L/w Strengthening

[Guest salty_monk]

See my post on Warwick's photo's. Out through the top with panel 15A removeable seems to be the only way to me...

[Guest ScotMac]

My promised update to how my l/w strengthening is progressing (topic has taken greater importance in the last couple of months! ).

 

Will try to get some photos out soon, but in general, they don't show much, since most of the stengthening is integrated into or replacements for the RH supplied pieces.

 

In general, i have:

 

1. Completely modified the diff box and rear suspension boxes, by adding a very thick plate (3/16") along the diff box sides and adding angled pieces to every one of the corners of the 15x sections. All are bolted and bonded in place.

 

2. I have added 2" x 1.5" boxed aluminum the *entire* length of the rolled over top box section on the side of the chassis. Note, the 1.5" fits perfectly into the chassis top. Used 2 sections, one 60" for the front, and one 40" for the passenger area. The pieces are bolted and glued into place (zinc coated strength rated (8. bolts). Note, the back of foot well panels have to be cut where they wrap around the top of the chassis side to allow these box sections to be slid into place, along w/ the fact that the rivetting on chassis top is all replaced w/ bolting, where it matches up w/ the new box sections (outside rivets).

 

3. Replaced the "layered" pieces of aluminum in the engine bay floor sides and the engine bay floor nose area w/ 1/4" thick (!!!) peices of flat aluminum, thoroughly bonded and strength bolted in place.

 

4. Replaced the angled pieces, used to connect the front lower box sections to the engine bay floor, w/ angled steel pieces (w/ cut-outs for lightness, and zinc coated and fully glued to ensure no corrosion).

 

5. The forward front-top box section is bolted to the new chassis top box section.

 

The box section bolting utilizes Graham's tubular section insert idea to ensure no squashed box sections. ie, overdrill one side, insert the tubular section all the thru the box, up against the non-overdrilled side, and washer both sides to lock it in place.

 

Todo:

 

6. Replace the 28x sections w/ 3/16" thick plate aluminum, adding a large solid piece of aluminum at the top to handle the fact that the top box is offset from the bottom box by about 3/4".

 

7. Stengthening plates for seat belt mounts (see if can hook them into other strengthened areas).

 

8. Add transverse box sections to the bottom of the chassis, tying them into lower box sections in the passenger bay, and use vertical box sections to tie them into the new top of chassis box sections. Note, this may be overkill, but is probably necessary to get it past the safety marshals when i try to race the l/w.

 

9. Add an extra plate under the rollbar (from Marcus and others).

 

All the bonding uses the Fusor 112b automotive glue i have detailed previously.

 

All the new aluminum is 6061-T6.

 

Hope this helps, and for the lw'ers that are going, have fun at the f2f!

 

Cheers, -sm

[Guest ScotMac]

Oh, and before anyone brings it up, all this has added less than 40lbs total to a car that will likely weigh ~900lbs.

[Guest warwick7735]

Scot

 

900lbs, blimey thats only 409kgs some 200kgs lighter than mine. I know the pinto is about 60kg heavier than what your using, so how have you saved the other 140kg.

 

Those tiny holes in the body are for rivets, not for weight loss

 

I'll eat my rivet gun if you can get it to weigh 900lbs.

 

Warwick

[Guest ScotMac]

Scot

 

900lbs, blimey thats only 409kgs some 200kgs lighter than mine. I know the pinto is about 60kg heavier than what your using, so how have you saved the other 140kg.

 

Those tiny holes in the body are for rivets, not for weight loss

 

I'll eat my rivet gun if you can get it to weigh 900lbs.

 

Warwick

 

 

You had better get some really strong teeth...i hear rivet guns can do major damage!!

 

Didn't i tell you that i got in my raceleda sierra replacement aluminum upright kit? Not only is it *gorgeous* , it also shaves about 17lbs a front corner. Also, what about engine auxilliaries? hmmm...let me see:

 

ITBs vs. carbs and carb manifold?

ultra lightened flywheel

t5 vs type-9 (?? might be about the same)

windshield vs aeroscreen

lightweight carbon fiber seats

lw scorpion racing motorcycle exhaust (maybe a bit loud!!! ;-) )

rear disc vs drums (???)

aluminum shocks on all corners vs zimmers

 

I think i will get it under 1000lbs...ok, so call the 900lbs a *goal*...w/ the rivet gun munching incentive!!!

