Subject: Re: [Fot] T5 conversion

From: "Robert M. Lang" <[email-masked]>
Date: Mon, 22 Dec 2014 07:54:11 -0500 (EST)

Hi,

I'm not an expert on this, so I'm totally open to ither comments on the 
matter...

My first comment would be that it's not clear that a T5 would give any 
benefit other than being an inexpensive replacement. For most T5 setups, 
the first gear is basically useless for road racing. Because of this, my 
first suggestion would be to skip the T5 and think more seriously about a 
T10. I'm suggesting this because you're more likely to find a good ratio 
mix in the 4-speed T10 and T10 knockoffs than with the T5 unless you want 
to not use first.

Also, I know we're talking current E Prod SCCA gearboxes here. That means 
that you are limited to NON overdrive replacement trannies. Most of the 
ratio sets for the T5 that I've seen are 1:1, so that's working in your 
favor.

That said, all the "successful" Triumph racing gears setups seem to be in 
the following range:

1st   2nd   3rd    4th
2.20, 1.75, 1.25,   1

The Dolly Sprint setup is:
2.19, 1.57, 1.23,   1

In the T10 world, the T10 c/r sets are in the range:
2.20, 1.66, 1.31,   1

If you want a usable first gear for road racing, you need to be closer to 
2.0:1, the Kastner first was 1.88:1 - 2.20 is a bit too much gear to be 
really usable in anything but the tightest corners...

So, if you found a Muncie "Rock Crusher" aka M22 (I think), you'd be 
pretty close to ideal gears, although 2nd is a tad too low compared to 
that 1.57 dolly gear. If you want, I could chart out the RPM ranges for 
you.

Now here's the thing: T10's are replicated in NEW gearboxes from everyone, 
but Summit Racing sells Richmond Gear T10 4-speeds for about $1800. If you 
have more $$$ to spend, then you cannot go wrong with a Jericho and the 
ratios that Kastner spec'd back in the day: 1.88, 1.42, 1.24 and 1 which 
I'm pretty sure is what Sam H runs in his boxes (plus or minus) - and he 
can chime in on that, if he wishes.

The bottom line is that if you are looking for a junk-yard replacement, 
you have to make some compromises in the gearing. From my research - 
that's pretty much "toss first gear from the mix" if you road race.

Note that wikipedia lists a lot of info on gear ratios for the B/W T5 and 
T56, you might be able to use that to zero in on a donor.

Last - there's lots of info out there, but Summit Racing lists the gear 
ratios for all the different boxes they sell. They have a number of 
Richmond Gear T5 clones and they list the ratios - you may be able to use 
that info to zero in on a particular box.

In the spirit of transparancy, I'm also looking at this conversion so I'll 
def. keep you posted on whatever I find.

Regards,
rml
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Bob Lang              Triumph TR6!!            |  This space for rent
Former NER Solo Chair                          |
Voice:617-253-7438                             |  Cell: 339-927-4489
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---

From: John Hasty <[email-masked]>
Date: Mon, 22 Dec 2014 15:16:08 +0000

There are many rations available for the T5...I like 2.87  1.89  1.28  1.0 0
.75  also 2.42  1.53  1.23  1.00  .75.  The last time I checked with SVRA a 5
speed is OK since we have 5 speeds with stock trans. + OD.

John H. Hasty | MULLEN HOLLAND & COOPER P.A.
Attorney at Law
301 South York Street  (zip: 28052)
P.O. Box 488
Gastonia, NC 28053-0488
Telephone: 704.864.6751 | Facsimile: 704.861.8394
[email-masked] | www.mhc-law.com

-----Original Message-----
From: Fot [mailto:[email-masked]] On Behalf Of Robert M. Lang
Sent: Monday, December 22, 2014 7:54 AM
To: [email-masked]
Cc: team, FOT
Subject: Re: [Fot] T5 conversion

Hi,

My first comment would be that it's not clear that a T5 would give any benefit
other than being an inexpensive replacement. For most T5 setups, the first
gear is basically useless for road racing. Because of this, my first
suggestion would be to skip the T5 and think more seriously about a T10. I'm
suggesting this because you're more likely to find a good ratio mix in the
4-speed T10 and T10 knockoffs than with the T5 unless you want to not use
first.

Also, I know we're talking current E Prod SCCA gearboxes here. That means that
you are limited to NON overdrive replacement trannies. Most of the ratio sets
for the T5 that I've seen are 1:1, so that's working in your favor.

