i would like to know how does the MCS react to octane boosters/fuel additives, with basic mods? is it of any use? the comp ratio not that high, but we do have a poor grade fuel here though.

 

i remember reading a very detailed write up on fuel aditives, it may of been here on NAM. but i know that it said they were a waste of time with no gains at all and in some cases it was a loss in power.
sorry but i could not find the info first hand.
do not waste your money.

 

Waste of money. Those little bottles only raise the octane in your fuel by like .03 or something ridiculous.

 

thanks for the heads up. Even on a poor grade of fuel, its no help?
should i rather use AVFUEL?

 

Even on poor fuel, it doesnt do you any good.

You mean aviation gas? Yeah, that would be fine as long as it is NOT leaded, if it is you'll destroy most of your emission system which is $$$$.

Why is it you want to run higher octane? Where are you located?

 

Don't even think about putting 100LL aviation fuel in your car.....it has more lead than car gas ever did....does not provide much luberication to the uppper end, will kill both you cats....setting check engine lights, and result in lead buildup. Unleaded aviation fuel, (when available) is just unleaded, ethanol free 93 octane...resulting on 91 octane...at 25-50% more cost per gallon than auto fuel.
Most octane boosters use MMT...and most manufactures recommend against it use....others use one of the 3 main chemicals used to make MOTH-*****, (an old hot-rodder trick), and long-term use and effects are unknown.

 

Some other links, I know they are apples and grapefruits, but I think its a good indication.
http://74.125.155.132/search?q=cache...ient=firefox-a

One of the things in common with both tests is that higher octane petrol from pump usually nets better results, despite article above is tested on dyno and later test for octane increase is done in lab.
http://74.125.155.132/search?q=cache...ient=firefox-a

And one more:
http://www.europeancarweb.com/tech/0...ted/index.html

 

Do not run any aviation fuel. 100LL as described will foul up our fuel pumps, injectors and catalytic converters.. it'll also build up on valves and valve seats. Most of the aviation fuel dealers are not allowed to sell fuel to anything other than aircraft. (shell, esso)

If you want a higher octane fuel for use with boosted or high compression race engines.. perhaps try http://www.rockettbrand.com/


I've used some of the 111 octane in my 2.5L turbo chrysler (28psi) with good results.

 

thanks for all the input, very good read. looks like ill stay away from avgas.

I came across this website though, which includes lab tests that mentions an octane booster that pushed the octane up by +3.9RON ??

http://hi-octane.co.za/OctaneBoosterTest/

and some are saying here that it pushes up by 0.3RON ? some clarity here?

 

Where do you live?
I assume California cause you say you use low grade fuel- 91 octane I assume again. The reason I ask where you live is that there are several vendors and service stations that sell 100 octane. What do you plan on using Octane Booster for? Dyno day? Track day? Auto-X? Drag stripping? Cause for minus the track day all you really need is a 5 gallon jug of 100 octane. The products you mentioned are not sold in US (sure you can find it somewhere though) it is an Aussie products. Other than the NF product there is Nulon also Aussie that both made only a 2.5 Ron improvement on a Aussie Ford magazine (the ones I linked) but like I said and the link I placed illustrates as well that higher octane fuel always will fare better results. And it's easier to get in CA than imported Octane Boosters from Austailia.

 

Both the NF and Nulon stuff seem pretty good but could not findtheir content anywhere online? As for Obtainable stuff in CA the Amsoil stuff and Toulene fare pretty well better than all the Auto Zone, Kragen type boosters sold.

 

I apologize, I missed that question. I am from South Africa. Although we have 95RON here, it is a poor grade. The tests in the website posted was done here. The MCS compression ratio is not that high, would using something like NF be effective on these cars?

 

although i haven't tried it, a friend mixed about 6 liters of avgas into his 06 325i. before putting it in his tank he had about a half-tank of 96 octane gas, poured the avgas in then filled up the tank with the 96 octane gas (he was already at the gas station before pouring in the avgas). no damage done, his butt dyno definitely felt the improvement

 

OWW......two dead cats, two dead o2 sensors, and a check engine light to go!! (not to mention...warranty voided)
And ANY aviation mechanic will tell you that lead build-up and wear from the lead deposits causes engine longevity to go down, and increases costs, in all but the highest compression aviation engines. The biggest problem with MOST engines in aviation that use unleaded fuels is it causes valve+ valve guide wear...due to the softer materials used in aviation heads.....so until you get above 200 HP, it is common to run a leaded/unleaded blend.....but lead fowled spark plugs are a problem too.
Just crazy.....

 

Just a remainder when looking at claims of octane improvement....be sure to look at the test which is used....
THE US uses a different test than most nations (a hybrid type of test, which is two test results added together, then dived by two to give a rating)....resulting in different ratings on the same fuel that is sold in other nations. This difference can make some additives sold overseas look like magic liquids that are better than what we have....when they are the same. If you do s search, you will find some really interesting articles about chemicals sold in bulk at the local home depot type of place which are the same as the stuff sold in tiny bottles in car places for 3 or 4 $ each. use caution.....but the info is outhere. The power of the web.

