A fitting destination if it could happen.

Well of course. I mean Charlies does have impeccable taste after all.

Dave,

As a guy with an engineering background myself, I greatly appreciate your analysis of the decisions that go into building a car like this. There's a big difference between building cars that promise on paper to be great real world performers, and cars that can back up the promise. And that difference in large part comes down to the kind of experience and knowledge that you and Mark represent. Thanks much for sharing.

The fan data is very helpful for me - I'm looking to upgrade the track day cooling on my car and I think airflow is one of the major areas for improvement. Trying to figure out the part numbers for the SRX fan, is this it?

http://www.gmpartsnow.com/auto-parts...and-motor-scat

And do you happen to have the part number for the fan controller? I'm switching over to a GM E38 controller, and am very familiar with HP tuners and the PWM fan control settings, so I think that part is straightforward ...

Again, thanks for your contributions.

Scott

Mr. Magoo needs all the help he can get!! :bump:

SRX turbo fan part number is 25931645 as you show. PWM controller is built in to fan motor - so no separate module like Corvette fan.

Max PWM duty cycle is 90% positive polarity @ 100 Hz (need this for calibration). Size wiring & fuse appropriately - 64 AMPS peak.

First used this fan on Red Devil and dropped coolant and oil temps ~10F just by changing to this fan from 400W Corvette fan.

Dave

Thanks much for the prompt response! 10F is a significant improvement when you're at or beyond the edge already. I'm ordering this fan tomorrow.

Waiting to hear how Mark is doing at OUSCI, as I'm sure you are too.

Thanks,

Scott

Also as Charley would say....... "SO?"

LOL








We did the swap once again tonight -- as this is much easier for Mark to not have to get in any later than is already playing out with this event. The car is far safer tucked away in the trailer at the track than in a hotel parking lot in Vegas where it might not survive the night!

Second night of driving - this time from the Shelby headquarters event back to LVMS... so now I'm not nearly as nervous driving someone else's baby.. and I get to enjoy the pure pleasure this car is. Smooth - powerful sound... real world pro-touring... by that I mean I would be HAPPY to drive this car to TEXAS! Tonight! Fire it up and cruise! All the sensual pleasures are there - stereo - great seats - SOLID well mannered road car. Power you can sense and feel in the throttle - but the clutch is silk as are the transmission and the brakes! Oh man this beast has great feel in the brakes.

Here's the deal -- My Mustang feels and drives like a race car.... I would not want to drive it anywhere but on a track. This car --- this is a car that you want to drive..... To me - it's the real deal of what people are trying to get when they're building a pro-touring car. This car on Hot Rod Power Tour would just be unimaginably good!






I'm old... okay!?!?! Good headlights are important! LOL

Why does your phone camera make me look so short and fat?

Actually the under dash LED access lighting is very functional too!

I'm not that old and I'm right there with you :lol:

Also what you are saying above about how nice it drives and you would drive on Power Tour, does that mean when Mark goes to sell this one Charley will have to out bid you :lol: of coarse we know he will but still will be fun!!

Apparently Greg really is getting comfortable driving the car. After the swap, me Mark and Laura are driving on the freeway north towards the hotel when Mark says "Hey, there goes my car!" As Greg goes bombing by us. Was kinda weird for Mark to see his car pass us unexpectedly

Take a rest then cruise it out to Scottsdale GG next weekend.

Pleeeeeease. Pretty please with sugar on top.

... X2

I bet that was a strange feeling. Sort of like letting your daughter go on her first date. "she better be in one piece when she gets back" hammer click

Yeah, the odds with Weld are better than locked up in a trailer in a parking lot at Caesar's.

I only passed you because the Viper wanted to race once we hit Las Vegas Blvd (by the way, it was just as weird seeing you in my Jeep). Does your head hit the roof?

Great Information
 

Great information. Would someone copy this over to the PWM cooling fan thread so we don't forget where it is ! Ok, so I don't forget where it is !!

