UN1 CWP upgrade

[John Drew]

If I told you that it is possible to make a super strong CWP for UN1, how many would be interested?

OEM crown gear has 35 teeth 194mm diameter; pinion has 9 teeth, both right hand spiral.
I'd like to revise number of teeth thus making parts stronger and keep 3.750 ratio. I'm considering using Klingelnberg-Palloid cut and the best steel on the market . Cryogenic tempering will be available at small extra cost. Since CWP is the next weak link, it makes sense to make this part(s) stronger. All V8 are vulnerable (especially tuned ones), as well as high performance 4L-s.
Please let me know if you are interested. I'd like to initiate a Group Buy in the near future

Price estimate would be under $1995 /piece, ground and Cryo Treated. They should be able to handle 400 LB-FT.
Approx 24 weeks lead time from the completion of the design.
Any thoughts?


Cheers
John
[email protected]

For UN1 with EMCO* shaft/gear kit:

***
Final Gear Ratio : 3.75
Tire Size : 285-35-18
Max Power RPM: 6400
Limit RPM : 7000
***

*
Gear Ratio Compound
*
1 ... 3.000*... 11.250
2 ... 1.940.*... 7.275
3 ... 1.381..... 5.179
4... 1.037..... 3.889
5 ... 0.820..... 3.075

***
Gear MPH/1000 ; MPH @6400;..MPH @7000
***
1 .......6.84.....44..... 48
2 .....10.58......68.....74
3 .....14.86..... 95.....104
4 .....19.78.....127.....138
5 .....25.02.....160.....175

***
MPH RPM (in Gears)
***
.......... 1 ........ 2 ......... 3 ...... 4 ........ 5
***
5 ... 731 .. 473 .. 337 ... 253 . 200
10 1462 .. 946 .. 673 . 505 ...400
15 2193 1418 1010 .. 758 . 600
20 2925 1891 1346 1011 . 799
25 3656 2364 1683 1264 .. 999
30 4387 2837 2019 1516 1199
35 5118 3310 2356 1769 1399
40 5849 3782 2693 2022 1599
45 6580 4255 3029 2275 1799
50 ......... 4728 3366 2527 1998
55 .......... 5201 3702 2780 2198
60 .......... 5674 4039 3033 2398
65 .......... 6146 4375 3286 2598
70 ............. 6619 4712 3538 2798
75 .............. 7092 5049 3791 2998
80 .......................... 5385 4044 3198
85 .......................... 5722 4296 3397
90 .......................... 6058 4549 3597
95 .......................... 6395 4802 3797
100 ........................ 6731 5055 3997
105 ......................... 7068 5307 4197
110 ...................................... 5560 4397
115 ...................................... 5813 4596
120 ........................................6066 4796
125 ....................................... 6318 4996
130 ....................................... 6571 5196
135 .........................................6824 5396
140 .........................................7076 5596
145 ................................................... 5796
150 ................................................... 5995
155 ...................................................6195
160 ....................................................6395
165 ...................................................6595
170 ....................................................6795
175 ...................................................6995
180
***
Gear Change RPM drop (change @6400) RPM drop (change @7000)
*
1->2 -2261 (To 4139) -2473 (To 4527)
2->3 -1844 (To 4556) -2017 (To 4983)
3->4 -1594 (To 4806) -1744 (To 5256)
4->5 -1339 (To 5061) -1465 (To 5535)
*

 

[JP Verweij]

400 LB Ft equals 400bhp.
Toghether with a Quaife ATB diff or other LSD will raise that number significantly.

But whats are the other weak links in the UN1 gearbox. Ill guess its not just the CWP thats the weak link.

 

[Neil]

400 LB Ft equals 400bhp.
Toghether with a Quaife ATB diff or other LSD will raise that number significantly.

But whats are the other weak links in the UN1 gearbox. Ill guess its not just the CWP thats the weak link.

400 lb ft = 400 BHP only at a particular RPM. What is important as far as a transaxle is concerned is its torque rating. That can be mitigated somewhat by how light the car is and how sticky the tires are.

 

[John Drew]

But whats are the other weak links in the UN1 gearbox. Ill guess its not just the CWP thats the weak link.

Next is the axle shaft with its dreadful undercut.

 

[Kev Farrington]

I don`t know if its been mentioned but the gearbox casing has been known to flex slightly allowing bearings to move as far as I can remember.. I wouldn`t really put lots of power through one. I`d use a Porsche box instead, given the choice.

 

[John Drew]

If you get Lotus Esprit V8 g/box, you won't have this problem. Casings have been beefed up in 1997/8.

 

[John Drew]

If anyone needs stronger casing for UN1, I can get it for you.
PM me at [email protected]