Hughes torque converters???

[sdkid]

I found a 2500 stall on racing junk. The price is right. I want to use it in my street/strip car. In the summit catalog they are described as a street rod converter. Can anyone tell me if it will hold up to some strip abuse.

[bloertcher]

Hughes is top notch stuff,I'd be more worried about the history than the brand.If it was on a tranny that got trashed,it can send a bunch of debris through your good tranny and destroy it.

[trkklr77]

i have the gm25 aka 2500 stall and it hookes up pretty soon. i dont think its any where near 2500.

[Rick Mills]

Originally Posted by bloertcher

Hughes is top notch stuff,I'd be more worried about the history than the brand.If it was on a tranny that got trashed,it can send a bunch of debris through your good tranny and destroy it.

That "good deal" could be costly.

[rage'nrat638]

yup.. i launched my coan converter and sent aluminum thru every thing. i had to flush all the lines replace the oil cooler and have the trans completely gone thru

[sdkid]

Yeah, I decided against it. A new one is $225 from summit. I'm not sure what I'll do at this point.

[Bowtie67]

I think a lot of people go a little overboard on stall converters, I did some searches on the internet for reasons and actual information from anywhere other than people that sell them or from people that think they know them. I see people all the time wanting to put a stall converter behind a moderately built engine and they dont need it. Example: A person has a 350/350hp engine, rpm peaks at 5500rpm, Peak Tq is 2600RPM (probally less) (You should actually put your vehicle on a dyno and find exactly where it is) According to the information below and several other sights I would want to use a Stall Converter 300-500rpm less than peak Tourque that puts me in the 2100 - 2300 stall range. Stock factory converters are usually between 1800-2000RPM and depending how much tuorque is applied they might stall as high as 3000RPM. So do you really need one? Your buddy will say yes, the salesman at Jegs, Summit, etc will 98% of the time will say yes. To really determine if you need one.

1. Get on the Dyno, You think it's to expensive? Usually $50 for a couple of runs and minor tuning, this will tell you exactly where your peak TQ is and if this guy is experienced with tuning and racing he will be able to tell you if you need a stall converter. It's far cheaper than wasting $250 on the wrong Tourque Converter that will only hurt your performance as well as getting even worse fuel econmy.

2. Can you smoke the tires real easy without reving it up and dropping it in gear? You dont need one, perhaps you have an open differential and only one tire spins, get a posi (better money spent) If you can spin the tires easily with road tires think about a set of DOT drag radials. If the vehicle is a combo street/strip and more for strret use then generally if your overall very happy with street performance you probally don't need one.

3. If the vehicle is a dog from a dead stop and doesnt really pickup untill your hitting the higher RPM's, you need a stall converter, or if the vehicle is overlly lazy through the entire range your gearing may be too high or maybe you just don't have the overall power you think you have.

My best advise is #1, I have a friend that owns a dyno shop, everytime I see him he tells me about people that bring their vehicles in after having them adding all these goodies to the engine (cams, headers, carbs, free flowing exhaust, etc. etc, etc.) and they think there putting out 450HP and after they dyno run their only putting out around 250HP at the rear wheels. If you are going to stay running street tires and you have no problem smoking the tires just off idle to having a stall of 2500 sittng at the lights reving your motor at 3000+RPM and then punching it, the tires are just going to sit there smoke.

http://www.kennedysdynotune.com/Torq...ter%20Tech.htm

Stall Speed and the "K" Factor
Stall refers to the maximum speed a the motor can achieve against the converter when the turbine is locked and prevented from rotating. The rpm achieved (stall speed) will be a function of the engine torque and the converter design. In general, the higher the stall, the less efficient the converter is at high speed. So why would you want a high stall converter? To allow the engine to get into the meat of the power band quicker. A converter optimized for drag racing will have a stall speed much higher than a street converter. Allowing the engine to get into the power band quickly more than compensates for the disadvantage of lower efficiency. On a street car, the penalty in gas mileage and heat generated by a high stall converter favors a lower stall. Also, a high stall can be annoying to drive on the street because it degrades throttle response. When you stab the gas, there is a delay while the engine revs before the car starts to accelerate. To illustrate how this works, there can be up to 0.5sec or more improvement in 1/4 miles times by switching to a high stall converter. The improvement all comes in the first part of the run, and interestingly, trap speeds may decrease due to the inefficiency of the higher stall converter at high speeds.

