New TRT Transaxle - Page 3

Richard Timte · 02-14-07, 04:58 PM

Brian,

Email sent to both addresses.

Richard

Steve Briscoe · 02-14-07, 10:17 PM

Richard -
Nice talking with you today. Good information and I appreciate your time. Check is in the mail.

Steve

Richard Timte · 02-15-07, 03:52 PM

All,

If you mailed me a letter to be put on the list and you did not include your email, please email your preferred contact email address so I can store it in my database.

Thanks again

Sandy · 02-15-07, 04:14 PM

Richard, I love your tag line, LG600 for sale! Nice, What am I going to do with 3 930 boxes :-)

Sandy

Doug Sainlar · 02-15-07, 10:15 PM

Quote:

Originally Posted by RTIMTE

The ZF is 10.125 from the block surface to the center line of half shafts, mine is 8.25.

In a kit where room for front end dress is critical, IMHO this extra 2 inches could easily be the deal maker.

Doug

Sandy · 02-15-07, 11:13 PM

Richard -

Question, Would it be possible for different input shaft length options and a spacer between the box and bell to retro fit alignment? Might help me and the ZF guys toss out their current boxes without having to do much work. Thinking lazy as I like what your doing.

Sandy

Richard Timte · 02-16-07, 12:45 AM

Sandy,

I was thinking the same thing. Making the the input shaft 1.875 longer and a thicker bell housing (or extension ring). I have been asked by a few people to do just that. They already have a car build and don't want to move the engine (exhaust, mounts and the like). There is another way to move the output shafts back that requires a different case and changing the length of of one shaft. The latter option does not increase the length of the box where the first option does. If I do the second option I could provide mounts in the stock ZF location as well. Kill two birds with one stone. I must admit the first option would be a lot quicker to pull off.

Doug Sainlar · 02-16-07, 08:13 AM

Quote:

Originally Posted by RTIMTE

The latter option does not increase the length of the box where the first option does. If I do the second option I could provide mounts in the stock ZF location as well. Kill two birds with one stone. I must admit the first option would be a lot quicker to pull off.

As long as you're designing different options, I still think it would be advantageous to offer the shorter block face to half-shaft length. It would provide 2" extra space into which a new builder could place front dress items and many builders rue the short clearances between pulleys/belts and the framework. I'm anticipatiing the GT40 will be my first build, and I have no enthusiasm for dealing with 1/4" clearances or rebuilding a bulkhead to gain clearance. Kit manufacturers are use to welding in special order motor mount locations, so I don't think that would be a problem for a new build.

Sandy's right, though--those retrofitting would be much better off with the same dimensions as the original ZF.

We'll all be watching as this exciting product develops!

Doug

Richard Timte · 02-16-07, 10:24 AM

Doug,

The castings being done today are the 8.25 version, and I will continue to build it that way. To help with the ZF and the people that have cars complete, I will do one of the two options stated above. I am leaning twards the longer input shaft and a new or spaced out bell housing. This will help out on tooling costs as well as a different case has a lot more capital involved.

Tye GT40 · 02-20-07, 04:31 PM

Looks like it will be the byers market soon;-)

Regards
Henrik

Johan · 02-20-07, 11:26 PM

There are huge differences between driving a car with a ZF and a car with a dog ring box like a Hewland on a race track.
Dog ring shifts are instant.
Bang, you're in the next gear with something like a Hewland.
Baawwwaaa, BBaaaawwwaaaaa with the ZF, where the driver has to do the work. With a hewland, you can just run it up to the rev limiter and bang it into the next higher gear without touching any pedals (the rev limiter part is important). Richards Trans sounds nice for lots of cars. ZFs are nice as well.
They were not designed for so much power and if it lasts being driven at its limit, it is good luck. Engineering is rooted in identifying limits and then staying
a safe amount within them. Transmissions have "redlines" just like engines.
Notice how the dog gear Hewland in this GTP Nissan sounds.

http://www.youtube.com/watch?v=FGwQ7w3Tkl4

Johan · 02-20-07, 11:49 PM

Here is a nice video of a T333 Lola doing a couple laps with a Hewland DG300, which is a dog ring trans.
Notice the difference between a dog ring trans and a synchro trans ?
This guy only used the clutch to get out of the pits.
http://www.warbirdsovernewzealand.co...downfriday.wmv

Brian Kissel · 02-21-07, 01:18 AM

There has been some interesting discussion of this transaxle over on the FF GTM site. I hope Richard doesn't mind, but I wanted to post some of his examples here.

"The drum in a sequential box engages each gear by moving the shift fork with a cam (a grove in the drum and a pin in the shift fork). As the drum is turned the cam moves the shift fork and in turn engages the gear. If you change the cam on the drum to engage 1.0 (old 5th) first and then engage the .73 (old 4th) then the box could have a overdrive. So the shift drum can engage any gear set in any order by changing the cam on the drum.

