87 octane and boost
87 octane and boost Yea yea yea...I know. Dumb idea. Search. Yada yada. Anyways, hear me out. First off I did search. Most of the crap I came across was people beating up on the op about this. No helpful info. So...
5.3, 9.4:1 compression. 93 octane right now, meth injected at 16psi with 5gph nozzle. I’m running a max of 22ish psi on 93, 11 degrees timing and going up to 12 in the upper rpms.
think I could get away with 12-14psi and maybe inject meth at a lower psi? Maybe lower the timing a few degrees. The reason I’m considering this is I’d like to start driving the car more but putting premium in it at $3+ a gallon and the distance I drive to work.....will add up quick vs $2.30 a gallon. That $10-$15 per fillup a couple times a week.
5.3, 9.4:1 compression. 93 octane right now, meth injected at 16psi with 5gph nozzle. I’m running a max of 22ish psi on 93, 11 degrees timing and going up to 12 in the upper rpms.
think I could get away with 12-14psi and maybe inject meth at a lower psi? Maybe lower the timing a few degrees. The reason I’m considering this is I’d like to start driving the car more but putting premium in it at $3+ a gallon and the distance I drive to work.....will add up quick vs $2.30 a gallon. That $10-$15 per fillup a couple times a week.
Staging Lane
Joined: Dec 2016
Posts: 82
Likes: 3
I like hearing about low octane builds, since I run 93, no E85 around. I kind of wish I had built a lower comp. engine, but it ended up (5.3) with flat top pistons, 799 heads, and a mild cam, no IC'er. I plan on an IC'er sometime. Just on a street hit @ 8 lbs, I have seen MAT's in the 180 deg range. If I could duct the intake air outside the engine comp. prob could knock that down some. I could prob get away with lower octane if I just cruised it, no boost. Are you running knock sensors, wondered how much they knock timing back.
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I'd be really curious to see what you'd come up with for spraying meth on 91 and meth on 87.
You know what else is gonna happen....you're gonna have a tank full of 87 for "cruising" and while heading to work you're going to run into someone who wants to play but that tank of 87 will make you think twice but not long enough to keep you from dropping the hammer lol.
I’d be less worried about the cost of meth and more concerned with the fact the lower octane you run as a primary fuel the more you rely on the meth. If the meth fails you’ve got less cushion than you had with 93 regardless of what safe guards you have in place.
I like hearing about low octane builds, since I run 93, no E85 around. I kind of wish I had built a lower comp. engine, but it ended up (5.3) with flat top pistons, 799 heads, and a mild cam, no IC'er. I plan on an IC'er sometime. Just on a street hit @ 8 lbs, I have seen MAT's in the 180 deg range. If I could duct the intake air outside the engine comp. prob could knock that down some. I could prob get away with lower octane if I just cruised it, no boost. Are you running knock sensors, wondered how much they knock timing back.
I try, i try. But I'm still a broke cheapass
There's an excellent point, you'd want to factor in the cost of fuel and then the total cost of meth used for each fuel.
I'd be really curious to see what you'd come up with for spraying meth on 91 and meth on 87.
You know what else is gonna happen....you're gonna have a tank full of 87 for "cruising" and while heading to work you're going to run into someone who wants to play but that tank of 87 will make you think twice but not long enough to keep you from dropping the hammer lol.
I'd be really curious to see what you'd come up with for spraying meth on 91 and meth on 87.
You know what else is gonna happen....you're gonna have a tank full of 87 for "cruising" and while heading to work you're going to run into someone who wants to play but that tank of 87 will make you think twice but not long enough to keep you from dropping the hammer lol.
I want to point out the fact that lately I've seen bags on the premium pump nozzle more than usual....so regardless, using regular is an option i'd like to have. i knew I'd get some negative comments, this is the internet....what else could I expect. However, the few that understand where I'm coming from, thx.
We all have to choose where we cut spending. That’s why I said IMO that octane isn’t where I’d cut spending on a boosted build.
I probably make less than most here. I started out homeless when I left home due to an abusive step dad as a teenager. Yet I don’t have a credit card, only buy with cash I have including all our vehicles. I owe around 15g on my house as our only family debt.
I probably make less than most here. I started out homeless when I left home due to an abusive step dad as a teenager. Yet I don’t have a credit card, only buy with cash I have including all our vehicles. I owe around 15g on my house as our only family debt.
TECH Fanatic
Joined: Feb 2015
Posts: 1,080
Likes: 178
Tune for 87 (read plugs) and see how far you can go w/o wmi then add wmi and tune to aid in some additional pwr. I would not expect 93 performance without significant increase in meth content. What WM % are you using?
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
You can run 87 with boost in an ideal combination/tune. 4-cylinders run 18-20 PSI with 87 from the factory and are reliable with extended warranties while running normal engine temps around 215-230.
Modern bikes can run 5-8 PSI on 93 octane despite being 12:1 compression.
Running low boost on a V8 on 87 octane, even without an intercooler, isn't at all outside of the realm of possibility.
You just need to understand that you can't run as much boost, or make as much power.
Something to remember: 87 octane that contains 10% ethanol is using the worst, garbage byproduct gasoline as the base. Stuff that often can't be sold on its own otherwise.
Modern bikes can run 5-8 PSI on 93 octane despite being 12:1 compression.
Running low boost on a V8 on 87 octane, even without an intercooler, isn't at all outside of the realm of possibility.
You just need to understand that you can't run as much boost, or make as much power.
Something to remember: 87 octane that contains 10% ethanol is using the worst, garbage byproduct gasoline as the base. Stuff that often can't be sold on its own otherwise.