Q&A With Joe Rivera At Pro Torque
CHP: What are some of the important factors in choosing the right converter?
JOE RIVERA:
I can answer that with three words: Combination, combination, and combination. Each combo is different, so the converter must be matched to the overall combination of the vehicle. Besides the common info we need, such as engine size and cam specs, one of the most important questions is the operating range of the camshaft. Because the operation range is actually a mathematical curve, the torque converter should be designed to operate as efficiently as possible throughout that curve.
CHP: On a race car, what is the most valuable tool used to determine how the torque converter is working?
JR:
For any kind of drag car, knowing the engine rpm over driveshaft rpm is critical. We recommend using some type of data-logging system, such as one of MSD Racepak's. These log the engine rpm and driveshaft rpm to show you, on a graph, how your converter is working. With this information, you may be able to compensate for tire spin by changing your launch rpm.
CHP: When someone is replacing a torque converter to achieve more stall speed, is there anything else they should consider?
JR:
Generally, if stall speed is increased on a given size converter, then the efficiency will decrease. So the best approach to increasing stall speed is to run a smaller torque converter. This way, the stall speed is increased and so is the efficiency.
CHP: Should the torque converter be considered part of the driveline package or the engine package?
JR:
The torque converter is definitely part of the engine package and needs to be matched to the engine's power curve. The torque converter will affect the engine's drivability more than just about any other combination.
Choosing And Sizing
For most street cars, an off-the-shelf torque converter is perfectly fine. For more dedicated performance cars, you can have one custom made. Either way, you'll need to make a solid evaluation of your engine and vehicle combination and your performance goals. Many cam manufacturers recommend stall speeds and rearend axle ratios so that optimal performance can be achieved with one of their cam grinds. On a mild street car with a mild camshaft, you may do well to select a converter that offers a few hundred rpm more stall speed to match the new cam's powerband. Remember too that if your engine is equipped with a long-duration camshaft, low-speed torque will suffer and even more stall speed will be needed to increase performance.
Tci 9 & 10-Inch Race Converters
*Pro X Turbo
*Able to handle 2,500-plus horsepower
*Designed for supercharged, multistage nitrous, and twin-turbo systems
*Handbuilt steel stator
*Forged mounting cover
*Furnace-brazed turbine and pump assembly
*HDT coating to help dissipate heat | 
Pro-X bolt together converter
*Enables trackside stall changes up to 400 rpm
*7075-T6 billet aluminum cover to eliminate ballooning
*Steel stator and billet sprag for strength
*Available for Powerglides, TH350, and TH400
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The proper mounting depth that must be achieved when installing a new torque converter is measured from the face of the bellhousing to the face of the torque converter. For most GM transmissions, it is typically about 111/48 inch in, but check with the manufacturer for the actual spec. To install the converter properly, first mount it onto the input shaft, then carefully rotate it while applying pressure to push it in. There should be two definite clunks as it spins and is pushed, and you'll need to spin the converter a dozen or more times before it is fully positioned. |