Gang:

First for the "bonus". Driving over to the track (Edgewater in Cincy) yesterday from my pad on the far eastern side of the metro area, I spotted two "interesting looking" vehicles pulled off the side of I-275 around the Montgomery road exit. As I approached, I identified a totally tricked-out SVT focus (like you would see in Mischief 3000, or something), with something white and weird broken down in front of it. The doors were open and (hood) up on the white cadaver, and the inside of the driver's door (only thing visible) was very much not identifiable.

Anyway, as I passed, I saw that the white vehicle was indeed a GT40. A glance in the rear view after I had passed revealed not only a dead GT40, but a dead NEW GT40 (Ford GT)! It was the white one with the blue stripes that you have probably seen in several magazines. Holy crap!

Well' that was a day-maker, but NOTHING compared to what was pulled over on the shoulder about a mile up the road. How's this sound?

Another tricked-out SVT Focus, followed by...
ANOTHER NEW GT (the red one), followed by...
ANOTHER NEW GT (the blue one), followed by...
ANOTHER NEW GT (the gray one), followed by...
ANOTHER NEW GT (the black one), followed by...
A red Ferrari 360 Modena, followed by...
Another tricked-out SVT Focus!

I'm guessing that this represents right about EVERY new GT in existence, give-or-take. Anybody know (allegedly) how many have been built? I'm guessing that this was some sort of media junket, but who knows? Maybe somebody on this board would know...

This was at around 12:40 PM, yesterday (Saturday, November 8).

How's that for a casual side-of-the-road sighting?

 

You are a lucky man

 

You should have stopped and offered to help. Maybe could have got a ride or drive in one.

 

Now for the obligatory "best ever" rave. Basically, if you live in the Midwest or Northeast and did'nt get to the track this weeked, you missed out. Yesterday in Cincy was BY FAR the best air I've seen since I got the 'Bolt in May 2000, and I run a lot. We were at 41 degrees F, very low humidity, no wind, and high pressure overhead.

For reference, I ran two weeks ago in similar conditions, but a bit warmer (around 60 degrees F). So the only difference, as far as conditions go, was around 20 degrees F. That outing, I managed best-ever times/speeds at every interval, to the tune of 1.969 / 13.266 / 102.61.

Anyway, my first pass yesterday, hot off the street (right from tech to the lanes) I busted a 1.988 / 12.924 / 106.21, and bettered the speed to 106.54 on a later pass.

Awesome. Simply awesome, and that was on F1's, FULL weight, stock ride height, blah blah blah. My mods are very minimal - almost nothing at all, really. Disclosure not forthcoming for warranty reasons.

Here's the questions I have...

I've run the truck with this setup a jillion passes, under every sort of atmospheric condition you can imagine, I have a very good grip on the "performance vs air" curve from about 60 to 90 degrees F. For example, it traps at around 100-101 at 90 degrees, and as high as 102-103 at 60 degrees. As for ET, figure around 13.6 or so at 90 degrees, down to around 13.2 at 60.

What in the world would explain picking up a consistent 3 tenths and all of 4 MPH (!) with the slightly less than 20 degrees of temperature to the good that I ran in yesterday? That sort of performance increase, relative to what I have seen, is just insane!

Perhaps this could be the effect of the extra added-back timing (2 degrees?) due to the intake temperatures being below 60 degrees F? I have a Cyberdyne gauge at the throat of the MAF and was reading 50 degrees F or so, which is the first time I've ran with intake temperatures under 70 degrees F. Can my 'Bolt be THAT hungry for timing?

Also, I have a Cyberdyne on the IC fluid. Even hot-lapping, that circuit never got above 60 degrees F, which is also a good 20 degree improvement over typical.

It's just that the MPH improvement seems insane. Another point of reference is:

Bone stock, in good air, it trapped at 99.5 MPH or so.

An extra 5 PSI of boost, a much freer-flowing airbox, a crisper-shifting tranny, new plugs, and some potential (mild) ECU shenanigans brught the good-air trap speed up to 102.5 MPH.

The EXACT same state of tune, but in GREAT air, yielded trap speeds above 106.5 MPH. Weird.

Any thoughts, other than "this post is WAAAAY too long"?

 

I would have stopped and ask if they needed help then you could have been up close and in person with it.

 

Congrats! Great time, and 106 is great times for minimal mods.

Positive displacement superchargers are very suseptible to atmospheric changes. An air pump feeding an air pump, with a linear ratio determined by the pulleys. If the air is good, the blower makes it very good. If it is bad, it makes it very bad. Normal sea level atmospheric pressure is 14.7psi. If you are running 14.7 psi boost, you are magnifying the air density by a factor of 2. So while everyone else has good air, we have good air times two. Likewise, when we have hot air, it's effect on hp loss is doubled.
This effect is minimized on turbos, because their boost is limited by a wastegate or blowoff valve, and their rpm is not mechanically linked to the engine RPM. That's why you'll see them running events like Pikes Peak, where they maintain a better powerband, even toward the top of the climb.

Of course, this is ignoring all the other factors you mentioned, such as more timing, cooler ambient IC temps, etc. They also have a large effect on the overall power output.

 

LOCO:

Tooling around in 60 degree weather, I see around 13 PSI boost, maximum. This usually peaks at the top of 2nd gear (80 MPH or so), right before the shift. I have a very trick one-off ram air setup, and am curious to see what sort of boost I could get at the top of FOURTH gear.

Anyway, I saw slightly over 14 PSI yesterday. That's an air density thing, but how could one PSI give 4 MPH, whereas the previous 5 PSi yielded only 2-3 MPH?

I agree that you are on track - it's the combination of air density, intake temperature, IC temperature, timing add-back, and whatever. However, I was not expecting the 40 RWHP extra I saw yesterday from just 17-19 degrees F. No doubt I was pushing 400+ RWHP to run 107 MPH in the quarter on F1's with a 60-foot around 2.0 seconds.

 

CONGRATS ON THE ET Silver-Y2K-SVT
And Holy Moly on the GT's and SVT's

As for air, man oh man does it make a difference.
I wish I went to Cecil yesterday, that 40 somewhat degree air
was bringing home some AWESOME ET's for everyone.
A lightning can run 3/10ths to 1/2 second better on a cold day with low humidity, thats why we hope for on race day.

CONGRATS AGAIN

 

HOLY ****!!!!! Man you need to carry a camera in your truck at all times. Its an unwritten rule.

 

Anybody else see such ridiculous improvements in this weekend's air?

 

Ahh, I see those Ford GT's all over the place, no biggie. I saw two at the grocery store yesterday! J/K

Actually, I did see one the other day in Boston at the Bayside Expo center, new car show....so you didn't see them "all!" I know one was personally assembled for Bill Ford, so I'll bet that one isn't out cruising the streets.