Martin - certainly not trying to pick a fight with you because I'm in the market for some Compomotive MOs for my ZT400, just fitted winter tyres to the OEM alloys and am interested in slightly wider rims for summer so I can fit slightly wider rubber and end up with tyres lasting longer than 3000 miles with my girlfriend driving.
But your thread title really does sound a bit of a troll doesn't it?
Saying 'who really thinks their car is quick' and then saying we all drive 'slugs' - when you're sitting there with a 700 bhp 4wd Escort... well yeah, most cars will feel like 'slugs' compared to what looks like a rallycross machine with monstrous power.
The ZT V8 is, what, 1800 kg? Yeah, that's heavy, but is it heavier than similarly sized large-engined sports saloons? It's got a lot of torque, but there are two main problems with the standard car.
1. The gearing is so long in the lower gears that there's little torque multiplier. I guess it's long because it's not a fast shift until you learn the gearbox, but the benefit of long gears is that they have a large range. With a big flat torque curve, you can leave the car in 3rd for any B road driving and 4th for anything up to very illegal speeds.
2. The standard engine can't breathe. Both intake and exhaust manifolding is tortuous, and the engine design itself isn't a high revver.
Calling the car a 'slug' though is flamebait, and it's testament to the maturity of the car's legion of owners that nobody has bitten. After all, it's not as if the majority of owners only bought them because they were cheap, and don't give much of a damn - most of the cars are owned by owner's club members, and are enthusiasts who love the cars.
The reason it 'feels' slow is the gearing and the rev range. Hence it's very deceptive and you only realise that it's a quick car when you actually *race* someone else. Forget standing starts and urban 0-50 dashes - even though the power-to-weight on my car (400 bhp, 430 lb ft) is reasonable, I can't get traction. Rolling dual-carriageway / motorway 'races' against other 'quick' saloons remind me that the Growler is actually pretty nippy.
When I think of the word 'fast' though, I think of insane acceleration, immediate transients, cricket-bat-to-face braking, and snap-snap-snap gearchanges, along with a screaming engine that revs high. You can have a 'fast' car with a top speed of 120 mph (some Caterhams won't go that fast flat out). My other car feels 'fast' to me - it's nothing like your 700 bhp Escort but it's fast compared to virtually everything else on the road, and can also drive to Switzerland in a day without being uncomfortable to the driver and passenger. It's a 240 bhp Lotus Exige PP. It feels fast.
The Growler doesn't feel fast but it's not far off the power-to-weight and well above the torque-to-weight. The difference is that the Growler feels like a passenger jet. Aeroplanes (of the passenger variety) don't feel 'fast' to me either. But they hold a steady, substantial acceleration and hold it for a long time. The Lotus is a short series of violent snaps of acceleration, the Growler just pushes hard. By the time I've made 5 gear changes in the Lotus, I'm still in 4th in the Growler (and at 80 mph, the Lotus has trouble staying ahead of the ZT, by 100 mph the ZT is continuing to pull and leaves the Lotus behind).
It's a different experience. But I wouldn't call it 'slow' or a 'slug'. The standard car simply hasn't got the power to be compared with M-division BMWs, you have to look to the supercharged cars (the popularity of which proves the point).
I'd love to see your project come to fruition, it's always great to see creative work and other options, but the reality of the situation is that I'm probably going to uprate the brakes, get slightly wider wheels for wider summer rubber, then ask Brian nicely for a smaller pulley, a remap and see what we can do with breathing to get more power without destroying the transmission. It's torque that limits gearboxes, not power, and since my engine torque drops off a cliff before the magic 5252, I've got more torque than power (in lb ft and bhp) - the transmission seems fine with the torque from my engine, so just getting the thing to breathe and rev another 1000 rpm (holding the same 430 lb ft) would give me more power...
Only *then* will the engine feel *fast* - give the Ford V8 a longer rev range, so you can stay in a lower gear and howl up to high revs with torque multiplier acceleration.
Anyway I love my car and it's only now that I'm going to be using it a LOT more than I'm considering more modifications

What about those Compomotive MOs, Martin? Got any photos of 18" wheels on a car without bodywork modifications? I absolutely ADORE Brian's race car but I can't go that far...