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Words and photos by Richard Kratz
The NAG1 transmission found in late model Mopar cars and trucks is an amazing transmission. Originally designed by Mercedes, this five speed overdrive unit can easily handle the 470 hp output of an SRT model yet is streetable and comfortable for average drivers who never modify their cars.
But what if you do mod your car? We’re getting over 600 hp out of our Magnuson supercharged project car, the Maulin’ Magnum. We certainly don’t want soft, smooth shifts at the track with the kind of power and torque we’re trying to throw to the track surface.
You have some options for firming and quickening your NAG1 shifts. You can upgrade the valve body in the trans to so-called “Blue Top” solenoids, which we’ve done. These are two solenoids (which actually have blue tops) which replace the stock Chrysler brown top solenoids in the valve body. Upgrading to this unit significantly firms up both up and downshifts in the car. But replacing them is not cheap, we just checked the ‘Net and found pricing of around $420 for a pair. Replacing them is also messy, you have to drop your transmission oil pan and remove the valve body. We’ve done this upgrade, it was our first transmission upgrade, and we’re very pleased with the improvement in shifting. For us, it was a good start.
Another option is the Mopar TCM, part number P5155177. This is a simple to install upgrade, replacing the stock TCM found under the steering column. We paid $416 for ours and had the swap done in under an hour. Look for a full review on this part in an upcoming issue. There are some very specific procedures you must follow if you use this part, and you have to be sure to follow a second procedure if you have a custom tune via a Diablosport product. Not difficult, but you can damage things if you don’t follow procedure.
Both of these upgrade paths are good options. But they’re also one trick, non-adjustable ponies, you either like their setup or you don’t. But now, thanks to Z Automotive, you have a third, rather amazing option. The completely adjustable and very affordable, TranZformer.
This magical little black box has eight wires you connect under the dash below the steering wheel and a USB interface you can plug into a laptop, or if you don’t have a laptop there are tons of clever ways to program the unit in the car using various buttons and column levers in the car.
Before we get to the install, let’s talk about what the TranZformer can do, although in truth it may be quicker if we were to just mention what it can’t do. It can’t make you look younger, reverse balding, or provide you next week’s winning Lotto numbers. That’s about all it can’t do.
What it can do is provide you 100% total control over your transmission’s shift characteristics and we mean 100%. You can control the shift firmness in small increments for each gear shift separately. You can control the RPM at which each gear shifts. You can control firmness and RPM for each gear separately for when your in “D” and when you’re manually autostick shifting. Getting the idea of what we mean by control?
Late night infomercial mode here, “But wait! There’s more!” And there really is, lots more. The TranZformer includes a plethora of extra features running from the “fun to play with” to the “how did I live without that” variety. Here’s a list of some of the things you can do with the TranZformer:
We weren’t so sure about the volume buttons for shifting up and down, but once we tried it on a mountain road we loved it. We have a mechanical front wheel line lock for burnouts and it was a long day and hundreds of dollars to get it installed. Now you can have one at the touch of a steering column lever.
The TranZformer retails for $249.99 and includes free shipping. When you consider that this is at least $150 cheaper than blue tops or an MTCM, you begin to see what a great bargain it is. But then when you look at the features list, at the very least you’re getting a free line lock, steering wheel fingertip shifting and a transmission temperature gauge. This thing has got to be the best bargain we have received since we bought that ’70 340 ‘Cuda from that pissed off divorcee for $200 back in 1979.