LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently April 18, 2024, 4:40 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 34 posts ]  Go to page Previous  1, 2, 3  Next
Author Message
PostPosted: May 1, 2018, 12:40 pm 
Offline
User avatar

Joined: October 23, 2010, 2:40 am
Posts: 1456
Stephan wrote:
the 10 gallon fuel cell over the rear axle is clearly a compromise : it will obviously raise the (otherwise ridiculous low) CofG a little, but I'm just not very comfortable with the cell behind the rear axle (in case I get rearended)...I rather have the trunk there to act as a little "crumble zone"
Stephan, you might consider mounting a fuel cell with bladder behind the rear axle. The bladder would provide additional protection to the "reverse flying wedge" protection built into your chassis shape. The folks at Fuel Safe have a number of odd shaped cells that might work, or you could get a custom one made. A bit on the pricey side, but good insurance value.

Looks like a fun project!

_________________
Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."

Ultima Spyder, Northstar 4.0, Porsche G50/52


Top
 Profile  
Reply with quote  
PostPosted: May 1, 2018, 3:49 pm 
Offline

Joined: June 5, 2016, 7:03 am
Posts: 235
Location: ontario
[quote="Stephan"]hi all , Stephan aka RoosterBooster here (forgot password lol)
after many years of planning and starting off in various directions (including Austin 7 special, BEC, Rat/offroad rod, ....) I finally settled on a plan ;
pushed by my best friend we desided to dust off my previous 1930'ish Austin 7 Special inspired look , but make it a two seater and skip the just a little too gutless bike engine drivetrain ...

Image
(pic is a photoshop rendering i made years ago and posted here previously)

the most important change is the motivation;
this Ford 2.0 ecoboost just arrived at our shop (out of a wrecked 2015/27000miles Lincoln MKZ , $940 fully dressed and with free delivery) :mrgreen:

Hi Stephan,
What an exciting project, quite out of the beaten path. I congratulate you on your originality. I drive a 2017 Ford Escape (our second one)with the turbo engine that you are referring to and I agree with you this is one of the most impressive production mill on the market. For you to put your hands on one for the price that you indicated is a miracle. I like the 1929 Bugatti (like) look of what you want to build and this will make for a one of the kind car. If I were building it I would make a 2 seater. Good luck in this project, thanks for the pictures. Keep us posted. :cheers:


Top
 Profile  
Reply with quote  
PostPosted: May 1, 2018, 4:32 pm 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
thanks Phil :cheers:

yes, I'm kinda developing this together with my best friend Ryan English here in Vegas
... and he had 3 key mandates;
- has to be a 2 seater (or his wife would feel excluded and stonewall the project lol )
- has to look and feel fairly period correct "vintage" , at least on the outside
- has to have an aircraft vibe/driving experience

he is an avid Pilot and shares my love for vintage & aluminum/rivets ...
pic is his vintage Cessna (iirc she is a `64) in front of my `52 Truck up at the Strawberry creek airfield
(currently I'm helping him building a cabin/hangar in that "fly-in" community )

Image

the "vintage" solid axles and quarter leaf suspension is definitly going to be a bit of a compromise,
but as we agreed with each other you can only go so fast on public streets anyway

the way i imagine the driving experience is that we are probably going a little slower into corners (as compared to IFS/IRS)
but definitly going to get a kick out of powering out of the corners :twisted:
... and braking into the next corner (i plan on brakes that are definitly on the "overkill" side for this light car)


Top
 Profile  
Reply with quote  
PostPosted: May 1, 2018, 4:42 pm 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
Tom
yes, i agree that I'm not too thrilled about the weight of the (sloshing) fuel so high up
i also agree that an enclosed soft bladder cell would absorb a crumbling/crash a lot better then an enclosed rigid plastic cell ,
but i guess my obsession with the pointy ass is biting me in the formerly mentioned :lol: ;
its very hard to find triangle shaped cells and a custom bladder does not agree with my tight budget :ack:
still thinkering with that detail ...


Last edited by Stephan on May 2, 2018, 1:40 am, edited 1 time in total.

Top
 Profile  
Reply with quote  
PostPosted: May 1, 2018, 5:09 pm 
Offline
User avatar

Joined: March 30, 2011, 7:18 am
Posts: 1615
Location: central Arkansas
Stephan wrote:
the "vintage" solid axles and quarter leaf suspension is definitly going to be a bit of a compromise,


Add some decent axle location and you'll be fine. I've driven thousands of miles in beam-axle vehicles. All of the horror stories of beam axle front ends seem to assume the front axle is restrained only by floppy leaf springs.

