Don't focus on dyno peak kW's

[pah]

Hi all,

Let me stick my neck out just a bit.

I've read a few threads where people bitch about pinging when using certain brans of PULP.

I suspect (you can correct me if I am wrong) these cars may have been dyno tuned with the BEST brand of 98 RON PULP. This may produce the best possible power figure when giving the car a BIG rev on a dyno, but the down side is that there's then the hassle of day-to-day driveability on the road.

In my humble opinion, I'd say that it would be better to target day-to-day driveability by filling the car with a lesser brand of 98 RON PULP, a 50:50 blend of 95 RON & 98 RON or just plain 95 RON PULP. This may result in a few less kW's on the dyno, but the up-side is that the car would be less of a hassle to drive. No need for a boot full of octane booster when the favourite drop of PULP is not available. Peak kW figures may be all important for dyno days but I'd guess most of us use our cars as daily drives.



Any thoughts?


PAH

[cosmo vyss]

Pah,
The better fuel will give better results across the board. It is not just about peak kw when tuning with 98ron. The better fuel will give you better gain across the whole rev range when tuned properly.
There is no driveablility issues with cars tunes on 98ron. I can understand though it sometimes can be a pain in the butt to get 98. I try and keep 1 bottle on nulon pro strengh octane booster in my glove box for these times. I had a bottle in there for a month and didn't need so i took it out.
Also high rwkw is good but the torque spread is more important. Its no good having a car making 260rwkw and make it peak torque power at 5500rpm. You are better off making 240rwkw and making your peak torque earlier in the rev range and then holding it all the way to redline.
Remember though bp ultimate is not the only 98ron fuel around. So if you can't get your brand just use another in the interim until you can get your favorite brand.
In the end better fuel equal better results
I hope this makes it somewhat clearer.
JB

[genpowr]

mate iam not sure what u mean by 98 oct being hard to drive , but mines tuned for 98 oct and mine runs/drives perfectly at all speeds and revs!

[blown senator]

i think you dyno the car on what ever fuel you use day to day most people would use 98 octane fuel day to day maybe if the where using race fuel or av gas to tune that would be a different storey

[SEN8R220]

I have built a few high compression engines for a few friends and found when tuning all o.k however its not so much the octane that is the cause of pinging but more so the brand of fuel, I have found that optimax is the main product of concern, also some weeks the fuel might just be a bit stale as it was whats left of the bottom of the stations reserve. Perfect eg. would you rather drink light beer or heavy beer, of course heavy even if it isn't appropriate, same with engines, but going back to stale fuel its like drinking the dreggs out of a beer tap, it may still be heavy beer but just isnt the same, and the same with different brands of fuel, crownies may be a premium beer but not everyone is fond of it same with engines optimax is suppose to one of the cleanest fuels but not every engine likes it. So best thing to do is try different(must stress full) tanks of different brands and go through the process of elimination

[markone2]

Driveability improved 10 fold when the car was edited and tuned for BP98......the only fuel I use by choice .

[OLS108]

Driveability improved 10 fold when the car was edited and tuned for BP98......the only fuel I use by choice .
I am not sure what to read into this thread but My car is tuned for 98RON and i have no problems with Driveability EVER, Nor have i ever had probs with gettin BP 98... But if what your saying is Dont get your car tuned for 98 then I Dont agree with you.

[MattJ]

It's more about tuning the car correctly in the first place.Ignition timing shouldn't be run on the ragged edge allowing detonation to take place anyway.You have a good point about tuning on the lesser quality 98 but how do you determine it without proper testing & it varys from place to place.It's the tuners job to read into this & tune to suit any possible condition(within reason).Good to see people asking questions like this though,thats what this forums all about,keep it up:)

Cheers Glenn

[pah]

Hi all,

My initial comment was prompted by all of the guys who have expressed their preference for BP 98 RON rather than other brands. I guess I'm assuming that guys are using what they believe to be the very best fuel to extract the most kW's out of their cars on dynos.

Given that the Gen III PCM has two spark advance tables, it strikes me as a trifle bizarre that an Edited car would ping on a lesser brand of 98 RON. Unless of course BOTH spark tables are programmed for 98 RON. And I don't like the sound of that because a batch of crook fuel or the need to run 95 RON etc would then cause dangerous pinging wouldn't it? If there's another cause of pinging on one brand of 98 RON but not another (after an Edit), I'd be interested to know.

If PCM's are being edited with BOTH spark tables set to 98 RON, then I think that it makes sense to tune to the brew that is least able to prevent pinging. I'd prefer a greater safety margin when I use the best 98 RON than pinging if I need to use another brand.

I understand that some may be happy to carry a bottle or two of octane booster. In my opinion, the very best option is to have a spark table for 91 RON and a spark table for 98 RON.

My Gen III runs well on Optimax and BP Ultimate. Both seem to help performance. I'm happy with the current tune of my car but sometimes wonder about a custom PCM Edit. If I get one, I'd be chasing one that maximises performance on 98 RON but also lets me run on 91 / 95 RON if I am forced to.




PAH