Track Testing ATI's 8" TreeMaster Converter
(Article begins on the Tech, Tests & Installs page HERE)

For years (since I’ve owned the Dodge in 1995) I’ve used a 10” converter from Brand X that stalled at 4,900 with my combination. If I shallow-staged the Dodge, I was able to hit the tree well, but not great. A number of years ago I tried a 9” converter from Brand Y. The Dodge flew like a bat out of Hell. It immediately went from running 10.90s to 10.70s at over 2 mph faster, but it would not hit the tree to save its life. Testing on a .500 Pro tree, the best I could get out of it was an .080. Yes, the car was flying alright, flying right back to the trailer after 1st round every week. I took the 9” out, went back to the 10” inch and dealt with it.

Being that I don’t know the intricacies of torque converters, I consulted with some fellow racers who said my experience was no surprise, that the best-reacting converter for my application (a relatively heavy car, pure footbrake, low compression, pump gas) was a 10”, because it has the momentum to get the car moving quickly. "A smaller converter," said they, "would just not do it." Maybe you've heard this, maybe not, and while each car is different it sounded reasonable to me so I accepted it as fact.

Jump ahead to 2010. If you’re a regular visitor to The Dragtime News, you’ve no doubt noticed that ATI Performance Products has become a supporter. In addition, however, they've also become friends. I was on the phone with them recently and described my experience with the 9” and what I had been subsequently told. The conversation went something like this:

Me: “So let me ask you, I was told that a 10” converter is the only way to hit the tree with a heavy car in a footbrake application.”

ATI: “Where’d you get that? Our 8” TreeMaster is the converter of choice for many Stock Eliminator cars, will go 2-tenths quicker and 2 mph faster than your 10”, and will drill the tree.”

Me: “Drill the tree staged dead-shallow, on a .500 Pro tree?”

ATI: “We’re sure it’ll do everything you need it to do.”

I needed to see for myself. I filled out ATI's detailed questionnaire and spoke with a tech adviser. I ordered the converter, installed it and took it to the track. The results were amazing, and are documented below. Racers, there are companies out there whose claims are valid, and this proves it. If you see me at the track, feel free to speak with me about my experience. I cannot wait for the 2011 season thanks to my ATI 8” TreeMaster converter.

Below is a time slip from US13 Dragway, when the Dodge had the 10" converter; this was the first time-shot on Thursday.

DATE: September 16th, 2010 / 10" converter

TRACK: US13 Dragway, Delmar, DE

Temperature: 80°
Humidity: 72%
Barometer: 30.14"
Density Altitude: 2,258'
Wind: low head
Sky conditions: sunny
Launch RPM: 3500
Reaction: .027
60 ft.: 1.489
ET @ MPH: 10.957 @ 120.74

Notes: Staged dead-shallow.

That's my baseline run, and will be used to compare the ATI 8" TreeMaster.
After the Bracket Finals, I took the Dodge to STR Transmissions in Stillwater, NJ to swap out the 10" converter for the 8" ATI TreeMaster. Hey, New Jersey looks pretty nice, doesn't it?
We got the Dodge on the lift and ready for surgery.
This is Steve Gillan, owner of STR Transmissions. Steve's a racer himself and has decades of experience building racing transmissions
Steve's not some drop & swap kind of guy. He has tons of know-how and a real eye for detail, and if anything didn't look right he'd know.
It's so cute! This cuddly little ATI TreeMaster 8" converter has found a new home.

Steve installs the TreeMaster into my Torqueflite, and then measures clearances. This is an important step, as the depths are critical for transmission, converter and crankshaft health & happiness.

Dodge reassembled, engine running, fluid level checked. Time to load the car up and get to Englishtown for testing.
On the way to the track I was behind this thing. I have no idea what it is. No windows, only a door and an air conditioner. Just a place to keep the vampires cool.

