My TFS Cathedral 416 LS3 on 87 octane?
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My TFS Cathedral 416 LS3 on 87 octane?
My recently built 416 is going to need a tune very soon. It has 350 miles on it running on my previous stroker tune and runs ok. Once I hit the 800-1000 mile mark I'll be looking to get a dyno tune.
Since the car will be my daily 20K miles per year, I was thinking how nice it would be to run 87 vs 93.
My questions are do you see any problem having it tuned on this fuel? How much power do you see it losing if successfully tuned on 87?
Combo:
LS3 416 (Wiseco -15cc with .045 quench) 11.2:1 scr
TEA TFS 225's
239/246 -- .623/.595 -- 113+2
Fast 92 opened to 95mm
100mm L'felter MAF
1.75"x3" FLP Headers
The car will occasionally see a 100 shot dry...when I spray it I would run it low on fuel and fill with 93.
What do you think?
Since the car will be my daily 20K miles per year, I was thinking how nice it would be to run 87 vs 93.
My questions are do you see any problem having it tuned on this fuel? How much power do you see it losing if successfully tuned on 87?
Combo:
LS3 416 (Wiseco -15cc with .045 quench) 11.2:1 scr
TEA TFS 225's
239/246 -- .623/.595 -- 113+2
Fast 92 opened to 95mm
100mm L'felter MAF
1.75"x3" FLP Headers
The car will occasionally see a 100 shot dry...when I spray it I would run it low on fuel and fill with 93.
What do you think?
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I know it's not apples to apples, but I (and many other) drag racers felt our liter bikes ran just as good if not better on 87. These bikes were all in the 11.5~12.5:1 scr range.
I think my cam spec's are going to play a huge part in determining feasibility...but I'm not that skilled
I think my cam spec's are going to play a huge part in determining feasibility...but I'm not that skilled
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KNOWLEGE... go look it up.
Just something I no... Basic engine building
Intake-Fire- Compression & Exhaust..we have 2 know @ what compression will the engine fire a lesser grade of fuel.
Just something I no... Basic engine building
Intake-Fire- Compression & Exhaust..we have 2 know @ what compression will the engine fire a lesser grade of fuel.
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That's my point.
I'm just thinking these stock motors are getting away with as much as 10.8:1 with a "regular" fuel rating. The cam they run must have less tendency to bleed off compression than mine, right?
https://ls1tech.com/forums/conversio...ification.html
I'm just thinking these stock motors are getting away with as much as 10.8:1 with a "regular" fuel rating. The cam they run must have less tendency to bleed off compression than mine, right?
https://ls1tech.com/forums/conversio...ification.html
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Problem....
Solution:
Prius C for dd will cost only $1,346 to drive 20.000 miles a year based on 52 mpg average @ $3.50 a gallon / 87 octane.
Wana see a pix of my Prius C ?
Yep, savings pay for the Prius.
Problem solved...worked for me !
Prius C for dd will cost only $1,346 to drive 20.000 miles a year based on 52 mpg average @ $3.50 a gallon / 87 octane.
Wana see a pix of my Prius C ?
Yep, savings pay for the Prius.
Problem solved...worked for me !
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Correct yet the ECU does the most part of controlling things, other than cylinder press. Ole schools just over cam it 2 bleed of cylinder press.
oh yeah try a new engine with iron heads and C if you can get 87oct to run. Alloy hold less heat... That is 1 reason 4 higher compression ratios.
oh yeah try a new engine with iron heads and C if you can get 87oct to run. Alloy hold less heat... That is 1 reason 4 higher compression ratios.
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I'd keep compression around 10.1:1. From a DCR perspective, 93 oct can handle 8.7:1 pretty cleanly and 8.5:1 safely. 91 octane drops that all down to 8.3/8.0. 87 would be even more dramatic. So you'll have to figure probably a DCR of around 7.0 safely and maybe 7.5 pushing it.
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Since the car will be my daily 20K miles per year, I was thinking how nice it would be to run 87 vs 93.
So in the end, it's basically a wash when it comes to cost of gas. Except the higher compression engine will make more torque and drive better.
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Even though it's cheaper to run 87 octane on a low compression engine, you will most likely get more MPGs out of a high compression engine running 93 octane.
So in the end, it's basically a wash when it comes to cost of gas. Except the higher compression engine will make more torque and drive better.
So in the end, it's basically a wash when it comes to cost of gas. Except the higher compression engine will make more torque and drive better.
Looks like to consensus is 93...oh well.
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Lower octane needing more fuel to run the same
It's the fact that a higher compression engine will make more torque from the same volume of air and fuel, thus you will need less throttle input to keep the car going at speed. So basically it's more efficient, does more with the same amount of gas.
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Every little bit add's up, but my main reason is I resent paying so much for fuel as it is.
Bottom line - I asked a tech question...your opinion about my spending habits aren't what's important
If it could be tuned safely and with little consequence on 87 I would do it in a second...H/C/I 416 on street tires ought to be ok even if it loses a couple HP.
Bottom line - I asked a tech question...your opinion about my spending habits aren't what's important
If it could be tuned safely and with little consequence on 87 I would do it in a second...H/C/I 416 on street tires ought to be ok even if it loses a couple HP.