That said, all the "successful" Triumph racing gears setups seem to be in the
following range:

1st   2nd   3rd    4th
2.20, 1.75, 1.25,   1

If you want a usable first gear for road racing, you need to be closer to
2.0:1, the Kastner first was 1.88:1 - 2.20 is a bit too much gear to be really
usable in anything but the tightest corners...

So, if you found a Muncie "Rock Crusher" aka M22 (I think), you'd be pretty
close to ideal gears, although 2nd is a tad too low compared to that 1.57
dolly gear. If you want, I could chart out the RPM ranges for you.

Now here's the thing: T10's are replicated in NEW gearboxes from everyone, but
Summit Racing sells Richmond Gear T10 4-speeds for about $1800. If you have
more $$$ to spend, then you cannot go wrong with a Jericho and the ratios that
Kastner spec'd back in the day: 1.88, 1.42, 1.24 and 1 which I'm pretty sure
is what Sam H runs in his boxes (plus or minus) - and he can chime in on that,
if he wishes.

The bottom line is that if you are looking for a junk-yard replacement, you
have to make some compromises in the gearing. From my research - that's pretty
much "toss first gear from the mix" if you road race.

Note that wikipedia lists a lot of info on gear ratios for the B/W T5 and T56,
you might be able to use that to zero in on a donor.

Last - there's lots of info out there, but Summit Racing lists the gear ratios
for all the different boxes they sell. They have a number of Richmond Gear T5
clones and they list the ratios - you may be able to use that info to zero in
on a particular box.

Regards,
rml

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---

From: "J.C. Hassall" <[email-masked]>
Date: Mon, 22 Dec 2014 16:24:11 -0500

Who makes a bell housing adaptor?  Does the crank have to modified for the
input shaft bushing?  I assume (uh oh) that clutch/PP can be adapted to the
wet sleeve crank?  My curiosity has been piqued.

Jim

Fat-thumbed from my iPhone

> On Dec 22, 2014, at 7:54 AM, "Robert M. Lang" <[email-masked]> wrote:
>
> Hi,
>
matter...
> My first comment would be that it's not clear that a T5 would give any
benefit other than being an inexpensive replacement. For most T5 setups, the
first gear is basically useless for road racing. Because of this, my first
suggestion would be to skip the T5 and think more seriously about a T10. I'm
suggesting this because you're more likely to find a good ratio mix in the
4-speed T10 and T10 knockoffs than with the T5 unless you want to not use
first.
> Also, I know we're talking current E Prod SCCA gearboxes here. That means
that you are limited to NON overdrive replacement trannies. Most of the ratio
sets for the T5 that I've seen are 1:1, so that's working in your favor.
but Summit Racing sells Richmond Gear T10 4-speeds for about $1800. If you
have more $$$ to spend, then you cannot go wrong with a Jericho and the ratios
that Kastner spec'd back in the day: 1.88, 1.42, 1.24 and 1 which I'm pretty
sure is what Sam H runs in his boxes (plus or minus) - and he can chime in on
that, if he wishes.
> Last - there's lots of info out there, but Summit Racing lists the gear
ratios for all the different boxes they sell. They have a number of Richmond
Gear T5 clones and they list the ratios - you may be able to use that info to
zero in on a particular box.
> Donate: http://www.team.net/donate.html
> Forums: http://www.team.net/forums
> Unsubscribe/Manage:
http://autox.team.net/mailman/options/fot/[email-masked]
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---

From: "Robert M. Lang" <[email-masked]>
Date: Tue, 23 Dec 2014 10:00:19 -0500 (EST)

Hi,

As far as I know, there is no crank mods needed for the T5 conversion. It 
looks like they supply an alternate pilot bushing for the kit.

You can read the installation instructions at:

www.dupontmachining.com

The neat thing about the T5 conversions is that the shifter location is 
aligned with the center of the case, so with the adapter included in the 
kit, you can locate the shift nob to very near the "proper" location of 
the stock shifter.

The "bad" thing is that a lot of the gear ratios are too production-like 
and therefore probably not suitable for a race car. There are aftermarket 
T5's with different gear ratios, though and some of these would be 
suitable for racing.

But, despite what SVRA allows, SCCA (where Rob runs, mostly) does NOT 
allow overdrive on alternate transmissions for the TR6 (and the TR3 and 4, 
for that matter). Tranny output must be 1:1 except for cars with the stock 
Laycock overdrive.

So, there are options out there, but for racing use and for strict 
legality, the options are a bit more limited.

