[Tanzanite2022]

Wanted to start a thread for those of you who are well into modding your G8x platform with the new 8HP76. Since there is no concrete proof of the tq rating, we are going off of the tq rating of previous models and determining it is 760 Nm or around 561 ft-lbs. It is not taking much at all in terms of modification to get to this number.

Who here is documented above this? Have you had any issues? Do you have the AWD or RWD varient? How many miles have you driven with tq above 561? How many times have you used launch control?

[Erebor]

Originally Posted by Tanzanite2022

Wanted to start a thread for those of you who are well into modding your G8x platform with the new 8HP76. Since there is no concrete proof of the tq rating, we are going off of the tq rating of previous models and determining it is 760 Nm or around 561 ft-lbs. It is not taking much at all in terms of modification to get to this number.

Who here is documented above this? Have you had any issues? Do you have the AWD or RWD varient? How many miles have you driven with tq above 561? How many times have you used launch control?

You are correct, the ZF8HP76 is rated for 760Nm. But the torque converter itself can handle a lot, and i mean A LOT, more than that.
I wouldnt expect any issues with it below 1000Nm. Depends on the usecase though. For constant launch control starts, which is a lot of stress for the transmission, you might want to reduce the torque a smidge. Keep the oiltemps in check and that thing can handle quite a punch.

[Tanzanite2022]

Originally Posted by Erebor

You are correct, the ZF8HP76 is rated for 760Nm. But the torque converter itself can handle a lot, and i mean A LOT, more than that.
I wouldnt expect any issues with it below 1000Nm. Depends on the usecase though. For constant launch control starts, which is a lot of stress for the transmission, you might want to reduce the torque a smidge. Keep the oiltemps in check and that thing can handle quite a punch.

Interesting and you definitely have some insight I had not read before. I have had my fun with very high hp cars but for this one I want to tweak it a little to make it mine but don't want to push any boundaries. For me it will probably just be intake, single midpipe conversion and a tune....maybe E85. With those alone I know I'll be over the 561 mark so 1000Nm sounds a lot more safe since that is around 738 tq.

[Erebor]

If you want to see what might be possible with that gearbox, check out what the M5 F90 comp is able to deliver with tunes. It uses basically the same transmission.

[FSociety]

Originally Posted by Erebor

If you want to see what might be possible with that gearbox, check out what the M5 F90 comp is able to deliver with tunes. It uses basically the same transmission.

Yep, on the F90 M5 HCP limits the Torque on the 18-19 models to 737 ft for daily use and 811 ft for racing days. There's some cars like the 2020 models that have only Torque Limits via the ECU so they do 785whp/760wtq

2019 Model Custom ECU & TCU by HCP
https://www.instagram.com/p/CXjga-2K..._web_copy_link

2020 Model - Custom ECU by HCP

[StockM4]

Safe to say we will need a built tranny after stock turbos?

[GixY2K]

I'm glad to hear these numbers.

My target is 650hp/650tq, which apparently this engine/trany is more than capable of generating/supporting.

I was telling the boss just yesterday how we had to change fuel injectors, fuel pump, go catless, flex-fuel, and a tune just to brake into the low 600s with the GTR.

And with the S58, all you practically need is a tune; e85 if you want to get in the 9s (from what I've heard, at least).

[FSociety]

Originally Posted by GixY2K

I'm glad to hear these numbers.

My target is 650hp/650tq, which apparently this engine/trany is more than capable of generating/supporting.

I was telling the boss just yesterday how we had to change fuel injectors, fuel pump, go catless, flex-fuel, and a tune just to brake into the low 600s with the GTR.

And with the S58, all you practically need is a tune; e85 if you want to get in the 9s (from what I've heard, at least).

S58 on the X3M/X4M which I currently have can make 650whp/650wtq no sweat!

Heck the BM3 OTS Stg1 & Stg2 E30 make 600-640whp already

[Visconti]

Originally Posted by GixY2K

I'm glad to hear these numbers.

My target is 650hp/650tq, which apparently this engine/trany is more than capable of generating/supporting.

I was telling the boss just yesterday how we had to change fuel injectors, fuel pump, go catless, flex-fuel, and a tune just to brake into the low 600s with the GTR.

And with the S58, all you practically need is a tune; e85 if you want to get in the 9s (from what I've heard, at least).

So far these transmissions have been good, and honestly so have the motors.

Our STG1 Tuning on the X3M with E50 goes 10.4x consistently full weight - and that thing is a heavy

Another X3M we do has stock downpipes, goes 10.22 - that's the record.

(Ricer Math) With Port Injection and better traction it's a 9second truck.

Driveshafts, front diffs have been the weakest link on the X3Ms - when drag racing.

The only time the transmission has a problem with slipping is when the tuner messes with the trq value going to the tcm. Some have done this in the past to bypass a trq limit - this isn't the correct way to tune.

