C16 vs TORCO 118

[gmturbo]

I was using C16 race fuel on my GN , no detonation car ran great , made good power . I was out of the C16 and decided
to try torco 118 a friend of mine had. The car detonated
like crazy until I took the timing out of the program.I though
because the octane as higher it would be better , but turns
out the specific gravity of fuel is what matters. C16 has a heavier
specific gravity and the torco 118 is lighter even. Has anyone
on the board experienced similiar findings with fuel?

 

[d0n_3d]

man i ran 118 torco in my GN a month ago and i redlined the knock meter somehow...but i mixed 4 gallons of it with about 2-3 gallons of 89 octane on accident (we won't go there)...but i figured i would still have plenty of octane for 25 lbs of boost on a te-44 turbo...guess not...i am lucky i didn't blow a gasket...when i get a chance i will run with straight 118 and tell you my experience...i bought a 16 gallon drum for about 120 bucks so i have about 12 gallons left...hehe

 

[gmturbo]

I can probably bet its not that you had 89 octane mixed
with it. I went from C16 to 118 so I should have had not knock
at all.....keep your boost down and slowly increase it
when using this fuel. If not yopu will probably putting on
new head gaskets or worse bearing knock.
It seems specific gravity has a great to deal to do with
detonation in our cars . just my 02 cents

 

[Louie L.]

My buddy ran torco race fuel in his car only to pop all the way down track.This was with 114 Torco. Never had the problem before. C 16 is the right stuff. I have just tried maximal and i dont like that either.

 

[Chuck Leeper]

118 gas?

A bit of info in the "FWIW", dept. Here's the writeup on 118 made by Union 76.
I use it and find no detonation problems at 25psi boost.

PROSTOCK 118

ProStock 118 (leaded) is designed for supercharged and turbocharged racing engines, pro stock racing engines with compression ratios exceeding 16 to 1 and pro stock motorcycle engines with compression ratios exceeding 17.5 to 1. Combustion efficiency is increased due to the fast-burning characteristic of this fuel, which also produces more horsepower. It's excellent for high performance, high RPM engines as well as two and four-stroke engines. In Nitrous Oxide applications, Prostock 118 has proven very effective.

Suggest you take a look at the plug heat range, and the timing map at higher boost levels.. DAMN! this FAST system is NEAT!!

 

[gmturbo]

so Chuck , why is it with C16 no detonation and with the
same timing map on my fast system with 118 detonation

 

[d0n_3d]

where the heck do you buy C-16 anyways???

 

[Chyke]

Funny

I would not run C16 in a GN unless you intend on spinning it to like 8000rpm. I know, I know, everyone and their brother is going to say, I run C-16 with no problem. Well I Think it's time everyone did some serious research on ALL the charateristics of Fuel. C-16 and higher, regardless of the brand Torco, Sunoco, 76, are high compression, high rpm fuels. I believe the SG of these fuels is around 0.716 or lower (ususally lower the higher you go in octane. Both MON and RON) The problem arises because it's great to a point in resisting detonation but, the motors don't turn high enough to take advantage of the fuel. Also C-16 has a concentration of 6 grams/gallon of lead. Compond this by considering that when you change the SG of any liquid, the flow of that liquid (volume) is changed. You should pick a fuel, preferably somthing in the 110 to 112 MON range and tune to it. Than stay with that fuel. I actually picked up around 20rwhp switching from C-16 to Torco 112 and the engine runs cooler. If you don't beleive me, (Phd) in Chemistry, call all the fuel companies and ask for a recommendation. Be sure to give all the details of your set-up. This is a simple case of more is not always better. Burn complete, burn controlled, burn as fast as is needed. Oh yeh, next time we'll talk about the BTU's fuel possess, and why this is important.

 

[dconnor]

It's not really a function of pulling enough RPM's to get complete burn with C16. It's more an issue of enough boost & timing to facilitate a complete combustion, just because the engine is revving faster doesn't mean it'll burn the fuel more completely.

I've done quite a bit of testing (lab and "real" world) over the years with various race fuels and homebrew blends. In my experience the C16 makes more power WHEN you have the car tuned in to take advantage of the extra octane, than any of the other ultra high octane race gases that I've messed with. Assuming of course that the car is re-tuned each time to maximize the characteristics of the different fuels used.

