Megasquirt? What's the Situation? - ZR-1 Net Registry Forums

tpepmeie · 03-03-2021

Quote:

Originally Posted by spork2367

The ignition is not a limiting factor on making power within the realm of what is considered standard modifications on an LT5. You are not limited by the ability to modify the ignition outputs.

These engines are not known for weak ignition, or a high rate of coil failure due to heat, or any issues you might alleviate by moving the coil closer to the plug or out in the open.

I think there is a general misconception about what drove OEMs to CoP to begin with. Reliability, fuel efficiency and emissions. Not power.

I tend to agree with all of this. To be fair, I have not done back-to-back testing to prove it (nor has anybody else). However, I have never found the ignition system lacking or causing a misfire in any of the builds I have done and tested. The two-tower coils seem to have plenty of energy, at least for N/A builds. I am not aware of any ignition related misfires on the few boosted cars out there. I suppose a rich methanol mixture might benefit from higher spark energy, but nobody has a methanol LT5....

Aside from the emissions and diagnostic benefits noted above, the only other compelling reason to go to individual coil ignition is a situation where the engine speed is high enough (and coil dwell long enough) that there is not enough time to fully charge the coils. That isn't remotely a problem for the LT5 coils at the engine speeds we run.

Apologies to the OP for getting this thread slightly off his original topic. Always happy to discuss further in another thread, or this one too.
Todd

rkreigh · 03-04-2021

you can make all the power you want with all stock stuff, no need to ever innovate or use faster processors, EGT, dual WB or tune by cyl, just keep the car stock if that floats your boat, not me.

when you start to increase cyl pressures, run E85, and push the limits, I'd rather have a more advanced engine management system than what GM did back in the 80s

Nothing wrong with it, but it's not up to par with current technology on many levels.

the stock system has been proven to support up to 700 hp and works just fine up to that and beyond.

but there are NO safeguards on par with what the MS3 pro or other systems or advanced individual cyl tuning like aftermarket systems have the ability to do. Integration will be a huge PITA and indeed NOT worth it to most. for normally aspirated, clearly gains would be not worth the squeeze.

Tuning with the stock stuff is not a limiting factor until you get to the limits which are beyond where most have been.

Thanks for your thoughts.

XfireZ51 · 03-04-2021

Ron,

Our community hasn?t gotten to where it has w 30yo technology by not pushing the envelope or adhering to common wisdom. The LT5 is very much a DIY project which is one of the characteristics that attracted me to it. And our ZRs are very much an expression of ourselves especially on the Registry.

spork2367 · 03-04-2021

Quote:

Originally Posted by rkreigh

you can make all the power you want with all stock stuff, no need to ever innovate or use faster processors, EGT, dual WB or tune by cyl, just keep the car stock if that floats your boat, not me.

when you start to increase cyl pressures, run E85, and push the limits, I'd rather have a more advanced engine management system than what GM did back in the 80s

Nothing wrong with it, but it's not up to par with current technology on many levels.

the stock system has been proven to support up to 700 hp and works just fine up to that and beyond.

but there are NO safeguards on par with what the MS3 pro or other systems or advanced individual cyl tuning like aftermarket systems have the ability to do. Integration will be a huge PITA and indeed NOT worth it to most. for normally aspirated, clearly gains would be not worth the squeeze.

Tuning with the stock stuff is not a limiting factor until you get to the limits which are beyond where most have been.

Thanks for your thoughts.

The thread is a little convoluted with the number of questions.

The only thing I was responding to with my last response was: "I would still like to quantify if there is anything to be gained w CnP on an LT5 w typical mods, ie cams, porting exhaust."

And the short answer is still no. E85, alternative fuels, boost, and altered architecture are not "typical mods" in the LT5 world.

I'm running my 1990 on an ms3pro. There is no need to replace the DIS and stock coils to do any of the things you listed aside from individual cylinder tuning, which for this engine will gain you little to nothing.

That's not to say you shouldn't do it, but it would be one of those things to do just because you could, not because of measurable benefits.

rkreigh · 03-09-2021

not a hp gain I agree. I don't know what the DIS limits are for spark but they are clearly north of 700 hp and a select few ventured beyond that.

