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Discussion Starter · #1 ·
I'm trying to locate a source for a new or used Holloway Performance single piece UN1 input shaft. I contacted Holloway but they said that they no longer have them available. Does anyone know if there is a supply of them left anywhere or does anyone have one they're willing to part with? I'm not sure if these were sold exclusively by Holloway or if they had distributors as well.

Thanks everyone for the help!
 

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Cal H
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Holloway was not exactly a very large enterprise. It was an Esprit owner who based his operation out of a residential neighborhood about 4 miles from me in Minnetonka. He made a limited run of kits and sales slowed towards the end of the supply. Unless there is a number of interested people in a group buy there probably is no plans for further production. I don't think the intent was to make a lot of money off of it but just an Esprit owner providing a service to fellow owners and covering expenses for himself.
 

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If Holloway don't want to produce the UN1 upgrade why not redirect the people who are interested to the source?
Use the source name other than holloway so their is no infringement issue. I'm sure Holloway will share this to us.
"MADE IN USA" TIME FOR US TO RISE AGAIN !
 

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If Holloway don't want to produce the UN1 upgrade why not redirect the people who are interested to the source? Use the source name other than holloway so their is no infringement issue. I'm sure Holloway will share this to us.
"MADE IN USA" TIME FOR US TO RISE AGAIN !
The actual manufacturer, EMCO, is a big manufacturer, not a job-shop. They have no interest in single part orders. They only worked with Craig, a private owner of an Esprit, because he stepped-up and paid the big bucks to fund the kit's development engineering and to buy a large minimum quantity of complete conversion kits (shaft, gears, bearings, etc). The shaft was never available separately, only a full kit specific to the Esprit version of the UN-1 transaxle (which is not what is in the DeLorean).

It was a huge out-of-pocket expense for Craig, but he was unwisely convinced the Esprit community would jump on the upgrade and quickly snap-up the inventory. However, the direct opposite was true and he sat on the inventory (and his $$ investment) for many, many years. It was only relatively recently that he finally unloaded the last kit. He has absolutely zero interest (maybe less than that) in repeating that financial disaster, and he has no stray parts inventory... like a shaft.

GTO Racing Ltd offers a similar UN1 upgrade kit. Check with them.

Kevin/Lee Jones
GTO Racing Ltd.
Scarletts Farm
Scarletts Lane
Hare Hatch
Berkshire, RG10 9XE
GTO Racing Ltd. | Home

GTO Racing also sells a six-speed upgrade for the UN1. However, it uses straight-cut spur gears that whine like a racing gearbox. It also has no synchros, so is only good if you know how to shift a crash-box.

You can also read more about the GTO Racing kit, and other UN1 upgrades on GT40s.com - Powered by vBulletin . Much of the info offered there is individual's opinions, and not worth the price you pay to read it (free). Use a little common sense.

Regards,
Tim Engel
 

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Discussion Starter · #9 ·
Since I've been working on this project, I wanted to give a quick update.

Since the Holloway shaft is no longer available I decided to take matters into my own hands. I couldn't justify paying the price that the GTO Racing gearset costs so being a Mechanical Engineer I decided to design my own.

This shaft is different than the Holloway and GTO shafts because I did not change the gear ratios. Unlike the Lotus cars with UN1's, the DeLorean does not have the 3.89 differential. Instead it has a 3.44 differential so I did not want to lower my ratios any more.

The shaft is AISI 4340 steel that is through hardened and tempered, with the first and second helical gear teeth shot-peened. I also modified the drilled end of 5th gear so that it still oils 5th, but doesn't remove as much material from the shaft. Between this and the significant material improvements, I'm pretty confident that even 5th gear will be fine.

Here is also a quick video of the shaft in the box with the outputshaft and transmission:
https://www.youtube.com/watch?v=QNTqEuTY5ZI
 

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The problem with the new development parts is the ability to use and test.

But...If he wants to make it for the Esprit V8, i can let him borrow my stock main shaft...just to help the V8 community.
I also think the main shaft is more of a problem in the V8 than the Deloren or the 4cyl Esprit ??

I have a GTO engineering upgrade on mine -- its tested - proven & works !
 

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Discussion Starter · #13 ·
The problem with the new development parts is the ability to use and test.

But...If he wants to make it for the Esprit V8, i can let him borrow my stock main shaft...just to help the V8 community.
I also think the main shaft is more of a problem in the V8 than the Deloren or the 4cyl Esprit ??

I have a GTO engineering upgrade on mine -- its tested - proven & works !
Truthfully I have thought about trying to extend the market to the Lotus community as well. Right now this shaft is made as a direct drop into the DeLoreans transmission (the Renault 369). That being said, to my knowledge there are very few differences between the Renault 369 and the UN1-016/026/027.

I know that the 027 has the double tapered roller bearings on the end instead of the double angular contact ball bearing that the rest of the UN1s and the 369 have. Still, I believe the ID of those bearings is still 25mm so that shouldn't make a diference.

