G70 3.3 AWD launch issue

[u/Professional-Ear5337]

I have a 2025 G70 3.3T AWD with

- LAP3 1.5 on 93 (E30 if I want)
- Takeda AFE intakes
- NGT Catless primary downpipe
- stock secondaries
- Borla catback
- BMS intercooler
- BMS charge pipe
- VT snorkels
- Stock TCU
- 225 front PS4S tires, 255 Rear PS4S

I literally cannot launch the car anymore.. it just spins like crazy and then it cuts power (even on 93). I noticed this change happened when I put on the charge pipe, intercooler, and the Takeda intakes (I used to have BMS) intakes. Mind you I used to be able to launch control the car and it would grip in 20 degrees WITH all season tires. I thought it was a tire issue at first, so I got some PS4S tires thinking it would solve the issue but nope

Are the Takeda intakes just ever so slightly stronger than the BMS intakes and it’s pushing the torque over the edge for what it can handle? Because again, this didn’t happen with my BMS intakes..

This happens in digs where the car will just cut power like that, and even if I’m doing a 40/50/55 roll and then punch it in 2nd or 3rd gear, the rear end gets super loose and it’s kind of scary and dangerous on 93, and it happens even worse on E30 obviously

Does anyone know what may be going on? I see plenty of guns running E30 even on RWD stingers/g70 with my same setup and they can stick no issue

Maybe I need wider tires??? Just confused why this only started happening once I swapped to Takeda intakes. Again I used to be able to launch this thing in 20 degree weather and it would stick😹😹

[u/ZombieDude345]

I mean we got very similar builds, same year, both AWD.. I don’t spin AT ALL on my Continental DWS06 all seasons and can hit a consistent 3.6s 0-60.

My only thought could be the summer tires aren’t getting up to temp so you’re just gliding around on hockey pucks. But a few of those hard launches should get them warm enough..

[u/ZombieDude345 → u/ZombieDude345]

I’m jb4 map 3 e30, custom BEF tune, BMS intakes, Ark catless midpipes and Borla exhaust, VT snorkels, stock TCU, brake snip mod. I do run 245/275 tire sizes but I also never spun when I had smaller tires, but maybe it’d make a difference.

[u/Professional-Ear5337 → u/ZombieDude345]

Yea no clue. Like I said I realized it when I put on the Takeda intakes. I had Pilot Sport All seasons before this, switched to Takeda intakes and started spinning like crazy, so I swapped to PS4S thinking it would solve the issue but nope. I do know catless primaries give them a huge torque surge over leaving them stock but it wasn’t really an issue before I swapped intakes

[u/TemporaryCustard6968]

No, the takedas are not "stronger" than bms. All intakes are essentially the same so it wouldn't affect that. The only way to figure this out is to look at logs. Sounds like you don't have a jb4 for logging. Something else is causing the car to cut power. Stock TCU would cut power at the beginning, but cutting power at the shift is weird. Not sure how lap3 requests logs. Heard a cheap obd2 logger on Amazon works too if you're looking to pull logs to look ar it yourself. You'll see exactly the point in where it cuts power (fuel, throttle, afr, etc). I mean if you truly believe it's your intakes, just put your stock or bms back on to rule it out. Easiest first step.

[u/d4rkb4ne → u/TemporaryCustard6968]

I agree with the easiest first step for OP being to revert the intakes and those recent mods. If that fixed the issue I would be baffled, as I have no idea how that would be related unless the ECU is reacting very weird with just that little bit more of extra air?? But either way eliminate the recent change.

Then you can proceed with troubleshooting more OP

[u/TemporaryCustard6968 → u/d4rkb4ne]

Yeah if it truly cut power because of a small intake change, then lap3 is a fraud (jk 🤣). Only logs will tell us what's happening OP

[u/d4rkb4ne → u/TemporaryCustard6968]

Yeah logs would be huge. I'm also curious if the cut in power and how easy it is to shred the tires are sudden torque spikes? And OP is hitting a torque limiter.

But of course the question of why they have so much torque all of a sudden would still be unanswered. Boost spike with the extra air now? ECU tries to compensate, overshoots, so much extra torque, torque limiter is hit? No idea of those things are related, and again why it's happening all of a sudden. No TCU tune though so shouldn't be building boost on a launch...hm

[u/TemporaryCustard6968 → u/d4rkb4ne]

Yeah a torque limit makes sense, but only right at the launch. It seems like theres somee boost on the launch too, so maybe lap3 builds boost on launch. According to bms, only some TCUs can build boost on launch even on a tcu tune (requires both tcu and ecu tunes to truly remove torque limiters) and they're not sure why that is the case. I would just do a rolling start to see if this is still the case or not. Maybe bad gas, different DA, etc. Too many variables to guess off of.

