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-   -   Chassis for a dino (https://madabout-kitcars.com/forum/showthread.php?t=6224)

rossnzwpi 11th March 2017 01:22

Have you seen Bloozebury's Canadian project? He is modifying a Fiero, widening, lowering, changing suspension geometry, fitting a transverse V8. There are many drawings, including a rear suspension that was originally strut and has been considerably altered. His website is: http://bloozeown.weebly.com/
and there's even more detail on the Dutch Fiero site : http://www.fiero.nl/forum/Forum3/HTML/000116.html

thecarbuilder246 14th March 2017 11:03

chassis
 
Hi all

Right-does anyone have an accurate set of dimensions for a Dino 246? I have a couple of sets of measurements from searching through my huge collections of dino books, and then several from the internet, that although similar are not the same!!! I'm after wheelbase, front track and rear track please. Or if anyone can point me in the right direction!! cheers

ian

thecarbuilder246 14th March 2017 11:55

chassis
 
hi all

update--
just for reference I have - taken from the anthony curtis Ferrari Dino book which seems to be a definitive book on the dino written around 1990-
wheelbase 2343 mm (7 foot 8.25 inches)
front track 1416 mm (4 foot 7.75 inches)
rear track 1441 mm (4 foot 8.75 inches)
these tally (within 2/3 mm I guess from rounding up/down) with several other books on the dino. But I do have another book with a set giving a wider track? Could this be from the "chairs and flairs" car? or was it just wider tyres and flared wheel arches. The internet search gives varied dimensions so I've taken them as not to be an accurate account due to armchair writers giving their take on the car!!

cheers Ian

NeilF355 14th March 2017 20:09

Hi Ian
I have a Brooklands "road test" book for the Dino which is basically a compilation of magazine road tests for the car.

There do seem to be several different figures quoted in the different articles but the consensus seems to agree with those quoted in the "Motor" road test No 30/71 which gives
Wheelbase 7' 8¼"
Front track 4' 7¾"
Rear track 4' 8¾"

I'm inclined to believe the above figures as the magazine article has gone to the trouble of detailing a lot of the car's facts and figures including such esoteric facts as the King pin inclination angle (9° 3’ in case you are interested lol)

Neil

rossnzwpi 15th March 2017 01:46

Hi, the official factory 246GT manual lists:
1425mm the front track (carreggiata a terra)
1430mm the rear track (carreggiata a terra)
my Italian is pretty basic but I think this is the measurement from vehicle centre to centre of wheel AT GROUND LEVEL.

The Ferrari brochure lists it as:
wheel base 92.2" in English (2340mm in French)
front track 56.1" (1425mm)
rear track 56.5" (1430mm)
http://www.ferraristuff.com/contents...1973_04_fs.jpg

The 206 GT is listed at rear=1400mm by the way. And the 'chairs 'n flares' would only have a different track if it had different offset - otherwise the centre of the wheel would be in the same place.
:)
cheers
Ross in NZ

rossnzwpi 15th March 2017 02:02

Ferrari would probably have measured in mm so the Imperial measurements are just approximate translations. I reckon the Factory manual and brochure are the best bet:
wb 2340mm
ft 1425mm
rt 1430mm
cheers
Ross in NZ

rossnzwpi 29th March 2017 21:56

There is a part finished Minotaur kit on EBay at present. It comes with a link to lots of chassis and detail pictures. The chassis looks a bit heavy with 50x50mm box section (?). 6 litre Chev and Porsche 'box. This is what 10 years and 30,000GBP of parts gets you!
https://www.amazon.co.uk/clouddrive/...are_link_email

thecarbuilder246 15th April 2017 11:03

chassis
 
3 Attachment(s)
Hi all

My adaptor plate has finally arrived and been offered up to the cosworth V6.
After looking at several options for a suitable gearbox I've decided to go with a E53 gearbox from a mark 2 toyota mr2 turbo. Some of the turbo guys run upwards of 400bhp!! Now these are getting quite rare and when the do come up they are snapped up within minutes or are quite pricey still requiring a rebuild. So my next option was a complete car.
Well after searching for a few weeks a suitable donor car appeared and the deal done. Low 89,000 Kilometer jap import car (not miles) dry stored for the last 4 years. I'm not a big fan of stripping rare cars that should really be put back on the road but I will sell on what I don't need-everything else apart from the gearbox/drive and intermediate shafts/starter motor/flywheel/clutch and gear selector with all cables.:high5:

Ian

ozi jim 16th April 2017 16:32

I had a bit of a look through the posts and I have built suspension from scratch.

