One of my favourite things about the little Spit...

"BiTurbo228 - Dr Frankenstein of Spitfires" (biturbo228)
10/19/2013 at 18:32 • Filed to: Spit6

...is comparing its projected power-to-weight against other cars. So far, it'll have a better power-to-weight ration than...

a BMW 3.0 CSL, BMW M635CSi, BMW 850CSi, BMW E30 M3 Evo 2, BMW M3 E36 Evo, BMW E46 M3, Porsche 930 Turbo 3.0l, Saab 9-3 Viggen, Audi Quattro 20v, Jaguar E-Type S1 and S2, Lotus Elan Sprint, Ferrari 308 Quattrovalvo, Classic Ford Mustang Boss 302, BMW E34 M5, Porsche 911 2.7 RS, Subaru Impreza STi and the Porsche 928 GT-S.

Lets step it up a notch shall we? It'll have a better power-to-weight ratio than...

a BMW M135i, BMW Z4M, BMW E39 M5, Honda NSX, Toyota Supra, Jaguar F-Type V6, Jaguar XK-R 4.2l, Lotus Elise 111R, every base-spec 911 Carrera up until the 991, Nissan Skyline GT-R R34 (even taking into account that the 276bhp rating is conservative) and the crowning glory, the BMW 1M.

It'll get smoked by the vast majority of these, but still. It'll be a right little giant-killer.

DISCUSSION (19)

Bluecold > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 18:37

How many crowning glories exactly? Also, I seem to have missed what you are going to do to the Spitfire. Is it a Rolls-Royce Merlin swap?

BiTurbo228 - Dr Frankenstein of Spitfires > Bluecold
10/19/2013 at 18:56

I've got a 2.5l I6 from a Triumph 2500PI (same engine as the TR6), which I'll be turning up to around 170bhp. Easily achievable.

The real difference comes with the kerb weight, which will sit at around 750kg (~1650lbs).

That gives it a power-to-weight of around 226bhp/ton. The closest to that is the Z4M, which is a 10th down on the little Triumph.

If I exceed my 170bhp and 750kg target, it'll be in with a shout of beating TT-RS', Aston V8 Vantages and De Tomaso Panteras.

Bluecold > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 19:05

That's seriously impressive. They weigh less than I thought. I would've thought more along the lines of 900 kg. Will feel like a rocketship at 5" above the ground Sadly, driver weight adds up with the uber lightweight cars. A laden spitfire including driver (say 850kg) with 170bhp comes in at 200bhp/ton.

A 1500kg car with the same dry power/weight, with 100kg added mass comes in at 212bhp/ton. And that's at lower speeds. At speed, you'll have less excess power to weight due to aerodynamic drag. I'm not trying to rain on your parade though, you'll have a seriously impressive car and because the car is so tiny, you'll have an Cd advantage, less tire wear and less fuel consumption.

/armchair science

BiTurbo228 - Dr Frankenstein of Spitfires > Bluecold
10/19/2013 at 19:16

Yeah, I know it's a deceptive statistic, but it's cool nonetheless.

I'm a pretty light person, so I reckon I'd only add 70-75 kilos all-in, but that's still around a 10% increase in weight.

The stock MkIV 4-cylinder cars weight in at 720kg, and the 6-cylinder adds about 50kg to that, and the non-deadly rear suspension about 8kg. There's a good few lightening measures that I'll be doing on the front to bring it back to the stock weight distribution and 750kg.

If I wanted to spend a ton of money, I could get it down to around 703kg with the 6-cylinder engine (695kg if I go with a tonneau cover rather than a soft-top).

Arch Duke Maxyenko, Shit Talk Extraordinaire > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 19:17

My favorite part of the spit is that they don't swallow. Wait, what?

BiTurbo228 - Dr Frankenstein of Spitfires > Bluecold
10/19/2013 at 19:20

Actually, I've just read that it's common in Europe to include the weight of a 75kg driver in kerb weight statistics.

Not sure whether they were doing that back in the 70s though.

Ramblin Rover - The Vivisector of Solihull > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 20:24

I'm going to try to tune the 4.2 Rover V-8 going into my Ranchero to about 220-250 bhp, a relatively mild tune all things considered, particularly with ITBs, an almost race exhaust, and a couple performance parts. The final weight should be not far north of 2400lb/1090kg. That sits me at as high as 220bhp/mton, which should be fantastic.

BiTurbo228 - Dr Frankenstein of Spitfires > Ramblin Rover - The Vivisector of Solihull
10/19/2013 at 20:32

Sweet. Props for using the RV8. Will we be getting a progress blog-type thing? Love build-threads.

