting a couple of mpg better. http://bbs.scoobynet.co.uk/biggrin.gif

Surely these factors must = better fuel than what I was using before (a mixture of Shell Super and Esso Super).

Matt http://bbs.scoobynet.co.uk/smile.gif

Matt,
After filling up my standard MY00 6 or 7 times with Optimax I generally agree with your comments. The car definitely runs smoother and fuel consumption is 2 mpg better. Have just switched back to Esso super unleaded to see if there was really a difference and the indicated peak and held boost is down a bit and the car doesn't 'feel' so smooth.
Jon

MyDreamCar, i think you will find its not 101 ron, as the higher the ron fuel the less effect the octane boost has, this is the usual case with all boosters.

I could tell yer roughly the octane but as a NF Supplier i don't think i should.

Although Shaggy's (CraigH) car felt smoother, it was detting, this is the reason for my post, at the end of the day, if yer car is detting at the top, yer engine ain't gonna last, whether it feels better and does more mpg, a new engine is a big pain in the arris. (ask Craig).

My MY00 with PPP is definitely smoother since switching from the old Shell SUL to Optimax, and mpg is up slightly.

I can't say I've noticed any more power though, we'll find out at the PE shootout in a few weeks' time http://bbs.scoobynet.co.uk/biggrin.gif

Andy.

I was just saying about this the other day, IMHO i found that throttle response and pull wasnt a good with optimax, i liked the idea of but on the road i think it doesent feel that much diffrent to UL. my car seems to prefer Esso Super. what octane booster does everyone use? i have a MY00, B/B snd K/N. would there be any need for my car to have it. and where do you get it from. ive seen it in halfords but it says not for use with cats. ? Cheers Lee

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by dingy:
<B>
I could tell yer roughly the octane but as a NF Supplier i don't think i should.

[/quote]

Excuse my ignorance BWTF is NF???

Cheers
Paul

Lee,

I've been using Millers for years, both with and without cats - no problem.

However, I have just changed to NF booster from New Age, as I have heard a lot of good things about it, not sure how it would interact with cats, best to check with Craig - unless he is out here somewhere?

Unsure just yet whether it is better or not, as I only used it yesterday for the first time, with Optimax coincidentally.

Matt

deleted due to double posting.

[This message has been edited by paulmon (edited 11 October 2001).]

Hmmm.. I used to use standard SUL with Millers and got occasional det, on the Knocklink. This was never really cured by adding additional booster?

On moving to Optimax and Millers I have no det whatsoever at any rev amount. (apart from the normal 'engine noise' on the knocklin) Perhaps the stuff is better down the South West (stupid comment I know)

Been using optimax for two weeks prior to official launch.

Have had no negative effects (like det) car feels better and im getting more mpg than i've had!

my99 sti5.

fwiw - you need to consider the station you got the shell fuel from - ie how full were their tanks when they took delivery of their first shipments of optimax etc. - is it 'diluted', have they actually had any delivered yet or just got the promotional flags etc. ???

also the ability of the ECU to adjust to the fuel will be different according to what car you have - newer EJ208, EJ209 engines with much faster processors and more frequent sampling will adjust very quickly - an old 97 JECS may need a reset. If you are using Link or Motec it will need re-mapping.

I would never up the boost until you get knock just to find out how far you can go- since you have already done the damage!

I have been monitoring my fuelling/ignition advance very closely using the techtom unit plugged into the select monitor socket - I can confirm that Optimax is no better (or worse) than other SUL fuels in the UK though fuel consumption does appear to have improved slightly - though measuring this is such a subjective thing I can't be sure.
Fortunately for me my 2001 B4 's engine is nowhere near as 'close to the edge' as the STI was, so there is never any trace of knock - I am monitoring the ECU's own knock sensor activity via the techtom and it has never shown any activity at all - I put this down , in part, to having fitted broquet catalysts - but that would be opening up an age old debate ;-)

If you are registering knock on a regular basis then I hope you have either changed the pistons for something more durable (though these engines will destroy even cosworth pistons) or are prepared for the likelihood of an impending engine rebuild :-(

Paul W

I don't agree with the damage being done, unless you are holding it there whilst it dets, then how can it be causing long term damage.

Car as had replacement pistons.

Paul,

Around the time of the launch Shell said that one of the delays in getting Optimax available at every pump was that they had to ensure that the SUL had been flushed from the tanks, I live in Preston and there are about 4 shell stations which used to sell SUL and all get serviced from the same depot, the smallest garage (the one nearest to me) was the last to advertise Optimax, not because they were being supplied it later, simply because their turnover of SUL was lower and it would take longer before the pumps were supplying pure(ish) Optimax.

That's what they told me anyway http://bbs.scoobynet.co.uk/biggrin.gif.

There is always the problem of the state of the tanks aswell, one local service station is renowned for having water in its tanks.

Andrew...

Poor Things

In OZ the Optimax must be different. I have only ever used Optimax 98Ron in my MY01 and its fantastic stuff.
Last week I filled with a 95Ron Caltex Vortex and the car ran like a dog. Poor mileage and sluggish. I have since switched back to Optimax and it goes like the clappers.
Ring Shell UK and see how the UK stuff compares to what we get in Australia.

OPTIMAX is the ONLY fuel Australian Scoobs like.

I was using Optimax since it's launch from various outlets around the country.

I noticed a little bit of det but assumed it was unrelated and couldn't clarify it as I don't drive the car that hard on the road to keep it high enough in the rev range and on boost.

Since using Esso SUL again it's been absolutely spot on - no det at all.