Torque converters

[ohnoitsjeff]

Many choices out there, If I dont plan on super charging or nitrous just the "typical" bolt-ons such as a bigger exaust, intake and head porting, what would be the stall speed of choice? www.brothersperformance.com (http://www.brothersperformance.com) offers 3 different ones for AOD mustangs, 2000 2400 and 3000 stall i believe. Another related issue...I assume the transmission in my 89 LSC is the same as in the mustangs. An earlier thread suggested I start with a more solid tranny, just looking for input on which route to take with it.

[pro-five-oh]

The transmission is the same AOD as the Mustang. I got a B&M 2000-2200 (they didn't specify an exact stall) converter from Pep Boys for my AOD and the car launches much quicker. I'd like to stay in the 2000-2500 range when you are running a stock cam. Higher lift cams and with high revving engines need more stall.

A tranny cooler and a shift kit is the next thing. Baumann engineering makes the best kit for AODs. I have heard that installing a shift kit on an older tranny will kill it sooner, but I have seen plenty of people do it and not complain. There is also a brass bushing retrofit for the throttle conncection which keeps the AOD's throttle cable firmly attached to the linkage...thus keeping equal line pressure and possibly saving the tranny if the cable slips.

Anything is at your own risk when dealing with an AOD. I got my tranny rebuilt when I added the converter/shift kit. I also went a step further and got racing clutches for 3rd gear and a kevlar OD belt. AOD overkill is good in my book. Hopefully some more opinions will filter in on modifying an AOD with 85k on the clock. Good luck!

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pro-five-oh
http://www.geocities.com/motorcity/street/3545/cougarview.jpg
88 Cougar XR-7 5.0 HO
15.0@93mph, 3740lbs
83 Continental 5.0 LO
My Mark VII Page (http://www.geocities.com/motorcity/street/3545/mark.html)

[This message has been edited by pro-five-oh (edited February 15, 2001).]

[This message has been edited by pro-five-oh (edited February 15, 2001).]

[90LSCdrvr]

My opinion is that it's always nice to start fresh. If can possible afford it, rebuild that sucker with heavy duty type parts. If you can't, then keep the filter and fluid fresh, throw a shift kit in it, drive it, then do the convertor shuffle. Just remember the higher the stall, the more heat is generated, the more you'll need a better trans cooler.

Popular opinion would apear to be to go with a Precision Industries (sp?) Converter, but they are not cheap (&600 and up, I beleive).

Good Luck

[Lscman]

Jeff, an original 10 year old AOD with 85K on it will be near death. Age and mileage both have a negative effect on seal and clutch life. Old, hardened and varnished clutches tend to slip when the fluid is changed or more HP is applied. You might be able to nurse it to 120K miles, but I would not remove it to install a higher stall converter without rebuilding it. The old, hardened converter seal will begin leaking when a new converter is installed anyway. The tranny should be rebuilt using a complete premium clutch & seal performance rebuild kit that will cost $125. Also, the 2000 stall converters Pro suggests are more than adequate for what you're suggesting and they'll cost about $100. Any higher and the car will feel like a 2 speed and the stall speed will be above the shift point at light to mid throttle. A $600 PI converter is for a 400+ HP trailered drag car. The cheapo remanufactured, brazed fan 2000 stall converters are good for 350 HP max and are stronger than stock. They will feel identical to a PI converter in a street car and you'll be amazed how the extra 400-500 RPM of stall speed feels. You'll think your car is on ice the first time you hit the gas. After a couple weeks, you'll hardly notice..except the car is in it's powerband on launch. Don Walsh of Ford SVO has stated a 2000 stall converter does more for acceleration than the $800 wide ratio gear kit and I agree. A good independent tranny shop will charge about $600 to remove, rebuild with top quality kit and reinstall and test. You may need to give them the correct converter of your choice and an A-Servo assy. I'd suggest driving the car for a while to break in the rebuild before you decide what shift kit mods to make. You can not predict how firmly the unit will shift or the shift RPM points after a total rebuild. You need this baseline info to decide what Baumann mods to make. If you go too far, the valve body will need replaced for $400. You can NOT undo a shift kit install, unless you replace the whole, expensive valve body.

