Do these headers need thermal lagging? Their advert (see Chrome's thread here) seems to state they are sprayed. Anyone know about the v2 spec?
911

 

ive just been into an exhaust manufacturer today and he commented on my headers being wrapped he says it voids any warranty as stailess steel cracks under high temps and by wrapping them you make it harder for them to cool down

 

911, you can get the jet coated ones ( i have )

 

GRaham, gruppe s v2 come either "raw" or jet coated. They dont "need" either, but it helps on the scoob, due to wiring locations. They cool down quick enough.

 

i can vouch for that as mine nearly melted due to touching the headers never seen my engine check light come on as much

 

The oil filter cops it too!
I think I have 2 thoughts here, keep it hot for the benefit of the gasses/turbo, and to insulate the 'surroundings' from the heat.
If the headers are polishes then the heat does not escape so readily.
Thanks for the responses as ever.
911

 

I wrapped my headers, uppipe, turbo and downpipe on this engine (hks headers) and my last car (gruppe-s) with no cracking/failure problems.

Andy

 

My headers and up-pipe are wrapped

Never heard of wrapping them voiding the warranty or cracking.............. (if they are properly coated and then wrapped maybe they would crack........)

 

Do one or the other as I found out to my expense.

 

Andy/Harvey, is there any tangible difference between HKS/Gruppe S in fit and performance, especially with the Sti v3 up pipe?
Been offered some wrapped HKS (''slightly unequal length'') at a reasonable price.
It will be matched with one of your turbo's Andy and an Apexi over Xmas!
911

 

Not a great deal of difference, the HKS collector looks a bit better inside as it has a cone at the junction of the 4 pipes to smooth out the flow. Also no flange problems on any of the early/late HKS that I'm aware of.
Both them fitted well, the later Gruppe-s giving greater clearance to the surrounding wires.

Andy

 

Thanks for that Andy.
I want to keep the burble, and it seems the Gruppe s V2's are better than the V1's.
The GB spec is with the helix flex up pipe.
Makes sense to fit it all when I order and get your turbo.
911

 

No experience with the HKS byt lots with Gruppe 's'. Some leak probs, header to up-pipe. Soted with a thicker flange adaptor from H+S.

 

I read that the V2 spec have mods to stop this (thicker flanges)
911

 

911 I have bought the Jet coated headers and also a v2 Helix up pipe which I am told addresses the leak problems as it has a flexible centre section.

Haven't fitted them yet so can't comment but will post again once they are on.

What I have been recommended to do is to rub the flange surfaces down with sandpaper to ensure a perfectly flat surface prior to fitting!

Have been told not to wrap the coated headers and to wrap the flexible up pipe in 3 stages - ie wrap at both ends and centre seperately as the pipe is flexible and if wrapped in one continous wrapping it would be more susceptible to breaking apart.

 

I have/had the v2 gruppe s headers on mine with the flexi up pipe, and they worked very well.

Mine were the 3rd set i have installed and there has been no problems. The flanges are certainly thick, but not perfect.

The procedure i used was as follows

install the headers.
remove brackets for turbo support
bolt up pipe to headers evenly
bolt up pipe to turbo

by removing the brackets, it allows for movement at the turbo end, and doesnt put as much stress on the bottom flange IMO

 

I also thought the Gruppe-s now has a 3 bolt flange on the up pipe intstead of two.

I filed the flanges flat on my V1 Gruppe-s and added a thicker gasket. If it leaks then I'll add 2 extra blots to the flange.

Mark A

 

Steven, are you saying that you have run the car with neither turbo/uppipe support bracket?

Andrew...

 

Andrew, you are correct.

 

The turbo support brackets are substantial parts, and the turbo quite heavy. Won't the vibration eventually fatigue the flex u/p?
The water pipes and oil filter run close to the stock header cross tube at the front of the engine, and on the www.flat4.com site (I think) there are a set of HKS headers with local shields bolted to the header tubes in these areas.
I'm sure a simple stainless shield could be arranged to protect these areas with the Gruppe S?
911