I'm considering building a 911-rivalling MGB GT V8 running either a highly tuned 3.5l, or a ubiquitous 3.9l Rover V8. Should be running around 220bhp, maybe more. Jaguar IRS as well.

Not as Ranchero as yours though.

A3R0 > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 20:33

Wow, cool.

Ramblin Rover - The Vivisector of Solihull > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 20:45

Definitely need a build thread, but the plan is to get "Busted", my cousin's '64 Series IIa more or less together by January some time and out of my way, and a shelter up so I can have a place to stash bits and strip it down to the body. I have a camera, even, but I haven't been motivated to freshen it up and start using it for the Rover projects.

I got the RV8 donor ( a highly rusted '95 County) for $500 and the car for $800, but the parts-making and labor will definitely run into the equivalent thousands. I'm strongly tempted to buy new on the trans . I can buy a GM-style clutch and a bellhousing from aluminumV8.com for not terribly much, so then the only major part left to obtain will be the Jag IRS. Well, that, and the megasquirt + injection. Looking at using two sets of these . Honda CBR 600 race bike throttle bodies - far oversized for their source engine, which turns 170hp out of four cylinders at 13,000+ rpm. As my air needs are fairly modest, the numbers check out for two pair

Ramblin Rover - The Vivisector of Solihull > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 20:49

Kinja'd!!!

Well, damn. Looks like I'm not the only person going clown with two pair CBR 600 bodies and a Rover V8. Not quite sure why this fellow put his fuel rails on the outside, though, otherwise pretty much exactly what I have in mind.

BiTurbo228 - Dr Frankenstein of Spitfires > Ramblin Rover - The Vivisector of Solihull
10/19/2013 at 21:02

Boss. I've heard I4s on ITBs and they sound pretty damn excellent.

I can only imagine what a V8 would be like.

Ramblin Rover - The Vivisector of Solihull > BiTurbo228 - Dr Frankenstein of Spitfires
10/19/2013 at 21:14

Speaking of I4s and unnecessarily doubling things, I'm going to try to dump heat through two Mini radiators - 1/fender. It' should carry weight even further back (I'm putting the engine back at least 7" - too far from a regular radiator mount, really), and keep the whole engine compartment cooler.

With mid engine placement, I'm going to have to have a forward-open hood to be able to get at things. Can't wait.

Wynot? > Ramblin Rover - The Vivisector of Solihull
08/19/2015 at 14:04

Did you finished your rover v8 Honda throttle body’s project? I’m looking in to it, and found your saying above. Maybe share some information and tips? Love the idea! Thanks

Ramblin Rover - The Vivisector of Solihull > Wynot?
08/19/2015 at 21:32

Sad to say, not much progress on the engine side of the project, at least not to that point. It’s still happening, but I’ve been working on the body of the project first, and that’s been very greedy of both money and time. The most recent big part of the project was mounting the rear suspension. I will definitely provide updates when I have them on the throttle body stuff.

Ramblin Rover - The Vivisector of Solihull > Wynot?
08/19/2015 at 22:07

I should mention, I’ve got a book on power builds that may be helpful to what you’re doing. Information on RV8s from top to bottom: main bearings to head porting to cams to valve spring suppliers. Just leave a reply to one of my comments or posts if you’d like info on anything specific.

Wynot? > Ramblin Rover - The Vivisector of Solihull
08/20/2015 at 02:32

Thanks for your reaction. I’m building a MGB GTB V8 together with a friend of mine. Body work almost finessed. The engine mounts lowered more to middle of the car, airflow enhancement in the frond of the car, replacing fan and cooling, roll cage, aluminium MGC hood, aluminium rear and frond. And we also decided to improve our rear suspension. 5 link system and watt’s linkage combined with a Volvo 240 rear axle. What are your improvement of the rear end? We outsourcing the engine hardware part. but we keep it a 3,5 liter whit injection and some modification tho the engine. Like to have 220 - 250 hp out of it.

Those guy’s just had a stock 3,5 with the Honda throttle body modification, around 180 hp on the wheels. sounds solid.

Wynot? > Wynot?
08/20/2015 at 03:40

Above first start, after adjustment the result:

Ramblin Rover - The Vivisector of Solihull > Wynot?
08/20/2015 at 08:38

My 60s Ford is using a Jag axle and rear suspension. Heavyish. But solid, independent, and limited slip. My engine’s a large bore one on the later style block, so the mains can be cross bolted for strength.

None of the engine mounting, etc. on mine is in any way stock, but I do have that part worked out. Its on fluid motor mounts from a 90s Thunderbird.