Since the future motor is probably going to put out more power at an idle than the stock T5 can handle, I figured that a new transmission was definitely going to be needed. So what’s a guy to do? Call D & D Performance of course and order up a balanced and blueprinted Viper spec T56.
For those who don’t know, this is a genuine Dodge Viper transmission that’s been completely gone through and built up.
It’s rated at 650 tq/ft and has been living happily behind much higher numbers than that. There has been a report of someone killing it with ~700 hp -800 hp but I feel that was an isolated incident (that I still haven’t gotten all the details on) and not truly indicative of the true nature of this tranny. If I’m wrong... well, the proposed motor will certainly let me know and I’ll come up with another solution then.
It should never die of overheating though as I will be plumbing it for cooling so that extended runs at high RPM won’t overheat the oil and fry the gears. I’ll be using a Setrab style cooler, Tilton (or Modine) fluid pump, and AN -8 fittings and hose. Since this will be street driven as well, a thermostat set for around 190* will be used as well.
The gearing in this tranny is referred to as “close ratio“ and is as follows:
1 -- 2.66
2 -- 1.78
3 -- 1.30
4 -- 1.00
5 -- .74
6 -- .50
So, coupled with the stock 3.08’s (which I plan to keep), here are some examples of speed vs rpm vs gear:
77 mph 5500 rpm 2nd gear
105 mph 5500 rpm 3rd gear
75 mph 3000 rpm 4th gear
91 mph 2700 rpm 5th gear
89 mph 1800 rpm 6th gear
Coupled with a ton of power, I should hit just over 200 mph in 5th at 6000 rpm and 300 mph in 6th (come on salt flats!).
The one thing I don’t like about this transmission is the weight. I weighed it at 136# dry (no fluid). I’m also going to be gaining some weight from the fluid pump, cooler, and plumbing. I’m hoping that the weight loss from the flywheel and driveshaft will help to offset this gain.
Since the T56 utilizes a reverse gear lockout to prevent you from accidentally hitting reverse, a little bit of electrical work is needed. I went down to Radio Shack and picked up a small, momentary-on push button switch that I plan to install underneath the steering column. Holding this button down will energize the lockout solenoid and allow me to shift into reverse. While the solenoid is de-energized (i.e. button is not being held down), it is impossible to engage reverse accidentally. It is true that you can physically overpower the solenoid, but so much force is required it can’t be done accidentally.
A dedicated switch is the easy way to do it but not the cleanest. What I’m considering is building a device that translate the Vehicle Speed Sensor’s (VSS) output and wire it to a relay. When the VSS reads 5 mph or less, the relay puts power to the solenoid. Clean, neat, trick. Whether or not I do it depends on how lazy I am over the next couple weeks.
A T56 won’t work in a SN-95 Mustang without a custom driveshaft. And with the power I have in mind, your typical aluminum shaft won’t cut it. I ended up getting a MMC (metal matrix composite) shaft from D&D as well.
Apparently, it’s a Kevlar reinforced aluminum composite. Built by Dynotech Motorsports, it’s the same shaft that Don Walsh is using on his 6.0 second Pro 5.0 car so it should be just fine under mine. Especially since I won’t be doing hard launches on sticky tires.
The stock driveshaft weighs in right at 22 lbs (according to my list of weights). A Ford Motorsports driveshaft tips the scales at 16 lbs. This one is 15 lbs even with the big, beefy Spicer yoke. I’m pretty happy with it based off of my initial impressions. Is it worth the extra $100? I’ll let you know after I get the motor done.
Of course, it wasn’t until after I ordered it that I realized Dynotech also offers carbon driveshafts. I do believe I’m going to call them up to see about a return and putting the cost towards a new carbon fiber driveshaft balanced to 10K. I’ll keep you all posted on my decision.
A McLeod Twin Disk clutch setup with aluminum flywheel was next on the invoice.
