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11:1+ Compression on Pump gas?

  • Thread starter Thread starter 90mustangGT
  • Start date Start date Dec 28, 2004
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90mustangGT

I felt sorry for girls because
Founding Member
Jan 15, 2002
2,773
17
89
Dallas, GA
Dec 28, 2004
#1
  • Dec 28, 2004
  • #1
Is it possible without problems running 93 octane?

I am rebuilding the engine, just considering options.
 

Motorhead6T5

New Member
Oct 21, 2004
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Marysville,CA
Dec 28, 2004
#2
  • Dec 28, 2004
  • #2
My 65 has almost that much compression and runs fine on 91.So you should be fine with the right tune.
 

MustangPunk302

Founding Member
Sep 11, 2002
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West Michigan
Dec 28, 2004
#3
  • Dec 28, 2004
  • #3
My civic has 12:1 and the mustang is about 13:1 and I run both on 93 octance... Though the mustang takes full advantage of 100+ of cousre . You shouldn't have any troubles.
 

giddyup306

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Oct 22, 2002
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Dec 28, 2004
#4
  • Dec 28, 2004
  • #4
I'm runnin 11.5:1 on my 347 with 93. I have the MSD retard box so in case if I get some bad gas, I can retard my ignition timing from the drivers seat. It also depends on your altituede. If you are at or near sea level, it may be iffy.
 

giddyup306

Founding Member
Oct 22, 2002
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Dec 28, 2004
#5
  • Dec 28, 2004
  • #5
You are talking about aluminum heads right?
 

willys1

Active Member
Dec 2, 2003
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New Jersey
Dec 28, 2004
#6
  • Dec 28, 2004
  • #6
I believe the new Vette is 11:1
 

giddyup306

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Oct 22, 2002
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Dec 28, 2004
#7
  • Dec 28, 2004
  • #7
willys1 said:
I believe the new Vette is 11:1
Click to expand...

It is also OBD II and can retard timing according to the knock sensor. The prius is 13:1.
 

willys1

Active Member
Dec 2, 2003
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Dec 28, 2004
#8
  • Dec 28, 2004
  • #8
giddyup306 said:
It is also OBD II and can retard timing according to the knock sensor. The prius is 13:1.
Click to expand...
who makes Prius??
 

giddyup306

Founding Member
Oct 22, 2002
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Dec 28, 2004
#9
  • Dec 28, 2004
  • #9
The Toyota Prius. Might have spelled it wrong but I think this is right.
 

dirtracer

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Jun 13, 2001
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Connersville, IN
Dec 28, 2004
#10
  • Dec 28, 2004
  • #10
My 408C is 11:1 and I run it on pump gas with iron heads. The tune up is a bit soft just for safety sake, but it runs good.
 

Ford_Racing

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Mar 21, 2004
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Portland Texas
Dec 28, 2004
#11
  • Dec 28, 2004
  • #11
I have been told 11:1 is the limit to run safely on pump gas.
 

thumper460

Founding Member
Jul 24, 2000
3,022
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Orange Park , Fl
Dec 28, 2004
#12
  • Dec 28, 2004
  • #12
tons of things will be needed to run the 11:1 on pump. Dont "lug" the engine around.. like 1800 rpm in 3rd and mash the gas.. or pull hard up hills in a high gear and low rpm. Or run hot.. blah blah...

I run 11:1 and use a set of gears and rpm ranges to keep the engine from detonating !! My ign timing is at 38* total at 1800 rpm and the Cam is in advanced!! but I drive at 2500-2800 rpm!! I keep the rpm up and the temp down!! ( I add Fuel when I race...) To me... Using that compression ISNT worth the trouble for the few extra HP gained!! drop to 10:1 and beat the mess out of it!! Rocking??

Just me..........................

Thumper
 

QDRHRSE

New Member
Dec 31, 2002
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Palmdale, CA
Dec 28, 2004
#13
  • Dec 28, 2004
  • #13
You will not be able to really run 11:1 all the time on pump gas. You will have to pull back the timing and drive very conservatively. You will probably have to avoid hot weather and traffic. I'm saying the same thing as everybody else but I'm attempting to be more practical. If the car is a dedicated toy you might be able to get away with it. Otherwise, I wonder why you'd want a 5.0 that you'd have to limp around town in?
 

BlackDrop50

Founding Member
Jul 14, 2002
217
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Bay Area, CA
Dec 28, 2004
#14
  • Dec 28, 2004
  • #14
I run 10.7:1 with 91 octane no problems
 

88GTStreetRod

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Jan 5, 2004
376
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Dec 28, 2004
#15
  • Dec 28, 2004
  • #15
I ran a 466ci with 11.5.1 on 93, ran fine. The motor really liked 110
 

willys1

Active Member
Dec 2, 2003
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New Jersey
Dec 28, 2004
#16
  • Dec 28, 2004
  • #16
giddyup306 said:
It is also OBD II and can retard timing according to the knock sensor. The prius is 13:1.
Click to expand...
What does OBD stand for??
 

Mike86Stang

Advanced Member
Apr 11, 2000
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Red Lion, PA
Dec 28, 2004
#17
  • Dec 28, 2004
  • #17
On Board Diagnostics
 

willys1

Active Member
Dec 2, 2003
1,004
1
36
New Jersey
Dec 28, 2004
#18
  • Dec 28, 2004
  • #18
MSTANG said:
On Board Diagnostics
Click to expand...
Thanks So the OBD-II started as the OBD-I ??
 

bluevenom867

I will have images of molesting stuffed animals in
Dec 15, 2003
1,704
1
0
St.Petersburg,FL
Dec 28, 2004
#19
  • Dec 28, 2004
  • #19
Hehe, I run 93 octane in my 351W with 10.7:1 and hit it with a 125 shot with 34* of timing.No detonation.
 

Mike86Stang

Advanced Member
Apr 11, 2000
10,296
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Red Lion, PA
Dec 28, 2004
#20
  • Dec 28, 2004
  • #20
Si senor.
 
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