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Using an NAG1 transmission in a restomod

36K views 10 replies 4 participants last post by  modernmuscle 
#1 ·
There are several great kits on the market for hotrodders to utilize the NAG1 transmission. These kits range in cost but are typically pretty pricey. This post is for the guy who wants to do things "on the cheap" (people like me).

I will add more later, but I need to at least start this before I head to today's job site :)
 
#2 · (Edited)
The NAG1 is a special animal. It's a Mercedes unit also known as the WA580 or W5A580. The NAG1 transmission can usually be identified by a round 13-way connector near the front corner of the transmission oil pan, on the right side. The gear ratios are a departure from the ratios found in a traditional Dodge trans:

GearWA580545RFE
13.593.00
2 / 2-kickdown2.191.67 / 1.50
31.411.00
41.000.75
50.830.67
Reverse3.2*3.00

This difference doesn't mean much to the casual observer, but that little extra .59 in first gear translates into more torque hitting the pavement from a dead stop. However, the Overdrive is also not as "over" of a drive as the 545RFE. So, what you gain on the bottom end, you end up losing on the top end (to a lesser extent).

Will your car be running stoplight to stoplight? Will your car spend more time on the highway? How much torque / horsepower will the NAG1 handle without blowing up? Is the NAG1 a more reliable unit than, say, the 545RFE? Will the NAG1 fit in my car? What about tuning? What about Autostick? What's it all worth? These are all great questions that need to be addressed.

Let's take a look at some basics... Power rating? Size? Tuning? Autostick?

How much (real-world) power can a stock 5.7L (because the 6.1L application was built slightly heavier-duty) NAG1 handle?

According to HEMI~C~ on 01/31/2009:
"The stock tranny is rated at 580nm which converts to 427ftlb TQ. This is a steady state rating. I have seen several references from Mercedes that thier trannies are able to withstand aprox 30% more tq on an intermittent basis (lets say 1/4 mile :) ) which works out to aprox 555ftlb TQ.

Personally, I can attest (going on my third tranny now) to the fact that the tranny was holding up nice until I bumped the power up a notch with a smaller drive pulley increasing the boost and tq to the 595 rwtq level. The pulley increased boost by approx 3psi roughly equating to 50-60ftlbs of TQ. Given the approx power increase, I estimate the tranny was surviving with the larger pulley and approx 540-550 rwtq level.

Something to think about is the fact that there are two other 706.XX trannies available from Mercedes that have higher tq ratings than ours. One is rated at 750nm and the other at 900-1000nm. Both have the same external case/internal gearing and should be bolt in except for swapping the bellhousing required to mount the tranny to the engine.

I have one of the Southern Hotrod trannies currently in the garage ready to be bolted up to my new stroker. No doubt its going to see a work out with my estimated 625+ rwhp and the additional 200hp shot I plan on spraying. Look for a write up on this in the next couple months as I get the car back to the track."

Last edited by HEMI~C~; 01-31-2009 at 04:51 PM.

That's a pretty decent load, in my book, but there are several ways for a builder to beef up an NAG1 transmission even further. Do a search on the LXFORUMS for "Builder Bill" and see what pops up.

What about size? Well, the NAG1 is physically smaller in every direction than the comparable 545RFE. Will it fit? Most likely, the answer is "yes." There will be a new (longer) driveshaft in your future, but "yes."

Uhoh... What About the driveshaft? There's no yoke! Well... There is an answer for everything if you search hard enough. There are a few companies making custom driveshaft adapters for the NAG1. The one I like the best (simply because one of my Ford buddies uses a driveshaft of theirs on his twin-turbo 9-second Mustang) comes from a company called DSS (Drive Shaft Shop). They will, not only, sell you an adapter, but will also supply you with a full shaft ready to bolt onto your car and handle more HP than any stock NAG1 could handle.

How do I tune it? Well... That all depends on what you use to control the NAG1. We'll get to those other options. But, in stock form, tuning can be done with a DiabloSport or with a Superchips tuner.

