42 replies to this topic

[S pack]

Found this Torana Gpak commercial

 

173 HQ Belmont had drums as std equipment but disc brakes were std with a V8 engine, also std on 6cyl LS and 6cyl Statesman.

 

HQ SS is reported to have a 1/4 mile time of 18.00 sec and top speed of 114mph, LH Gpak 18.1 secs and 105mph.

Edited by S pack, 22 September 2016 - 10:14 AM.

[yel327]

Almost Dave, disc brakes were standard on V8 models. Pedantic I know but there was no optional 253 in HQ, it was always standard in V8 models (except not available in Deville or GTS350).

 

I'll dig up the SS's road test quarter mile times if I can find them. A 308 manual HQ GTS was around 16.4 from memory and the SS was not that far behind as a 308 with single exhaust had about the same power as the 253 with dual exhaust (but a bit more torque) and they both ran the same diff ratio. As a guess I'd say early 17's for the SS. If you can find a January 1973 Modern Motor it'll have the times in it. AMC in recent times did an SS article too.

 

Original road tests by wheels of a HQ Kingswood 202 4spd with 3.36 rear axle got a 19s quarter. What diff ratio did the Gpak have? If it was 3.36 with 13" tyres that is like a 3.55 in a Holden with 14" tyres so 18.1 sounds pretty right. 

[S pack]

 

Almost Dave, disc brakes were standard on V8 models.

I thought that's what I said? 173 HQ Belmont had drums as std equipment but disc brakes were std with a V8 engine

[yel327]

Very close, but not exactly the same thing. As I said I was being pedantic. A HQ Belmont was standard with drums, a HQ V8 model (not engine) got disc brakes standard. What I'm getting at is a 253 (L32) was never an optional engine you could order and thus didn't automatically come with discs. The 253HC was the standard engine on most V8 models and these models all had front discs. To most intents and purposes the same thing as you say, except when reading original GMH literature you have to make the distinction or it gets confusing, example, there is no place on an order form to option L32. Also disc brakes became standard at some stage I think on HQ Premier.

[S pack]

The Gpak ad says it has a 'Performance Axle' so that should be the 3.36:1 diff?

[yel327]

The only road test data I can find for the SS shows 17.5s in Modern Motor November 1972. Tests in these days were lift throttle shift and two people in the car. What I find interesting though is Wheels June 1973 managed a 16.9s quarter out of a 253 manual GTS sedan which was heavier, ran a 3.08 rear axle and unless optioned would have had a single exhaust. Possible Wheels didn't test it as per normal though.

 

Norm's book has the Gpak with 3.36 rear axle and 175SR13 tyres. SS had 195SR14 tyres and 3.36.

 

175SR13 is approx. 175/75/13 at 593mm OD.

195SR14 is approx. 205/75/14 at 663mm OD, so approx. 11% bigger.

 

So by rough calcs the 3.36 rear axle with the 13" tyres equates to the 14" tyres with a 3.73:1 rear axle. So the 6cyl 4spd Gpak with this combo would be nippy off the mark. Funnily enough, the HK GTS327 with 3.36 rear axle and D70 14" tyres is supposed to be identical gearing to a Camaro with the same driveline but with 3.73 rear axle and D70 15" tyres. 

[yel327]

Also found HQ SS as 3021lb (1373kg). Not sure what Gpak weighs

[S pack]

Found LH Gpak kerb weight at 2612lbs (1185kg)

[yel327]

LH Service manual lists the SLR as 1183kg and the S as 1143kg which is 173 3spd with drums and bench seat. In a HJ a 308 adds 68kg over a 173 so your LH SLR5000 will be about 1250kg. Also 9/74 Sports Car World has an LH SLR doing 18.3s quarter, which will be with a 3.08 rear axle. Also has an LH SLR 4.2L 4spd in Wheels July 1974 doing 16.9s quarter, this will be with a 2.78 rear axle which is the equivalent in a HQ of a 3.08 rear axle with the 14" tyres. So the HQ SS doing 17.5s with a 3.36 rear axle and lugging another 120kg makes total sense.

[kiwi-lilj]

We have a major hijacking situation here

[yel327]

Yeah we do. But at least the discussion is related to the Gpak in the OP!

[yel327]

Which one? Big block Opel or the truncated Starfire?