This will give you some rules of thumb that may give you a guide or confuse you more.

My approach.

Start with the wheel offset that you want for the car that you are building.
The upright ,disk and caliper has to fit inside the chosen offset.
Once you place this on the ground you then know how long the arms need to be.

Scrub radius.
A line through the top ball joint passing through the lower ball makes contact at a point on the road.
This is part of an angle called KPI
With the wheel fitted it will land somewhere on the inside of the Tyre patch, this is the scrub radius ,zero SR is the centre of the tire this will make the car very vague at high speed, front wheel drives generally have a low SR as it cancels out torque steer but not good on RWD, I would not go any less than about 60mm inside the CL off the tire.
If you have to much ,lets say it lands not under the tire contact patch but inside that it will give heavy steering and high feed back on the wheel if you get ruts on pot holes on the road.
SR helps with self centring which is very handy if the car steps out you can just let go of the st wheel and the wheels will self centre then you just regrab the wheel and you are back in control.

The lower arm height location is all about the upright lower ball joint height of the road.
You need to have the lower arm running slightly uphill to the chassis pick up point.
This will help control the roll centre movement across the car and also in the vertical position when the car dives and turns in.
A car that has poor RC control is unpredictable, EG All the weight above the RC applies a load onto the tyre, the higher the RC the less load applied.
The lower the RC the more load because you have more weight above the RC.
If a car if cornering and it has X RC then you get on it harder and the RC changes dramatically then the attitude of the car can change sometimes for the worse.
The upper arm needs to run down hill from the upright to the chassis, changing the angle will change the RC height I have found on rear eng cars it likes to be lower say at about 60-30mm of the ground.
Reason being you have less weight over the front (no eng) so you use RC to get tire loading.
Steering arm.
I like a bolt on steering arm as it gives you a better chance of getting the bump steer correct.
Steering rack location.
If it’s a front steer you need to be careful that you can get a reasonable ackerman.
On rear eng cars I always run anti ackerman meaning it has neg toe out on turn because no weight in the front the front inside tire goes into slip very early so having less to out on turn will give more grip on entry but makes no difference after apexing.
Also having the rack forward of the steering arms on a front steer will give the same effect.
Upright
What ever you choose you need to know the KPI if it has 6 deg that is about the caster you will run as a starting point.
Knowing this will give you a point to start on upper arm length and setback for the upper ball joint.
Rear roll centre
Very important on a rear eng car as they generally have to much rear grip because of the weight on the back tire.
This will generally cause under steer issues because the rear just keeps overpowering the front tires.
To sort this you raise the rear RC and reduce the grip and it balances the car and allows you to get on the power early and get it to sit on the back tire at point of entry.
Hope this helps you make decisions on set up or what components to pick.
Bit hard to change RC on struts from memory ,probably easier to adjust the lower inner up or down.

One thing I have seen done and it was smart was a strut leg was cut down and a fitting welded in that had a 5/8 thread in it to accept a rose joint that was fitted in the upper arm, so the leg was turned into an upright.

That arm in your pics made to take a r/joint as a ball joint is fine but you cant do that on the loaded arm ( the one with the spring/shock attached) say the lower you cant use that idea it will break eventually, I know this because I have done it and it did break at 23.000km road and track miles.

Any r/joint if in single shear (upper lower b/joint, outer tie rod on steering arm) should have a washer larger than the joint so as it is still captive if the joint fails.


Jim

rossnzwpi 18th April 2017 04:43

Once again your down-to-earth engineering knowledge amazes Jim. Thanks.

rossnzwpi 21st April 2017 00:34

This thread has some very in-depth engineering and description of the suspension requirements. Unfortunately it is also pretty dense and takes a long time to digest. Someone might find it useful:
http://reversetrike.proboards.com/thread/343

ozi jim 27th April 2017 11:07

I think hes an engineer, they love crunching numbers.
To many numbers to be honest ,he is over thinking it.
People can make it look like a black art, but its not complicated if you keep it simple.

If you guys want to start from scratch type or heavily modified projects buy Susprog3.
It is a great suspension program and it will punch out s/loads of data,I dont look at all off the data because it is what it is and there are things you cant change and there are things that make no difference.
I only use about 4 or 5 key things.

