EV Spitfire 345v

[steveJM]

4 hours ago, mpbarrett said:

Steve I expect you know about this but there was another EV spitfire in Canada 
https://www.linkedin.com/pulse/e-fire-triumph-spitfire-ev-paul-martin

Its was involved in a crash and written off.

Mike

Yes, I've reviewed his build on diyelectriccar.com He has since transferred all the running gear into a TR6. There are at least 6 spitfire builds i've followed over the years. All went the gear box option. My approach was to go for higher torque, hence the R160 diff replacement. 

[BiTurbo228]

Higher torque and no gearbox could well pay dividends. No transmission weight. Much lower driveline inertia to spool up with the motor. No losses through gearsets. Will be very interesting to see how this approach works out

Do electric motors have differing efficiency through their rpm range? That would be the only reason I could see for needing gears (say, if your cruising speed was at an inefficient rpm).

Edited June 19, 2020 by BiTurbo228

[Nick Jones]

2 hours ago, BiTurbo228 said:

Do electric motors have differing efficiency through their rpm range? That would be the only reason I could see for needing gears

They do.... though variable with motor type/controls combination and generally much higher than an IC motor (eg worst case E motor is still way better than best case IC motor)

Really liking it.  If someone would just hand me £15k to get me started, I'd be right on it!

[steveJM]

All Battery boxes now have there homes, along with radiator. Next stage is to remove and tidy up details and send off for powder coating.

[BiTurbo228]

Very nice. I'll be very interested in what this all weighs by the end of it. Interesting that you've measured 841kg as a starting weight. Is yours a later 1500 with the crash structure under the boot? 

If not then the book figure for Spits is closer to 721kg, but I've long had a suspicion that's without fluids or something misleading. Unfortunately I'd alread stripped mine by then so couldn't weigh and check... 

[spitfire6]

Hi SteveJM,

 I will be starting a new job soon with an EV truck company in the UK. SW & HW.
I hope in a few year I will be able to be gifted their motors & power packs to follow you in EV. Nine phase apparently. 

Please keep posting! & thanks for keeping the Triumph Spitfire alive.

Cheers,

Iain.

[Escadrille Ecosse]

Interesting job that. Good luck 

[spitfire6]

Just now, Escadrille Ecosse said:

Interesting job that. Good luck 

Thanks.

More future than in all honestly the best manufacture of Cam & Crank grinding machines that I work for. No money in making machines that last 30 years. I now would not touch a Cam or crank that was not ground with a Fives Landis machine. Brilliant machines with no future.

[Escadrille Ecosse]

Sad but unfortunately too true 

Colin 

[steveJM]

 

Thanks for the comments. 

Strip down and repairs continue. Battery boxes at powder-coater.

worked out a solution to lift body off on my own! was pretty chuffed. seems so obvious in hindsight...

 

made trolley to move body-tub around. now up on hoist, so i can work from underneath.

front bonnet hinge rusted out. so the repairs started. 

hoping to get Chassis all repaired in the next week. Then strip down to send off, new motor mounts and chassis to powder coater .

that will give me some time to learn how to do repairs and clean up of the underside of the body tub. rust holes etc...  

[steveJM]

When making the motor mounts for and aft i deliberately tilted the motor slightly down at the back. 

Discovered today with body tub off, motor is tilting about 2.5 degrees.

According to google ... drive shafts perform best if the output shaft of the motor / & Diff are parallel yet can be off centre with angle upto  3 degrees ...  (i previously thought is was upto 7 degrees ?) To have the least vibration. 

Any one know what std triumph 4 cyl angle tilt is? or Std diff ? or are they flat ? 

Alas, I lifted the front of the diff by 5mm  packing shims between diff and support plate, to match motor angle, looks like tail shaft is now running at 4- 3 degree . Happy with that!

[BiTurbo228]

What with all my engine swapping I've been looking into propshaft orientation quite a lot. What I've discovered is that, like so many things in the motoring world, the '3 degrees' suggestion is an American rule of thumb that people seem to parrot blindly and out of context. What people seem to miss is that the magic number of 3 degrees was developed on old American cars which were almost universally live axle. As the suspension compresses, the angle of the propshaft will change radically. I suspect that means that the number of 3 degrees is set conservatively to allow for sufficient suspension travel without the UJs binding, meaning that in any suspension setup with a body-mounted diff you can probably run much higher offsets without major issues (possibly where the 7 degrees comes from).

