FYI FORD MustangSteve's Ford Mustang Forum / AOD

**Posted by Brents65** 11/14/2024 7:33 AM

Well, it’s apart and I’m still going down the rabbit hole so why not switch to an overdrive trans? I see Summit and Jegs have AOD trans for about $1800. What would be a good torque converter stall speed for my set up? I’m not looking to pull the front tires off the ground necessarily but do want some performance. Thank you in advance for your advice!

**Posted by Bullet Bob** 11/14/2024 7:40 AM

I ran a 2800 in mine for years. Mostly stock 5.0, 3.55 gears, didn't find it to be weird in any way.

BB

**Posted by wsinsle** 11/14/2024 10:05 AM

You got the Mustang and have $1800 left to buy an AOD, you must of had a really good divorce lawyer.

**Posted by Brents65** 11/14/2024 10:11 AM

I actually got bent over and spanked. Not even a get ready kiss on the cheek! But I’m looking forward and keeping on keeping on!

**Posted by TKOPerformance** 11/14/2024 10:25 AM

The converter needs to be matched to the engine and rear gear and intended use. Cruise RPM and stall speed will determine whether or not a lockup converter is necessary.

**Posted by Raymond_B** 11/14/2024 10:45 AM

TKO is right, I would give Circle D a shout, go over your combo and see what they recommend. They are great to deal with and are located in Houston.

**Posted by Rufus68** 11/14/2024 11:14 AM

That is a good question. With my T5, my cruise RPM is 2000 +-200 (depending on cruise speed). What would the expected cruise RPM be for you with an AOD?

**Posted by Brents65** 11/14/2024 11:38 AM

I have a 3.70 gear and will be on the highway occasionally at about 70-75 so ideally would like to keep below 2500 rpm.

**Posted by Ron68** 11/14/2024 12:32 PM

351W, 4R70W, 2400 stall converter, 9" 3.25 rear end - cruise rpm at 60 is ~ 2000

**Posted by 6sally6** 11/14/2024 2:04 PM

Do they make a 2800+ stall converter that locks up ?! (just wondering!)
3.70:1 gear-in-the-rear might still sound pretty busy at 70+ MPH.......(butt then again... with a blower whining along you're not going for the 'quiet-cruiser' ride anyhow !)

I realize those rides with the 'Wuhhhh-Wuhhh-Wuhhh' blower surge go'in on is a sign of a combination that's not set up correctly BUTT............Man does it sound wicked cruis'in through the lot !!!
{Remember....Pitcherz....lotsa Pitcherz maybe a few videos when complete !}
6sal6

**Posted by TKOPerformance** 11/14/2024 3:55 PM

6sally6 wrote:
Do they make a 2800+ stall converter that locks up ?! (just wondering!)
3.70:1 gear-in-the-rear might still sound pretty busy at 70+ MPH.......(butt then again... with a blower whining along you're not going for the 'quiet-cruiser' ride anyhow !)

I realize those rides with the 'Wuhhhh-Wuhhh-Wuhhh' blower surge go'in on is a sign of a combination that's not set up correctly BUTT............Man does it sound wicked cruis'in through the lot !!!
{Remember....Pitcherz....lotsa Pitcherz maybe a few videos when complete !}
6sal6

Sure, but they get expensive because a car needing a high stall speed is a monster typically so the lockup parts need to be a lot stronger. That's why I asked, because a non lockup converter is cheaper. If your cruise speed is above the stall speed there's no need to run a lockup, because the converter is going to basically be locked up anyway. If you run a nonlockup and cruise at a lower RPM you create a lot of heat, and could kill the trans, because the converter is basically slipping all the time.

Here's a high stall lockup converter for an AOD.

https://www.summitracing.com/parts/ape-26401/make/ford

Keep in mind stall speed is a relative thing, which is why talking to the company you buy from is a good idea. Engine size, compression cam, rear gear, vehicle weight, etc. can all effect exactly where a converter stalls, so it may be listed as a 2,400 RPM stall, but that assumes a bunch of stuff. In your car it might stall lower or higher based on how far from those assumptions you are.

**Posted by Bullet Bob** 11/18/2024 11:14 AM

Keep in mind that the AOD converter is "locked up" in overdrive no matter what rpm its turning. In OD it is using the "outer" input shaft exclusively and that is solid to the TC shell. If I remember that keerectly.

**Posted by Brents65** 11/23/2024 5:57 PM

I reached out to Circle D and they recommend a non lock up 2800 stall converter. Do you guys know what is meant by a 9” converter or 12” converter? I’m pretty close to purchasing everything and want to be sure parts are right.

**Posted by TKOPerformance** 11/24/2024 6:31 AM

Brents65 wrote:
I reached out to Circle D and they recommend a non lock up 2800 stall converter. Do you guys know what is meant by a 9” converter or 12” converter? I’m pretty close to purchasing everything and want to be sure parts are right.

Yes, its literally the diameter of the converter. My understanding is higher stall converters tend to be smaller because its easier to get a higher stall out of a smaller diameter converter. Also, they are more race oriented, so moving the weight towards the center of the crank helps the engine rev more easily. I wouldn't think a 2,800 stall would be a 9" converter. Usually 9" converters are 3,000+ rpm stall.

**Posted by Brents65** 11/25/2024 5:42 PM

TKOPerformance wrote:
Brents65 wrote:
I reached out to Circle D and they recommend a non lock up 2800 stall converter. Do you guys know what is meant by a 9” converter or 12” converter? I’m pretty close to purchasing everything and want to be sure parts are right.
Yes, its literally the diameter of the converter. My understanding is higher stall converters tend to be smaller because its easier to get a higher stall out of a smaller diameter converter. Also, they are more race oriented, so moving the weight towards the center of the crank helps the engine rev more easily. I wouldn't think a 2,800 stall would be a 9" converter. Usually 9" converters are 3,000+ rpm stall.

thank you. I wound up buying a 9.5” non lock up converter and AOD. I just feel I will like it better for cruising with the extra gear. Thank you everyone for your input.

**Posted by Raymond_B** 11/25/2024 5:45 PM

Brents65 wrote:
TKOPerformance wrote:
Brents65 wrote:
I reached out to Circle D and they recommend a non lock up 2800 stall converter. Do you guys know what is meant by a 9” converter or 12” converter? I’m pretty close to purchasing everything and want to be sure parts are right.
Yes, its literally the diameter of the converter. My understanding is higher stall converters tend to be smaller because its easier to get a higher stall out of a smaller diameter converter. Also, they are more race oriented, so moving the weight towards the center of the crank helps the engine rev more easily. I wouldn't think a 2,800 stall would be a 9" converter. Usually 9" converters are 3,000+ rpm stall.

thank you. I wound up buying a 9.5” non lock up converter and AOD. I just feel I will like it better for cruising with the extra gear. Thank you everyone for your input.

That's awesome, you won't be disappointed with anything Circle D.