[Snapperpaul]

Good to see positive postings for the Lightwieght.

With all the work done so far and if its incorporate in future builds, SVA's should be passed.

[Guest zoomzoom]

Scotmac thanks for the posting, its given me lots of ideas on what to do

 

Marcus

[Guest diyer]

With respect, I'd be shocked and suprised if you can hit 900lbs ScotMac, a tricked out bike engined westfield is about 400kgs!!

My lightweight weighed in at 590kgs with a Zetec engine in it.

 

regards

Simon

[Guest ScotMac]

I did say it is a goal!!

 

I have also seen BECs weighing in around 400-450kg. I saw a comparison of a hayabusa (one of the best bike engines) to a zetec, that showed the zetec about 80lbs heavier and a duratec is lighter than a zetec.

 

Also, remember i don't have pass SVA. My car, at least initially, will be very stark. Not much more than the minimal parts necessary to make it roadworthy and get it past the CHP inspection (lights and brakes inspection) and DMV.

[Guest ScotMac]

Scotmac thanks for the posting, its given me lots of ideas on what to do

 

Marcus

 

Great. In fact, I firmly believe all the strengthening i have done, plus the proposed roll bar and seat belt mods, would be enough to get a l/w past the chassis strength SVA inspector concerns.

 

Cheers, -sm

[Guest gdc]

hi

my weights for the test were 310 front and 300 rear i dont know how that relates to total weight in kgs.

i think a good split weight though.

my lightweight will never be a true lightweight though as the material to make it stronger has signifiquentley added to the overall weight.

scott you have used some exotic materials to keep weight down ,ie alloy front upwrights ect.

the tester commented that the car was verey light though.

my impression is that the car weighs arround 750 kgs.

i may be wrong and if lighter i would be happier.

ie 750 *2.2 =1100lbs

seems heavy to me?

a 2b weighs less than this.

how to calulate the total weight without putting it on a weigh bridge??????????

 

regards graham

[Guest ScotMac]

hi

my weights for the test were 310 front and 300 rear i dont know how that relates to total weight in kgs.

i think a good split weight though.

my lightweight will never be a true lightweight though as the material to make it stronger has signifiquentley added to the overall weight.

scott you have used some exotic materials to keep weight down ,ie alloy front upwrights ect.

the tester commented that the car was verey light though.

my impression is that the car weighs arround 750 kgs.

i may be wrong and if lighter i would be happier.

ie 750 *2.2 =1100lbs

seems heavy to me?

a 2b weighs less than this.

how to calulate the total weight without putting it on a weigh bridge??????????

 

regards graham

 

 

 

I believe locostbuilders have the answer to that question...i'll take a look and get back shortly (unless someone beats me to it!!! ;-) ).

[Guest ScotMac]

Here is a good discussion of it (sva weights):

 

http://community.rhocar.org/index.php?showtopic=7811

 

It appears (from that thread) you can take off about 50 to 80kg's from the added sva weights. So that puts you at about 300 + 310 - 80 = 530kg * 2.2 = 1160lbs. That's actually pretty good!! Congrats!

 

 

BTW, i agree, your weight distribution is quite good. I still have not heard one peep from a l/w owner in terms of how the car handles!!! Graham?

 

Guess i'll have to finish mine to find out!!!

[Guest diyer]

When i had mine SVA'd the tester indicated that the car weighed 590kg's

 

Simon

[peter_m7uk]

Getting confused now, although I do know for definite that adding together the weight

over the two axles measured separately equals the total weight of the car - You can prove this

with a bit of A-level Physics (moments and forces).

 

So, are the axle weights people are talking about a] measured on scales at SVA or b] some

sort of estimate of maximum capacity? The only way that a weighbridge can give a different

weight for the total car is if either the weighbridge or the SVA scales are out of calibration!

 

Pete