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Discussion Starter · #1 ·
whats the difference in "feel" going from a 1800 or a stock D5 converter to a 3k stall L/U converter? im saving for a 3k orange stripe w/anti-ballooning plates and want to know how it will act at part throtle, going in traffic, from a lite, boost hold ability, etc as opposed to my current 1800 stall converter. i can hold about 4-5 psi w/both pedals floored before i start to spin the 275-60-15 Radial T/A's. and this is after driving it for over an hour in the hottest part of the day and making "tuning runs".
 

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Well, a stock converter should stall around 2400 rather than the 1800 that you currently have in there. I am surprised it allows you the boost it does.

I don't much care for 3000 rpm stall 12" converters as the blades have to be bent to virtually a negative angle to get that much slip and they are very inefficient.

Not knowing what turbo you are running makes it hard to suggest a converter.


If running a stock to TE44, I would suggest a stock converter that will slip to 2400 or a modified one that will slip to 2600-2800. An anti-balloon plate is seldom needed on a 12" converter.

If you are runnning a 51 or larger, I would suggest a smaller diameter converter so the efficiency will be high. Lot's of us seem to have good luck with Bruce Toelle's 9/11 converter. Stall speed will depend upon turbo size.
 

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Discussion Starter · #3 ·
im running the stock turbo now and will be for a while. gonna add alky then a te-44 later on. i really have to stand on both pedals to build boost now b/c of the converter. what about a red stripe converter? should i get itwith or without ballooning plates? and can you explain the pros and cons of the different size converters? what size is a red stripe? what makes a 3K stalle converter so inefficient and what does the inefficiency affect? i have a tranny cooler if that helps anything.

TIA
 

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Discussion Starter · #4 ·
BTW, here is my current combo,

1987 Grand National

Mods: stock turbo, stock intercooler, cold air ind. w/ KN filter, 160 thermostat, no cat, MSD 50's, hotwired walbro 340, J.D. ECM, Red Armstrong spark plug wires, autometer boost, water, oil, and volt gauges, adj. fuel regulator, engine tie down strap, dump pipe, TB coolant bypass, passenger side valve cover breather, tranny cooler, and adj. WG. no times as of yet
 

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Ideally, a stock D5 converter would be the best and cheapest choice. If your current converter is only reaching 1800 rpm against the brake, then it appears that someone swapped converters before you bought the car.

So called red stripes or orange stripes are both 12" converters. Anti-balloon plates are largely a waste of money on 12" converters as they are not prone to ballooning.

To increase the stall in a converter, the internal fins are bent over so that they can spin to a higher rpm before sufficent torque is transferred to the input tranny shaft in order to move the car. In order to achieve 3000+ stall in a large diameter converter, the blades must be bent to such an angle that slippage continues to be a factor at higher rpms and the rpm applied to the tranny shaft might be 15% or more lower than the rpm applied to the converter shell at wide open throttle....

Smaller diameter converters do not require so much bending to achieve the intial stall and that permits higher efficiency of transfer at wot.

With a stock cam, stock or near stock turbo, stock heads, etc., the power output of the engine drops sharply around 4800 rpm. Therefore, one does not want to use a very high stall converter which would narrow the usable rpm band.

Guys run into the mid 11s, and sometimes quicker, with stock converters that stall around 2400 when combined with small turbos like the 44/49. Using much looser converters tend to just blow the tires away and help you run out of rpm before you hit the finish line.

I would suggest you stick with no more than a 2600-2800 rpm 12" converter which can be purchased from most vendors....some may call it a red stripe, others may just call it a 2800 rpm converter. The red stripe/orange stripe designation originally came from the converters the GSCA was selling, I believe. Nothing magic about them.

You might get lucky and find a good converter from someone that bought a high stall converter to match their new big turbo that would not spool with the lower stall converter....


Remember that a converter that is rated at 2800 rpm may stall to 3000 rpm in a high hp car and only 2500 in a low powered car....stall ratings are very approximate.
 

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Discussion Starter · #6 ·
okay i see. i think ill go with a regular red stripe 2800 stall converter due to limited funds


thanks

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1987 Grand National

Mods: stock turbo, stock intercooler, cold air ind. w/ KN filter, 160 thermostat, no cat, MSD 50's, hotwired walbro 340, J.D. ECM, Red Armstrong spark plug wires, autometer boost, water, oil, and volt gauges, adj. fuel regulator, engine tie down strap, dump pipe, TB coolant bypass, passenger side valve cover breather, tranny cooler, and adj. WG. no times as of yet
 

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Don't think you can go wrong there...may need some stickier tires but that is a nice problem to have.
 
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