Arthur Mallock was the god of the beam axle in the British "750" racing series. His cars were highly competitive. He passed away a while back, but some of his magazine articles and handwritten notes are available here: https://www.arthurmallock.com/

Note that there's no fancy handwaving about things like roll centers when you're running a woblink or Watts link. "Where roll center? THERE roll center!"

I'd be running a beam axle up front, except was way cheaper to do IFS.


Top
 Profile  
Reply with quote  
PostPosted: May 1, 2018, 6:55 pm 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
TRX wrote:
Stephan wrote:
the "vintage" solid axles and quarter leaf suspension is definitly going to be a bit of a compromise,


Add some decent axle location and you'll be fine. I've driven thousands of miles in beam-axle vehicles. All of the horror stories of beam axle front ends seem to assume the front axle is restrained only by floppy leaf springs.

Arthur Mallock was the god of the beam axle in the British "750" racing series. His cars were highly competitive. He passed away a while back, but some of his magazine articles and handwritten notes are available here: https://www.arthurmallock.com/

Note that there's no fancy handwaving about things like roll centers when you're running a woblink or Watts link. "Where roll center? THERE roll center!"

I'd be running a beam axle up front, except was way cheaper to do IFS.



lol .... oh yes, the beam axle idea kinda ended up a little more expensive then initially expected :ack:
mainly for me refusing to buy a $100 china (probably cast steel ?!?) knockoff beam and buying a Socal Speedshop designed and forged in the US of A beam instead
(it has the telltales of forging ; big fat part line and rings like a bell when you strike it with a wrench :P )
total overkill, probably even on a 3500 lbs hotrod , but peace of mind.

initially I wanted to locate the axle by using the quarter leafs as lower links, but the length variation of the compressing leaf put an end to that idea :ack:
now im thinking perfectly horizontal/parallel 4 link with a panhard bar that perfectly matches the cross-steering link to eliminate any bump-steer.
at least by design the beam has no suspension/track scrub going tru its travel (unless your kingpins are shot lol ) :P
yeah, a decent pothole will probably upset the beam some (at least thats usually the only thing that throws my beam axle Truck a little out of shape)
but im not too worried

talking about steering;
i plan on a "cross steering" setup, but using a quicker and more responsive rack&pinion instead of the traditional vega steering box.
Unisteer is selling them one sided racks for ~$450 ,
but looking closely at them i realized its nothing more then a polished Polaris RZR rack with one tie-rod whacked off :roll:
so i bought a basic RZR rack for mockup ($80 on ebay) but plan to actually use the beefed up late model (EPS) version for final assembly
(bigger housing, larger diameter heat treated rack shaft, etc)

Image

the rack fits like a glove into the oil pan recess
ratio is ~ 2.5 turns lock to lock on its ~ 5.5" stroke
late RZR`s are way heavier plus have to endure high long travel/off road off-center loads,
so im not worried about its strenght, even when only used one-sided
(after all Unisteer sells the lighter duty version for use on way heavier hotrods)


Top
 Profile  
Reply with quote  
PostPosted: May 1, 2018, 11:32 pm 
Offline

Joined: June 5, 2016, 7:03 am
Posts: 235
Location: ontario
[quote="Stephan"]thanks Phil :cheers:



The main thing about a solid front axle is bump steer. I lived with one for 10 years (Samurai), one can get used to it. On a fun vehicle it is quite acceptable. I like the quarter leaf springs. My first seven is equipped with two posies in the back. My current build suspension is also based on quarter elliptic springs. Your friend should not worry the car you propose to build will offer all the thrills of a light aircraft before take off. :)


Last edited by phil on May 2, 2018, 4:21 pm, edited 2 times in total.

Top
 Profile  
Reply with quote  
PostPosted: May 2, 2018, 2:24 pm 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
while I had the parts out of the shop I also checked on charge cooler/radiator/grille shell fit ...

