How To Improve MPG & Performance With An Overdrive Transmission - CHP How It Works

Going Broke Filling Up Your Hot Rod? Here’s How to Improve MPG and Performance With an Overdrive Trans

Stephen Kim Jun 15, 2011 0 Comment(s)
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Selection Process

Zack Farah: GM has made so many great overdrive transmissions over the years that it can be challenging to pick the right one for your car. That said, there are some important differences between them to remember to help with the selection process. With the advent of the 700-R4 and 200-4R in the early ’80s, technology had not yet evolved enough at the time to enable us to manufacture our transmissions into what they are today. In the ’70s and ’80s, the TH350 and TH400 were the only choices for high performance since they had been around for many years and the aftermarket technology had fully developed. By the ’90s, however, the 700-R4 and 200-4R had proven themselves to be durable units when the right parts and manufacturing techniques were employed. Our 200-4Rs can handle 800 hp. Today we see 4L80Es being built to withstand three times the horsepower and torque over the factory’s original ratings. Moreover, the stock 6L80E, being the newest and most technologically advanced of the GM transmissions, has limited high-performance capabilities. The 6L80E and 6L90E, with proper modifications and high-performance upgrades, can handle higher amounts of horsepower over stock, but they still haven’t caught up to the TH400 and 4L80E. The 6L80 is controlled by its own internal computer, and therefore, it is very challenging to install into anything other than its original application. Gearstar Performance and HGM Performance are in the final stage of development for a stand-alone computer controller of the 6L80E.

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Achilles Thomas: Of all the GM transmissions Monster offers—like the 200-4R, 700-R4, 4L60E, 4L80E—there is a lot of overlap among different models. For instance, both the 4L60E and 4L80E would be suitable for a 500hp street/strip machine. That said there are many options when trying to select the best overdrive trans for your car. The first step in the selection process is determining your current transmission model. Let’s say you have a ’70 Chevelle that has a TH350 with a 9-inch tailhousing, and you will be dropping in a beefed-up 383ci small-block with 500 hp. Furthermore, you are looking for some better top end and improved fuel economy while staying on a tight budget. For a street/strip application like this, the best choice would be our Monster 700-R4 SS package. It would be the same length as the TH350, has awesome top end gearing, and requires no computer so it offers the most bang for the buck. If the plans called for running some nitrous and you really wanted to gear it toward track use, another option would be the 4L80E, which is virtually bulletproof. There are literally hundreds of different variables, and our staff is always glad to help you through the selection process.

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Total Cost Involved Trans Lineup

Stan Poff: Several things separate TCI’s Street Rodder, Street Fighter, and Super Street Fighter lines of transmissions. These transmissions feature specific shift characteristics and horsepower capacities to suit a wide range of applications. The Street Rodder transmission is capable of handling 475-525 hp and shifts slightly firmer than a stock transmission. Our Street Fighter transmissions are rated at 525-725 hp with firmer shifts than the Street Rodder. The additional horsepower capacity comes from clutch and band upgrades as well as increased fluid pressure and flow. TCI’s Super Street Fighter transmission is the next step up and can handle 825-1,025 hp depending on the specific model. It has the best of everything internally, and is just one step away from being a competition transmission with a full-manual valvebody.


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