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PostPosted: September 24, 2019, 11:29 am 
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Also, plan on how the drivetrain will be installed or removed. As shown, it's hard to see how it can go in through the top or bottom, unless the tubes are removable, which can be an issue in itself.

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PostPosted: September 24, 2019, 11:31 am 
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Kinetic Research wrote:
... I will do track days initially to test out the reliability but I don't plan on racing competitively (I can barely afford to build it as it is, let alone have other people bashing into it and destroy it for fun). It is supposed to be a daily driver primarily...

Going with two V6 engines doesn't sound like something intended for sitting in rush hour traffic... Just sayin'

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PostPosted: September 24, 2019, 2:05 pm 
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KB58 wrote:
Also, plan on how the drivetrain will be installed or removed. As shown, it's hard to see how it can go in through the top or bottom, unless the tubes are removable, which can be an issue in itself.


Good observation, I have been taking liberties with the cad model as it is a 1 piece for FEA analysis. The detail missing from model is the 5 spigotted and bolted flanges that allow the entire rear section to be removed for easy maintenance, you all know how many times this thing will be in and out as well as I do!


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PostPosted: September 24, 2019, 2:33 pm 
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KB58 wrote:
Going with two V6 engines doesn't sound like something intended for sitting in rush hour traffic... Just sayin'


I can suspend one engine by locking open its clutch (solenoid on the hydraulic line between the master and the slave) and turning off the ecu for that engine (I have to run an ecu per engine). This thing will drive around fine as a stock 270 hp 3.5l v6, my current daily driver is a 2008 V6 accord.

The commute is rarely fully stopped, usually just crawling in merge points so the double nose radiators and only a single running engine should be fine for hot days and crawling conditions.

A point you may have missed from the verbage in my first post is the design allows for multiple powerplants to bolt in. I can see a final vision of one front section and up to 3 rear section options sitting in my workshop.
1) Fully electric option - ideal for the commute and red light drag racing

2) GT option - 2 x mild tuned V6 stock engines - this is build 1 = 540 hp - the south island of NZ has some lovely roads.

3) Insane option - 2 x highly tuned race engines and low geared diff in close ratio transaxle to suit = 700hp NA, 900Hp quad turbo. The track I will be testing at (hampton downs) is where Mad Mike Whiddett is based, so I don't see him resisting an offer to take it for a drift.

The last option is not locost but is why I am spending some time focusing on the chassis rigidity! :D

:cheers: Marcus


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PostPosted: September 25, 2019, 7:31 am 
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Roughed out the front crash structure tonight. It is thick wall aluminium tubing running forward of the steel frame and will position the concealed front aluminium bumper that will absorb some frontal impact energy if the worse should happen. The bumper structure will also rigidly mount the headlights and the radiators. This shot shows the right front wheel in full bump and lock and there is no fouling with bodywork - tick.

Headlights will be 90mm Hella LED projector units - expensive but what modern headlight isn't.

Attachment:
front crash structure.jpg


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Last edited by Kinetic Research on November 24, 2019, 3:23 am, edited 1 time in total.

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PostPosted: October 1, 2019, 5:14 pm 
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Kinetic Research wrote:
KB58 wrote:
Going with two V6 engines doesn't sound like something intended for sitting in rush hour traffic... Just sayin'


I can suspend one engine by locking open its clutch (solenoid on the hydraulic line between the master and the slave) and turning off the ecu for that engine (I have to run an ecu per engine). This thing will drive around fine as a stock 270 hp 3.5l v6, my current daily driver is a 2008 V6 accord.

The commute is rarely fully stopped, usually just crawling in merge points so the double nose radiators and only a single running engine should be fine for hot days and crawling conditions.

A point you may have missed from the verbage in my first post is the design allows for multiple powerplants to bolt in. I can see a final vision of one front section and up to 3 rear section options sitting in my workshop.
1) Fully electric option - ideal for the commute and red light drag racing

2) GT option - 2 x mild tuned V6 stock engines - this is build 1 = 540 hp - the south island of NZ has some lovely roads.

3) Insane option - 2 x highly tuned race engines and low geared diff in close ratio transaxle to suit = 700hp NA, 900Hp quad turbo. The track I will be testing at (hampton downs) is where Mad Mike Whiddett is based, so I don't see him resisting an offer to take it for a drift.

The last option is not locost but is why I am spending some time focusing on the chassis rigidity! :D

:cheers: Marcus



Option 4: 2 2.5 wrx turbo engines, roughly 600hp total. why you ask? cuz i think it'd be interesting! plus low center of gravity! also pretty unique!


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PostPosted: October 4, 2019, 3:42 pm 
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Indeed, if the Tbox idea works out any engine combo can be doubled up. I originally intended to make a replica Mazda 787B racecar with 2 x Triple rotor engines - then you are talking insane power and super low COG - would probably go better than an original one! But decided to go the road car route as I will get more use out of it and it wouldn't be so lethal.


