How much boost on 110

A

apexjunki

New member

May 3, 2008

106

3

18

Grand Rapids, MN

• Sep 17, 2009

• #1

I need to know how much boost I can run on 110 octane. I have an 07 apex with .060 head shim and a split head gasket.
I run a alpine/mcxpress kit with a gt2871 turbo. Any help would be great thanks.

 

E

EEEK FACTOR

Active member

Nov 26, 2007

308

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28

50

• Sep 17, 2009

• #2

elevation?

 

Last edited: Sep 17, 2009

B

bigrhett

Active member

Lifetime Membership

Nov 26, 2007

108

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Alpine, UT

• Sep 17, 2009

• #3

Over on totally yamaha forums there was an octane calculator posted in an excel spreadsheet. Here's the forum link: http://www.ty4stroke.com/viewtopic.php?t=23214

You can input your specific situation (compression ratio, head shim, elevation) and then get a good idea of how much octane you need for how much boost.

Don't ask me for specifics on how to set up the spreadsheet, but it should give you some ideas. Low compression pistons make a bigger difference. In my case with 10 to 1 pistons, I says I can run like 29 psi at 8500 feet on 110 octane

 

Last edited: Sep 17, 2009

A

apexjunki

New member

May 3, 2008

106

3

18

Grand Rapids, MN

• Sep 17, 2009

• #4

elevation

7 to 10k feet.

 

A

apexjunki

New member

May 3, 2008

106

3

18

Grand Rapids, MN

• Sep 17, 2009

• #5

boost calculator

When I pull up the link from totally yamaha the spread sheet is for lobe center and cam specs.

 

B

BCBOOST

Free Member

Oct 17, 2004

192

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Kelowna B.C.

• Sep 18, 2009

• #6

apexjunki said:

When I pull up the link from totally yamaha the spread sheet is for lobe center and cam specs.

Click to expand...

Junki.....Scroll up should be at the top of the page.... Spread sheet works good.

BC.

 

J

johnny be bad

Well-known member

Nov 26, 2007

11,936

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113

in the getto

• Sep 18, 2009

• #7

bigrhett said:

Over on totally yamaha forums there was an octane calculator posted in an excel spreadsheet. Here's the forum link: http://www.ty4stroke.com/viewtopic.php?t=23214

You can input your specific situation (compression ratio, head shim, elevation) and then get a good idea of how much octane you need for how much boost.

Don't ask me for specifics on how to set up the spreadsheet, but it should give you some ideas. Low compression pistons make a bigger difference. In my case with 10 to 1 pistons, I says I can run like 29 psi at 8500 feet on 110 octane

Click to expand...

thanks for that calculator info. that was cool.

 

T

TurboKeith

Free Member

Nov 26, 2007

136

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18

Granite Falls, Wa

• Sep 18, 2009

• #8

Just keep in mind that it doesn't account for intake temps that will rise as boost goes up. Higher temps = detonation. Try to run a few extra points of octane above what it tells you for a little margin of safety.

 

E

EZmoney

Well-known member

Nov 27, 2007

980

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West coast

• Sep 18, 2009

• #9

TurboKeith said:

Just keep in mind that it doesn't account for intake temps that will rise as boost goes up. Higher temps = detonation. Try to run a few extra points of octane above what it tells you for a little margin of safety.

Click to expand...

Keith can you post it here please? thanks

 

T

TurboKeith

Free Member

Nov 26, 2007

136

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Granite Falls, Wa

• Sep 18, 2009

• #10

Here's a link to the boost calculator... Let me know if you have any questions on how it works. http://www.toyzfortrucks.com/boostcalculator.xls