From knowing nothing to having a Thunderbird supercharger on an m20b27i

[ButtJuice]

We need lots and lots of videos.

[Victell]

Also, Victell, taco, dark side, and FLG (and anyone else), what are your actual names? I'm Jacob. I'd just love to refer to yous by your actual names instead of your handles. I bet I can guess Darker side's name...

Victor

[Victell]

Preignition and detonation are very different things. Preignition is instant death to an engine (e.g. holing a piston). Detonation is survivable... for a while. How long depends on how much boost the engine is running.

The "corners" of the map, like the situations to which I alluded earlier in which the engine or intercooler might be heat soaked, or other combinations of operating parameters which are rarely experienced--and thus difficult or unlikely to be correctly tuned--are going to be risky.

High coolant temps are especially bad... He'll need to be very familiar with and have very conservative settings in the ignition advance vs. coolant temp and mixture vs. coolant temp tables to make sure he doesn't pop the engine on the first hot day he drives it hard.

Awesome. Thanks for the reply.

[Ether-D]

I'm not dead set on using 87. I just thought that if it could be done, maybe I could try it. No biggie.

I guess I'll cross the youtube bridge when I get to it.

Also, Victell, taco, dark side, and FLG (and anyone else), what are your actual names? I'm Jacob. I'd just love to refer to yous by your actual names instead of your handles. I bet I can guess Darker side's name...

[The Dark Side of Will]

I do not have any knock detection anything, but cept for my ears. Let's take it there. How do I go about getting my ms2 to listen for knock?

I don't know about MS2 specifically, but I'm sure there's ample info out there on how to do it.

There are also dedicated external systems (like the J&S Safeguard I previously mentioned) which have a logic level output that can be used to trigger timing retard on an engine computer.

Knock detection will be CRITICAL to making this combo live, especially on 87 octane.

Meanwhile, I'll be getting my o2 sensor on Monday.

When it gets running, I know you guys are gonna want video. I have no idea how to put a video on the intertubes. Especially with this shit satellite internet. It really sucks so completely. But if you have an iPhone, I'll send you a vid that way I guess. I'm pretty technologically impaired.

YouTube account... Youtube videos can be embedded in some forums via specific tags.

[Ether-D]

Meanwhile, I'll be getting my o2 sensor on Monday.

When it gets running, I know you guys are gonna want video. I have no idea how to put a video on the intertubes. Especially with this shit satellite internet. It really sucks so completely. But if you have an iPhone, I'll send you a vid that way I guess. I'm pretty technologically impaired.

[Ether-D]

I do not have any knock detection anything, but cept for my ears. Let's take it there. How do I go about getting my ms2 to listen for knock?

[The Dark Side of Will]

So from what I gather, 87 can be run on a FI motor if the boost is relatively low and the timing is retarded enough to keep it from detonating, resulting in a loss of horsepower. Is this correct?

Correct. Your boost is going to be pretty constant and determined by your pulley size.
So the way it will work is that you'd install a pulley for, say 5 psi and tune that on 93. Once you're comfortable with that, run your tank all the way down, fill up on 91 and drive/log/tune from there.
Then repeat for 89 and then 87.
If horsepower creep happens, pulley for 8 psi and repeat starting with 93.

Now... you *DO* have a knock detection system, right? Knock sensor on MS? J&S Safeguard or something similar?

[The Dark Side of Will]

How come? I thought ignition tables would be different but Im not sure what else. What would be the difference in learning from different octanes? Other than wasting your time on a tune that you'll end up not using anyway.

Because as he learns, he'll make mistakes along the way. He needs some safety margin for that.

I would say the "safety" has to do with how close your tune is to the point of preignition, not so much with the octane. If you tune for lower octane and stay far away from detonation with grossly retarded timing, then your octane/tune combo would then be "safe". Although you're really leaving a lot of power on the table by doing that. Personally I would run the highest octane possible to get the most from the setup. If I was rich I would run race fuel in my daily driver.

Originally you said "I was hoping I could tune it for regular" which is true, but some replies you indicated you CANT. As long as you understand that you CAN.

Preignition and detonation are very different things. Preignition is instant death to an engine (e.g. holing a piston). Detonation is survivable... for a while. How long depends on how much boost the engine is running.

The "corners" of the map, like the situations to which I alluded earlier in which the engine or intercooler might be heat soaked, or other combinations of operating parameters which are rarely experienced--and thus difficult or unlikely to be correctly tuned--are going to be risky.

High coolant temps are especially bad... He'll need to be very familiar with and have very conservative settings in the ignition advance vs. coolant temp and mixture vs. coolant temp tables to make sure he doesn't pop the engine on the first hot day he drives it hard.

[Ether-D]

I'm not really all that hell bent. I just have to separate the facts from the opinions. Sometimes, opinions come across as as facts. Hell, a lot of opinions are facts. But not all. I really appreciate you guys having my engine's back.

[TheTacoMan]

If you are hell bent on running 87, I would mix it with high octane gas or use meth or both.

[Ether-D]

Why is this such an issue, the difference of price between 87-91 isnt that much for a little more peace of mind in having a longer lasting engine and avoiding detonation?
87+ meth may be doable but I personally wouldnt do it. Spending all this time building a FI setup and then running shitty gas does not make sense to me.

I just have a regular gas station that is owned by a really nice local lady who really likes it when I fill up my cars there. She only has regular. I feel like it helps her. Her prices for non-ethanol regular are the same as premium in town. It has nothing to do with cost. I just like doing business with local folks.

So from what I gather, 87 can be run on a FI motor if the boost is relatively low and the timing is retarded enough to keep it from detonating, resulting in a loss of horsepower. Is this correct?

[FLG]

I would say the "safety" has to do with how close your tune is to the point of preignition, not so much with the octane. If you tune for lower octane and stay far away from detonation with grossly retarded timing, then your octane/tune combo would then be "safe". Although you're really leaving a lot of power on the table by doing that. Personally I would run the highest octane possible to get the most from the setup. If I was rich I would run race fuel in my daily driver.

Originally you said "I was hoping I could tune it for regular" which is true, but some replies you indicated you CANT. As long as you understand that you CAN.

Yes you can but why would you? Honestly I feel this convo shouldn't even be here haha. Unless you only had 87 avail then we'll you have no choice, but you have a better grade fuel and I'd be running it. When I go to the track I even throw some 100 octane in my drift car and mix it with the 93 simply because I know air temps and engine temps are at their highest, I'd never risk my engine.

Sent from my SCH-I545 using Tapatalk 2

[TheTacoMan]

[Victell]

DO NOT learn how to tune on a supercharged engine using 87 octane fuel.

How come? I thought ignition tables would be different but Im not sure what else. What would be the difference in learning from different octanes? Other than wasting your time on a tune that you'll end up not using anyway.