What about Autostick? Can I have autostick in my RestoMod??? Yes sir... Yes you can! Now, it may come at a small price, but creativity (yeah, I know it's supposed to be neccessity, but I like my way better ;) ) is the mother of invention. It has been said that you will need a stock shifter from a car/Jeep runnning an NAG1 in order to have autostick. ...Yeah... I don't know that I would agree with this. If I have a shifter that has the correct cable throw to put my transmission into Drive, then I'm halfway to the goal. IF guys can add paddle shifters to an NAG1 THEN I see no need for the the actual autostick control to be on the shifter. A user should be able to control the Autostick solely through add-on paddles on the steering wheel (with some fancy-wiring, of course).

While on the subject of Autostick... It has been said on another forum: "The absolute best thing about the NAG1 (with either tuner) is the complete control the "true" autostick gives, and the instanteous WOT downshifts. The so called autostick on the 545RFE's is not really an autostick and all the WOT downshifts, especially the 4th to 2nd prime, are about as bad as it gets.....takes ~2-3 seconds to figure out what you want it to do."

So... You may be saying: "What's the deal? Why hasn't he gotten to the meat and potatoes of hooking it up and making it go yet?" Well... "Making it go" is the tricky part.

Next come the options...
-Stock TCU setup
-Hotwire
-Mopar Performance TCU setup
-Standalone TCU
-others??

Next time :)
 
#3 ·
Ok... So it's been a month or so of business for me. Almost immediately after I started this thread, I got a call from a customer who was ready to have his house remodeled. You can guess what I've been doing (Strip it down to the studs in the living room, kitchen, upstairs hallway, downstairs hallway and foyer. Take down a couple walls. New electrical, drywall, five new doors, painting the seven remaining doors, new built-in bookcase, new kitchen cabinets, granite, etc.). But the remodel is nearly done and it's time to get back to my own projects a bit.

Last post I made, I was about to investigate the options for making a donor Hemi run in a hotrod. Let me just say, there are some real viable options out there for the engine. Not so much for the NAG1 transmission though. Then, you have the one option that allows the hotrod to end up with ABS.

Honestly, I don't feel like going through all the options. But here are a few of them (by category)

Just the engine:

Holley EFI 558-107 Gen III HEMI Main Harness - Late Crank & Cam Sensors - Holley Performance Products
Holley's EFI Harness (Gen III HEMI Main Harness, For Late Crank & Cam Sensors, for Dominator EFI, Requires DBW Throttle Body Harness. This harness DOES NOT have IAC / TPS connectors.)
The harness (p/n: 558-107) can be picked up (today on eBay) for as little as $425
The Dominator EFI controller (p/n: 544-144) can be picked up (today on eBay) for as little as $1,970

MS3 Gen3 Hemi Plug & Play Gold Box - EFI Source
Megasquirt MS3 Gen3 HEMI Plug & Play Gold Box
This system can be picked up for $1,295 from efisource.com

Mopar Performance 345 Crate HEMI Engine Wiring Kit (Part No: 77072455AB)
Mopar's answer is the Mopar Performance 345 Crate HEMI Engine Wiring Kit
This system can be picked up for $1,561.36 from Mopar

https://www.google.com/url?sa=t&rct...mXkQIgBcA&sig2=golXzihqr0LRol1LAuof8w&cad=rja
FAST (Fuel Air Spark Technology) seems to be out of the HEMI business :( Or, their website is REALLY THAT BAD!

Just the NAG1 Transmission:

Powertrain Control Solutions - Programmable Electronic Transmission Controller
Powertrain Control Systems makes a standalone controller (P/N: TCM-2000) that handles the Daimler NAG1
Price is suggested to be $750, but it's misleading... One website (http://soundgermanautomotive.com/pcs/) suggests it will work for the NAG1, but the PCS main site does not seem to list the NAG1 (nor the Daimler counterpart). I don't know what to make of it. This Is encouraging though...

That seems to be the beginning and END of the list of aftermarket standalone controllers for the NAG1 transmission. Yup... That's it.

