TRNW-2: 6L80e performance builds ?

[jbockus at hiwaay.net]

I've done one on a 13 GMC Sierra 4x4 with a supercharged 6.2 producing 
700 rwhp. The customer supplied their own performance rebuild kit which 
included the Sonnax 4-5-6 hub, Sonnax billet 1-2-3-4 piston, Sonnax HD 
4-5-6 apply piston kit and a Sonnax Sure-Cure kit. It also came with 
Raybestos clutches and kolene steels and all bushings and bearings. He 
had also ordered a billet torque converter but I forget the stall, he 
wasn't happy with the stall and we ended up replacing the converter with 
a PTC billet converter and I don't remember the stall on it either. He 
originally had someone that I am unfamiliar with tune it and he wasn't 
quite happy, so I referred him to our local tuner, Tommy Blackard who 
works for PTC and he was able to get another 150 HP out of the engine by 
just tuning! This truck is bad-ass! It is his daily driver but he does 
take it to the drag strip on the weekends. I built it about 4-5 years 
ago and it's still running strong. By the way, the Raybestos clutches 
caused a 2-3 squawk which was eliminated with 2 tubes of Lubeguard 
shudder fix.

On 2025-10-21 5:41 am, Fred Whitaker via trnw2 wrote:
> I have never done any "performance" 6L80's either. But I did the
> Transgo kit once in a big box truck.  I wasn't all that impressed. It
> was back when they first came out.  I remember the shifts not
> matching. (some were almost harsh,while others seemed normal)  That
> said I didn't HP tune it,which is probably why.
>   Intermediate shaft (or 456 shaft) is the second thing that comes to
> mind as weakest link. Torque converter would be #1 and is where I
> would spend a big part of the money.
> 
> -------------------------
> 
> From: trnw2-bounces at trnw.net <trnw2-bounces at trnw.net> on behalf of
> Steve Everett via trnw2 <trnw2 at trnw.net>
> Sent: Monday, October 20, 2025 9:02 AM
> To: Technical Discussion Forum <trnw2 at trnw.net>
> Subject: TRNW-2: 6L80e performance builds ?
> 
>   We have an insurance inspector inquiring about his own personal
> truck,  which has a 5.3 with twin turbos !  I've not done any
> "peformance" builds on 6L's as of yet, haven't had anyone ask really,
>   I know there is a heavy duty 4-5-6 hub and shaft, but I thought
> someone might have come up with some stronger 3/5/r or 1/2/3/4
> hub/shafts by now ?  but I've not seen any in a quick search,
> transgo has their tow n pro kit
> 
>    Anyone done any performance stuff on 6L's ?  what did you use ?
> 
>    Steve
> This message was sent from the TRNW Technical Discussion Forum (trnw2). 
> You were sent this message because you have subscribed to our mailing 
> list. If you don't want to receive these emails from TRNW in the 
> future, please unsubscribe here:
> https://www.trnw.net/unsubscribe.php?forum=2
> TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355