ATCO report 10/7

[YO-EL]

Good conditions made for an even more FRUSTRATING night, as I got 2 runs in 5, yes, thats FIVE hrs! :mad:

I was car #6 in the lanes at 5:00 PM..

First 4 pairs...... OIL DOWN...

OIL DOWN
OIL DOWN
OIL DOWN

Yep over 3 hrs before my 1st run. They said we'd get another time shot right away because they wanted to heat up the track for the Gamblers, but as usual, it didn't happen.

We got right in line, only to wait another 2.5 hrs before my 2nd & last run at 10:30PM.

First 3 Gamblers cars:
OIL DOWN
OIL DOWN
OIL DOWN

No tech in is making it difficult to go to Atco, when ANY car in ANY condition is allowed to run, although the OIL was SPEWING from what looked like good clean well kept cars too.

I think I'm done with this mid week stuff.
The days of getting there early and doing 6-8 hot lapped runs are over.

Looks like it will be private rentals from here on out.

Many guys are willing to pay the $150 for unlimited runs all day, no waiting, testing & tuning their cars, and having the ability to experiment with launches etc, try other peoples cars, without all the hassles that come with being part of a 400 car night.

I am one of them.
If anyone is interested, we will be putting together a private rental the 1st or 2nd WED of NOV.

Interested parties please contact me. We already have a group, but ATCO has increased the # of participants to 15, so some spaces are available.

[Al Betz]

I am interested in the private rental, but Wednesdays are tough.

Would it really be an all day thing or just a night thing?

I will not be able to make first Wednesday in Nov but I may be able to make the second Wednesday (11/12)

[REDGAR]

Ellis, crazy night.

I take it you did not run very well follwing the cleaups

[Richy]

Any Wed. is good for me.For private rentals,do they enforce the
safety stuff?Most likely I won't have a bar by then.

[YO-EL]

Al...

They only do it on WED, so whatever is available we'll book.
The track is ours from 9-5...

Edgar:
I ran .04 quicker & 2 mph faster with 3:42 gears; I am majorly disappointed with the investment. I want to hover on the 12.0 bubble, and I am roughly 12.1-12.2 in 50 degree conditions.
Was hoping for a little more. I'd like to be 12.0-12.1 in 60-70 degree weather.

I honestly believed the gears would give me at least .1 quicker ET.
.04 is something, but not what I wanted. Driveability is nice, but for .04, I could have lived with the 3:15's.
I do notice faster acceleration though.

Richy:
Not sure how stringent they're going to be with the under 12/roll cage etc.

One thing is that we will require all participants to use drag radials or slicks. No street tires.

[Rick and Arleen Ball]

Did your 60' times improve?
They should have.

[C5pilot]

El, I was reading your post on corvetteforum and realize your car is usually very consistant. But here are a few things to consider before you curse the 3.42's...

1. Have you been to the track with your 3.15's since your car was tuned?

2. How accurate is your new weather station going to be, most of your data was in the old one.

3. You claim there is a SOTP increase in acceleration, that has to amount to something. Perhaps shifts points can be tweaked further to get full potential.

4. Weather stations are nice but they are still estimates at best. What is the largest error you can remember recently... estimated ET vs actual ET? Remember, you're talking 6 hundreths off what you expected to see... and you've never logged your car into the new weather station in these lower temps.

There must be a chart somewhere that will give you actual ET's between gear ratios based on HP. Did you check the site I sent you with all the conversions? I'm not home right now so I can't look it up.

[REDGAR]

El, don't feel bad cause a I was not thrilled with the 3.42 to 4.10 upgrade myself.

.04 and 2 MPH does not jive. You know that bro. Each MPH should be close to .10

The one thing that I have learned after logging 550 or so time slips in my excel spreadsheet is that the more numbers I have the more questionable they all become.

Drag racing is not an exact science and I would never even count a .04 increase or decrease from a mod as measurable.

Look at time slips from each day race. While you are very consistent, I would bet you will more often than not see a time slip that is at least .04 off from others on the same day with no mod change.

Don't bum yourself out on the 3.42. If you truly picked up 2 MPH, you will see the ET difference eventually.

[REDGAR]

Oh yeah, two things on the Atco day.

1. If it is the Thanksgiving week, I plan to be home so I might be in too. (probably too late anyway)

2. Since it is a small group doing testing would they let us/you have an eliminator with 8 cars as well as the unlimited time trials. Best practice for me is bracket racing.

[YO-EL]

Joe, after the tuning, & proir to Thursday, I went to the track twice and was able to log in about 8 runs, so I feel pretty confident that I did lose the .04.

Before that, I added the Vararam, and was able to confirm a solid .06 drop in ET as well.

So with 3:42's and the Vararam, I am a consistent .1 quicker in ET.

Rick...

My 60' did get slightly better, however, I have run faster ET's, with the same 60 before, so as Edgar states, that brings up some questions ...

Edgar:
You comments are right on.... There's always questions.
I have seen guys say they were blown away, going to 4:10's, yet you didn't feel the same. Just like me, 3:42's are nice, quick acceleration etc., but I feel like I want more...

Maybe I'm getting used to how my car feels, and can only notice a dramatic difference. Not sure.

I have never run 113 mph. Its har for me to believe that I picked up 2 mph while only dropping .04 in ET.

That run was 113.15 mph ET was 12.125

On my all time best 12.02 run, MPH was 111.58.

