Manifold insulators problem/flaw?

[treyflip]

Hey everyone,

At the moment my setup on my VZ SV6 is something like

Pacemaker full length headers
100 cell stainless cats (i think)
2 1/4 inch catback
Underdrive pulley
Mace Insulators
Growler Intake (previously mace)
VCM tuned

Pulling around 155.1rwkw...

Now i've had the insulators in from the beginning of modding the car and can't remember whether it did it without them. The problem occurs in active select in 2nd gear.
When changing from 1st to 2nd gear around 3000rpm the car during acceleration in 2nd will have a hiccup around 2300rpm. The revs go up, cut out then start back at around 2100rpm.
Its more prominent at half throttle. I can also replicate the problem at most mid range revs if i take off in first 1/2 to 2/3 throttle and change at around 4000rpm into second, again it will accelerate for a while then cut out as if it was in a phantom gear (only dropping by about 200 revs) and continue to accelerate.
It only happens in second gear.

Can it be confirmed if the change in runner length after the insulators causes confusion in the computer hence causing uneven acceleration?

Can anyone tell me if anyone else experiences this problem and is a common but accepted flaw in the vz alloytecs?

And lastly while im here, is it possible to remove the plenum and inlet manifold at once to reach the head as i have a snapped plenum to head bolt that I need to remove.....

ANY THOUGHTS WOULD BE APPRECIATED!


Ps. The car has been tuned before the exhaust and after all mods and the problem was still there making me think it could be a factory flaw... But I will be taking the insulators off to see if it resolves the problem.

 

[treyflip]

Oh and i forgot to mention it is the 5spd auto hence active select.

 

[DevilDRake]

There's been no problem with mine, but mine is a VY not VZ.

I was almost going to call bullshit on the figures, but then i realised you were talking about a VZ not a VY.

 

[treyflip]

Haha, nah its a VZ...
I had another mate with a vz ute that ive been in but didnt get a chance to drive it before he sold it, I think his might have had the same problem in active select but can't remember too well. It was stock.

The only other thing is maybe if someone else with a VZ 5spd auto can see if happens in there car and post back...

 

[kuzman89]

I'd blame the tune before I blamed the manifold insulators. There is no reason why increasing the runner length would do this unless the tune is out imo

 

[one_and_only2004]

And lastly while im here, is it possible to remove the plenum and inlet manifold at once to reach the head as i have a snapped plenum to head bolt that I need to remove.....

ANY THOUGHTS WOULD BE APPRECIATED!

I'd be blaming this Before anything else.

 

[Immortality]

Flat spots would be tune related or a vac leak from the broken bolts. No way that will be from the spacers

 

[treyflip]

everything is sealed and it has.nothing to do with the bolt. its been there eversince I've had the spacers. it was there.before the exhaust before and after two tunes... its not.a.vacuum leak. also its not as though it just hovers.on a certain rev like a flat spot its more like the car changes into another gear.. sorry i can't explain it any better. it does not happen in drive only active select

EDIT: "its been there eversince I've had the spacers." meaning the flaw in acceleration not the snapped bolt. the bolt only happened a couple days ago. This problem has been since i can remember which was when i changed to the spacers.

 

[adz_vy]

the fact that it doesn't occur in drive tells me it probably not the spacers. If you are sure that it only happens in active select then my money would be on the auto or tune.

 

[treyflip]

as it seems like a phantom gear, could it be related to the gearbox or diff? i mean the car seems like it has 2 changes per gear in auto, i dont understand that? im beginning to think im going to have to accept that auto alloytecs are spastics of cars. unless someone else with a 2005 sv6 could test it out for me and see if it happens in theirs..