For a high HP TR6, a 4-speed, close ratio box with a 3.70 or 3.45 rear end 
is probably the place where you want to be or with a 4.10 for hillclims 
and short tracks.

Just sayin.

rml

---

From: "Robert M. Lang" <[email-masked]>
Date: Tue, 23 Dec 2014 10:19:42 -0500 (EST)

Hi,

Last point for now, then I'll shut up. If you look at the list of T5 ID 
numbers here:

http://www.britishv8.org/articles/borg-warner-t5-id-tags.htm

you'll see that there are lots of different ratios out there. If you limit 
to reasonable choices you'll see that the jump from 2nd to third is pretty 
large, hence my suggestion that they aren't ideal for racing. But you can 
limit your choices another way - stay away from the O/D 5th that's more 
than about .8 (for example, the .63 ratio 5th for the 84 Mustang / Capri 
V8 is totally unsuitable for a Triumph)

Again, just IMHO.

Regards,
rml

---

From: Larry Young <[email-masked]>
Date: Wed, 24 Dec 2014 13:07:56 -0600

It should be mentioned that some groups don't allow a 5-speed (e.g. 
CVAR).  The jump from 2nd to 3rd is one reason I switched from a 3.7 
close ratio to a 4.55 close ratio with overdrive.  With the later setup 
3rd replaces 2nd, 4th replace 3rd and 4th-OD replaces 4th. The jumps in 
the top three gears are about 20 percent.  It seems that with most of 
the tracks I ran on, I needed 2 gears for most of the track with perhaps 
a higher gear needed on the longest straight or a lower gear in the 
tightest corner.  I remember one time when I lost a throw out bearing at 
Hallett.  I lost only about a second using just 3rd and 3rd OD. I know 
an overdrive is "old school", but you get some good ratios and the 
satisfaction of knowing you a truly vintage. I seldom had trouble with mine.
  - Larry

On 12/23/2014 9:19 AM, Robert M. Lang wrote:
> Hi,
>
> Last point for now, then I'll shut up. If you look at the list of T5 
> ID numbers here:
>
> you'll see that there are lots of different ratios out there. If you 
> limit to reasonable choices you'll see that the jump from 2nd to third 
> is pretty large, hence my suggestion that they aren't ideal for 
> racing. But you can limit your choices another way - stay away from 
> the O/D 5th that's more than about .8 (for example, the .63 ratio 5th 
> for the 84 Mustang / Capri V8 is totally unsuitable for a Triumph)
>
> Again, just IMHO.
>
> Regards,
> rml

---

From: John Hasty <[email-masked]>
Date: Thu, 25 Dec 2014 00:17:13 +0000

Neat!  I agree having run Larry's car for 4 years now, but not being able to
find syncros that work are costing me at least a second or two a lap.  This
makes a T5 really appealing

Sent from my iPhone

> On Dec 24, 2014, at 3:34 PM, "Larry Young" <[email-masked]> wrote:
>
> It should be mentioned that some groups don't allow a 5-speed (e.g. CVAR).
The jump from 2nd to 3rd is one reason I switched from a 3.7 close ratio to a
4.55 close ratio with overdrive.  With the later setup 3rd replaces 2nd, 4th
replace 3rd and 4th-OD replaces 4th. The jumps in the top three gears are
about 20 percent.  It seems that with most of the tracks I ran on, I needed 2
gears for most of the track with perhaps a higher gear needed on the longest
straight or a lower gear in the tightest corner.  I remember one time when I
lost a throw out bearing at Hallett.  I lost only about a second using just
3rd and 3rd OD. I know an overdrive is "old school", but you get some good
ratios and the satisfaction of knowing you a truly vintage. I seldom had
trouble with mine.
to reasonable choices you'll see that the jump from 2nd to third is pretty
large, hence my suggestion that they aren't ideal for racing. But you can
limit your choices another way - stay away from the O/D 5th that's more than
about .8 (for example, the .63 ratio 5th for the 84 Mustang / Capri V8 is
totally unsuitable for a Triumph)

---

From: Larry Young <[email-masked]>
Date: Fri, 26 Dec 2014 12:17:57 -0600

I have seen the Dolomite Sprint gearset ratios frequently stated as 
2.19,  1.57, 1.23, 1.00.   I counted : 26,29,33,33 on the main shaft and 
31,28,25,16 on the counter shaft.  Unless I'm mistaken, that gives 2.46 
for 1st. I see that Quantum agrees - 
http://www.quantumechanics.com/qm-htm/triumph1.htm.
  - Larry
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