[This message has been edited by Lscman (edited February 15, 2001).]

[90LSC]

Mr. Pro-Five-O, do you recall the price and or part number for that B&M convertor? I was already toying with the idea of making the switch but this thread pushed me to the edge.

[FLA-LSCSE]

. A $600 PI converter is for a 400+ HP trailered drag car
Rick I take offense to that and say that is total BS your throwing out at this guy!I have the PI converter and have since my car was stock and it was a TREMENDOUS improvement over the stocker.Also my car has NEVER been on a trailer!I drive it everywhere as my daily driver and still knock down 21 mpg on the hwy.My car is now heavily modified with the same converter and I still think it is the best on the market bar none!
Dave
12.87@106.00 1.77 60'
Moderator of Nitrous (http://www.fordvschevy.com/cgi-bin/forumdisplay.cgi?action=topics&forum=Nitrous+Oxide&number=21) forum at FordvsChevy.com (http://www.fordvschevy.com)
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[This message has been edited by FLA-LSCSE (edited February 16, 2001).]

[pro-five-oh]

Oooooh no, don't remind me what that tranny costed!!! http://www.lincolnsonline.com/ubb/frown.gif

Guys, I took a bath on my AOD rebuild. The B&M unit I got was about $200, and the guys from Pep Boys just looked it up in a catalog and ordered it for me. Total parts on my AOD was about $900. I got that hi-perf rebuild kit, an "A" servo, and a new 3rd gear drum. Labor was another $800, and that was one of the cheaper bids I got for it.

I also put a NEW 3-core radiator from Pep Boys ($98) and 8x11" tranny cooler at the same time. That whole job costed me close to $2000, but I was in a rush to get the car fixed and I was busy with school. If you spend your time wisely you can save a few hundred off of that and still get what I got.

[Lscman]

FLA-LSCSE,

I fully agree with absolutely everything you said, aside from the unnecessary B.S. statement. I understand why you feel differently, but there is really no good reason to make such a comment, just because I recommended a certain piece of hardware. If you disagree, how about limiting your response to technical opinion and avoid the personal attacks. Readers can decide what's good info.

>>In my opinion also, the PI converters are the best on the market for the AOD "bar none" and a TREMENDOUS improvement over the stocker. They are fine for daily drivers and will knock down 21 MPG on the highway too. Hmmm, I sound like you so far...

>>So why am I not recommending a PI to Jeff?? Because for a measily $100, the higher stall brazing-reinforced reman converters provide the EXACTLY the same performance characteristics for about 1/6 the price and they are strong enough for 350 HP street cars. The exceptional PI converter durability is only necessary in cars with huge power that can warp the thinner fins of typical OEM/factory and heavy duty brazed converters and cause catastrophic transmission failure. Installing a bulletproof PI converter in a 275 HP Mark VII with a couple bolt-on's is like installing a 450 lb ft Richmond 5 speed and centerforce dual disk racing clutch in a near stock T-5 Mustang. Your heavy car runs 12's and is undoubtedly pushing 400 HP. The PI is almost mandatory in your application, but IMHO it is a total waste of money for cars like Jeff's.

>>For general info......I have heard from several sources that the B&M 2000-2200 stall AOD converters are simply re-boxed Recon Brand high stall converters available from transmission shops/jobbers for as little as $85. That's what I chose and it's lasted 80K abusive miles so far.

[This message has been edited by Lscman (edited February 20, 2001).]

[FLA-LSCSE]

Originally posted by Lscman:
FLA-LSCSE,

I fully agree with absolutely everything you said, aside from the unnecessary B.S. statement. I understand why you feel differently, but there is really no good reason to make such a comment, just because I recommended a certain piece of hardware. If you disagree, how about limiting your response to technical opinion and avoid the personal attacks. Readers can decide what's good info.

>>For general info......I have heard from several sources that the B&M 2000-2200 stall AOD converters are simply re-boxed Recon Brand high stall converters available from transmission shops/jobbers for as little as $85. That's what I chose and it's lasted 80K abusive miles so far.

[This message has been edited by Lscman (edited February 20, 2001).]