We watched all the Optima cars roll out on Friday. There were some radical and loud cars. Marks car sounded docile compared to others. Very unassuming, but we know what's really going on under the hood. Can't help but be impressed with a car that does it all.

Tim

Now that's a funny story.

Greg and Tim, thanks for relaying your impressions of the car. I love it and think it's the pinnacle of pro-touring. Of course, I think each of his builds are. I doubt I'll ever see any of them in person though so I appreciate your responses.

I was able to get in early and check the car out with almost no crowd in the show. I spent a half hour just looking the car over. Mark was even nice enough to say hi and ask me if I had any questions about the car :thumbsup:

Some more impressions of the car
- The Jake Skull on the shifter and rear window are nice touch.
- The car is clean its hard to see all the technology in the car. The hoses, wiring, connectors, are all well hidden.
- The Z28 influence is evident in the front splitter, and rear wing.
- The underside components are invisible they are tucked so high up.

I could have looked at it all day!

http://i62.tinypic.com/2ez4mfs.jpg
http://i61.tinypic.com/flxd1d.jpg
http://i61.tinypic.com/b5l8x5.jpg
http://i61.tinypic.com/eqtrg3.jpg

Mark,

I really enjoyed reading your feedback on how Hellfire has been performing each step of the way to OPTIMA. I know last week had to be very hectic and you are probably still trying to get your feet back on the ground. When you have an opportunity, can you give those of us that were foolish enough not to go to SEMA your thoughts on the car's performance? :thankyou:

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 :thumbsup:

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

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.

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

http://photos.smugmug.com/photos/i-z...-zTHbZ9z-L.jpg

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 !

question came up before....
 

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.

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

2014 OUSCI Road Course
 

Here's a video from the final road course session (about 1/3 into it).

It gets really wild about two minutes in :D.

Some really sweet driving by all and a great perspective on how hard these guys track their cars.

OH MY GOOD GRACIOUS! My office chair was all over the place watching that. I was on the binders way before Mark. And that's just watching the video! LOL Thanks for posting that video, it made my afternoon! :king:

I was thinking the same thing there .... except my heart was pumping lots, and looking in the mirror there Mark is calm and in control. WOW :king:


Thanks for posting .... I could waist a whole day watching Mark take the fastest line!!!!

That was an awesome video, could only imagine how well it would work with racing slick tires ! Thanks for sharing ! It sure seems like it pulls like freight train ! Wow !

LOL... I know what you mean. I was watching this last night on the big screen and found myself leaning into each turn!

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

The development you guys have put into this package is fantastic. Your work and attention to detail is very evident!

Your statement above is all the motivation needed to do an AWD 69! Hint Hint Nudge Nudge Wink Wink!

Dog Fights!

http://photos.smugmug.com/photos/i-2...-2ZFgjkj-L.jpg

http://photos.smugmug.com/photos/i-w...-wkHKWCj-L.jpg

http://photos.smugmug.com/photos/i-z...-zbPrFq2-L.jpg

This photo was taken at about 5:20 on the video, quick heavy application of mid-range throttle.
http://photos.smugmug.com/photos/i-z...-zTHbZ9z-L.jpg

So how did Mark do overall at the event?

That... was... Awesome...

Thanks for posting. Really nice driving by Mark in an obviously very well prepared car.

Mark Donohue would be proud!

It really is an amazing accomplishment making this kind of HP, pump gas, thermal management, and totally drivable. Crazy good. All on a production block and oiling system, as well.

Does the E67 ECU have any advantages over the E38 for this kind of application? Also interesting to note that you're running hybrid MAF/Speed Density - SD tuning on those ECUs is a PITA, at least with HP tuners, and I've found no discernable advantage in normally aspirated performance applications (the GM crate motor ECUs all run MAF-only as well). But it may well be that, at this HP level, that extra bit of fine transient control is important?