The twin disk setup differs from your typical clutch in that it actually has two clutch disks inside of it. This doubles the effective clamping surface while still providing decent street manners. Pedal effort is comparable to stock (lighter in some cases and considering my current clutch, I’m positive it will have less tension) yet it’s torque capacity is rated at well over 800 tq/ft. I’ve heard some sources say that it’s good for nearly 1200hp while dumping it on slicks. For what it’s worth, the LS1 guys haven’t found its limits on the street.
Since I already busted the bank with everything else, I spent a few extra bucks on a new quadrant, firewall adjuster, and pedal height kit.
The quadrant is from Maximum Motorsports and mimics the stock ramping. Considering the clutch, I didn’t want to get a quadrant that increased the ramp any. This unit replaces the stock quadrant which is made of plastic and utilizes a spring tensioned pawl and plastic teeth to automatically adjust for clutch wear. The plastic is far too weak for performance clutches (and even has a hard time with the stock clutches on occasion) and so needs to be replaced in order to handle the increased loads brought on by working against a stronger pressure plate. Since the aluminum quadrant doesn’t have a self adjuster, a firewall adjuster must be used so that clutch wear can be manually adjusted for.
The firewall adjuster I’m using is the double lock, extreme firewall adjuster from UPR, anodized in pimpy blue. It utilizes a neat setup to lock the adjuster securely by screwing a locking ring down to put tension against the threads. It also uses two screws to securely fasten it to the firewall. I’m not a big fan of UPR based on some of their past business dealings with acquaintances of mine and their over abundance of bling vs. performance, but I really think they have a winner with this piece. It’s solid, it works, and it was reasonably priced. 3 out of 3 makes me a happy guy.
The pedal height adjuster is also from Maximum and allows you to change the height of the clutch pedal (through the use of a firewall adjuster) so that foot work is made a bit easier. I have a bad habit of catching the side of the brake pedal as I’m hitting the clutch and feel that this might help me out significantly. Of course, smaller feet might help too. With this installed, I should be able to get the clutch pedal even with the brake.
All told, I’m really excited about this next phase of the project. Once I get around to installing it, I plan to do a write up as I know that there are a lot of people who are curious about this swap (and a limited number on the 94-95 forum that have done it).
Questions?
For those who don’t know, this is a genuine Dodge Viper transmission that’s been completely gone through and built up.
It’s rated at 650 tq/ft and has been living happily behind much higher numbers than that. There has been a report of someone killing it with ~700 hp -800 hp but I feel that was an isolated incident (that I still haven’t gotten all the details on) and not truly indicative of the true nature of this tranny. If I’m wrong... well, the proposed motor will certainly let me know and I’ll come up with another solution then.
It should never die of overheating though as I will be plumbing it for cooling so that extended runs at high RPM won’t overheat the oil and fry the gears. I’ll be using a Setrab style cooler, Tilton (or Modine) fluid pump, and AN -8 fittings and hose. Since this will be street driven as well, a thermostat set for around 190* will be used as well.
The gearing in this tranny is referred to as “close ratio“ and is as follows:
1 -- 2.66
2 -- 1.78
3 -- 1.30
4 -- 1.00
5 -- .74
6 -- .50
So, coupled with the stock 3.08’s (which I plan to keep), here are some examples of speed vs rpm vs gear:
77 mph 5500 rpm 2nd gear
105 mph 5500 rpm 3rd gear
75 mph 3000 rpm 4th gear
91 mph 2700 rpm 5th gear
89 mph 1800 rpm 6th gear
Coupled with a ton of power, I should hit just over 200 mph in 5th at 6000 rpm and 300 mph in 6th (come on salt flats!).
The one thing I don’t like about this transmission is the weight. I weighed it at 136# dry (no fluid). I’m also going to be gaining some weight from the fluid pump, cooler, and plumbing. I’m hoping that the weight loss from the flywheel and driveshaft will help to offset this gain.