While my reply was biased I did not intend for it to be a "personal attack" on you.I just don't think that the PI is a "race only piece for 400+hp trailered drag cars".I do not want to turn this into a flame topic so I will refrain from furter comments in here. As far as the B&M you have been lucky.
I have seen no less than 3 catastrophic failures related to using the B&M piece. One thing I would highly recommend to anyone who is considering a converter purchase is to stay with a lockup version unless it is going to be used primarily for racing.

------------------
12.87@106.00 1.77 60'
Moderator of Nitrous (http://www.fordvschevy.com/cgi-bin/forumdisplay.cgi?action=topics&forum=Nitrous+Oxide&number=21) forum at FordvsChevy.com (http://www.fordvschevy.com)
http://tnmotorsports.com/Images/FLA-LSCSE.jpg (http://www.tnmotorsports.com/lsc.htm)

[This message has been edited by FLA-LSCSE (edited February 21, 2001).]

[stinkin' Lincoln]

GENERALLY, the more you spend on a converter, the better it is...

the better it is, the more efficient it is at multiplying torque and actually applying it to the rear wheels...

I had a B&M 2800 lockup, and it worked alright, but compared to driving some cars w/ higher quality converters, it wasn't laying down the torque and converting the slippage to power... it was converting the slippage to heat inside the tranny...

was it quicker than stock? yes

was it as efficient as a higher priced converter? no

would I recomend one? if you're bound by an ultra-tight budget? sure, but if you can afford a higher quality converter, DO IT!!!!! it will pay for itself in gas mileage and wear and tear on the tranny and the actual amount of "life" in the converter in the long run.

Forrest

[Lscman]

I agree with both of you. A 2200 stall $85 Recon converter will have slightly less efficiency than a theoretically equivalent state-of-the-art 2200 stall $600 PI converter. How much...no mfr is willing to say in clear, comparable numbers. A converter fluid dynamics and hydraulics expert will tell you the difference is tiny, but enough for the mfrs to brag about it without providing comparison data. To be clear though, a 2600 stall PI converter will have far less efficiency below 2600 RPM but more torque multiplication (slip) than the stock converter or even the 2000 stall Recon. That is the distinction that should be made when comparing these two products. Torque multiplication and efficiency are totally different. A zero stall converter has 100% efficiency and a 7000 stall converter will have nearly 0% efficiency in a stock 5.0L. I think your negative experience with a B&M 2800 points out the limitations of a conventional design converter with such high stall speeds. When the stall speeds approach 3000, I believe an expensive, advanced variable stall design is almost mandatory for durability and to allow a reasonable flash speed for good driveability. Some 2600+ stall cheapo conventional converters have sections of fins removed to raise the stall rate.
This is a mickey mouse method that actually reduces torque capacity by placing a greater burden on remaining fins. However, I do not feel such a high stall speed is a good choice for a near-stock daily driver. The stock 5.0L HO converter stall speed is approximately 1600 in it's intended application. The lower stall cheapo aftermarket converters (1800 to 2200) with brazed-reinforced fins are stronger than stock and well matched to near-stock cars. In fact, they are virtually identical in construction to 60's vintage high torque big block converters that had similar slip rates from the factory. I did not intend to imply that the PI converter is only "suitable" for trailered race cars. I meant they were only "necessary" hardware for vehicles like trailered race cars. If you have a big budget or you're planning substantial future HP upgrades, a high stall PI is a wise investment.

[This message has been edited by Lscman (edited February 22, 2001).]

[stinkin' Lincoln]

you make good points...

if you're just going to buy a 2200 converter, you can cheap out, but the Mark VII's really want/need a 2600-2800 converter...

they are heavy as hell, and their torque peak is right around 3000rpm... so letting them come out of the hole very close to that rpm is VERY beneficial!

yes, the higher the stall, the more you gotta pay to get it done "right"...

that 2800 I had felt like it was putting less torque to the ground at 2500rpm than my buddy's high $$$ 4500 converter!

when it comes to converters, the "best bang for the buck" usually has a direct relationship between "bang" and "buck"! http://www.lincolnsonline.com/ubb/smile.gif

Forrest