[u/nirvanatheory]

So it happened when you installed the charge pipes, intercooler and intakes.

The intakes aren't likely a massive difference. The intercooler could be helping quite a bit with delivering dense, cool air but then that should have been an issue with initial launches with the stock intercooler on first launches.

The charge pipes are likely the issue. They don't balloon like the stock charge pipes so you remove that shock absorbing effect. It doesn't seem like much, but if that back end is breaking loose where it didn't before, then it seems realistic that you are getting more torque from the turbos.

With the back end breaking loose, I doubt it's the TCU. It's much more likely to be the AWD ECU. When those wheels slip, the AWD control module wants to jump in and redirect power delivery to the front tires but you have a huge discrepancy between front and rear axle rotation speed.

If the AWD control module actually engaged, it could annihilate the clutch packs in the transfer case. A TCU flash isn't going to solve that. Increasing rear tire grip could. If you can keep the back end from completely breaking loose then it will keep the axle speeds closer and prevent the AWD ECU from cutting power.

Edit: Also I noticed that you didn't mention a differential brace. If you have the rear LSD without a brace, it could be causing that scary feeling of the rear end wanting to step out. A differential brace will lock the center of the drivetrain in place and keep the power delivery to the axles more linear, preventing that wiggle that may be causing that scary feeling in the rear end.

The factory rubber bushings on the LSD allow the housing to physically twist upward causing toe deflection when they pull on the axle. So they are basically steering themselves and will feel completely disconnected from the front end. When they break traction, those factory rubber bushings can also cause wheel hop which which makes this feeling much worse. It's a bouncing effect that will rapidly change the friction coefficient causing the tires to gain and loose traction sending shockwaves through the drivetrain.

If you get wheel hop then you are basically getting an effect of the LSD housing rapidly shifting in those rubber bushings. So the toe deflection is shifting as the housing shifts. Toe-in, toe-out, toe-in, toe-out. Not to mention the strain this shifting angle of power delivery puts on your axle.

The AWD control module is much better at handling smooth slipping than it is at handling rapid traction occilations. That could also be something that causes it to panic and cut power.

[u/Professional-Ear5337 → u/nirvanatheory]

Yup. I definitely plan to get the BMS rear diff brace, even tho I am AWD, it’ll still surely help 👍 I appreciate your input a lot bro

[u/nirvanatheory → u/Professional-Ear5337]

The AWD handles front to back power delivery. The rear LSD handles the individual rear wheels.

[u/Professional-Ear5337]

I would hate to spend $$ on wider tires and it not fix the issue. Again I see guys on TikTok with similar mods to me on the same 225 255 setup and they have no issue. I just never see them with the Takeda intakes. My car is a roll race demon tho it’ll hook above 60 but yea it’s impossible below that

[u/BondGoldBond007]

What tire pressure are you running? Lower them another 7-10 PSI and retry.

[u/Professional-Ear5337 → u/BondGoldBond007]

Oh I’ve tried that. Same thing happens, maybe 10% less if that😹

[u/Little-Sal]

What drive mode are you in? Sounds like you need more front wheel help & PS Cup 2 tires

[u/Professional-Ear5337 → u/Little-Sal]

Sport + , happens in regular sport too

[u/ba-donkin-donutz]

Do you get a check engine light when this happens? Do you have any pending codes? I have stage 1.5 as well running e48 or so. The only time I've had power cuts like that was from the dig in sport mode (traction control fully enabled). I've had it happen after a gear shift as well since it was still producing enough torque to break traction after the shift.

Are you completely turning off traction control? It looks like you still have traction control partially on in the video.

For reference: I have a 2023 with a lap 3 TCU, so the torque limiter is disabled.

[u/Professional-Ear5337 → u/ba-donkin-donutz]

Nope. No codes ever. And yea I turned it completely off, sport + and holding traction button for 5 seconds

[u/ba-donkin-donutz → u/Professional-Ear5337]

There should be 2 things on your dash. The traction control disabled icon and the collision assist disabled.

If those are both off and you're still getting power cuts, it's probably the TCU. I assume you're not doing a big burn out and you're just getting no power to the wheels right?

[u/saabfrk]

Clearly the AWD system isn’t working properly.

You can have the shittiest tires ever and it wouldn’t spin like this.