Bracket Talk
2 speed vs. 3 speed

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https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1347053186

July 09, 2018, 06:04 AM
Wallace Cleaver
2 speed vs. 3 speed
I'm used to running a powerglide in my FED, however, when I begin the door car build, I was told it might be in my best interest to look into a TH400 for the extra gear. I know the TH400 eats a ton of power so I'm concerned that will slow the car more than I'd like. I may use the car for some S/G stuff from time to time so would this play in your decision to go 2 speed?


Multi-time First round runner up extraordinaire
July 09, 2018, 06:28 AM
"The Bender"
What will the car weigh?


272" Spitzer
540 Chevy
The Blower Shop XR1
FTI XPM Series Converter
FTI Level 6 Powerglide
3.69@199
.916 60'

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July 09, 2018, 06:58 AM
<DOTracer>
My car is quicker with the 3 speed.

I would say the decision will come down to budget and what first gear ration you feel will best suit the combination.
July 09, 2018, 07:38 AM
Larry Woodfin
Wallace, give us some details about your build up. Weight, power, expected performance.


Larry Woodfin



July 09, 2018, 08:45 AM
markemark
If deciding to go th400 consider installing one that the brake works in both 1st and 2nd gear.

I’ve looked at several this year and have decided to use Hipsters new 22748-1A from ATD.
July 09, 2018, 11:40 AM
Curly1
On my Camaro at 2900 Lbs the car was faster and more consistent when I went to powerglide. It lost a little in the 60foot but made up for it later down track.

One other thing with the T-400 the car would often do big wheel stands and pop tires out of the beams for a red light. Powerglide calmed it down a lot with out hurting ET. T-400 was more fun to drive but went more rounds with the glide.


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July 09, 2018, 11:56 AM
BP758
Even with the weight the 400 is .05 quicker and with a better 3 speed... maybe a dime.
5 years ago ( Firebird)...We tested the Coan xlt against Hughes glide back to back same day (1 hour), it was .04-.05. Same speed, same converter. The glide first gear 1.80, 400 was 2.10. If my memory is correct right at 40 lbs diff.
You might consider a Pro Trans if you have the money.
2000 Firebird TS Ness car 2390 # 632 Cu In

Yes the glide is more consistent.


Raceless in California!
July 09, 2018, 11:59 AM
Lenny5160
I'd stick with the glide regardless of which performed better as far as ET.


Tony Leonard
July 09, 2018, 05:21 PM
Wallace Cleaver
Thanks guys. I dont have the new car in my possession yet so I can't answer well enough to be helpful.
If I were to guess, it should be around 2500#, will have my stack injected 470" that makes my 1700# fed run 8.40's in 6000'+ DA air. The new car has 4.10 gears and I'm not sure tire size yet.
However, I'll update once I have the car in my garage. Need to finish the season with my old heap first. Thank you!


Multi-time First round runner up extraordinaire
July 09, 2018, 06:26 PM
<DOTracer>
quote:
Originally posted by stk 758 BP!:
Even with the weight the 400 is .05 quicker and with a better 3 speed... maybe a dime.
5 years ago ( Firebird)...We tested the Coan xlt against Hughes glide back to back same day (1 hour), it was .04-.05. Same speed, same converter. The glide first gear 1.80, 400 was 2.10. If my memory is correct right at 40 lbs diff.
You might consider a Pro Trans if you have the money.
2000 Firebird TS Ness car 2390 # 632 Cu In

Yes the glide is more consistent.


I should have explained my comment further. I previously had a Rossler 1.80 terminator 5 glide and recently switched to a 2.10 Coan 400XLT, light weight, low drag, small drum th400. The 400xlt with the Reid case is 128 lbs where a stock th400 is 150 and the Reid case is somewhere around 10 to 15 lbs heavier than a stock case. The glide was 111 lbs. The 3 speed cost double what the glide was. I considered a Pro Flite but they are too fragile to be reliable.

I index race (8.50 at 3000 lbs) and the 3 speed ran similar 60's to the glide but was quicker to the 330', 660', 1000' and 1/4 mile, but lost mph. Probably lost 2 to 3 mph or so. Had to close the plate to keep the ET on the index after the switch.

That said, both setups can work just fine, it really personal preference. Most bracket guys will more than likely choose the glide.
July 09, 2018, 10:16 PM
AlkyIROC
I like my glide. Slightly less torque multiplication off the line with the 1.76 first gear compared to a 3 speed but with only 1 shift point, it increases consistency. When track conditions are very good, I can still put the car on the back bumper. I'd hate to see what it would do with a 3 speed and a lower first gear.

Downside of using a glide is that you're in a gear for a longer period of time so your rpm range in each gear is a little longer. If you need to keep your rpm in a smaller range while going down the track, then more gears should be used. I shift at 7400 and it only drops back to around 6400 after the shift.

You can also convert a glide to be high gear only. A high HP car should provide more than enough torque to get you moving and with no shift points, consistency should improve.

Another advantage of a glide is axle size. With less torque multiplication off the line, larger, heavier axles are not required. I run 31 spline Moser axles. When I installed them, I painted a line down the axles. Years later when I pulled them to fix a leak, the lines and splines were still straight. If I went with a 3 speed, I would need 33 or 35 spline axles because of the increased launch torque.


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Best ET: 9.029
Best MPH: 150.45