Is E85 worth it? LS1 heads cam
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Joined: Sep 2013
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Is E85 worth it? LS1 heads cam
Hey guys,
I haven't really found a definite answer on it, but is e85 worth it on a heads cam LS1 with a CR of 11:1 or more?
I'm looking to do an all motor LS1 build with my C5 and I would like to squeeze as much power out of it as possible(obviously) but I don't want to do mods to the car that aren't going to really benefit much if the work/$ is a lot. I have a friend who says E85 is the way to go but I do have a tuner that states that E85 is probably going to gain 3-10hp at the very most.
Currently I'm full bolt ons and tuned on 93 making around 330-350whp and would like to be as close to 500whp as possible without going forced induction or nitrous. Hopefully I won't have to sacrifice too much drivability & reliability when doing so.
E85 is also readily available in my area & I would do flex fuel
Thanks for any information!
I haven't really found a definite answer on it, but is e85 worth it on a heads cam LS1 with a CR of 11:1 or more?
I'm looking to do an all motor LS1 build with my C5 and I would like to squeeze as much power out of it as possible(obviously) but I don't want to do mods to the car that aren't going to really benefit much if the work/$ is a lot. I have a friend who says E85 is the way to go but I do have a tuner that states that E85 is probably going to gain 3-10hp at the very most.
Currently I'm full bolt ons and tuned on 93 making around 330-350whp and would like to be as close to 500whp as possible without going forced induction or nitrous. Hopefully I won't have to sacrifice too much drivability & reliability when doing so.
E85 is also readily available in my area & I would do flex fuel
Thanks for any information!
Melting Slicks
Joined: Nov 2013
Posts: 2,049
Likes: 316
From: USA
Heads/cam LS you won't gain much of anything. Very high CR piston, max effort NA build yes!
Generally speaking, the higher strung the motor, the more you have to gain from E85 or additional octane in general. Typical bolton LS1, 91 vs 93 isnt huge....
All that said, I converted mine to flex fuel just for the fun of it. Ported stock z06 heads, cam, boltons ~450whp. Flex fuel is neat that I can just dump in some E85 and it takes care of everything automatically and it runs fine.
From a value perspective of course this isn't the best, as you need to get larger fuel pump, injectors etc. I already had a 450 walbro in the car, and it was pretty easy to for me to set up at that point, which is what led me there.
If I ever go back to the track I will put in some E85 for sure, for an extra safety margin.
Hope this helps
Generally speaking, the higher strung the motor, the more you have to gain from E85 or additional octane in general. Typical bolton LS1, 91 vs 93 isnt huge....
All that said, I converted mine to flex fuel just for the fun of it. Ported stock z06 heads, cam, boltons ~450whp. Flex fuel is neat that I can just dump in some E85 and it takes care of everything automatically and it runs fine.
From a value perspective of course this isn't the best, as you need to get larger fuel pump, injectors etc. I already had a 450 walbro in the car, and it was pretty easy to for me to set up at that point, which is what led me there.
If I ever go back to the track I will put in some E85 for sure, for an extra safety margin.
Hope this helps
Le Mans Master
Joined: Jul 2010
Posts: 6,014
Likes: 726
Cam heads compression min 13.1 and you'll get ur 500 easy. E85 likes compression. That's the olny way u will get there. N/A. 
But like aaron7 said fuel system has to be capable of the more fuel needed to run e85. 30% more
So to answer your question. Yes e85 will get u there.
But like aaron7 said fuel system has to be capable of the more fuel needed to run e85. 30% more
So to answer your question. Yes e85 will get u there.
Drifting
Joined: Aug 2017
Posts: 1,932
Likes: 360
From: Dayton, OH
Any increase you could get from E85 on a NA car is not worth the expense. If you are looking for a serious bump in power look at a centrifugal supercharger.
Last edited by SteveJewels; Jul 4, 2021 at 07:49 AM.
Melting Slicks
Joined: Nov 2013
Posts: 2,049
Likes: 316
From: USA
Yeah, it will never be a good value. Only way I would do this if I happened to be rebuilding the motor anyways or something. Then sure, might be kinda cool just to do a really high CR motor rebuild and run E85 on it. From where you're standing now.... .probably not worth it at all to be honest.
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not worth it in my opinion... in my area I see a lot of n/a cars not making much power running e85 and it just sounds cool but isn't doing much of anything at all lol... when your car becomes knock limited then you can start looking into a higher octane fuel
Le Mans Master
Joined: Jul 2010
Posts: 6,014
Likes: 726
I was just answer his question is it possible, and yes it is. to me it sounds like he doesn't want to send over 6k for a S/C or somewhere in that ballpark. off course that's the way i did it when i researched. But i'm not that intelligent to understand what he wants.
Race Director
Joined: Oct 2004
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I'll bet I'll catch Hell for this one, but any engine that runs higher octane than necessary to keep KR at bay, is leaving power (and fuel efficiency!) on the table. 40years ago, I once owned an 1,105cc, Yoshimura engined, Kawasaki Z1 street/strip bike. One time I went to the airport and picked up some 115 octane av gas. Even with the timing bumped several degrees, the bike ran2-3/10s slower,and was down a good 4mph on trap speed. Went back to pump gas premium and original timing, and it all came back. If your C5 motor is at 13:1 compression, if you aren't running a radical cam to lower the dynamic compression ratio, you'll probably need E85, or some sort of racing fuel will be mandatory.....AND expensive!!
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I'll bet I'll catch Hell for this one, but any engine that runs higher octane than necessary to keep KR at bay, is leaving power (and fuel efficiency!) on the table. 40years ago, I once owned an 1,105cc, Yoshimura engined, Kawasaki Z1 street/strip bike. One time I went to the airport and picked up some 115 octane av gas. Even with the timing bumped several degrees, the bike ran2-3/10s slower,and was down a good 4mph on trap speed. Went back to pump gas premium and original timing, and it all came back. If your C5 motor is at 13:1 compression, if you aren't running a radical cam to lower the dynamic compression ratio, you'll probably need E85, or some sort of racing fuel will be mandatory.....AND expensive!!
Last edited by StingrayRebel; Jul 4, 2021 at 03:47 PM.
Running Guns & Moonshine
Joined: Aug 2001
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From: CT
I don't see the point N/A. It's certainly not where I'd focus my attention.
Why no interest in a blower kit? It's like having your cake and eating it too. All the power you want or more while making it with a low profile cam of your choice. Kits can be had used with fresh head units if you wait and hunt. I ran an A&A kit for several years which I grabbed used for 3200 or so. When I was done I sold it for 200 more. My expense was the tune.
Why no interest in a blower kit? It's like having your cake and eating it too. All the power you want or more while making it with a low profile cam of your choice. Kits can be had used with fresh head units if you wait and hunt. I ran an A&A kit for several years which I grabbed used for 3200 or so. When I was done I sold it for 200 more. My expense was the tune.
Burning Brakes
Joined: Jul 2018
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From: Miami