 

When I had my Grand National used to mix Xylene into the fuel, it's an agent you an purchase at Home Depot in the paint thinner area. With it mixed in with pump gas I was able to increase boost from 15 to 22 with reduced knock.

http://www.gnttype.org/techarea/misc/octanebooster.html

Just another option to consider.

 

Yup.....one note to add....be careful as it can increase the vapor pressure on fuel and increase the possibility of vapor-lock....there are a couple of options....they just all fall into the use at your own risk catagory....but a cheaper way to make fuel for the track rather than buying race fuel in some cases. Remember...OFF_ROAD_ONLY!!

 

Meaning it is less the 95 RON?

If your engine is stock (or even lightly modded) there is absolutely no benefit whatsoever to using higher than 95 RON fuel. None. If the engine is not knocking, there is never any benefit to using higher-octane fuel.

Now, with the knock sensors of modern engines, telling when they're knocking is not easy - rather than hearing it, you'll notice the reduction in power as the knock sensors cut it abruptly when you push a lot of throttle at low RPMs.

Again, if your car is not exhibiting any outwards sign of running poorly or the knock sensors engaging, there will be no benefit to higher octane fuel or octane boosting additives.

- Mark

 

Well... You could figure out what kind of signal the ECU looks for from the knock sensor. The sensor is more or less a microphone piped into the ECU which then performs some filtering. If you wanted to you could do something that would definitely induce knock and look at at the frequency response of the knock sensor (or look at a the signals the ECU puts out). Once you you know what to look for you know when you are knocking!

 

That would be pretty cool, and that is exactly what a knock sensor is. I see you're a fellow FSAE member, Some Guy. I just graduated UCF; did our senior design project on intake/exhaust design which also meant adapting our F4i to a Superflow dyno set up for a 350 Chevy.

One of the professors we worked with did a lot of work on Nascar motors and gave us a big lecture about knock. It actually occurs after the flame front. It's very close to a delta spike (infinite amplitude over zero time). A regular flame front may move at 20m/s while a knock pulse is over 100m/s. Minor knock occurs when a small pocket of mixture ignites. Major knock occurs when one small pocket ignites another, and another, all the way to the cylinder wall. When the pressure wave hits the cylinder wall, it actually rings the wall like a bell, which can cause the ringlands of the piston to lift up into the combustion chamber. This ringing is what a knock sensor listens for. Engines with large bores are more susceptible to knock as there's more distance for the pressure wave to travel and build up power. Combustion temps that are too high, but also too cold, will increase chances of knock. This is another reason why engines with aluminum heads can generally have higher compression as the aluminum dissipates heat faster than cast iron.

 

Just to make sure i am understanding this right. If the flam front is expanding from the sparkplug outward then you are saying that the knock pulse actually occurs along the radius of the plug to the flame front? If so, then I just learned something new.

Anyway, the Xylene trick has been tossed around here before. I wouldnt be worried about vapor lock so much as if it has any weird effects on the seals in fuel system.


Sidebar:
The team I am on has an old (1970s!), Stuska dyno, 800hp model, mounted to some equally old and odd manner of frame. When you guys had your F4i hooked up to the dyno where you using a drive shaft or a chain to transmit the power? We're doing a shaft drive, which in hindsight might not be the best idea given the odd way Suzuki set the clutch lever (well... pin) up on the GSX motor.

 

Yeah, that's the way I understand it. The normal flame front goes through, leaving pockets of unburned mixture. These pockets then ignite, causing knock.

We used a Superflow SF-901 dyno and a driveshaft. We had to design and build a frame to mount the F4i, then bought a PTO adapter with the same spline as the output of the engine and a bolt pattern for a u-joint carrier. The dyno had a Ford clutch spline so we had to make an adapter for that end as well. We had a short driveshaft made to go between the two.

 

Octane Boosters definately work. What people fail to realise is that simply increasing octane won't necessarily give you more power (although most modern ECU's will advance timing), but tuning on higher octane will give you more power.

The NF Octane Booster (http://www.hi-octane.co.za/OctaneBoosterTest) was tested with South African 95RON fuel. RON is the fuel standard used worldwide except for the U.S.) Here are the tests:

95RON:
Tested: 96RON, 84MON which gives PON/AKI of 90 (U.S. Standard - (RON+MON)/2)

95RON + NF Octane Booster:
Tested: 99RON, 87MON which gives PON/AKI of 93.

A 3 octane increase is pretty significant for a small bottle of octane booster, and I don't think you will get a stronger octane booster than NF.

NF is available from http://www.nitrous.co.za (online shop opening soon).

 

wow.....thet tested 2 addiditives....both with the same common chemicals we talk about, MMT and/or xylene, etc....and you want us to pay international hazmat shipping, duties, etc for a product that is the SAME as is sold in wallywold, autozone, pepboys etc. Not to make fun of you, just saying like before, it is hard to compare the fuels, and the hundreads of boutique fuels sold in differant locals for compatibilty to a item that may not even be compatible with our fuels or emissions system. To get good products do not require that you travel around the world, only you buy a good product at a good local seller, and start with quality fuel. Rant done.