My desire is this,

1. easier maint, coil on plug, no spark plug wires or plenum pull
2. better monitoring and tune on the fly with the o2 (and egt if you like) - stock system just doesn't have these inputs. Even with a 12.5 to 1 LT5 get a bad batch of fuel and you can rattle it's brains out. The monitoring and active alerts like chopping fuel, spark or any combination there of based on a bad plug, injector, or coil. Worth it to save some pricey LT5 ponies based on a failure issue.
3. flex fuel. E85 won't gain much if anything on a stock lt5 but up around 12.5 compression or clearly with boost, flex fuel makes sense.
4. twin turbo. the stock ecm for sure can do it (and has) but for all the reasons above I would want the "safe guards" and faster response times.

The C5 has very similar challenges. I'm going to go with a haltech platinum on that project as I've had it laying around for years (bought it then couldn't afford to deploy it) It's "aged out" technology wise compared to new Holley and even the Nexus Haltech, but it's a very capable unit that can do dual WB, 8 channel EGT, and has a driver box control for running an alchy injection pump, and flex fuel sensor ready.

On both my c5s, I boost them till they break (and have broke) and try to just build stronger next go.

FYSA the new iron block truck motors with a stock block have gone past 2000 hp so the ICE might be on last legs, but they are stout ones.

03-04-2021	#2
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,080	Re: Megasquirt? What's the Situation? you can make all the power you want with all stock stuff, no need to ever innovate or use faster processors, EGT, dual WB or tune by cyl, just keep the car stock if that floats your boat, not me. when you start to increase cyl pressures, run E85, and push the limits, I'd rather have a more advanced engine management system than what GM did back in the 80s Nothing wrong with it, but it's not up to par with current technology on many levels. the stock system has been proven to support up to 700 hp and works just fine up to that and beyond. but there are NO safeguards on par with what the MS3 pro or other systems or advanced individual cyl tuning like aftermarket systems have the ability to do. Integration will be a huge PITA and indeed NOT worth it to most. for normally aspirated, clearly gains would be not worth the squeeze. Tuning with the stock stuff is not a limiting factor until you get to the limits which are beyond where most have been. Thanks for your thoughts.

03-04-2021	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,686	Re: Megasquirt? What's the Situation? Ron, Our community hasn?t gotten to where it has w 30yo technology by not pushing the envelope or adhering to common wisdom. The LT5 is very much a DIY project which is one of the characteristics that attracted me to it. And our ZRs are very much an expression of ourselves especially on the Registry.

03-09-2021	#5
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,080	Re: Megasquirt? What's the Situation? not a hp gain I agree. I don't know what the DIS limits are for spark but they are clearly north of 700 hp and a select few ventured beyond that. My desire is this, 1. easier maint, coil on plug, no spark plug wires or plenum pull 2. better monitoring and tune on the fly with the o2 (and egt if you like) - stock system just doesn't have these inputs. Even with a 12.5 to 1 LT5 get a bad batch of fuel and you can rattle it's brains out. The monitoring and active alerts like chopping fuel, spark or any combination there of based on a bad plug, injector, or coil. Worth it to save some pricey LT5 ponies based on a failure issue. 3. flex fuel. E85 won't gain much if anything on a stock lt5 but up around 12.5 compression or clearly with boost, flex fuel makes sense. 4. twin turbo. the stock ecm for sure can do it (and has) but for all the reasons above I would want the "safe guards" and faster response times. The C5 has very similar challenges. I'm going to go with a haltech platinum on that project as I've had it laying around for years (bought it then couldn't afford to deploy it) It's "aged out" technology wise compared to new Holley and even the Nexus Haltech, but it's a very capable unit that can do dual WB, 8 channel EGT, and has a driver box control for running an alchy injection pump, and flex fuel sensor ready. On both my c5s, I boost them till they break (and have broke) and try to just build stronger next go. FYSA the new iron block truck motors with a stock block have gone past 2000 hp so the ICE might be on last legs, but they are stout ones.