turboc87gn
Darkside in Detroit
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...
Who has found the E85 boost limit?
- Thread starter sakudog
- Start date
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marleyskater420
still needs to learn
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- Aug 14, 2004
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- 1,879
Pump E85 is rated by volume, not weight. So if you know the ethanol %, and you know what octane ethanol is, you can roughly calculate the octane level.
marleyskater420
still needs to learn
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- Aug 14, 2004
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- 1,879
I wasn't going to say this...but thanks
Werd. On average I've gotten that methanol is around 120-125 octane. Ethanol seems to be right there. Between 118-123 from what I've learned.
The cool part about the fuel that I'd like to offer this board (I never heard back from Shane about sponsoring the board) is that they rate their E85 by weight, not volume. So if the ethanol weighs less than the gasoline, you'd be getting proportionately more ethanol, and henceforth more octane
.northerngn
Master Monkeywrench
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- Oct 8, 2006
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- 770
show off
Did you notice how small his turbo is? (no offence meant beatav8)
I could run big boost 25+lbs with an old te45a (which is bigger than what he has) (ta49)
Once I switched to a modern 67/65 the boost had to be backed all the way down to 18 to keep d/c under 100%
Good number for THAT combo for sure!
Once the turbo get upsized to something modern that really moves a lot of air, there will be a new tread.....
-Dan
BEATAV8
The Engine Whisperer
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- Feb 14, 2002
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- 5,673
Tru dat... tru dat... it's a little TA49.
It can push up to 32, but it's really not any faster at 32psi than it is at 27-28psi (track MPH proven). Good news is at 28psi it's very much "bomb proof". Never see any knock. Car has a wad of timeslips in the console that could heat the house for a week!
northerngn
Master Monkeywrench
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- Oct 8, 2006
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- 770
COOL!
forcefed86
Member
- Joined
- Jul 28, 2005
- Messages
- 337
My low budget 3.8 is still using factory iron heads (shaved a bit! 42cc ) With the acception of cheap forged power pistons, its an OEM rotating assy right down to the original bolts. Using the RJC steel shim “bullet proof” head gaskets compression is roughly 9:1. I’ve run over 30 psi on a pt68 at 18* of timing. Never had an issue. Currently running a cheapo 72mm at 28psi on the same setup. Still trapping 134-135, but I seem to get ignition break up over 28psi with this turbo. Once that’s worked out I’ll turn it up more.
On a side note I run E50 on the 4 banger daily driver. Boost is set at 34psi /15* timing. It’s a 2.0 liter, 9:1 with an HX-40 turbo. The previous tiny 16g turbo I ran would spike to 37psi initially and settle around 28 by redline. Ethanol is some powerful stuff!
On a side note I run E50 on the 4 banger daily driver. Boost is set at 34psi /15* timing. It’s a 2.0 liter, 9:1 with an HX-40 turbo. The previous tiny 16g turbo I ran would spike to 37psi initially and settle around 28 by redline. Ethanol is some powerful stuff!
northerngn
Master Monkeywrench
- Joined
- Oct 8, 2006
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- 770
Why dont you turn the boost down and the timing up..18 is super low!!! I have run 24* at 26 lbs with no spark issues...and that was on race gas...E-85 will take even more!!!
forcefed86
Member
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- Jul 28, 2005
- Messages
- 337
I've always made more power with low timing and high boost. Never needed higher timing with e85. Also with the 9:1 compression and iron heads I'm a bit nervous to run timing to high. Going by the heat strap on the plug I'm right where I need to be anyway. About a 1/4 way down the plug. I let the engine tell me how much timing to run.
northerngn
Master Monkeywrench
- Joined
- Oct 8, 2006
- Messages
- 770
Every car is different!I've always made more power with low timing and high boost. Never needed higher timing with e85. Also with the 9:1 compression and iron heads I'm a bit nervous to run timing to high. Going by the heat strap on the plug I'm right where I need to be anyway. About a 1/4 way down the plug. I let the engine tell me how much timing to run.
forcefed86
Member
- Joined
- Jul 28, 2005
- Messages
- 337
Very true! Always best to just read the plugs IMHO. Heres what I consider a good "safe" e85 plug timing wise.
that's awesome!
BEATAV8
The Engine Whisperer
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- Feb 14, 2002
- Messages
- 5,673
Are you using a 6.2 chip or an SD?Very true! Always best to just read the plugs IMHO. Heres what I consider a good "safe" e85 plug timing wise.
forcefed86
Member
- Joined
- Jul 28, 2005
- Messages
- 337
6.2 chip MAFT and ls1 MAF.
Just a little FYI I got greedy last night at the track. Bumped timing from 18* to 21*. Actually I didn't remember I had unplugged the battery and the chip reset to default settings. Default settings on turbo tweak chip were 21* of timing. AFR's in right at 11:1. I usually keep AFR's at 10.5:1 ish.
Ended up blowing the "Bullet Proof" RJC steel shim head gasket. Bad way to end the season! lol. Didn't even get to the 330' mark. Let go in first gear around 28psi, 1st pass! I had made a few 2nd gear pulls on the way to the track to 120mph or so. Car felt great! No knock registered, plugs looked great, no speckling etc... Go figure!
6.2 chip MAFT and ls1 MAF.
Just a little FYI I got greedy last night at the track. Bumped timing from 18* to 21*. Actually I didn't remember I had unplugged the battery and the chip reset to default settings. Default settings on turbo tweak chip were 21* of timing. AFR's in right at 11:1. I usually keep AFR's at 10.5:1 ish.
Ended up blowing the "Bullet Proof" RJC steel shim head gasket. Bad way to end the season! lol. Didn't even get to the 330' mark. Let go in first gear around 28psi, 1st pass! I had made a few 2nd gear pulls on the way to the track to 120mph or so. Car felt great! No knock registered, plugs looked great, no speckling etc... Go figure!
Forcefed how much does your car weigh "race weight" if you dont mind me asking?