Since the T56 utilizes a reverse gear lockout to prevent you from accidentally hitting reverse, a little bit of electrical work is needed. I went down to Radio Shack and picked up a small, momentary-on push button switch that I plan to install underneath the steering column. Holding this button down will energize the lockout solenoid and allow me to shift into reverse. While the solenoid is de-energized (i.e. button is not being held down), it is impossible to engage reverse accidentally. It is true that you can physically overpower the solenoid, but so much force is required it can’t be done accidentally.
A dedicated switch is the easy way to do it but not the cleanest. What I’m considering is building a device that translate the Vehicle Speed Sensor’s (VSS) output and wire it to a relay. When the VSS reads 5 mph or less, the relay puts power to the solenoid. Clean, neat, trick. Whether or not I do it depends on how lazy I am over the next couple weeks.
A T56 won’t work in a SN-95 Mustang without a custom driveshaft. And with the power I have in mind, your typical aluminum shaft won’t cut it. I ended up getting a MMC (metal matrix composite) shaft from D&D as well.
Apparently, it’s a Kevlar reinforced aluminum composite. Built by Dynotech Motorsports, it’s the same shaft that Don Walsh is using on his 6.0 second Pro 5.0 car so it should be just fine under mine. Especially since I won’t be doing hard launches on sticky tires.
The stock driveshaft weighs in right at 22 lbs (according to my list of weights). A Ford Motorsports driveshaft tips the scales at 16 lbs. This one is 15 lbs even with the big, beefy Spicer yoke. I’m pretty happy with it based off of my initial impressions. Is it worth the extra $100? I’ll let you know after I get the motor done.
Of course, it wasn’t until after I ordered it that I realized Dynotech also offers carbon driveshafts. I do believe I’m going to call them up to see about a return and putting the cost towards a new carbon fiber driveshaft balanced to 10K. I’ll keep you all posted on my decision.
A McLeod Twin Disk clutch setup with aluminum flywheel was next on the invoice.
The twin disk setup differs from your typical clutch in that it actually has two clutch disks inside of it. This doubles the effective clamping surface while still providing decent street manners. Pedal effort is comparable to stock (lighter in some cases and considering my current clutch, I’m positive it will have less tension) yet it’s torque capacity is rated at well over 800 tq/ft. I’ve heard some sources say that it’s good for nearly 1200hp while dumping it on slicks. For what it’s worth, the LS1 guys haven’t found its limits on the street.
Since I already busted the bank with everything else, I spent a few extra bucks on a new quadrant, firewall adjuster, and pedal height kit.
The quadrant is from Maximum Motorsports and mimics the stock ramping. Considering the clutch, I didn’t want to get a quadrant that increased the ramp any. This unit replaces the stock quadrant which is made of plastic and utilizes a spring tensioned pawl and plastic teeth to automatically adjust for clutch wear. The plastic is far too weak for performance clutches (and even has a hard time with the stock clutches on occasion) and so needs to be replaced in order to handle the increased loads brought on by working against a stronger pressure plate. Since the aluminum quadrant doesn’t have a self adjuster, a firewall adjuster must be used so that clutch wear can be manually adjusted for.
The firewall adjuster I’m using is the double lock, extreme firewall adjuster from UPR, anodized in pimpy blue
. It utilizes a neat setup to lock the adjuster securely by screwing a locking ring down to put tension against the threads. It also uses two screws to securely fasten it to the firewall. I’m not a big fan of UPR based on some of their past business dealings with acquaintances of mine and their over abundance of bling vs. performance, but I really think they have a winner with this piece. It’s solid, it works, and it was reasonably priced. 3 out of 3 makes me a happy guy.The pedal height adjuster is also from Maximum and allows you to change the height of the clutch pedal (through the use of a firewall adjuster) so that foot work is made a bit easier. I have a bad habit of catching the side of the brake pedal as I’m hitting the clutch and feel that this might help me out significantly. Of course, smaller feet might help too.
With this installed, I should be able to get the clutch pedal even with the brake.All told, I’m really excited about this next phase of the project. Once I get around to installing it, I plan to do a write up as I know that there are a lot of people who are curious about this swap (and a limited number on the 94-95 forum that have done it).
Questions?
I think you'll like it 
