Supercharger ?s - Plugs, high octane ?
12-05-2007, 02:52 PM
#13
2nd Gear Member
Join Date: Nov 2007
Location: CO
Posts: 439
RE: Supercharger ?s - Plugs, high octane ?
ORIGINAL: zkiller
Higher octane fuel is only better if your motor needs it.
If you are stock, then you don't need it. If you are aggressively tuned, have a high compression ratio and/or you are running boost - then you need higher octane.
Higher octane fuel is simply harder to combust than lower octane fuel. So 87 octane will combust easier than 93 octane.
Pre-detonation (pinging) is caused by your air-fuel mixture igniting BEFORE it should. It is lighting from either compression or a highly advanced timing setting. Pre-detonation can put a hole right through your cheap little pistons.
If you use 93 octane it will be farless likely to pre-detonate than 87 octane fuel. The 93 octane won't make you faster. It will just allow your motor to run correctly with more compression (boost adds compression to cylinder) or more timing advance.
So if you are going to join the forced induction club, you may want to re-consider your feeling about the fuel you use. The extra 5 bucks you spend may keep your motor in one piece.
I run 100 octane all the time because I am at 11 PSI on the stock bottom end.
Higher octane fuel is only better if your motor needs it.
If you are stock, then you don't need it. If you are aggressively tuned, have a high compression ratio and/or you are running boost - then you need higher octane.
Higher octane fuel is simply harder to combust than lower octane fuel. So 87 octane will combust easier than 93 octane.
Pre-detonation (pinging) is caused by your air-fuel mixture igniting BEFORE it should. It is lighting from either compression or a highly advanced timing setting. Pre-detonation can put a hole right through your cheap little pistons.
If you use 93 octane it will be farless likely to pre-detonate than 87 octane fuel. The 93 octane won't make you faster. It will just allow your motor to run correctly with more compression (boost adds compression to cylinder) or more timing advance.
So if you are going to join the forced induction club, you may want to re-consider your feeling about the fuel you use. The extra 5 bucks you spend may keep your motor in one piece.
I run 100 octane all the time because I am at 11 PSI on the stock bottom end.
12-05-2007, 02:57 PM
#14
6th Gear Member
Join Date: Apr 2007
Location:
Posts: 6,414
RE: Supercharger ?s - Plugs, high octane ?
ORIGINAL: breathegood
This is good, correct information. I would just like to add that running a higer octane than is necessary over a prolonged period of timeWILL NOT burn cleaner, and WILL leave carbon deposits due to unburned fuel.
This is good, correct information. I would just like to add that running a higer octane than is necessary over a prolonged period of timeWILL NOT burn cleaner, and WILL leave carbon deposits due to unburned fuel.
12-05-2007, 08:08 PM
#15
3rd Gear Member
Join Date: Jun 2007
Location: Danville, VA
Posts: 890
RE: Supercharger ?s - Plugs, high octane ?
ORIGINAL: desslok40
Getting dangerously close tobuying a SC, I have a couple of questions.
Do I need to run colder spark plugs?
Do I have to run with higher octane fuel?
Really want to keep87 octane unless it is totally required !!
My current tune is Brenspeed 87 octane
Any help would be appreciated
Getting dangerously close tobuying a SC, I have a couple of questions.
Do I need to run colder spark plugs?
Do I have to run with higher octane fuel?
Really want to keep87 octane unless it is totally required !!
My current tune is Brenspeed 87 octane
Any help would be appreciated
I recommend HT0 plugs---like everyone else
You will have to run premium fuel
The Brenspeed 87 tune will not be appropriate for running any type of FI.
12-05-2007, 08:22 PM
#16
Join Date: Aug 2007
Location:
Posts: 41
RE: Supercharger ?s - Plugs, high octane ?
You might try reading December 2007 issue of Modified Mustangs. Jim Bell (Kenne Bell) has the first installment of an article entitled "The 17 myths of supercharging." He does state in myth #2, Supercharged engines must use high octane fuel, "Not really." I am learning a lot as a newbie from the article(s).
12-07-2007, 07:26 PM
#19
4th Gear Member
Join Date: Nov 2007
Location:
Posts: 1,699
RE: Supercharger ?s - Plugs, high octane ?
ORIGINAL: jlmphillips
You might try reading December 2007 issue of Modified Mustangs. Jim Bell (Kenne Bell) has the first installment of an article entitled "The 17 myths of supercharging." He does state in myth #2, Supercharged engines must use high octane fuel, "Not really." I am learning a lot as a newbie from the article(s).
You might try reading December 2007 issue of Modified Mustangs. Jim Bell (Kenne Bell) has the first installment of an article entitled "The 17 myths of supercharging." He does state in myth #2, Supercharged engines must use high octane fuel, "Not really." I am learning a lot as a newbie from the article(s).
The other thing to remember about high octane is to use what's appropriate for your set-up. Using too high octane can be bad too. Run C16 in your car with low boost and your car will run like crap cause it will have a hard time detonating the fuel. You also have to consider your mods. If you have cats and all of your 02 sensors, you shouldn't exceed 104 and you NEVER EVER NEVER want to run leaded fuel with cats either. The highest unleaded fuel made is 109.
The last point nobody brought up is when you get the HTO's, make sure to gap them. Out of the box they are not right. Get yourself a little gapping tool from somewhere like pmpparts.com for around $25 and for 6-8 psi, gap them around .035 and for 9-10 psi, gap them around .032-.034, for 11-14 psi, gap them around .030-.032, and for big psi, you want to gap them around .028-.030.
12-07-2007, 07:32 PM
#20
1st Gear Member
Join Date: Jun 2007
Location:
Posts: 145
RE: Supercharger ?s - Plugs, high octane ?
the saleen s/c tune says "at least 91," does that mean you can use 92 or 93 and be fine, because there is no 91 around here. what are any problems that could happen running 92 or 93? thanks