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PostPosted: October 4, 2019, 10:39 pm 
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Kinetic Research wrote:
Indeed, if the Tbox idea works out any engine combo can be doubled up. I originally intended to make a replica Mazda 787B racecar with 2 x Triple rotor engines - then you are talking insane power and super low COG - would probably go better than an original one! But decided to go the road car route as I will get more use out of it and it wouldn't be so lethal.


:shock: 2 20B's would be insane! even 2 13B's would be crazy! now you got me thinking what other crazy combos can i think of!


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PostPosted: November 24, 2019, 3:29 am 
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1) All pictures referred to in text reloaded after the apocolypse
2) Slow progress but still plugging away making the full scale MDF, cardboard and steel tube interior to test ergonomics first hand
3) Sourced some free tubing to make the test engine stand, roll on summer holidays!

:cheers:


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PostPosted: December 20, 2019, 3:53 am 
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My digital hanging scale finally arrived (thanks Banggood) so on a mission to weigh all the parts I have and integrate the measured values into the CAD model for a reality check.

For the record a honda J35Z2 engne block with coolant and oil but no upper intake manifold or exhaust weighs 122kg (270 lbs) and puts out 270 HP. Have bought an old Xbox kinect unit that can be converted into a 3D scanner so I will be able to accurately scan the engine shown below.

Attachment:
j35z2 engine weight 122kg.jpg


Also spent a few hours at a local dismantler ripping out a J32A1 head from a 225hp 1999 honda saber - intending to use it as a sacrificial lamb to explore head porting, cam and flowbench improvements as it wasn't the high power J32A2. Not sure how well the ports will scan - not a high priority.

Also check out this guys effort;

https://www.youtube.com/watch?v=uIMh-kXNTC8&t=1458s


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PostPosted: February 2, 2020, 5:28 am 
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I have spent some of my NZ summer holiday reworking the mockup cabin and adjusting the CAD model to the fullsize values, and sitting in it has made me realise I can add some extra beam strength to the chassis by augmenting the steel frame with some carbon honeycomb spars on the inside edges of the drivers tub and running these up the sides of the fuel tank hump.

Attachment:
mockup.jpg


The passenger seating is really comfortable and there is ample clearance between the drivers elbows and the passenger knees, although the gear change gets really close and passengers will probably be advised to skew their legs off to the outer area of the footpanel.

No, I didn't eat all those cornflakes - the boxes will be cut into the door outer skin profiles once I have build approval from LVVTA.

The chassis is up to Version 8 - and weighs 154 kg. Total dry weight for the track mule should be just under 900kg - so am confident that I can hit the 1300kg curb weight target with bodywork.

Now that the seat size and positions are frozen I can place all the seat and seatbelt retaining bolt bosses - critical for safety as restraints and mounts have to withstand 20G loading according to NZ regulations. The door hinge sizes and positions have been determined as these are another critical item for the certifier to have calcs on.

Attachment:
Camber and Caster plate.jpg


Shown above is rough detail on the CNC cut interchangeable camber and caster plates (will put some stiffening ribs between the bosses later) - these "bolt in" plates give lots of scope for fine tuning of the front end geometry without touching the chassis. Goal is to get the manual steering as light as possible while still having good straightline and heavy braking stability. The steering rack will be similarly adjustable on interchangeable plates so that bump steer is minimised.


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PostPosted: April 4, 2020, 11:06 pm 
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Hope you are all well. NZ is in lockdown so trying to use the time productively while also working from home - here are the most recent shots of progress on body surface modelling.


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PostPosted: April 8, 2020, 6:44 am 
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Still have a long way to go, but getting closer each day. Next step is surfacing the rear deck and wing and then onto the interior.


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PostPosted: April 8, 2020, 8:44 am 
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Looks good. If you plan to use it on the road and not draw the wrong kind of attention, plan to have a lot more room for mufflers, and how the radiated heat will be handled. For both reasons, you may want to consider one muffler instead of two for each engine.

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Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/


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PostPosted: April 8, 2020, 10:33 pm 
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KB58 wrote:
Looks good. If you plan to use it on the road and not draw the wrong kind of attention, plan to have a lot more room for mufflers, and how the radiated heat will be handled. For both reasons, you may want to consider one muffler instead of two for each engine.


Thanks! Shown are the catalytic converters at the top of the rear section just like in the original, they can will run up to 1600 F (871 C) which will be very challenging for any composite bodywork nearby, which is why the original was coated with gold leaf as its the best heat reflector. I won't be using gold, will most likely have an aluminium panel for the cat cover.

As per the original the muffler/s (1 per pipe as you suggest & as they did on the GTR's) are vertical in the rearmost position and form the rear crumple zone. The mufflers will be in the space between the rear of the subframe and the rear panel. I have to keep it under 90 db to be road and track compliant.


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