For a street/strip car, converter stall is a compromise. For example, a given combo may need a 4,500-5,000rpm stall for the best 1/4 mile times but be annoying on the street due to excessive "slippage" but a converter which stalls at 3,000-3,500 will allow tolerable street driving without too much effect on the 1/4 mile performance. Stock converters typically stall in the 1,500-2,000rpm range. Of course, what is tolerable to one person may not be to another and vice versa. To get a converter that stalls at the right speed for your application, you need to speak to the converter manufacturer. For best drag strip results, we like to see a converter that stalls ~300-500rpm below peak torque.

Labeling a converter as having a specific stall without reference to the motor it is behind is misleading and naive. That stock converter, which stalls at ~1,500rpm behind a stock motor, might stall at 3,000rpm or more behind a blown big block, if it didn't blow up first! To elaborate a bit: stall speed is not just a function of the converter. It is also a function of engine torque. This can be relatively easily described by defining the "K" factor. K is simply the constant in the equation K = rpm/sqrt{torque}. The equation describes the observed behavior of the converter behind a specific engine. What this allows us to do is determine what the stall speed of a given converter will be if we put it behind a different engine.

For example, if a motor has 400 ft-lbs. of torque and stalls a particular converter at 3,000rpm, K = 3,000/sqrt{400} = 150. Since we know K = 150, we can predict the new stall speed if torque is increased to say 500 ft-lbs by rearranging the equation to rpm = K*sqrt{torque}. In this case, the new stall would be rpm = 150*sqrt{500} = 3350. This formula isn't perfect. It won't work if the engines have wildly different torque curve, for example. And it won't tell if a particular converter will hold together under markedly increased torque. But it gives a decent ballpark estimate and serves to illustrate a basic aspect of torque converter function. For most street and street/strip, you probably want a stall in the 2,500-3,500rpm range. But do not buy an off the shelf converter thinking it will give you the advertised stall unless it has been proven to do so on an identical setup. Speak to the manufacturer first to be sure you are getting what you need for your particular combo.

[cableguy0]

the main reason for going with aftermarket converters in strength. the stock converters do not hold up to very much abuse. my tci converter has been through 3 transmissions all of which i shattered other hard parts. one time broke the case the converter still is fine. its a 2500 stall which i do need to make driving tolerable with the power band. most stock converters stall wayy under 2k rpm. 1800 is considered high stall stock for a th350 which is actually just using a th400 on the th350 but they do not hold up to any abuse.buying a used converter that you have no clue on the history is a bad idea because you just never know. its impossible to know the condition of a converter without cutting the welds and cracking it open.my advice is to get a tci converter around the stall your looking for and make sure it has an antiballooning plate for nitrous. even if you arent running nitrous it will strengthen the converter a ton and make it live a lot longer while being abused

[70c10]

I took cableguy's advice on the anti-ballooning plates even though I don't plan to run nitrous. I figured it's extra insurance. I bought a 10" converter last year off ebay from Redneck Performance in Texas . I paid about $159 delivered and it stalls at 2500. All of their verters come with the plates and they are nice pieces. Here is the one I got: http://cgi.ebay.com/ebaymotors/REDNE...QQcmdZViewItem
The price has jumped some but look at their feedback!

[martinkh]

I am thinking of having my th350 rebuilt for now, rather than jumping to an upgrade. If I was running a mild 383, mild 400, with 4:10's, 35 inch tires, would something like the TCI maximizer with a 1200rpm stall hurt me or help me in technical off road work? I would think I need low stall, so that I get better low speed response and "engine braking".