The rules of thumb that do seem to check out are that you don't really want 0 degrees as it makes the UJ cut a furrough into its bearings, and that you want to keep the plane of the two flanges the same so that each UJ has the same deflection angle (meaning that the speed variations can be cancelled out by offsetting the UJs 90deg from each other).

I expect the Triumph engineers know about UJ alignment, but packaging constraints meant that it went completely out of the window in the Herald and Spitfire. The gearbox output flange points pretty much towards the diff, but the diff itself is horizontal, meaning they are not in the same plane as each other at all. This should produce a bit of driveshaft whipping (changes in the speed of the driveshaft which gets translated into the diff and driven wheels). I expect it's not noticeable as the power levels aren't high enough to start causing issues. In big power cars you can start bending driveshafts or tearing apart propshaft doughnuts (or in odd drivetrain setups like the Alfa 75 with a flywheel at each end). Unfortunately I'm not sure at what point this starts becoming an issue! I know Alfa 75 V6 don't tolerate misalignment of the propshaft well, but the Twinsparks are easier going (190bhp vs 148bhp).

Because if this, I've gone with the later 1500 CV driveshaft. With these I think the typical best practice is to point the UJ end directly at the diff (possibly with a small misalignment to promote bearing movement, but not enough to create much whipping), and us the CV to take up any alignment issues. I expect that's the reason the 1500 CV driveshafts were made in the first place

Edited August 5, 2020 by BiTurbo228

[Escadrille Ecosse]

The diff in the Spitfire is mounted horizontally. The input flange is also offset slightly from the centreline. Without a lot of measuring I would think that the combined angle is around 3 - 4 degrees.

The diff should always be mounted as in the original vehicle , usually with the pinion shaft nominally horizontal or you run the risk of inadequate lubrication on the pinion bearings which are highly stressed due to the lift from the helical CWP gear mesh.

Cardan shafts can cope with pretty extreme angular displacement. The main vibration issues, other than simple imbalance is if the UJs are installed 90 degrees out from one another at manufacture or if there is a significant difference between the drive angles. This is due to the natural angular velocity change of the UJ as it goes through a revolution. Ensuring a mirror image at each end cancels this out.

In reality though for an automotive installation there is so much else going on that the the shunting caused by this angular velocity change is absorbed in the system. Just look at the standard drive shaft installation on the Spitfire and GT6 which only have a single joint the speed variation is not noticeable over a much greater angular range.

Colin

Edit Just read BiTurbos response which beat me to it and his point about the non-zero alignment is spot on. As are his other comments. basically you will be fine.

Edited August 5, 2020 by Escadrille Ecosse
additional information

[BiTurbo228]

Agreed, athough I think the R160 is pretty unfussy when it comes to mounting orientation. It's in a lot of cars (Imprezas, Datsuns and later Nissans etc.). It's possible that they're all at the same orientation of course, haven't checked. However, it's also used backwards at the front of Nissan Skyline GTRs, and people use them upside-down in AWD VW Beetle/Subaru conversions.

Also agreed that the driveshaft angles as standard in small-chassis Triumphs is far from ideal and they don't seem to have excessive issues. I do wonder if it contributes towards failure of diffs in higher power applications though. What you'll get is interactions between the power pulses of the engine, and the whipping of the driveshaft which will periodically put greater and lesser shock loads into the diff gears and stub axles. Unlikely to be an issue if the forces are well within the design tolerance of the diff (say, in 4-cyl applications), but possibly a factor in beefier 6-cylinder cars.

[Spit131]

Are you selling copies of your turret brace bar ?

[spitfire6]

Hi SteveJM,

I'm interested in how you will use regen? Wise use and the rear shoes will last forever & front pads much longer?
Algorithm wont be fun.

Cheers,
Iain.

[steveJM]

3 hours ago, Spit131 said:

Are you selling copies of your turret brace bar ?

Hmm sorry, was not on my list to do. considered a one off for my particular application. 

Did take a few photos ..

The tube is 25mm thin wall. I used pipe bender to angle to match engine mount clamp bolts, used some 5mm flat. and then decided to get a bit creative with the welding of the tube-ends to flat plate, by making an arrow head type end. 

