High torque "wobble"?

[TTahoes]

I have a stability issue on my 2018 PPV that I am curious whether anyone else has experienced.

Details:
-2018 Tahoe PPV 2wd
-Full Belltech drop kit (springs and shocks)
-slight negative camber and slight toe-in alignment

Issue is this beast is turbo'd and putting down 800-1000 ft-lbs of torque on a typical on-ramp acceleration and it starts oscillating (rolling) back and forth while on the power that creates a puckering, handful of a ride. I thought this may be an alignment issue due to me correcting the steering but I had a really wide on-ramp run yesterday and held it steady and it is the same experience. I'm thinking this is due to the soft initial spring rate from the Belltech springs but it is just a theory. Truck rides so much better than the PPV springs, reinforcing my theory.

I'd like to keep the new stance with lowered springs but I can't afford the instability. If the consensus is the spring rate, any suggested suppliers for lowering springs that are straight rate and/or stiffer?

My next step, assuming no one has experienced this, is to change out the Belltech front springs for the PPV springs and use the Belltech drop spindles I also have in the garage. This could fix the front but then I will have a new handling imbalance I'm sure....

Let me know if there is any additional information or something I haven't thought of.

Cheers,

Kim

 

[ReaperHWK]

1000 ft-lb of torque?? I want to see this engine and specs!

 

[strutaeng]

HoLee Chit PPV Batman!!!

Let's see a video of the complaint...

 

[89Suburban]

@randeez

 

[TTahoes]

1000 ft-lb of torque?? I want to see this engine and specs!

I have a fueling issue that I'm hopefully solving tomorrow with the installl of a Walbro 525, but we'll see.

Example punch before "the clatter" and I lifted:

I'll see if I can find an on-ramp run later.

Once I get the tune fully dialed in with the new fuel pump (spark, SOI/EOI, etc.), I'll put it on a chassis dyno to confirm all of the numbers by a third party.

 

[TTahoes]

HoLee Chit PPV Batman!!!

Let's see a video of the complaint...

I'll grab one in a couple of weeks. Fuel pump tomorrow and tied up thereafter for a few weeks. TBC...

 

[LsHart]

I just went thru this or something close. It's the panhard bar. Need an adjustable one.my 04 tahoe

 

[TTahoes]

I just went thru this or something close. It's the panhard bar. Need an adjustable one.my 04 tahoe

So is the axle off centerline? I'm going to have to pull some measurements. What is the specific issue that the OEM panhard bar is causing in the lowered condition? I'm "all ears" as I have to get this addressed.

 

[PG01]

So is the axle off centerline? I'm going to have to pull some measurements. What is the specific issue that the OEM panhard bar is causing in the lowered condition? I'm "all ears" as I have to get this addressed.

Yes and iirc, rear end pushes out towards driverside when lowered but i could be making that up… lol

 

[TTahoes]

I have a fueling issue that I'm hopefully solving tomorrow with the installl of a Walbro 525, but we'll see.

Example punch before "the clatter" and I lifted:

View attachment 494600

I'll see if I can find an on-ramp run later.

Once I get the tune fully dialed in with the new fuel pump (spark, SOI/EOI, etc.), I'll put it on a chassis dyno to confirm all of the numbers by a third party.

Walbro serious disappointment. Pressure falls off even worse than stock. Posted details in "Performance" if anyone here can guide me into a solution. So frustrated, that I was hoping I missed a connection and the thing caught fire on the shakeout run....

 

[LYNMUP]

I just replied to you over at HPTuners Forum, get you a set of these to cure this for good...I returned the panhard bar as it didn't look like it would fit. I didn't need it anyhow. Got them from Jegs. Stay with the Walbro 450 for better control with our voltage modulated FCM.

 

[LYNMUP]

I would like to ad that I went with the Bilstein shocks for the XL and it does not squat as bad now and helps with stability while keeping the front down on the ground.

 

[Joseph Garcia]

I would like to ad that I went with the Bilstein shocks for the XL and it does not squat as bad now and helps with stability while keeping the front down on the ground.

Are you saying that the Bilstein shocks lifted your truck's back end, or are you saying that the momentary back end sag during acceleration has been reduced with these shocks?