It pretty much boils down to, use what YOU like and what works best in YOUR car for the tune you are able to "tweak" into it.


Doug C.

 

[Chuck Leeper]

Octane and detonation??

I'm wondering?? Since the compression on a forced induction engine is in the area that diesels operate at, why we should step down on octane, as is suggested???
I have a chart around the shop, [IF I can find it!] that gives the compression ratios at various static levels plus some different boost levels.. 1 that sticks in my mind is 22:1 at some reasonable boost w/ an 8+ to 1 engine.. Makes me wonder why 118 is not a good choice for that kind of compression level....
Does it burn too fast?? [Guess we could cut the spark lead a bit and still get good burn % and max cylinder pressure at the right time too??]
I am calling my fuel supplier application engineer tomorrow... more later...

 

[Chyke]

Sound Great

Chuck,
Can you let us know what he says. Maybe you/your friend can further clarify some mysterys about fuel. My understanding is also based in another factor used when rating burn time of a fuel. That is the 20 degree ATDC mark. AS rpm increases the time spent at this point is significantly lower. Thus the change in intended operating range vs octane vs denisity (SG). Nothing ignorant meant here. I and I'm sure others will wait for an industry insider to shine some light. Thanks.

 

[d0n_3d]

yeah i am just wondering if my 118 is actually SLOWING me down compared to say 114 or 116 being i have too much octane and does it cause knock more?

 

[49-blues]

would 100 octane unleaded and alky put me in the 110-112 octane range and how would this combo perform compared to 112 leaded fuel?

 

[ChrisCairns]

Read this:

http://www.racefuels.com/compchart.htm

and this:

http://www.racefuels.com/fuelterms.htm

Chris

 

[Chuck Leeper]

OCTANE ???'s

I'll do some research and see what I can get for info and perhaps we can even get them to post something that all can download.
will keep the progress posted.
I'll also ask about such as alky and toluene mixes, etc..
I have access to 114 NO LED!! Makes your kids born naked and w/ other enhanced body parts!! [My dad was a user of 114 no led!]..
CYA!

 

[dconnor]

When talking alky, it's kinda hard to relate it to equivilant octane #'s because it doesn't really add any octane to the fuel & actually has quite a bit less BTU's than gasoline. Biggest benefit is the significant cooling of the intake charge (which is WHY you can run more boost ) and the steam cleaning effect (which keeps the combustion chamber nice & squeeky clean.)

Trying to run it with race fuel (esp above 100 octane) is kinda defeating the purpose of the race fuel & can be a tuning PITA. IMO it works best when used with pump gas which is limits us to 15~16 psi under "normal" circumstances.

Chuck, I want in on some of that 114 unleaded gimme the source!

dconnor@buickturbo.com

Doug C.

 

[49-blues]

i d also like to know how i can get a drum of that 114 fuel if possible-thanks chuck

 

[Chyke]

Drum of fuel

49-blues
Getting a drum of fuel is actually pretty easy. Do a search on yahoo, for race fuels or any one of the manufacturers. Try VP, Sunoco, Torco, you should be able to find a number that will lead you to a distributor in your area. Some are easier to deal with than others. Example, I can buy Sunoco 112 directly from the distributor. Torco wants you to go through a retailer, usually a speed shop and they add a nice % to the cost. Good Luck.

 

[49-blues]

thanks chyke-i ll try that

 

[kjhansen]

Re: OCTANE ???'s

Originally posted by Chuck Leeper
I'll do some research and see what I can get for info and perhaps we can even get them to post something that all can download.
will keep the progress posted.
I'll also ask about such as alky and toluene mixes, etc..
I have access to 114 NO LED!! Makes your kids born naked and w/ other enhanced body parts!! [My dad was a user of 114 no led!]..
CYA!
__________________
Chuck, Just plain OLD!
86 GN . "mostly stock" 12.40@133

Chuck,
What I want to know is how come you're running 133mph and only getting 12.4's out of your combination! You should be in the low 10's/high 9's.
Keith