This brace works to provide at least 3 functions i needed to resolve. Strengthen /support the shock towers, attach engine block-pos' battery boxes, provide support to 30kg inverter which sits on top. The inverter also extends to the top of the Motor frame, and so, i use soft rubber vibration mounts on all positions to absorb any movement from the motor, although expect to be some what minimal  as I'm using race type high density rubber mounts on the motor to Chassis ..Soft rubber on the inverter to motor mount..

 Brace along with 20 other small components dropped off to the powder-coater yesterday. Am very appreciative he is still operating, as this covid thing has us nearly full lock down in Melbourne for 6 weeks. Not sure how he managed the critical services claim to stay open.

Should have the Chassis to them before end of the week.

[steveJM]

2 hours ago, spitfire6 said:

Hi SteveJM,

I'm interested in how you will use regen? Wise use and the rear shoes will last forever & front pads much longer?
Algorithm wont be fun.

Cheers,
Iain.

Plan A for Regen is to use a pressure transducer in the brake line. available from EVTV or EVwest, the GEVCU controller has inputs to receive  0-5 v signal as pressure is applied to the brake line. apparently  it should be a matter of tweaking in the program already installed, instructions included...

options B. also included in the gevcu is to adjust the hall effect throttle in the program so that before pedal reaches 0v pos' the throttle goes from throttle to regen. Again this is adjusted in the installed program. not sure i want this, more inclined to maybe have some creep function instead so the motor is creeping forward like on an automatic... and the brake is required to hold pos'.. will see?

option  C.  which is not for this project, but maybe another i have in mind . Saw this on a  build of a  2014 Lotus  Evora with tesla rear motor. Where the paddle shift levers on the steering column are converted to be regen paddle. Using part listed below or similar. Idea is as you need to apply regen you use the paddle shift when it suits you. Would be good to provide regen at high speed in straight line, but I'd imagine regen in the back wheels on tight bend might be undesirable .. anyway would be fun to do! . 

[spitfire6]

Nice one.
You have planned way ahead!
Great job!

Edited August 8, 2020 by spitfire6
edit

[Spit131]

Thank you for the details .

Electric does not appeal ,  not even F1 E , but very impressed with the engineering going on  .

M

 

Edited August 9, 2020 by Spit131

[PeteStupps]

On 8/8/2020 at 1:31 AM, steveJM said:

Plan A for Regen is to use a pressure transducer in the brake line. available from EVTV or EVwest, the GEVCU controller has inputs to receive  0-5 v signal as pressure is applied to the brake line. apparently  it should be a matter of tweaking in the program already installed, instructions included...

options B. also included in the gevcu is to adjust the hall effect throttle in the program so that before pedal reaches 0v pos' the throttle goes from throttle to regen. Again this is adjusted in the installed program. not sure i want this, more inclined to maybe have some creep function instead so the motor is creeping forward like on an automatic... and the brake is required to hold pos'.. will see?

I wonder if it's possible to combine the two, but only have the throttle pedal element active above a certain engine speed so it's similar to engine braking. Maybe that's over-complicating things.

Tangentially and an entirely personal rant, the 'creep' on modern automatics is a pet hate of mine. Boneheads at every set of traffic lights who can't quite keep still, like pushy children inching forward all the flippin time. Plus, when I was learning to drive my instructor taught me that - after dark - it was discourteous to sit with your brake lights dazzling the car behind, and you should use the handbrake. This doesn't seem to be a popular part of etiquette nowadays.

Sorry, wanted to get that off my chest... 

[JohnD]

Steve,

Have you read Xun, Liang et al?

Braking force decoupling control without pressure sensor for a novel series regenerative brake system, Proceedings of the Institution of Mechanical Engineers, Part D,   July 25, 2018

 https://doi.org/10.1177/0954407018785740

John

 

 

[spitfire6]

9 phase HV truck motor. 3500Nm from zero RPM to 3700.

[steveJM]

starting to reassemble after blasting and powder coating...

As discussed, have converted the Spit1500 to GT6 Rotoflex with various mods...

Looking for some advice... I purchased replacement Handbrake cable from Rimmer. 149353 was listed as GT6 Rotoflex. After installing it appears to be same length as what i removed, if not longer...? which is way too long .... waiting on Rimmer to come back with comment on total length... any experience out there with this?

[Nick Jones]

What did you do about the cable guides Steve?

Roto cars have them mounted on the tub, further inboard and forward of the chassis mounts.  This placement is important minimise the length variation with suspension height which is quite severe if the chassis guides are used with Roto.

The cables are definitely different lengths though I can’t tell you what lengths and which is the longer offhand