Miltec Posted September 9, 2008 Share Posted September 9, 2008 Does anyone know the weight of a seven without engine and gearbox? VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
Molecular--Bob Posted September 9, 2008 Share Posted September 9, 2008 It's a guess, but around 420kg, for a road going crossflow. Link to comment Share on other sites More sharing options...
ashaughnessy Posted September 9, 2008 Share Posted September 9, 2008 If you want a precise answer you'll need to be more precise with the question. What type of 7 with what specification? Live axle or de-dion? Ital or Ford axle? Windscreen vs. aeros? Seats and trim? Wheels and tyres? etc. If you don't need a precise answer, then 400 to 450Kg. Might be easier to ask how much a particular engine and gearbox weigh and then subtract that from your particular 7. Anthony Link to comment Share on other sites More sharing options...
rj Posted September 9, 2008 Share Posted September 9, 2008 K-series engine 86kgs 6 speed gearbox ~ 30 kgs How about radiator etc? 2-4kgs Alternator & starter ~ 3kgs each Link to comment Share on other sites More sharing options...
Miltec Posted September 9, 2008 Author Share Posted September 9, 2008 thanks guys my guess was about 400kg, I take it with engine in pace weight would be front bias? VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
BBL Posted September 9, 2008 Share Posted September 9, 2008 Due to import restrictions, I bought my Seven as a "rolling chassis" (fully assembled, minus engine, gearbox, and battery), with the exhaust system in the engine bay and all the miscellaneous parts, hoses, and hardware in the footwells and boot, and the shipping weight came in a bit under 400 kilos. I believe 386 kg was written on the shipping tag IIRC. Sean Link to comment Share on other sites More sharing options...
Miltec Posted September 9, 2008 Author Share Posted September 9, 2008 So if we take the rolling chassis at 386kg as per BBL - hoses and exhaust etc as @ 25-30kg gives an weight of around 350 - 360 kg, does that sound right? VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
blade_runner Posted September 9, 2008 Share Posted September 9, 2008 My blade was weighed at the North kent meet by Len of freestyle, and it was 417 kg with 3/4 of a tank of fuel, the blade engine and transmission weighs about 60 Kg its an ital axle, with no carpets and 2 Vx race aero screens, so as stated id imagine a rolling chassis to be under 400 Kg 'Pinky Pics' here Link to comment Share on other sites More sharing options...
rj Posted September 9, 2008 Share Posted September 9, 2008 It would still help if you told us which type chassis it is. A live axle (Ital) is probably 45kgs lighter than a DeDion. Yes, without driver it's front biased Link to comment Share on other sites More sharing options...
Miltec Posted September 9, 2008 Author Share Posted September 9, 2008 Sorry it all sounds a bit vauge, it's just a thought process at the moment. if the live axle is that much light then it would have to be that. wondering about the weight so I can work out how much an electric drive train would have to weight. VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
BBL Posted September 10, 2008 Share Posted September 10, 2008 Mine is a Freestyle superwide S3 DeDion with CF wings/nose/dash/Tillets, MB 13" & A048 in 185 & 205. Weight figure provided by British Airways or equivalent. I believe I can confirm the number after I get home from work if required, but I would think for your stated purpose you're close enough with the figures above. edit -- Okay, home now. I had it wrong. It was British Airways (BA285 LHR to SFO), but the tag reads: Net weight (kg): 368 Tare weight (kg): 147 Total weight: 515 kg Sean Edited by - BBL on 10 Sep 2008 21:21:27 Link to comment Share on other sites More sharing options...
rj Posted September 10, 2008 Share Posted September 10, 2008 The Ital axle may well suffer under the torque from an electric powerplant Why not do it properly and fit a motor in each wheel hub? No transmission loss etc... OK unsprung mass will be an issue but it seems that technology has moved quite far recently. My own DeDion car weighs around 450kgs dry - but this is with windscreen and wipers. MB wheels and CR500s Carbon Kevlar Tillets etc... Link to comment Share on other sites More sharing options...