Image

Image

Image

Image

the charge cooler is for a Suabaru BRZ and fits into the curved `29 shell like it was made for it :)
(besides that big top tab that needs to go)

by using a narrower (but chopped by 4") `32 radiator in the wider `29 nose I should have just enough room
to squeeze the (slightly flattened) 2.25 charge cooler tubing past the rad.

driver side will get a little crowded with the cc and lower rad hose fighting for space with the alternator, but does not seem to be a huge problem.
upper rad hose needs to run on top of valve cover to the (FWD car oriented) coolant outlet at the back of the engine/head
again, nothing that cant be solved with a selection of silicon elbows and SS tubing

a 16" Spal "slim-line" fan should fit (barely) between the setback rad and the serpentine pulleys ...

kinda satisfying when theory & online "hunted down" parts actually fit together :cheers:
(I guess its a little love&hate deal ... love the hunt, but the lack of reliable dimensions online is sometimes frustrating :BH: )

btw
mockup is actual ride height ...clearing a standing beer can (5.5") is our target
(don't want to go too low for the sometimes rough roads and deep storm ditches around here)


Top
 Profile  
Reply with quote  
PostPosted: May 3, 2018, 10:05 am 
Offline
We are Slotus!
User avatar

Joined: October 6, 2009, 9:29 am
Posts: 7651
Location: Tallahassee, FL (The Center of the Known Universe)
Quote:
clearing a standing beer can (5.5") is our target
Yep, the basis of all science is accurate measurment...
Attachment:
8 22 10 Axle at Ride Height.jpg


You do not have the required permissions to view the files attached to this post.

_________________
JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


Top
 Profile  
Reply with quote  
PostPosted: May 3, 2018, 8:47 pm 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
Gonzo ; lol ... yeah whatever works, right ?!? :cheers:

looking for some inspiration online i stumbled over this pic @ conceptcarz.com that nicely shows what im after 8)

Image

no racing and/or killing orange cones for me :P ... just some fun up here in the mountains


Top
 Profile  
Reply with quote  
PostPosted: May 3, 2018, 11:33 pm 
Offline
User avatar

Joined: December 4, 2011, 6:19 pm
Posts: 830
Stephan wrote:
up at the Strawberry creek airfield
(currently I'm helping him building a cabin/hangar in that "fly-in" community )


Where is that? I can't find it on the net.

Bill

_________________
Bill H
Winnipeg, MB, Canada


Top
 Profile  
Reply with quote  
PostPosted: May 5, 2018, 10:32 am 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
BHRmotorsport wrote:
Stephan wrote:
up at the Strawberry creek airfield
(currently I'm helping him building a cabin/hangar in that "fly-in" community )


Where is that? I can't find it on the net.

Bill


Bill
its a grass air strip south of Duck Creek Village UT... about 8200 ft elevation :wink:

for shopping you need to go down to Cedar City (but cross a 10000 ft summit first)
super fun & twisty road (any day other then weekends :ack: ) ...and the altitude is one reason why i wanted a turbo engine


Top
 Profile  
Reply with quote  
PostPosted: May 5, 2018, 10:48 am 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
one feature that most "special" bodies of the `30 shared was "rolled under" sides...

Image

it adds a little complexity to the frame/pan construction,
but thankfully i already made a radius bender that is perfect for that years ago (need to dust/rust it off a little :roll: )

Image

Image

its a 4" tube, so with springback it should give me a nice ~2.25 radi

i plan on using .065 6061-T6 for the stressed skin pieces (and probably regular "soft" 5052 for the hood and trunk)


Top
 Profile  
Reply with quote  
PostPosted: May 5, 2018, 2:21 pm 
Offline

Joined: June 5, 2016, 7:03 am
Posts: 235
Location: ontario
The rounded lower sides indeed makes this model's body even more graceful. Not all makers bothered to do this. I think that Bugatti did not on his famous 35s.
It is a good thing that you had this large metal roller handy. On my current build I had to radius about 30" x 9" (.050 steel) over a 4 " round tube. It worked but it was not easy. :)


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
Reply with quote  
PostPosted: May 14, 2018, 4:08 pm 
Offline

Joined: April 4, 2018, 1:32 pm
Posts: 34
Found the Miata 6-speed ratios online,
so I entered them into the Tremec gearing calculator;
looks like I was wrong that the rear axle ratio (3.27) is too long
here is the ratios & speed at 2500 rpm / 5500 rpm engine speed:

1st - 3.76 - 17/37 mph
2nd - 2.27 - 28/61 mph
3rd - 1.65 - 39/85 mph
4th - 1.26 - 50/111 mph
5th - 1.00 - 64/140 mph
6th - 0.84 - 76/167 mph

first is still a short "loading it up into the trailer" one ,
but I do like the low rpm's in 6th @ highway cruising speed :wink:


what do you guys think ?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 34 posts ]  Go to page Previous  1, 2, 3  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 16 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
POWERED_BY