Replacing the T5 with a six speed gearbox.
Discussion
Has there been some work into the prospect of having a six speed gearbox fitted in place of the T5 box, or if there is a modification for the T5.
There are many companies offering ratio changes as far as I can see. While my engine and box are out for the next few weeks, I thought it might be worth a look into this area.
There are many companies offering ratio changes as far as I can see. While my engine and box are out for the next few weeks, I thought it might be worth a look into this area.
Took a while but found it..
www.g-forcetransmissions.com
Here are their available gear ratio's :
Spur Dog Ring Ratios
3.22 2.94 2.46
2.05 1.94 1.54
1.34 1.34 1.22
1 1 1
.59* .59* .59*
.73* .73* .73*
0.9 0.9 0.9
The third option looks like the same (or very similar)
that TVR have choosen..
Reading this lot - looks like TVR don't just take the std box (WC or NWC) anyway :
"The Borg-Warner T5 manual five-speed transmission has been used in a wide variety of applications since it was first put into production in the late '70s; in fact, there are currently over 260 part numbers for T5 assemblies on the books. This has resulted in numerous variations over its production 20-plus-year lifespan. The original intent of this gearbox was to provide a relatively lightweight (under 80 pounds), smooth-shifting manual transmission with overdrive for improved fuel efficiency. But it wasn't long before it was providing an excellent bridge between performance and economy. The two versions most familiar to car crafters are the '83-'95 Ford Mustang 5.0L and the '83-'92 V-8-powered Camaro and Firebird. Despite the similar parameters of both of these vehicles, the gearboxes used in each are significantly different from one another, and to make matters even more confusing, there were changes to each during their respective runs. The upside is that these changes were almost always done in the name of increased durability, as the Detroit horsepower race escalated.
The primary differences in T5s for both the Mustang and the F-car can be split into two classifications: World Class (WC) and non-World Class (NWC). The term World Class is often thought to be reserved for the best T5s built, but actually there were further upgrades after this nomenclature was first applied. The World Class upgrades consisted primarily of caged needle bearings for First, Second, and Third gears, compared to the gears riding on a solid shaft as they do in NWC versions. The counter gears in WC boxes use tapered roller bearings in place of the standard rollers in the NWC. World Class boxes also use fiber-lined blocker rings on First through Fourth gears to improve synchronizing for smoother shifts. Despite these upgrades, the first WC boxes carry the same 265-lb-ft torque rating as the NWC units before them, probably since the changes were actually aimed at improving the transmission's operating performance rather than its integrity.
T5 WC
The NWC gearboxes use a 2.95 First gear while the later WC units have a 3.35 First. This holds true for both Camaro and Mustang boxes, though the Mustang went to the WC for the '85 model year while the Camaro didn't make the switch until '88. For the '90 model year, Ford worked with Borg-Warner to further upgrade the T5, resulting in new Second and Third gearsets using course-pitch gear teeth and higher nickel-content steel. These changes raised the torque rating to 300 lb-ft in Mustangs. Later, the T5 was further upgraded to harness the power of the '93 Mustang Cobra. This version, dubbed the T5 "Z" because of its Ford part number designation, has tapered output bearings and a steel front-bearing retainer (versus aluminum) among other things, pushing its torque rating to 330 lb-ft.
Speaking of the T5's durability, this gearbox has garnered a reputation as being wimpy and incapable of handling the power of a typical street machine. In truth, the better variants of the T5 can handle a healthy V-8 just fine--until it comes to full-on power-shifting, particularly with sticky tires. In those situations, the pinnacle of T5 development may be necessary: the G-Force T5 (see G-Force sidebar)."
>> Edited by rev-erend on Monday 26th September 09:41
www.g-forcetransmissions.com
Here are their available gear ratio's :
Spur Dog Ring Ratios
3.22 2.94 2.46
2.05 1.94 1.54
1.34 1.34 1.22
1 1 1
.59* .59* .59*
.73* .73* .73*
0.9 0.9 0.9
The third option looks like the same (or very similar)
that TVR have choosen..
Reading this lot - looks like TVR don't just take the std box (WC or NWC) anyway :
"The Borg-Warner T5 manual five-speed transmission has been used in a wide variety of applications since it was first put into production in the late '70s; in fact, there are currently over 260 part numbers for T5 assemblies on the books. This has resulted in numerous variations over its production 20-plus-year lifespan. The original intent of this gearbox was to provide a relatively lightweight (under 80 pounds), smooth-shifting manual transmission with overdrive for improved fuel efficiency. But it wasn't long before it was providing an excellent bridge between performance and economy. The two versions most familiar to car crafters are the '83-'95 Ford Mustang 5.0L and the '83-'92 V-8-powered Camaro and Firebird. Despite the similar parameters of both of these vehicles, the gearboxes used in each are significantly different from one another, and to make matters even more confusing, there were changes to each during their respective runs. The upside is that these changes were almost always done in the name of increased durability, as the Detroit horsepower race escalated.