Here's the whole ball of wax. One phrase sums it up... "Get a running donor car and take it all." Got it? Get it. Good. Actually, there are companies that will "re-program" your factory computer to delete the ABS, ECS, speed limiter, oem security system, etc. so you end up with exactly what you want. One company (Hotwireauto.com) really seems to have a good handle on the situation. Check out what they have to say:

We have developed a complete wiring and computer package to run the 5.7L/6.1L/6.4L Hemi engines and the Nag-1/WA580 transmission found in the LX cars and some Jeeps. There is a common misconception that this transmission is not suitable for hotrod or muscle car projects. We have been successfully creating systems for this transmission since 2007. The benefit of using this transmission over the 545RFE found in the trucks is that it can handle more input torque and it has a slightly smaller size. Also, all of the Hemi motors from the LX cars and Grand Cherokees came with the Nag-1/WA580 transmission, these can usually be purchased as a package for less than getting the engine and transmission separately. There are a few more items that are needed to make the transmission shift properly and this is why it has not been the first choice for hotrods and muscle cars.

With some planning and understanding this transmission can work very well in your project.
The following items are required to make the transmission shift:

  • Engine Computer
  • Transmission Computer
  • ABS computer and wheel speed inputs
  • Factory shifter
  • Front Control Module
These items along with our new engine/transmission wiring harness (R-0028) and some custom programming make using the modern Hemi and Nag-1 transmission a fairly straightforward project. Detailed information is listed below. Overall Project

It is best if you have a complete donor vehicle to get matching computers. There are some slight changes in the different years that can cause the parts to not be compatible. If you cannot get parts from the same vehicle then stay with the same year whenever possible. You can call us to see if there are any known compatibility issues with the parts you have. You need to send as many of these items in to us as you can for testing on the new harness. At a MINIMUM you must send in the ABS computer and the Front Control Module (FCM). All computers that you send in are connected to the new harness and tested with a OE scan tool to verify communication.
Engine Computer

The factory engine computer comes with built-in security when pulled from a salvage vehicle. To use this computer in a hotrod/muscle car application will require that we either remove security or we can use the factory ignition key and SKIM module from the same donor vehicle to make the security work as intended. We can provide a new engine computer if you need one, the new engine computers do not come with security. Transmission Computer

The transmission computer is a small black computer with two wiring connectors. See a picture of one Here. A used TCM from a Hemi car is needed, we do not recommend purchasing a new TCM. ABS computer and wheel speed inputs

The ABS computer must be sent in to us so that we can verify the wiring, there are a couple different types of modules and the wiring is different for each. The purpose of the ABS computer is to provide wheel speed signals to the other computers. If you are using the rear-end out of a donor vehicle (LX car or Grand Cherokee) then the speed sensors on those axles can be used. If you have an older rear-end then we have a tone ring and sensors kit that you may purchase to mount on the back of your transmission. These signals are required to make the transmission shift properly. We do not recommend purchasing a new ABS computer. See a picture of one Here. Factory shifter

The shifter module from a donor vehicle is required for this system. These shifters have a flat base so installation is fairly simple. The LX car shifter is a shorter item than the Grand Cherokee shifter. You must get a shifter from a car that had the NAG-1/WA580 transmission. The early V6 shifters will not work. The shifter is part of the computer system and tells the other computers what gear you have selected. It also provides the ability to use the +/- shifting feature. Make sure you also get the shift cable and the wiring connector from the donor vehicle as these items will simplify installation in your vehicle. Front Control Module

The Front Control Module (FCM) is the only part where we do not try to match model year with the other parts. For the FCM we recommend getting it from a 2006 vehicle. Any of the 2006 LX car or Grand Cherokee FCM modules will work. The FCM is a communications module used by the other computers in the system to share information. It is a small silver computer that is bolted to the side of the fuse block in those vehicles. This module must be sent in to us so we can add wiring directly to it, we may also need to do some custom programming to it depending on your setup. We do not recommend purchasing a new FCM.
Please call 479-243-9115 if you have any questions about your Hemi Nag-1/WA580 project.

I realize that "hotrods" are meant to be simple. No frills. Nothing more than an awesome motor, basic controls and seats. However, I'm used to more. I want handling. I want to be able to stop. I want to be safe while going fast. I want to take my 1950 Dodge Panel Van on a road course if I so choose! (Well, that may be a tall order. We'll just have to see about that one.) I have realized I may be the single person in the world who wants this, but that's okay. I like to be my own man.