At this point, its probably time for Al to chime in to interpert the wackiness! hahaha

[Mike Campbell]

El, it certainly sounds puzzling, but, I think a couple of things are happening. First, I run 111 to 113 mph all the time, but,if I pull a 1.9 sixty footer I'm really lucky. I think what's happening to you is that your 60' times are actually going to be harder to hold down, since your wheels are moving faster. Where you are gaining, with the 3:42's is in 2nd & 3rd gears....hence the higher mph. What you probably will find out is that your lower end traction is costing your ET's. As we talked about it before, give it a little more practice. I still think overall you should gain between .2 to .4 on a good day. I think we should consult "Professor Betz!" ;yn ;yn
He'll be able to give you real calculations and facts other than just all of our "guess-timations". ;bt

Saturday sounds like it's going to be okay weather and cool...60's
so we'll all have a chance to see if anything's getting better.

[YO-EL]

Mike:

I hear ya... BUT....

On the first run with hard 2000 launch & 1.75 60', I DID have wheel hop..

On the second run my normal 1700 launch & 1.72 60' I did not spin or hop, it was a solid hook, but the 12.125 ET was only .045 faster than the predicted 12.17.

I think 3:42's and a good 60' should give me more than .04.

With the 3:15's in these conditions my 60' was at best 1.72.
So using the same converter, the 60' should be the same, but with the increased gears & MPH I "thought" the ET gain would be more significant than .04.
However, you're right maybe more runs are needed.

And Joe, based on my #'s, I usually run within .01-.02 of the predicted ET, unless I spin.

[REDGAR]

El you predicter does not take into account wind.

For example, i have seen 120 mph and then 117 in successive runs. Tail wind bro. If it hurts MPH it hurts ET too.

It also does not take into account electronic adjustments you car makes for knock and temperature sensors. I really would not use it to measure gains from mods only activity for that day/track (remmber atco has more oxygen (trees) so will usually get you a MPH or 2 more than E-town).

Also you did vararam and gears and both should help your top end so that might explain why 2 mph and only .04 ET.

I wonder though, doesn't the rear affect your launch?

[YO-EL]

Not sure Edgar.

As with the 3:15's, it seems anything over 1500 puts me into spin.

First run where I had the 1.75 with hop, was a 2000 rpm launch.

Second run at 1500 rpm was a 1.72 hook.

I still believe something is still not right somewhere.

Shift recovery??? I don;t know.

Will be autotapping at some point soon.

Maybe that can shed some light.

[Al Betz]

Everything Edgar says is true. There are a lot a variables from day to day and run to run.

Having said that here is my take on this.

1. Some of the extra speed is coming from the VaraRam. It really starts to work at 80MPH and above, but there would not be much difference in launch than with the Vortex.

2. The 3:42 will get you through the gears faster and get you into the engine power band sooner. Essentially this gets you across the finish line at higher RPM (more power) so the speed should go up a bit from this too. In your case you should be crossing the stripe at about 400RPM higher than with the 3:15

3. Sad truth is that the extra torque you get with the 3.42 vs the 3.15 is peanuts compared to what you get from going to a higher stall speed converter. The difference between the gear ratios is about 8% i.e. 8% more torque to turn the tires. The flash stall on a 3000rpm stall converter probably provides 300+% more torque. That is one of the reasons why there is such a dramatic improvement in ET when you go to a higher stall speed converter. In a standard automatic the torque multiplication is typically 200% or more. So I am not overly surprised that your not seeing much difference at launch.

4. You may also be getting a little more wheelspin from that extra 8%.

My guess is that all your improved et is coming from 330' on. Take a look at a few similar et time slips from before and after and see if the ET for the last half of the run is where you are gaining the .04 seconds.


Bottom line is make more torque (horsepower) with the engine and let the converter multiply it by 3 for a harder launch. Oh by the way more power means you may need those ET Streets again.

[YO-EL]

Al...

I was told torque, gets you out of the gate, & HP keeps you going.

My Yank 3000 stall had a 2.0 STR, so a higher stall might create traction issues, therefore possibly moving to ET Streets.

If I didn't want to test the traction issues, as I have seen MANY guys run low to mid 11's with drag radials, wouldn't the answer be more HP?

As I understand it, if I can bump up the HP, torque would also move up, maybe not porportionally, but it would move up.

Some tuners have told me that would be the ticket. (HP only)
Like a cam only, rockers only, or a mild & streetable heads/cam package.

I am not sure what I should do, as I really don;t want to go full bore just yet, just want to be .1-.2 faster in ET, to be on that 12.0 bubble in 60-70 degree conditions, not the 12.3 where I'm at now..

[Al Betz]

Right El

Torque - HP it's all the same. Torque is force, Force applied over time and distance is (worK) HP.

Soooooooo.... Horsepower = (Torque)(RPM)/5252.

Engine dynos all measure torque and calculate horsepower.

And yes, torque gets you off the line. Engines usually make more torque at higher RPM so a higher stall speed converter does 2 things:
1. gets your engine to higher RPM faster (more slip)
2. Multiplies the torque more (the slip acts like a higher gear ratio)

If you want to keep your present Yank 3000 and not spin too much you should probably go for something that makes more power in the higher RPM range so your launch doesn't change too much but the added power comes in after you are off the line a bit. Like a 50 shot of NOS about 2 seconds into the run. :D
Hotter cam and/or better flowing heads will make more power in the upper RPM ranges, and I think you only need to make about 15-20 more RWHP to get what you want.