I have recently had some work done to my LS1 5.7 Holden. Do you know a reliable way to convert horsepower at the wheels to horsepower at the flywheel?
The relationship between flywheel and ATW power depends on many factors - gear selected for the chassis dyno run and dyno-to-dyno variation to name just two. As a guide, however, consider what a standard LS1 makes at the wheels - we've dyno'd a 225kW CV8 Monaro and found a 27 percent driveline loss, a 255kW HSV R8 suffered a 32 percent loss and a 300kW HSV300 had a 30 percent loss. Note that these figures were all 6-speed manual vehicles driven in third gear on ChipTorque's Dyno Dynamics chassis dyno. We can only assume the manufacturer's claimed flywheel figures are accurate, so - given this - we'd suggest there's a 30-odd percent power loss through the standard 6-speed manual driveline.
Slow and Thirsty RX-7?
Regarding your Series 4 RX-7 article - where did you get your 0-100 time for? It sounds hugely pessimistic, since most other sources quote mid-6s for the manual turbo. I think mid-6s feels much closer to the mark. Also, quality low kilometre Australian delivered S4 RX-7s are often found up here (Queensland) for $11 to $12k, so an import doesn't always make as much sense. Oh, and the fuel consumption of my stocker is 10-litres per 100km on the highway and 13 to 14-litres in the city.
The 0 - 100 time we listed for the manual was based on a new car test by Wheels in 1989. Certainly - at the time of writing - the price of locally-delivered S4 RX-7s varied hugely depending on mods, kilometres and whether or not an engine rebuild had been performed. There wouldn't be much point buying an import RX-7 if an equally good condition local example was available for the same price - as always, you have to shop around. Perhaps our relatively poor 15-litres per 100 consumption was partly due to the auto trans - but we doubt whether you'd get much better in the particular car we tested.
Doesn't Really Suck
I just wanted to drop you a quick note to say how helpful your article 'Rex Sucks' has been and how easy and simple it was to follow. I own a 1992 Liberty RS and, up until Saturday, it was completely untouched. I ordered the replacement inlet plenum from MRT some time ago and, with a heat gun and some poly, had the job completed by Saturday arvo. As you would know, the Liberty does not have the same front brake scoops as found on your Rex; I made a snorkel to connect to the existing mounts for the factory in-guard resonant chamber (what a beast!) and the inlet is only just visible from the road. Once completed, I took the car for a drive on the roads around Kalgoorlie and noticed an immediate improvement in throttle response and pick-up. I look forward to your next update on the progress of the mods to your car - you make it very simple for beginners like me, so please keep up the good work.
Bigger than Big!
I received this email today and thought you guys might be interested. I wonder what sort of dyno they use to read the power figures!
Not A-n-o-t-h-e-r WRX or Evo!
I hate to complain as I think your mag is great but... I am sure I'm not alone in saying that I'm sick of technical articles on nothing but goddamn Subaru Imprezas or Mitsubishi Evos. We all know they are powerful and easy to tune but, hey, we can't all afford to buy them and furthermore we can't all afford to insure them. How about a few more tech articles on 'real world' cars, eh? Tuning hot hatches or, as the Americans call them, sports compact cars? Turbo conversions, nitrous applications, air filter guides, exhaust tests - all for the average petrolhead type cars, not rally-bred supercars.
Sorry to moan, but each time I look forward to receiving notice of the latest issue of you mag and each time you publish more Subaru or Mitsubishi stuff... BORING! I hope you take this as it was meant - constructively.
First - in Australia at least - Impreza WRXs can be bought for around $20,000 and Lancer GSRs (non EVO) can be bought for about $17,000. A new base-model family sedan, meanwhile, is about $30,000...
Certainly, cheaper hot hatches can be bought from around $4000 (an old Pulsar turbo or twin-cam Corolla, for example) but by the time you bring them up to a level of performance that'll be competitive at the traffic lights, you need to do a l-o-t of mods. The turbo conversion you mentioned can cost in excess of $5000 on its own and, of course, reliability and resale value fly out the window. That's why it's easier - and often cheaper overall - to buy one of the aforementioned "supercars".
Granted, insurance for these cars can be a major issue in Australia as well, but as soon as you start modifying any car, insurance premiums skyrocket. The more mods, the less chance you have of finding coverage.
Furthermore, many of the stories that we do are relevant for any type of car. The moulded cold air snorkel we made for our WRX (Rex Sucks article), for example, is an idea that can be transferred to all cars with an airbox. The same goes for our previous stories on exhaust systems and more. Don't just look at the cars being modified - look at the concepts.
Vanished Water Pump
I was just wondering why you say the write up of the Davies Craig electric water pump is no longer available? Did the pump not increase power as per Davies Craig's claim?
As quoted in place of Part One of that evaluation...
"We recently spent a great deal of time and energy extensively testing the newly-released Davies Craig Electric Water Pump. The story in this issue was intended to be Part 1 of a 3-part series on this interesting device. Testing of the pump was carried out on two different cars on both the road and dyno. As a courtesy, we showed Davies Craig the test results that we had found. Unfortunately, because of their responses, we now feel that we cannot bring these stories to you.
Thinly veiled threats of legal action from large companies can do that...
Other than that we can't say too much - aside from the fact that none of the AutoSpeed staff cars are using the aforementioned product.