The G8X's do have wheel hop issues which has already caused a very expensive failure for someone.

I know of 2 S58 failures in the G8X platform, 1 was a hydro lock from a meth kit gone bad, and another was pushing the platform - we weren't involved with either.

Point is, the S58 is a beast, and so is the transmission.

[Erebor]

Well engine wise, since the S58 has taken over the connection rods from the S63 engine, i guess it's safe to assume that the engine itself wont push far beyond 900Nm, before the rods are starting to bend.

[Froz3n_M]

If we can see 650 ish TQ to the wheels, safely, I would be satisfied.

[Limegrntaln]

I saw this posted on FB, yesterday. People are definitely pushing the envelope. Id be down for this, safely. 911 Turbo S killer.

[Froz3n_M]

I wonder what it would take to make 650 HP and 650 TQ to the wheels max, and then run a map for 550 hp and 550 tq daily.

I know its obviously possible, just what the setup to achieve that would entail.

[GixY2K]

Originally Posted by Froz3n_M

I wonder what it would take to make 650 HP and 650 TQ to the wheels max, and then run a map for 550 hp and 550 tq daily.

I know its obviously possible, just what the setup to achieve that would entail.

I'm going to go on a limb here to say that this would most definitely require full access to your DME (unlocked), e85 flex-fuel capabilities, a tuner that has access to a dyno. CAI & pipe may just not be necessary with this extremely capable engine.

[Limegrntaln]

Originally Posted by GixY2K

I'm going to go on a limb here to say that this would most definitely require full access to your DME (unlocked), e85 flex-fuel capabilities, a tuner that has access to a dyno. CAI & pipe may just not be necessary with this extremely capable engine.

I remember seeing a car on FB, probably a week ago, with the fully unlocked DME, with just an E50 blend, everything else, stock, running 9.90s. in the 1/4. Im sure that car has to be close.

[Froz3n_M]

We don't think the JB4 can do it with some blend? Not running a crazy map either. Maybe with some supporting mods?

[GixY2K]

Originally Posted by Froz3n_M

We don't think the JB4 can do it with some blend? Not running a crazy map either. Maybe with some supporting mods?

My take on the JB4 is that it maxes out, CURRENTLY, somewhere around low to 'maybe' mid 600s since it's limited to e40.

I forgot to mentioned that on the fully unlocked DME, you'll require a fueling system that will support e85. Now this opens the question as to whether that's all you need to go full e85 with the JB4 and thus increasing hp output.

But full disclosure, I'm also learning about the tunability of the S58. Not like my GTR which was pretty simple in comparison; point and shoot when it came to upgrades.

[Limegrntaln]

Originally Posted by Froz3n_M

We don't think the JB4 can do it with some blend? Not running a crazy map either. Maybe with some supporting mods?

Im not sure anyone is in the 9s with a JB4, even with full boltons. I think Darrell Coleman is pretty close, if that's the case.

[Limegrntaln]

Originally Posted by GixY2K

I forgot to mention that on the fully unlocked DME, you'll require a fueling system that will support e85.

Read the bottom of the picture, then the HP figures, I posted in post #12.

[FSociety]

Originally Posted by Froz3n_M

I wonder what it would take to make 650 HP and 650 TQ to the wheels max, and then run a map for 550 hp and 550 tq daily.

I know its obviously possible, just what the setup to achieve that would entail.

You can do it with E30 easier than on 93 and safer, we do 600whp/600wtq on BM3 STG1 E30 OTS on X3M/X4M
630-650whp i've seen on STG2 E30 OTS
Custom Maps would prob be better to have it right where u want it

on BM3 Custom Tune with either a HCP, Paul Johnson, or Cary Jordan to name a few great tuners on the platform.

[GixY2K]

Originally Posted by Limegrntaln

Read the bottom of the picture, then the HP figures, I posted in post #12.

I just saw that. That is crazy and unbelievable.

On one hand, I'm happy to stand corrected. But on the other, I wonder how long this set up will last, or if said dyno is just a snapshot/milestone of a 'work in progress' of an S58 that will eventually get upgraded parts, and so we won't see the reliability of running those numbers w/out at least an upgraded fuel system.

Has anyone posted the telemetry from the S58 stock fuel system? Are the pump(s) and/or injectors running within specs or are being maxed out?

[Limegrntaln]

Originally Posted by GixY2K

I just saw that. That is crazy and unbelievable.

On one hand, I'm happy to stand corrected. But on the other, I wonder how long this set up will last, or if said dyno is just a snapshot/milestone of a 'work in progress' of an S58 that will eventually get upgraded parts, and so we won't see the reliability of running those numbers w/out at least an upgraded fuel system.

Has anyone posted the telemetry from the S58 stock fuel system? Are the pump(s) and/or injectors running within specs or are being maxed out?

I definitely agree. And I haven't seen any fueling specs to compare anything to. You'd think, by now, we'd see some injector duty cycle and turbo maps.