Can we Discuss Effective Compression,Elevation,Fuel type?
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
Ok. So It's been a while since my last turbo charged car. While it was a paltry entry level system with moderate goals for the time (Think TurboEdit). Included are screen shots of the same build,only different compressions
I am currently researching everything for my new turbo charged project.
I am going to be using E85.
My Elevation is 1558ft. Which changes my Static Compression ratio.
Had planned on 10.1:1 which at my elevation turns into 10.03 with an Effective ratio of 19.64:1 at a moderate 15 psi

This could be the difference in 500+hp or falling short
The Other option I have is 10.8:1.
Which puts my Static (Using B16 Head in both cases) to 10.9:1
and pushes my Effective to 21.41

I know plenty of builds are running way more extreme compression than I am even in some cases as a street duty
Mine will not be a daily driver,but I would like to enjoy as often as possible when the weather is nice.
My question is how much Effective Compression is too much with my chosen choice of fuel? Or am I just being a worry wart?
all the while hoping to enjoy the car for 50-60k or more before any real work would need to be done.
I am currently researching everything for my new turbo charged project.
I am going to be using E85.
My Elevation is 1558ft. Which changes my Static Compression ratio.
Had planned on 10.1:1 which at my elevation turns into 10.03 with an Effective ratio of 19.64:1 at a moderate 15 psi

This could be the difference in 500+hp or falling short
The Other option I have is 10.8:1.
Which puts my Static (Using B16 Head in both cases) to 10.9:1
and pushes my Effective to 21.41

I know plenty of builds are running way more extreme compression than I am even in some cases as a street duty
Mine will not be a daily driver,but I would like to enjoy as often as possible when the weather is nice.
My question is how much Effective Compression is too much with my chosen choice of fuel? Or am I just being a worry wart?
all the while hoping to enjoy the car for 50-60k or more before any real work would need to be done.
Last edited by sikefcrx89; Dec 30, 2018 at 07:21 AM.
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
Doing some more reading,it looks as if the marginal gain from my would be 10.03 to 10:9.1 while using e85 would take away a ton of safety margin. So ragged edge without a safety net that could potentially last,or give myself a margin of error and whatever it makes is whatever it makes..
Doing some more reading,it looks as if the marginal gain from my would be 10.03 to 10:9.1 while using e85 would take away a ton of safety margin. So ragged edge without a safety net that could potentially last,or give myself a margin of error and whatever it makes is whatever it makes..
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
Effective only drops the higher the altitude.
at 10.9:1 at 2300ft it goes from 21.51 at 1558ft to 21.11 and at 3200ft it drops to 20.75 from a base where my home is located at 1558ft.
I am looking for a clean comparison of Effective compression and Elevation. 3/4 of the time will be semi flat ground with a +/- of 1-200ft. So E85 with the 10.9:1 runs safely at effective compression listed? Tuning will play a real aspect,but tuners are hours away under a separate set of circumstances.
Zeal Does Not factor in Fuel Type
at 10.9:1 at 2300ft it goes from 21.51 at 1558ft to 21.11 and at 3200ft it drops to 20.75 from a base where my home is located at 1558ft.
I am looking for a clean comparison of Effective compression and Elevation. 3/4 of the time will be semi flat ground with a +/- of 1-200ft. So E85 with the 10.9:1 runs safely at effective compression listed? Tuning will play a real aspect,but tuners are hours away under a separate set of circumstances.
Zeal Does Not factor in Fuel Type
Trending Topics
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
I am reading 15-16.1 Static. Maybe there are some folks here that a higher comp setup that can shed light..
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
Why I am kind worry warting. Elevation change will make the car richer,so being ragged edge and planning out the drastic elevation changes could be a hindrance.
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
One of the elevation changes I will be fighting. Highest point here is 4397ft
30 Mins from my place
https://en.wikipedia.org/wiki/Shenandoah_Mountain
30 Mins from my place
https://en.wikipedia.org/wiki/Shenandoah_Mountain
because compression lowers with elevation, I wouldn't see an issue with the 10.9:1. Because you'll be using E85, I wouldn't worry about higher compression. Because you'll be changing elevations throughout your travels in this car, your tune is the biggest concern.
You will be fine with that compression ratio at any altitude on a turbo engine on e85. Don't worry man, that is plenty in the safe range so I wouldn't sweat it.
Thread Starter
Joined: Aug 2006
Posts: 1,392
Likes: 15
From: Somewhere,WV
I will contact a couple guys and get some more input. Not saying I wouldn't take him at face value,but this is the last Honda I ever do.
Thread
Thread Starter
Forum
Replies
Last Post
Boostage
Forced Induction
28
Apr 11, 2005 07:11 AM







