Cam I know you probably think this is crazy when your tank is nearly empty and you fuel up add some TC-W3 outboard oil to the fuel 1.9 ml per litre I just use the gulf western from supercheap no need for the most expensive one

Then when the tank is empty don't use it do it a couple times and then tell me if it does not make you car go better

I started doing it 4 years ago in my XJR6 and all my diesel cars could feel it instantly on light throttle opening

I started doing it to the X350 from the day I brought it home never thought about it much anyway

I was away for a couple weeks and the wife filled the car up a couple times while I was away (she has been lectured on using 98 only)
I hopped into it didn't give it a second thought drove around tank was nearly empty like women usually do

I went down and filled it up did my usual TC-W3 routine drove of and instantly noticed the car felt more responsive on light throttle opening
Here is a google page on it its a big read the guy from the LS1 forum got me started that was when he first posted
https://www.google.com.au/search?q=l...ums+using+tcw3

 

I work the law of averages and splash in "about that much"

 

And what's you opinion plums am I crazy?

 

I use snake oil in our cars. The performance improvement is unreal.



. . . .

 

No.

I think we are open to the idea that there are practical, observable
benefits of unconventional practices and don't bow down to the alter of
the infallibility of engineers.

I'm just more haphazard about the measuring.

The same guy who will repeatedly shoot a laser 50 feet
for the same alignment measurement. Slows down
completion a LOT!

 

The noob moderators should go back and find the "red medicine" threads
in the mod section

You won't find them all because the acronym RM was adopted very
quickly.

For more serious situations, there are also the mentions of untaxed
gin smuggled into the UK and scotch running down rivers.

 

+1 as the kids say. I doubt putting oil in the fuel will lessen or eliminate deposits or contamination.

 

Thanks for write up glad you got it sorted nice to see a problem through to completion

 

Cheers fellas.

Now that it's running clean, i've decided to keep it running clean by fitting a catch can and water/meth injection.

Will start a new thread when the time comes.

 

+1 for updating on Water-Meth injection

I wanted to fit that to my old XJR6 but was put of by the cost and complexity

I had it done to a Datsun 180B SSS with draw through turbo system in the early 80,s worked really well

 

I would recommend against using any 'octane booster' additive. The only additive that works - to the best of my knowledge - is MMT (Methylcyclopentadienyl manganese tricarbonyl). simplistically manganese compound rather than lead compound.
I headed up an oil industry lobby group promoting use of MMT in unleaded. BUT that was more than a decade ago and in South Africa where the vehicle emissions standards and hence technology was back at Euro II levels.

MMT supplier showed lots of test results showing no clogging of catalytic converters, limited degradation of cat and oxygen sensor performance.
Auto makers showed limited test results showing rapid blockage of cats.

As I recall, big difference - MMT supplier tests undertaken at light load high speed cruise for hours on end.
Auto manufacturers' tests undertaken at heavy load (climbing from sea level to 2000m) modest speed and lots of cold start, stop-start urban commuting.

MMT supplier could boast of 10s of thousands of miles of testing (actually I think I recall more than 250k kms!), whereas Auto manufacturers' tests were barely 10k miles in total. BUT the auto maufacturers did manage to block several cars' cats in only a few thousand miles under their test regime!

Impact also seemed very dose sensitive.

I would not put MMT in any vehicle with a cat.

Adding benzene or toluene is 'blending' not adding an additive.

 

I'm still in two minds about the Octane booster causing the cats to choke up.

One one hand, I didn't use it at all when we were in Europe, only when the car came to Australia. But that was with 100'000 miles on the original cats already, and maybe they were already a bit choked up from age/mileage & the octane booster tipped it over the edge?

On the other hand there are lots of people here who run these octane boosters, and i've never heard of choked cats being attibuted to it...

Who knows...

In the meantime I came across some interesting information that would have been very useful to know back when I was having all these problems. Regarding the "normal" fuel pressures. Here straight out of the X350 Technical Guide



4.8BAR = 70psi = normal at WOT

Interesting that the S/C cars actually do ramp up the pressure whereas the N/A cars hold a constant 55psi.

 

It is important that you note the "to atmosphere" part.

If you hook up an external gauge to the rail you will be reading psig (gauge pressure) with an atmospheric reference.

The fuel pressure sensor has a manifold reference and is reading psid (differential pressure).

If you have positive pressure in the manifold (boost) then the pressure across the fuel injector is reduced and so is the resulting flow.

Let's say you car makes 15lbs of boost at max RPM. You would read a gauge pressure of 70 psig but the pressure the fuel injector sees when spraying into the pressurized manifold is 70-15=55psid.

SDD and torque know only what the sensor reads with respect to manifold pressure so should be around 55psi excepting spikes due to rapid throttle changes etc.

 

That statement "3.8-5.0 bar referenced to inlet manifold pressure" could also be interpreted as "3.8-5.0 bar above inlet manifold pressure"

I've been thinking about this and i can't see how the pressure sensor on the fuel rail could be anything but a differential sensor.

??psi fuel pressure on one side of the sensor minus 15psi boost on the other = 55 to 70psi

No?

 

To help sway your thinking- off the shelf boosters in almost all cases are ineffective in significantly increasing octane levels. An advertized 'full point increase' translates to a change from (ex.) 95 RON to 95.1 RON, not the assumed 96 RON.

For those few products that do actually work, they are not cost effective as compared to just buying the higher rated (98 vs. 95) fuel in the first place.

Most importantly- there is no benefit in using fuel with a higher octane rating than recommended by the OEM. In the case of your car and almost all Jags, that's 95 RON.

I guess we'll never no for sure what caused your cats to clog, but I'm glad the problem is sorted.

 

Well I wholeheartadly disagree with you on that point. There is plenty of evidence to suggest otherwise. But that's for a different thread...

 

NOT looking to start a fight, honestly wanting to learn.

Can you point me to something that discusses the benefits and explains the hows and whys? In 40+ years of dealing with this subject both professionally and as a hobbyist, I have yet to come across a valid example.

Given that the octane rating of a fuel is strictly an expression of it's resistance to detonation and nothing more, for a car to run differently (better) on a higher octane fuel, the engine would need to experience detonation while operated on the recommended fuel. It would be regularly dependant upon the knock sensors to get it out of trouble. No OEM I am familiar with follows this path.

 

For N/A versions I doubt it will make a difference and I would stick with the recommended 98 RON.

As the manual states 98 RON is a Minimum. It also states some markets have only 91 Ron and a recalibration is done for these markets.
The main thing here is the timing will be retarded to control the detonation

The octane thing comes in with boosted engines. The more boost the higher the cylinder pressures and charge temps and the closer to detonation.
So in simple terms the S/C on 98 is in the Minimum octane where the N/A is on the Maximum

Running on a higher octane it is also good to reset the adaptions so the ECU learns the new limits quicker.
How much power does this translate to it all depends but when you are chasing the last once of performance small things matter
The quickest measure of a higher octane fuel is having some benefit will be seen in the timing advance numbers and trims.
No benefit no additional advance it just depends on the limitation of the engine

PS Im refer here purely to octane bot any specific octane booster, most of which are hocus pocus. Id give it a go for a specific run on the track but would much prefer to just purchase a drum of 110/120 race fuel


Cheers
34by151

 

A very interesting read. Well done Cambo for your perseverance. I had a difficult problem to resolve too, different from yours but it sent me chasing in all directions eventually cured by fitting a new Cat. 2006 STR 4.2 s/c.
This is the old cat that was constantly throwing a MIL caused by contaminated fuel causing fuel starvation and misfiring. MoT test showed excellent CO levels which threw me.