flash convertor?

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7demon2

7demon2

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i saw in a thread recently a statement about a flash convertor. i have never heard of this type before. exactly what is a flash convertor? is this a better type or not . i see most don't state if it is a flash type or not. how do you know if it is? is there some external difference? i saw by chance comp cams makes flash convertors. they only offered up that they are more efficent at highway speeds......ok transmission guys lets here some knowledge! :thumbup:
 
usualy when people talk about flash and converters they talk about the rpm the engine will se when you realy mash the throtle from a standing still.
 
My new dyanmic will 'Flash' at 3800rpm but only really slip to about 2,800rpm under casual driving. Meaning if i'm sitting at the tree (strip) and revving to whatever rpm it seems to like...say 1,500rpm and NAIL it at 'green' it will let the motor wind to 3,800rpm before moving the car. Sorta like driving a nail with a hammer. A say stock converter (usually 2,000ish rpm stall) is like tapping on the end of a nail with a hammer....will take forever to get the job done, right? A higher stall will be like winding up and driving it in with one blow. Theres a term for it to be able to do that, but still maintain highly streetable charateristics such. It's known as a 'tight' converter meaning it doesn't slip much under regular driving, and it being a high quality converter will do that, and be able to flash at 3,800rpm for me without worrying about converter slip at cruising speeds. Hope that helps/makes sense lol
 
ok goody i can understand the "flash" aspect of the convertor. that is a good answer. i am still a little unclear on the normal driving aspect of it. why would this type of convertor be more efficent on the highway verses a regular convertor?
 
7demon2 said:
ok goody i can understand the "flash" aspect of the convertor. that is a good answer. i am still a little unclear on the normal driving aspect of it. why would this type of convertor be more efficent on the highway verses a regular convertor?
Click to expand...


When a regular converter do you mean stock? My converter that will 'flash' at 3,800 from a dead stop, will cruise down the freeway like it were a 2,800rpm stall converter (which with 3.91s...2,800rpm is nothin MPH wise cruising down the road.) Lovely aspect of a quality made converter.

Found this little explaination of the two, hope this elaborates on what i said earlier in some way.

In a car, true stall is the maximum engine rpm attained with the transmission in gear, the brakes locked, and the throttle opened to the highest rpm possible. But achieving this ultimate stall speed in the vehicle is often difficult because frequently the brakes are not able to hold the power transmitted through First gear and the axle ratio to the drive wheels. Transmissions equipped with a transbrake can reach a converter’s true stall because of the ability to lock the transmission up internally by engaging two gears simultaneously.

Flash stall is the maximum amount of stall the engine obtains from a full-throttle launch at a complete stop with no brakes applied and is higher in rpm than the stall speed created with the brakes applied.
Click to expand...
 
i understand the "flash " aspects of the convertor. what i mean is why is the "flash" convertor supposed to be more efficent at highway speeds than a regular higher than stock convertor (say b&m holeshot , or any other brand) from what i have read the "flash" convertors are supposed to be better for both stall at launch and better for driving down the highway than the other brands of "non stock" convertors
 
hold on i think i may understand this now. lets say the flash convertor is a 3000 flash. what you are saying is that this will work like it is a 3000 stall convertor but cruise as if it were a much smaller convertor...am i right on this?
 
Aftermarket converters designed with higher stalls than stock have more efficent fines inside the converter for fluid transfer into the tranny. This makes them more efficent at higher speeds. However, the higher speeds needed to get the full bennifit of it's increase efficeny (sp) is pretty high and because it is designed to apply max. amount of fluid transfer at the big end of the 1/4.

Unless you plan to travel at high RPM's, a stock converter will do for the Hwy.
A light stall converter for a mild engine will get you off the line faster, but may have you suffer at cruise. Exceeding cruise (Lets just say 55 mph) to get into the converters most effective power transfer area (Again, lets just say 75 mph) is where the bennifit becomes (Possibly) apparent.

Engine combo dependent;
A converter with 2000 stall may flash @ 2700
The flash point is allways higher than the rated stall.
Consider the flash point a point where the converter has full power engaugement. The point where the engine and trans are working as close as one unit as possible. No slippage.
The best race converters exceed a 90% rate of non-slippage. Meaning the engine makes one full revolution and the tranny is making 90% of that revolution.
(This is also why manual trans cars can use a deeper rear gear and if you can shift the manual trans like no bodys bizzness, be faster than a auto. It was that way for years in the earlie days when converters were not so effcient and shifting was slow. Times have changed and it's hard, if not really impossible to find a person that can shift a manual better than a preped auto)
 
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