The "Mighty" A9L

[Sniper]

Gotta luv that Exhaust story ... I've also got an exhaust story circa 1989 that involves Walker in SA - but it not A9L related so it can wait for another day ...

But I have another question that needs clarity and I must state hear and now that I didn't buy a VK in 85 ... I bought mine in 93 so I missed that buying experience .... however there was (apparently) at the time an issue with the noise emissions or something that fundamentally had HDT build the VK GPA with the OE exhaust (complete with chrome tip) and then fit the "Big Bore" (as it was called at the time) exhaust later either at the dealer or Bertie street ... but the Headers were definitely fitted as part of the A9L VK package at Bertie street !!!! ....

[Pickles]

Gotta luv that Exhaust story ... I've also got an exhaust story circa 1989 that involves Walker in SA - but it not A9L related so it can wait for another day ...

But I have another question that needs clarity and I must state hear and now that I didn't buy a VK in 85 ... I bought mine in 93 so I missed that buying experience .... however there was (apparently) at the time an issue with the noise emissions or something that fundamentally had HDT build the VK GPA with the OE exhaust (complete with chrome tip) and then fit the "Big Bore" (as it was called at the time) exhaust later either at the dealer or Bertie street ... but the Headers were definitely fitted as part of the A9L VK package at Bertie street !!!! ....

I think the VK Group A was delivered with the standard rear muffler fitted, the big bore muffler was in the boot, but I think the rest of the exhaust was fitted, just the rear muffler that wasn't!
It could also boil down to the dealer, some dealers would fit the big bore muffler.
Pickles.

[HSVGTS125]

What treatments did the VK "SL" SS Group A get?
I remember a Waltons Blue Group A driving around Townsville in the late 90s early 2000s. I saw it again recently in traffic. I never new much about them other than being Blue or White

[skaifeman]

Great stories fellas.
Very good read for a Wednesday morning.

[TPKW30]

Gotta luv that Exhaust story ... I've also got an exhaust story circa 1989 that involves Walker in SA - but it not A9L related so it can wait for another day ...

But I have another question that needs clarity and I must state hear and now that I didn't buy a VK in 85 ... I bought mine in 93 so I missed that buying experience .... however there was (apparently) at the time an issue with the noise emissions or something that fundamentally had HDT build the VK GPA with the OE exhaust (complete with chrome tip) and then fit the "Big Bore" (as it was called at the time) exhaust later either at the dealer or Bertie street ... but the Headers were definitely fitted as part of the A9L VK package at Bertie street !!!! ....

VK Group A definitely had headers fitted from new - Brock to Dealer.
Story I remember from the day was the rear muffler had a "plug" (similar to welsh plug) fitted to rear
muffler which would allow the car to pass noise tests, but after an x amount of km's, the plug would burn away &
then you would have the natural V8 sound back....
I cant exactly remember (phuck getting old) but I'm almost certain it was the early VH's that came with headers in boot??
I know when the VH Group III's came to the dealer they had headers fitted.
And I also remember doing a stack of leaking "header to head" gaskets- where HDT instructed us to remove the
gaskets, and apply silastic instead. Been using that method ever since.

[Sniper]

There are certainly some fading memories occurring - inc mine .... but I'm sure the rules of international Group A stipulated the Exhaust was "free" beyond the first join on the headers which enabled manufacturers to get creative with header design for the track .... the VKGPA has a slip join approx 12" from the heads which was certainly fitted at HDT along with a streetable set of secondaries .... they got more creative with the VL onwards by creating a dedicated bolt up join from approx 50mm from the heads ... as a consequence of this the VL onwards roadcats had a pretty basic Exhaust header whereas the VK header was a far better street performance proposition ..... someone needs to put pics of these up - I'm hopeless with that tech ...

[TPKW30]

There are certainly some fading memories occurring - inc mine .... but I'm sure the rules of international Group A stipulated the Exhaust was "free" beyond the first join on the headers which enabled manufacturers to get creative with header design for the track .... the VKGPA has a slip join approx 12" from the heads which was certainly fitted at HDT along with a streetable set of secondaries .... they got more creative with the VL onwards by creating a dedicated bolt up join from approx 50mm from the heads ... as a consequence of this the VL onwards roadcats had a pretty basic Exhaust header whereas the VK header was a far better street performance proposition ..... someone needs to put pics of these up - I'm hopeless with that tech ...

I remember also working on L34's & from factory & they also had headers with the first join approx
5cm from the head. First time that idea used I think.
Still trying to picture in my head what VK's had - it will come to me sooner than later.......

[Smitty]

VKs....exhaust were longish with a slip joint bit like the Genie set up
(have a set at home as I ran them when I started back circuit racing, running Paccies now)

the VL looked like these VNs... with a joint right up close to the head



L34 type was completely different, have seen one and have the LH manual
which clearly shows the long flange setup on the exhaust headers

pics give you the sort of idea with the L34 ...

[TPKW30]

VK Group A had H & M headers & 2 inch system from new - I'm 99.9% sure on that.

The VL/VN type you have pictured is what the race L34 had - once again 99.9% sure.
I remember x-mas eve, gee, around 1980 everyone had gone home but I was stuck at work
doing an exhaust leak on an L34 at the four flanges on the headers......

[Sniper]

A9L Cams are a touchy subject and I've read all sorts of conjecture on the net over recent times .... so here is my overview

The VK had a special cam supplied by Aunger in Adelaide which later became Crane Technologies and is now Automotive Performance Distributors .... it was base around milking the "lift" rules and sadly had pretty open lobe separation (111 or 112) and short duration to pass 1985 emissions

These lift rules were dropped by the FIA in 86 so Holden was able to use stock type cam profiles in subsequent A9L's

The VK Cam was no real favourite with owners and many were replaced with the Crane 276 .... which HDT had Wade copy and refer to as the Wade 169 .... HDT used the 169 in their HO packs in the VH - VL ...

HDT also used a copy of the Crane 264 which was called the Wade 242 in the Auto HO packs in non A9L's

There were varying HO packs used by HDT with the most popular being the removal of the heads and whipping off 45 thou to raise the comp to 9.2:1 .... there were other HO packs that got the full job inc L34 pistons that generated a comp ratio of 10:1

Being a South Aussie, I wasn't totally across all the shenanigans at Bertie Street but this info will be close

None of the HDT Engine options floated my boat so I went down my own path to achieve the results I felt were possible !