Differences between 1gen and 3gen

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wachu
Posts: 2
Joined: 18 Jan 2026, 11:02

Differences between 1gen and 3gen

Post by wachu »

Hi guys,

I need some help with understanding the differences between 8HP generations.

Lets assume that all following transmissions are more than enough for my project when it comes to maximum torque:

1. 1gen 8hp70
2. 2gen 8hp50
3. 3gen 8hp51

1gen - According to 8hp.info and some wikipedia, the 1gen should be the slowest and "worst" one.
2gen - Brings major internal improvements as well as better gear ratio's.
3gen - Minor improvements over the 2gen, also does not work with TCU without swapping the valve board.

So my question is, with the turbolamik TCU will i feel some improvement if i choose 2gen transmission instead of the 1st gen? or i should just find the cheapest 1gen available and call it a day?


Thank you in advance.
M4comp
Posts: 105
Joined: 26 Jun 2024, 03:21

Re: Differences between 1gen and 3gen

Post by M4comp »

My take is that you need to build the transmission for the application—meaning the clutch materials and hard parts should match what you expect it to do. If you’re building a hot rod that you occasionally drive to work, almost any of them will work just fine.

I’ve had 50-series units hold torque they really shouldn’t have, mainly because they were maintained with frequent fluid changes. On the flip side, I’ve seen people buy a used transmission and then blame everyone else when it suddenly finds an extra neutral.

It’s honestly hard to give a one-size-fits-all answer. Personally, I’d take a good deal if I found one, but I always base the decision on torque capacity. If you’re close to the advertised “max” I’d step up to the next size if space allows.
wachu
Posts: 2
Joined: 18 Jan 2026, 11:02

Re: Differences between 1gen and 3gen

Post by wachu »

Hi M4comp,


Forum seems to be a lil bit dead, so thank you for the response, was not expecting that.. :)

I opted for 8HP50. I really wanted 8HP51 as it is the latest gen and according to all info i found should be the most efficient and overall the best one, but not supported by TCU unfortunately. I think i will be just happy enough with 8HP50, i will probably never reach its maximum "official" torque anyway.

Best Regards,
Wachu
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