Automatic Transmissions

[kiwi belly tank]

Well John, maybe you might want to focus on where you want to go & not on where you don't. There are more reasons to keep it simple than over complicated!
  Sid.

[ggl205]

Sid, you are probably right. Time to deploy Occam?s Razor.

John

[JR529]

On the Waters roadster we run a Kilgore manual valve body T400 behind the 2JZ and use the ATFspeed adapter to mate them. The engine is turbocharged and we don't have any drop in boost over the shift. The car used to have a 4 speed in it. I personally would not give up the A/T for anything in the world. 265MPH in a traditional roadster on the salt and almost 230 at El Mirage in the dirt. between 1,000 HP and ~1,300 HP to the wheels depending on the class, fuel and boost. 

[ggl205]

That settles it, JR529. One cannot argue with success and my path is now clear.

Thank you, everyone who chimes in. The information was extremely valuable. What a tremendous resource landracing.com is.

John

[ggl205]

OK, now that the question of what transmission to use has been settled, the next question is what type of bell housing does SCTA find acceptable for a T400. I checked the 2020 rule book and it only addresses non automatic flywheels and clutches. Do automatic transmissions need a steel bell or will aftermarket bells like the cast aluminum J.W. unit be acceptable?

https://racewithjw.com/product/ultra-bell-big-block-chrysler-to-th400-th350/

John

[racergeo]

  Should be no worries, SFI approved

[kiwi belly tank]

It's been a while but from memory I believe the front pump bolt pattern on a 4L80 is different to a 400. If there's not an SFI housing for the 4L80 you can keep the stock one & build a custom shield over the top to SCTA spec. The trans needs a shield as well so rather than wrapping it in a blanket that keeps the heat in it could all be incorporated into one shield.
  Sid.     

[ggl205]

JR529, are you using a 3-speed T400 or the 4-speed 4L80?

John

[desotoman]

On the Waters roadster we run a Kilgore manual valve body T400 behind the 2JZ and use the ATFspeed adapter to mate them.

I don't understand the question to JR529 on which transmission they use?

Am I missing something?

Tom G. 

[ggl205]

The 4L80 is the T400 with an overdrive gear making it a 4-speed. Just trying to find out if they run the 3-speed or 4-speed version.

John

[kiwi belly tank]

The 4L80 is not a 400 with an OD. It has many similarities & internal components from the 400 but it is incorrect to call it a 400 with an O/D so don't confuse yourself there John. They are different animals.
  Sid.

[ggl205]

Sid, I am led to understand the 4L80 3-speed internals are identical to those in a T400. Is this incorrect?

John

[kiwi belly tank]

I've never rebuilt a 4L80 so I can't give you a blow by blow answer & I don't understand why that info is important to you!
The bellhousing & converter bolt up to the engine the same. The front pump & converter spout are different. The output shaft is the same 32 spline. You can put a short 400 extension housing on 4WD trans to make a short one & have to address the oiling port to the rear bearing. Early 4L80's have both the oil cooler lines at the front like a 400 & late ones have the feed at the front & the return at the back. Gear ratios are the same plus a .75 O/D. I built my own manual setup without a TCM but it's been a few years. I looked up what solenoids were powered in each gear & hooked up micro switches on the ratchet shifter to perform those functions then added a converter switch to the knob. You can buy a stand alone TCM if that backyard system is not for you.
 It's been a really long day, I'm wiring the liner & it has more redundant relays that one vehicle should have so my brain is fried.
  Sid.

[ggl205]

I sympathize with how difficult wiring can be. I have no natural abilities with wiring or electrical, for that matter. I am in the beginning stages of wiring an ECU to the engine and know this will be a long and challenging experience.

Sid, the only importance of my knowing if the Waters team uses a T400 or 4L80 is if they need the overdrive to get the mph. That?s it. If I can?t determine this, I will likely go with the 4L. If I don?t need the overdrive, then it won?t be used. The downside of doing it this way is carrying an extra 50 pounds and a longer transmission case.

John

[Stainless1]

Detour alert 
Sid... redundant relays??? are you adding failure points or concerned that the relays are not reliable enough that you are giving parallel paths.  I trust you are using the totally sealed Delphi relays... not those kinda sealed parts store ones.