To that end, I am chosing to go Mopar all the way. I will still need to get the computer programmed for a different cam, exhaust, etc., but that will be about it.

So what do I REALLY need from the donor? That's a loaded question...

If I only want it to run and drive, then I need (hopefully from a numbers-matching donor so modules don't have to be sent out to have the VIN altered):
  • 5.7 (or 6.1 or 6.4 or ...Hemi) Engine
  • ECM (Engine Control Module) AKA: ECU (Engine Control Unit); AKA: PCM (Powertrain Control Module)
  • NAG1 Transmission
  • TCM (Transmission Control Module) AKA: TCU (Transmission Control Unit)
  • Transmission Shifter
  • Autostick Module (located just behind the shifter in my '06 Charger donor car)
  • FCM (Forward Control Module) AKA: FCM (Front Control Module)
  • ABS Control Module
  • Wheel sensors
  • All the wiring you can grab

However, I want more. I also want to retain the ABS, power windows, power locks and remote entry system. And, I want the updated suspension (Currently, my panel van has an '88 Dakota front frame clip and a custom triangulated 4-link rear suspension. The Dakota suspension alone is ok... But it's antiquated and has inherant problems. The triangulated 4-link rear would be ok... But I was never all that "sold" on the theory and would rather have a complete IRS.) Utilizing both front and rear suspensions from the donor Charger avails me to endless braking and suspension upgrades from the aftermarket world. Hey Eibach... How You Doin'?! Plus... I don't have to fabricate my own way to mount the "special" LX wheel sensors to my 29 year old '88 Dakota suspension or my '01 Mercury Mountaineer 8.8 rear differential.

There is a reason guys are body-swapping entire LX chassis' under older Mopars. ...it's called "all the engineering is done already!"

For me, I will be combining my current custom frame with the IRS and IFS crossmembers from the '06 Charger donor car. ...Well, I think I will anyway. I've also been entertaining the idea of making this panel van a uni-body vehicle with a mile of welding wire.

It's time to go spread some touch-up paint on the interior of a house.
 
#7 · (Edited)
This is the only true plug and play option. I know it is pricey but you will not have to be a rocket scientist to install it and programe it. .

Modern HEMI Engine and NAG1 Management Package - Modern Muscle Xtreme
I see your screen name is ModernMuscle and presume that you may be personally associated with the company that offers the item you listed. Please don't take this wrong, but as a buyer, the ad is confusing. I'd be interested to see what, exactly, is supplied with this "package." Though the description states that the package "gives you the ability to use the NAG1 transmission with you build," the actual list of "items included" only seems to include engine management hardware (A TCM is not listed and a Dodge PCM for these cars does not control the NAG1 transmission). I'm probably missing something, but that's how it appears. But wait... The picture Does show the classic NAG1 transmission wiring connector. And I don't know what that black block is in the bottom right of the picture. It might be some sort of non-Mopar ABS block?? I just don't know because I don't recognize it. There is hope, though. Perhaps a more inclusive list of "included items" would be good. Also, maybe a different graphic would better show the different parts included. Maybe a picture that shows the items included (and labeled) connected to the wiring harness and sprawled out on a white background. The harness could be coiled between the items to save space. It would help skeptical buyers like me who have been disappointed before. That picture would also allow buyers to better see the custom fuse block that appears to be included.

(the forum won't allow me to add the picture from the modern muscle page... it exceeds my quota. http://www.modernmusclextreme.com/images/PRODUCT/medium/150.jpg)
 
#10 ·
The less things to play with, the better, especially when it comes to trying to not only save money now, but also the Nightmares associated down the road from a Cobbled together kit(If you dont know what you are doing)...
With that said...
COMPUSHIFT II - HGM Automotive Electronics
GearStar is a Vendor, as well as a Great Group of Rodders/Racers who put their own products through regular paces...
GearStar: The Source for Premium Performance Transmissions
Not a Seller/Affiliated with either them, but who I would go through when I have the Funds finally for the different Projects I want to build...
 
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