Otherwise the only question would be the gear ratios. As long as the gear ratios are the same for 1st, 2nd, and reverse (the gears cut into the input shaft), it should be the same. The 3rd, 4th, 5th, and differential ratios should have no affect on whether or not the input shaft works. Below are the ratios that I have been able to gather (if someone can confirm the esprit ratios it would be nice).

369 Gear Ratios
DeLorean DMC-12
1st - 3.364
2nd - 2.059
3rd - 1.381
4rd - 1.057
5th - 0.820
Rev - 3.182
Dif/Final - 3.444

UN1 gear ratios:
Esprit SE, S4, S4s, V8
UN1-016 026 & 027
1st - 3.364
2nd - 2.059
3rd - 1.381
4th - 1.037
5th - 0.820 - (V8 = 0.76)
Rev- 3.546
Dif/Final - 3.889

So the only concern it looks like could be reverse. I'm not sure if the ratio is altered by a different number of teeth on the input shaft, intermediate gear, or the output shaft reverse gear (the one on the 1st/2nd gear selector coupler).

Can anyone confirm for me how many teeth are on the input shaft of the Esprit input shaft reverse gear? Mine has 11 teeth (same number as 1st gear). I'm hoping that it is the same (and would hope so since the concensus is that the GTO shaft works in both Esprits and DeLoreans).

The only other question then is with regard to the reverse gear input shaft design. some pictures I've seen looks like the teeth on the Esprit transmission are extra long, as though the intermediate gear does not ever disengage the input shaft. Can anyone confirm this or if it is needed? Thanks!
 

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I don't know if this will help you.
This is the complete GTO engineering kit that installed in my Esprit V8
I think the 1st in 2nd is different ratio from GTO kit vs the Stock
 

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Discussion Starter · #16 ·
The GTO and Holloway kits both have/had straight cut first gears because they also require the replacement of the cooresponding output shaft gears.

The GTO kit changes 1st to 2.66:1 and 2nd to 1.75:1.
The Holloway kit changed 1st to 3.00:1 and 2nd to 1.94:1.

The shaft I've made is a direct dorp in and works with all of the existing components. The original ratios remain with mine. 1st is 3.364:1 2nd is 2.059:1.

The only thing I dont know is how many reverse teeth are on an Esprit input shaft.
 

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"The only thing I dont know is how many reverse teeth are on an Esprit input shaft."

I will dig the stock shaft in the barn when I get time this week.

Some notes:
The present sources of uprated gearbox parts are in GTO Racing in the UK. They provide different gear ratios to ease stress on third to second downshifts, and a strengthened shaft to alleviate issues with the cantilevered fifth gear. The weakness in the box primarily exhibits as fried second gear synchro’s. While upgrading my transaxle & clutch we also installed a Quaife LSD, which is considered the best single upgrade to these cars;
 

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Hi folks,
..recently did a GTO upgrade w/LSD on one of my UN's.
I did need to: modify the bearing carrier (OD), add a shim to align the geartrain, and shave the mainshaft nut down a bit for good fit.
Interesting discussions with Kevin over at GTO re...He agreed. Nice bunch.
If you still need any info on the original shafts/gears/material let me know.
PM is likely best for detail.
Pete
 

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Discussion Starter · #19 ·
Hi folks,
..recently did a GTO upgrade w/LSD on one of my UN's.
I did need to: modify the bearing carrier (OD), add a shim to align the geartrain, and shave the mainshaft nut down a bit for good fit.
Interesting discussions with Kevin over at GTO re...He agreed. Nice bunch.
If you still need any info on the original shafts/gears/material let me know.
PM is likely best for detail.
Pete
Thats very interesting to hear. I'm definitely interested in whatever info you have. Can you elaborate on those changes? What was the bearing carrier modification? Where did you have to shim the geartrain; do you mean axially? Is the new mainshaft nut bigger than original? If you want to PM that works too.

Last weekend I finished installing the one piece shaft that I posted above ^ into the transmission of my LS1 engine swapped DeLorean. It didn't require any modifications; I just want to be sure there isn't anything I'm overlooking. So far the results have been very good. There is a tiny bit of whine in first and second gear but thats it. I'm sure it's because the gear faces of this shaft aren't as smooth as the output shaft. The gears are hobbed, but not finish ground to the extent that Renault would have been able to at the factory. Still, I'm sure it's no where near as loud as a straight cut gear.

I'm planning to drive somewhat easy on it for the first 500-1000 miles. I've got some conventional gear oil with break in addatives in it just to break in the shaft for now. After the break in period I plan to drain the transmission and re-fill it with Redline 75w90NS. Red Line Synthetic Oil - Gear Oil for Manual Transmissions - 75W90 NS GL-5 Gear Oil Then theres no holding back :D
 

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