Camaro XV

[Lous69]

Mark,

My favorite part of the day Saturday was when I was watching you make a pass on the Autocross. When you finished your run and idled by, a nice gentleman next to me nudged me and said "That's my son". I said "You are Mark's Dad? You must be very proud. He's an engineer's engineer and one heck of a nice guy who doesn't let all of his success go to his head."

As a proud father myself, I could see how proud he was in his eyes and maybe even a little emotional crackle in his voice.

That was a very cool moment.

Lou

[Sieg]

Originally Posted by Lous69

Mark,

My favorite part of the day Saturday was when I was watching you make a pass on the Autocross. When you finished your run and idled by, a nice gentleman next to me nudged me and said "That's my son". I said "You are Mark's Dad? You must be very proud. He's an engineer's engineer and one heck of a nice guy who doesn't let all of his success go to his head."

As a proud father myself, I could see how proud he was in his eyes and maybe even a little emotional crackle in his voice.

That was a very cool moment.

Lou

Very cool Lou

Don is an absolute gentleman and it was a true honor to meet and converse with with him during the week.

[syborg tt]

Where is the like button.

Lou thanks for sharing this and Mark this has to be the best car to date and I a happy I was able to see it at Sema.

Originally Posted by Lous69

Mark,

My favorite part of the day Saturday was when I was watching you make a pass on the Autocross. When you finished your run and idled by, a nice gentleman next to me nudged me and said "That's my son". I said "You are Mark's Dad? You must be very proud. He's an engineer's engineer and one heck of a nice guy who doesn't let all of his success go to his head."

As a proud father myself, I could see how proud he was in his eyes and maybe even a little emotional crackle in his voice.

That was a very cool moment.

Lou

[Sieg]

Living up to the name........

[LS7 Z/28]

Could Mikels or Mark explain why the car has so much un-burnt fuel coming out the exhaust and creating this "hellfire"

I'm not completely familiar with LS engines yet and what and how the computer regulates things, but I'm trying to pick things up.

Generally with an old school carb on a race engine, when you are shooting flames out of the exhaust that's not exactly a good thing. Obviously it's loading up and the carb is running rich, so depending on air temperature etc.. You would change jets in the carb.

I'm just interested to know what's going on here. I looks badass I know that much. I laughed like crazy when I saw a photo of hellfire really flamed up and people were commenting thinking Mark blew it up. Now that was funny.

[66tintop]

Originally Posted by Valve Lash

Could Mikels or Mark explain why the car has so much un-burnt fuel coming out the exhaust and creating this "hellfire"

I'm not completely familiar with LS engines yet and what and how the computer regulates things, but I'm trying to pick things up.

Generally with an old school carb on a race engine, when you are shooting flames out of the exhaust that's not exactly a good thing. Obviously it's loading up and the carb is running rich, so depending on air temperature etc.. You would change jets in the carb.

I'm just interested to know what's going on here. I looks badass I know that much. I laughed like crazy when I saw a photo of hellfire really flamed up and people were commenting thinking Mark blew it up. Now that was funny.

I'm sure it only happens on decelaration !

[Vince@Meanstreets]

Its common on RPM-MAP based ecus in race applications for the lowest MAP bins to be set at the max vacuum that you can pull while opening the throttle quickly. When you quickly close the throttle quickly at high-load, high-rpm, you can often get the MAP to dip below that value and it will cause a rich condition that produces popping and flames. You can tune it out by spreading out your MAP bins, but it will lower the resolution of your fuel tables in the normal operating range and hence isn't usually done in race applications.

[Flash68]

Mark, I am curious if you think you may revisit this thought for 2015 and/or beyond.

Originally Posted by Stielow

I really like the OUSCI event; it is a lot more fun and way easier than One Lap of America. LOL. I gave serious thought on building a C-6 Corvette for the 2012 but I like the Pro-Touring route better. It is where I came from and what I like to do.

Mark

[mikels]

Originally Posted by Vince@MSperfab

Its common on RPM-MAP based ecus in race applications for the lowest MAP bins to be set at the max vacuum that you can pull while opening the throttle quickly. When you quickly close the throttle quickly at high-load, high-rpm, you can often get the MAP to dip below that value and it will cause a rich condition that produces popping and flames. You can tune it out by spreading out your MAP bins, but it will lower the resolution of your fuel tables in the normal operating range and hence isn't usually done in race applications.

Controller is GM E67 and is using MAF primary control with parallel speed-density control. So I have seen what you are speaking of, but this is slightly different.

Flames are result of how quickly ramp out of PE (power enrichment) combined with spark control when transitioning from on throttle to off throttle to DFCO (de-acceleration fuel cut-off).

Non-issue from an engine standpoint - from a visual, well, it barks flames on lift-throttle transitions from high airflow.

While there are many changes I can make that could reduce this effect, we haven't had time to revisit cal since last development trips to Gingerman and now OUSCI. That and some of those potential changes would be undesirable such as how quickly power drops when reducing accelerator pedal (@ 950hp, when you lift, you likely really want to reduce power.....)

Mark and I were talking that we've reached point where more power is not likely to result in much improvement of lap times (never thought I'd say that.....). Ability to maintain fluid temps at this power level has been a challenge as well - but Mark is now able to run 20 minute sessions in any ambient with controlled temps and no drop in delivered power.

First 7.0L supercharged engine (for road racing) we did at Thomson's in 2009 made 780hp/830tq. We are now at 950hp/970tq (1010hp/1020tq on E85). Amazing what refinements can bring paying attention to the details.

Dave

[Stielow]

Originally Posted by Lous69

Mark,

My favorite part of the day Saturday was when I was watching you make a pass on the Autocross. When you finished your run and idled by, a nice gentleman next to me nudged me and said "That's my son". I said "You are Mark's Dad? You must be very proud. He's an engineer's engineer and one heck of a nice guy who doesn't let all of his success go to his head."

As a proud father myself, I could see how proud he was in his eyes and maybe even a little emotional crackle in his voice.

That was a very cool moment.

Lou

Lou

Thanks for sharing the story. I'm glad my Dad was there.

Mark