You have to spend the time inputting the data which can be overwhelming at first but it is worth it.

If you are not happy with something you adjust it in the program and run it in bump or roll and you recheck the dynamic figures.

http://www.susprog.com/

thecarbuilder246 12th May 2017 12:22

chassis
 
2 Attachment(s)
Hi
I'm in the middle of mocking up the adaptor plate. I've had a rough one cut to start with and I've made one up from the gearbox to place on top to see where bolts etc pass through. I think I'm going to have the final one made in alley as I need to have it 20mm thick to clear some bolt on the gearbox diff.
Anyone know of cuc guy's doing alley plates?
ian

rossnzwpi 14th May 2017 01:58

adaptor plate
 
Hey, if you google turbonutter and his Stratos replica with Alfa V6 fitted to an MR2 Toyota gearbox you'll find photos and some advanced tips. He may even have CAD files that could be of some use in your MR2/FordV6 adaptor.
Cheers
Ross

thecarbuilder246 14th May 2017 10:35

chassis
 
Hi Ross

I've already been in touch with him. He had a local to him motorsport firm do all the measuring and manufacture. Said it wasn't cheap. They also have the files.

ian

thecarbuilder246 21st May 2017 10:24

chassis
 
3 Attachment(s)
Hi

I've drawn up my own adaptor plate and with a vernier measured the hole dimensions on the trail plate I had done. I have a friend who works with perspex and he has cnc'd me a trail jig.Fits onto the V6 crankcase perfect and all holes line up.
Next up is to measure the Mr2 gearbox and have another jig made up to check alignment of the two.He will load it onto a memory stick for me and then I'll have it machined in 20mm allet plate.

ian

rossnzwpi 22nd May 2017 20:43

Hi Ian, are you putting a spacer on the end of the crankshaft to push the flywheel/clutch out 20mm to match what the MR2 gearbox had with its Toyota engine?

thecarbuilder246 23rd May 2017 08:08

chassis
 
Hi Ross

I will not be using a spacer on the flywheel. As I'll need a flywheel to go from the ford crank to toyota clutch I will have one made the 20mm or so thicker. A company here in the uk TTR racing do them from around £300.
I'm planning on using a stock format toyota clutch and release bearing so I can keep the toyota starter motor which is mounted on the gearbox. I'm trying to keep to stock equipment wherever possible and not go to over the top.

ian

rossnzwpi 25th May 2017 22:47

adaptor plate
 
Thanks Ian, I'm trying to visualise this.
So you are having a new Flywheel made that will have it's friction face further out from the crank end to match the original position of the Toyota clutch/flywheel interface (and this is 20mm because that's the thickness you need for your adapter plate). And the new flywheel will also have its starter teeth/ring gear in a place to suit the original Toyota.This new flywheel will have a bolt PCD pattern to match your Ford V6 crankshaft. It will have a friction surface to match the original Toyota clutch you are going to use. The nose of the Toyota gearbox will be supported how? I guess either a bearing in the crank elongated by 20mm or by an extension of the transmission shaft. Or perhaps the transmission shaft is long enough anyway or isn't supported in the crank?

Wow - its a lot to get my head around and that's without even thinking about the clutch actuator!

Clairetoo's locost posts and her company Crap Engineering make an adapter to fit the Mazda V6 to the Mazda MX5 gearbox that looks like this:
http://crapengineering.weebly.com/up...799133.jpg?325
as you can see the position of the starter causes a few headaches in this setup. She chooses a spacer on the crank to avoid having a new flywheel made and because she wants a light flywheel.
cheers
Ross in NZ

thecarbuilder246 26th May 2017 09:04

chassis
 
2 Attachment(s)
Hi Ross

Yes. The flywheel will be made to bolt to the ford V6 crank then mate up to the toyota clutch. In theory it will need to be 20mm thicker but as the V6 originally came as a automatic only the flywheel will actually be thinner than the OE market one fitted to the V6.
As regards the starter this will be kept standard and in it's original position but using an upgraded unit. The clutch operation will either be kept as standard or I may use turbonutters idea of an hydraulic thrust bearing.Keeping things simple.
You mention that the gearbox input shaft will not engage in the crank. Transverse engines do not generally engage in the crank like inline set ups and there is no bearing nosing machined on the end of the gearbox input/drive shaft. See photo.

ian


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