The primary differences in T5s for both the Mustang and the F-car can be split into two classifications: World Class (WC) and non-World Class (NWC). The term World Class is often thought to be reserved for the best T5s built, but actually there were further upgrades after this nomenclature was first applied. The World Class upgrades consisted primarily of caged needle bearings for First, Second, and Third gears, compared to the gears riding on a solid shaft as they do in NWC versions. The counter gears in WC boxes use tapered roller bearings in place of the standard rollers in the NWC. World Class boxes also use fiber-lined blocker rings on First through Fourth gears to improve synchronizing for smoother shifts. Despite these upgrades, the first WC boxes carry the same 265-lb-ft torque rating as the NWC units before them, probably since the changes were actually aimed at improving the transmission's operating performance rather than its integrity.
T5 WC
The NWC gearboxes use a 2.95 First gear while the later WC units have a 3.35 First. This holds true for both Camaro and Mustang boxes, though the Mustang went to the WC for the '85 model year while the Camaro didn't make the switch until '88. For the '90 model year, Ford worked with Borg-Warner to further upgrade the T5, resulting in new Second and Third gearsets using course-pitch gear teeth and higher nickel-content steel. These changes raised the torque rating to 300 lb-ft in Mustangs. Later, the T5 was further upgraded to harness the power of the '93 Mustang Cobra. This version, dubbed the T5 "Z" because of its Ford part number designation, has tapered output bearings and a steel front-bearing retainer (versus aluminum) among other things, pushing its torque rating to 330 lb-ft.
Speaking of the T5's durability, this gearbox has garnered a reputation as being wimpy and incapable of handling the power of a typical street machine. In truth, the better variants of the T5 can handle a healthy V-8 just fine--until it comes to full-on power-shifting, particularly with sticky tires. In those situations, the pinnacle of T5 development may be necessary: the G-Force T5 (see G-Force sidebar)."
>> Edited by rev-erend on Monday 26th September 09:41
The tvr t5's are wc bolt pattern,but an unusual 23 spline input shaft.(Chrysler)
I'd buy the whole box off G force as its not worth the hassle of landing the wrong kit,plus you get a 26 spline input shaft (chev) so you can have a huge choice in clutche's.(go for a centre centre thrust release bearing while your at it.)
I'd buy the whole box off G force as its not worth the hassle of landing the wrong kit,plus you get a 26 spline input shaft (chev) so you can have a huge choice in clutche's.(go for a centre centre thrust release bearing while your at it.)
Perhaps sir would like one of these - but I suspect it would be a really major mod ...
www.hewland.com/svga/productrange/igt-c.htm
www.hewland.com/svga/productrange/igt-c.htm
There is a Griffith 500 (with a 5.3 upgrade) that has a T56 box in it. These are the same boxes that are used in the Viper, and while the standard one can handle "only" 350 - 550 lbs-ft, there are some modified ones coping with nearly 1000. i.e. it's reasonably unbreakable. I know that Joolz also measured a car for this conversion, but I don't think carried it out. There are T5 to T56 conversion kits available, and various descriptions on how to go about it on the web. The T56 is about 20kgs heavier (54 compared to 34 for the T5). The car I mentioned at the start was converted by the Swiss TVR dealer www.tvr.ch
Cheers,
David
Cheers,
David
I've got t5 wc boxes and t56 boxes here if anybody needs a measurement. The 56 is very heavy. The viper version is also heavy and it's stick is 3" forward of the stock position. You can make a strong hybrid t56 with viper internals and rear end. A ford t56 also has a forward stick position but the ford boxes aren't so common second hand and cost more then the others.
Boosted.
Boosted.
See TVRlet has not seen this one - correct me if wrong but t56 (yes Too heavy) is also too big without chopping and redoing alot of the centrebraceing around the box area on a std TVR Grif / chim or Tuscan (racer chassis - all basically the same in this area as regard the sizing of the centre backbone area.
thisnk there maybe a t5 upgrade to 6 speed kit like chevtrev says - but why bother - you want it for extra miles per gallon with the long top!?
thisnk there maybe a t5 upgrade to 6 speed kit like chevtrev says - but why bother - you want it for extra miles per gallon with the long top!?
Go to Tremec (www.tremec.com/English/home/home.asp) - they have a few possible options (mainly the TKO box for 5 speed and the T56 box for 6 speed). Speak to Dave Davies at Autocraft - tell him John Kyle sent you (www.autocraftsve.co.uk/) as I was thinking about getting rid of the T% and replacing it with the TKO short ratio box.
jkyle69 said:There are about 4 tremec dealer in the UK - see there UK distributor list at tremec.com - tko600 on the .82 not the .6 ratio is the kiddy.
Go to Tremec (www.tremec.com/English/home/home.asp) - they have a few possible options (mainly the TKO box for 5 speed and the T56 box for 6 speed). Speak to Dave Davies at Autocraft - tell him John Kyle sent you (www.autocraftsve.co.uk/) as I was thinking about getting rid of the T% and replacing it with the TKO short ratio box.
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