On-Track Testing

Here are the time slips with the new 8" ATI TreeMaster: two at Englishtown, two at Island Dragway. What a brutal beast the Dodge is now, considering it's still just a low-compression, pump gas 440. The Englishtown testing was done on a .500 Pro tree at night. Therefore, I thought perhaps the Pro tree at night might be leading to quicker-than-reality reaction, so the next step was Island Dragway during the day, but that had no negative effect; the Dodge is still reacting like gangbusters, and is just charging all the way down the track.

DATE: September 29th, 2010 / 8" ATI TreeMaster

TRACK: Old Bridge Township Raceway Park

Temperature: 72°
Humidity: 75%
Barometer: 30.05"
Density Altitude: 1,587'
Wind: calm
Sky conditions: dark
Launch RPM: 3,200
Reaction: .006
60 ft.: 1.438
ET @ MPH: 10.622 @ 124.52

Notes: Staged dead shallow, .500 Pro tree.

DATE: September 29th, 2010 / 8" ATI TreeMaster

TRACK: Old Bridge Township Raceway Park

Temperature: 68°
Humidity: 91%
Barometer: 30.07"
Density Altitude: 1,383'
Wind: calm
Sky conditions: dark
Launch RPM: 3,200
Reaction: .000
60 ft.: 1.441
ET @ MPH: 10.642 @ 124.48

Notes: Staged dead shallow again, .500 Pro tree.

DATE: October 17th, 2010 / 8" ATI TreeMaster

TRACK: Island Dragway

Temperature: 59°
Humidity: 59%
Barometer: 29.51"
Density Altitude: 987'
Wind: low / medium tail
Sky conditions: sunny
Launch RPM: 3,200
Reaction: .004
60 ft.: 1.425
ET @ MPH: 10.603 @ 125.00

Notes: Staged dead-shallow, .500 Full tree.

DATE: October 17th, 2010 / 8" ATI TreeMaster

TRACK: Island Dragway

Temperature: 67°
Humidity: 47%
Barometer: 29.41"
Density Altitude: 1,691'
Wind: medium tail
Sky conditions: sunny
Launch RPM: 3,000
Reaction: .013
60 ft.: 1.430
ET @ MPH: 10.617 @ 125.03

Notes: Staged dead-shallow, .500 Full tree. Lowered the launch RPM by 200 to 3,000.

Summary: as you can see in the above time slips, the ETs with the 8" ATI TreeMaster converter were more than 2-tenths quicker than with the 10" (taking into account the wind and air temperature in the baseline run), and the reaction is killer. So much for the myth about not being able to hit the tree while footbraking with an 8" converter.

This photo shows the end result : the Dodge proudly wearing its new ATI TreeMaster stickers as I put it away for the winter, now ready and waiting for the 2011 season.

Sources:
ATI Performance Products, Baltimore, MD;
www.atiracing.com.
STR Transmissions, Stillwater, NJ; 973-579-2055 or on
Facebook.

UPDATE 11/7/2011: up until now I hadn't been back to US13 Dragway to see how the 8" Treemaster compared to the 10" converter at the same track. Below is a comparison.
US13 Dragway, September 16th, 2010; 10" converter.

DATE: September 16th, 2010 / 10" converter

TRACK: US13 Dragway, Delmar, DE

Temperature: 80°
Humidity: 72%
Barometer: 30.14"
Density Altitude: 2,258'
Wind: low head
Sky conditions: sunny
Launch RPM: 3500
Reaction: .027
60 ft.: 1.489
ET @ MPH: 10.957 @ 120.74

Notes: Staged dead-shallow.

US13 Dragway, September 21st, 2011; 8 " ATI TreeMaster converter.

DATE: September 21st, 2011 / 8" converter

TRACK: US13 Dragway, Delmar, DE

Temperature: 78°
Humidity: 91%
Barometer: 30.21"
Density Altitude: 2,121'
Wind: low head
Sky conditions: cloudy
Launch RPM: 3400
Reaction: .003
60 ft.: 1.470
ET @ MPH: 10.692 @ 124.32

Notes: Staged dead-shallow. Note the difference in humidity. I don't know about your car, but humidity kills the Dodge.

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Photos: The Dragtime News