Lets look at the gear set I am putting in the prototype box.

1st 2.625
2nd 1.909
3rd 1.485
4th 1.179
5th 1.000

If you put in the quick change gear set 14 (R&P ratio 3.30).

Now with a 26.5 inch tire and max rpm of 7000 we get the chart below:

code:
--------------------------------------------------------------------------------

Gear Max Speed(MPH) RPM next gear RPM Drop1st 63.7 5901 19092nd 87.6 5444 15563rd 112.6 5556 14444th 141.9 5940 10605th 167.2

--------------------------------------------------------------------------------

Lets change the quick change gear to set 22 (R&P ratio 3.13) and same specs 26.5 inch tire and 7000 RPM max.

code:
--------------------------------------------------------------------------------

Gear Max Speed(MPH) RPM next gear RPM Drop1st 67.2 5901 19092nd 92.4 5444 15563rd 118.7 5556 14444th 149.6 5940 10605th 176.3

--------------------------------------------------------------------------------

Change the quick change gear set to 34 (R&P ratio 2.97) and same specs 26.5 inch tire and 7000 RPM max.

code:
--------------------------------------------------------------------------------

Gear Max Speed(MPH) RPM next gear RPM Drop1st 70.8 5901 19092nd 97.3 5444 15563rd 125.1 5556 14444th 157.7 5940 10605th 185.8

--------------------------------------------------------------------------------

The above examples are for one set of drive gears, there are 100's available.

Lets do the above example with a overdrive setup.

1st 2.638
2nd 1.723
3rd 1.266
4th 1.000
5th 0.829

If you put in the quick change gear set 14 (R&P ratio 3.30).

Now with a 26.5 inch tire and max rpm of 7000 we get the chart below:

code:
--------------------------------------------------------------------------------

Gear Max Speed(MPH) RPM next gear RPM Drop1st 63.4 4571 24292nd 97.1 5145 18553rd 132.1 5529 14714th 167.2 5803 11975th 201.7

--------------------------------------------------------------------------------

Lets change the quick change gear to set 22 (R&P ratio 3.13) and same specs 26.5 inch tire and 7000 RPM max.

code:
--------------------------------------------------------------------------------

Gear Max Speed(MPH) RPM next gear RPM Drop1st 66.8 4571 24292nd 102.4 5145 18553rd 139.3 5529 14714th 176.3 5803 11975th 212.7

--------------------------------------------------------------------------------

Change the quick change gear set to 34 (R&P ratio 2.97) and same specs 26.5 inch tire and 7000 RPM max.

code:
--------------------------------------------------------------------------------

Gear Max Speed(MPH) RPM next gear RPM Drop1st 70.4 4571 24292nd 107.9 5145 18553rd 146.8 5529 14714th 185.8 5803 11975th 224.1

--------------------------------------------------------------------------------

As you can see the combinations are endless.

Richard "

The complete discussion can be found here------
FFCobra Discussion Forums: New Transaxle

I really like what I hear so far , and await more details.

Thanks Johan for the video clips, they were great !!!!!!!
Regards Brian

Russ Noble · 02-21-07, 02:13 AM

Quote:

Originally Posted by Johan

Here is a nice video of a T333 Lola doing a couple laps with a Hewland DG300, which is a dog ring trans.
Notice the difference between a dog ring trans and a synchro trans ?
This guy only used the clutch to get out of the pits.
http://www.warbirdsovernewzealand.co...downfriday.wmv

Johan,

Great footage. That is Stan Redmonds T332 which has been reliveried in it's original colours and signage. Talking to Stan a couple of weeks ago I think he said at that meeting it was driven by it's original Aussie driver (who's name momentarily escapes me).

Dog box is the best and nicest to use for racing.

Cheers,

Russ

Johan · 02-21-07, 10:16 AM

Sorry yes of course, T332, one of my favorites. I call them T333s because here in the USA, they have all been converted to Center Seat Can Am and called T333s. There was actually a T333 factory model, but, we digress.

Dutton · 03-02-07, 05:29 PM

Richard,

What sort of care and feeding for the transaxle is recommended at this point?

Best,

T.

Richard Timte · 03-03-07, 12:58 AM

Dutton,

I'm not sure what you are asking? What preventative maintenance is needed?

Richard

Dutton · 03-03-07, 10:57 AM

Maintenance would be what I was after, Richard - my apologies for being less than clear.

Several years (and 40 pounds) ago I was intimately acquainted with the Hewland Mk 8/9; complete regearing could be done in very quickly. While the TRT is clearly a more robust transaxle, are gear changes/dog ring replacement/etc expected to be as simple and straightforward as the Mk 8/9?

Thanks in advance,

T.