Miltec Posted September 10, 2008 Author Share Posted September 10, 2008 My plan was to use a single motor (more motors more weight) and if you double the motors you need double the power to run them. isn't the english (ford) live axle better able to cope with the power? VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
jackb_ms Posted September 10, 2008 Share Posted September 10, 2008 Should you not be more worried about the torque of the motor rather than the power? maximum torque is available at 0RPM which coupled with all inertia and other forces on the car my be the problem? Jack PS: if you know that already I apologize Emily, The Very Yellow 21 Link to comment Share on other sites More sharing options...
ashaughnessy Posted September 10, 2008 Share Posted September 10, 2008 There was a video (which I probably found from a blatchat link) of an Ariel Atom with an electric motor absolutely destroying a variety of supercars on a dragstrip. Extremely impressive acceleration. I'm not sure if there is any difference in the car's inertia at rest to its inertia at speed - its the same inertia. An applied torque is the same regardless. I would think the characteristics of application would be the important factor, plus the gearing. But I'm not an engineer. Anthony Link to comment Share on other sites More sharing options...
Miltec Posted September 10, 2008 Author Share Posted September 10, 2008 sorry Jack wasn't clear, I meant double the battery power not double the motor power. so bigger batteries means more weight. VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
rj Posted September 10, 2008 Share Posted September 10, 2008 Well If you've got two motors you'll only need each of them to be half the power, don't you - unless you get greedy Link to comment Share on other sites More sharing options...
jackb_ms Posted September 10, 2008 Share Posted September 10, 2008 I understand that, my remark was more about what you said: isn't the english (ford) live axle better able to cope with the power? I thought your question about if the ford live axle can cope with a large amount of torque from standstill Jack Emily, The Very Yellow 21 Edited by - jackb_ms on 10 Sep 2008 11:10:12 Link to comment Share on other sites More sharing options...
Miltec Posted September 10, 2008 Author Share Posted September 10, 2008 maybe the live axle isn't the way to go then? VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
MartinWoodham Posted September 10, 2008 Share Posted September 10, 2008 I think you'll need to decide from your motor spec whether you need/ want a diff or not. It's a fair amount of weight and an electric motor speed range is very broad, plus as has been said, torque max is at 0 rpm, so you may find its unnecessary weight. Two motors straight to the hubs in series will give you a differential effect anyway. Good luck though - light weight is the way to go. Whether the chassis can take enough weight for the batteries will be the main issue, I predict. For decent range you'll need around 30kWh capacity which ain't light.... Aero is another area of concern at higher speeds - a Caterham will be one of the lightest start-points, but not the most aerodynamic. GTM Libra (GRP monocoque)/ Matra Bagheera or Murena? (I'm giving away all my good ideas here..!) - much better aero for not much more weight. Keep us posted.. Martin supersported ex-Roadsports B Link to comment Share on other sites More sharing options...
Miltec Posted September 11, 2008 Author Share Posted September 11, 2008 Having done some more research 144v battery will weigh @150kg 30 kg for the motor and 20kg for the controller and wiring etc, so if we take BBL's weight of 368kg this would bring us in at just over 550kg. But get this... With the maths I've been doing, it works out that a 10hp motor would be enough and would give 0-60 of around 4-5 seconds..... VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
MartinWoodham Posted September 11, 2008 Share Posted September 11, 2008 motor hps aren't directly comparable though, because an electric motor is rated at the maximum power it can produce for a sustained period - ie its peak power will be considerably more than this. A petrol engine is rated at its peak power - so you're comparing bosons with quarks there (to get with the zeitgeist..!) You also need to consider the batteries bulk, and where you can site them without putting bending loads onto the chassis rails. What AH rating are you planning on? and have you factored battery life into the cost/ benefit analysis? Martin supersported ex-Roadsports B Link to comment Share on other sites More sharing options...
Miltec Posted September 12, 2008 Author Share Posted September 12, 2008 Looked at loads of batteries so far, none really gives the output I would want. Batts would be in the Engine bay and would hopefully weigh about the same as the engine. to get the weight / speed is fine but range suffers. VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now