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Chassis weight
scutter - 16/2/14 at 02:39 PM

Folks, Whilst I realize it maybe a little late, I've started to wonder if the extra bracing we've stuck in my Haynes Roadster might be too much! (Quiet Cheffy before you start ) I've still the engine bay to sort, and it seems to be quite a bit heavier than my old Locost.

Would the collective be kind enough to look over the photos and give an opinion?

Yes it will be running that 3.0 alfa V6

Regards Dan.

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Mark Allanson - 16/2/14 at 02:54 PM

I did very similar to you, but with a Pinto, the completed car weighed 690kgs at SVA and is a much better car because of it. The ratio of sprung weight to unsprung weight is much more favorable, giving a production car ride quality without compromising handling, the tyres work better at 20-22psi which is closer to their design pressure that the lightweight cars running 16psi.

My day job is repairing accident damaged cars, so my additional bracings were to improve crash resistance as well as stiffness, triangulation of the transmission tunnel was also in case of prop breakage.

Car is looking good, keep us updated


pewe - 16/2/14 at 03:42 PM

That's looking a bit like my Formula 27 chassis.
That weighs 650kg all up but it sits on the road a lot better than some of the BEC's I passengered in.
Also because it's a CEC the extra weight isn't as punishing on the engine and transmission.
Unless you were aiming for an out and out racer I think it will be fine.
Keep the posts coming.
Cheers, Pewe10


43655 - 16/2/14 at 06:38 PM

I can't help much, my chassis is massively over-engineered in comparison. but do you know what the V6 weighs?
I want to run the audi 2.7 biturbo V6, and at 190kg it's a heavy lump!

However i guess if you're worried about strength see what the V8 guys have done, if anything (extra that is)


adithorp - 16/2/14 at 06:44 PM

Completely off topic but... It'll sound epic!


scutter - 16/2/14 at 07:31 PM

The v6 weights 170kg dressed but dry. I'm looking for 220hp and the same in torque.

I hadn't thought of the increase in ride comfort, but this one is definitely a tourer as I got the last down to 540kgs but with the live axle it did skip about unless you were on a track.

I leave the chassis as is at the moment and make it presentable, I'll just have to be careful around the engine bay.



Regards Dan.

[Edited on 17/2/14 by scutter]


scutter - 16/2/14 at 07:57 PM

Ok, how do you put that Youtube link in a playable window within a thread?

Regards Dan.


43655 - 16/2/14 at 08:22 PM

ooh okay, 190 does't sound so bad, being capable of 450hp

That does sound fantastic!


umgrybab - 16/2/14 at 10:42 PM

I think extra bracing can be beneficial at times but you have added it to a largely stiff portion of the chassis anyway. From the bulkhead to the dash is a very stiff area to start with, whereas the dash to the seat back is the part of these cars with the least torsional stiffness. I would be inclined to decrease the amount of extra bracing around the tunnel and increase the amount adding the cockpit sides and seat back to suspension points. I would also add small diagonals from bulkhead to engine mount points in the 3rd dimension as with more power and vibration going in this area is looking fairly planar and could use small improvement.


iank - 17/2/14 at 08:17 AM

quote:
Originally posted by scutter
Ok, how do you put that Youtube link in a playable window within a thread?

Regards Dan.


Use the YouTube button (right hand side of the formatting mode buttons)
Enter the youtube id in the pop-up box. i.e. in this case MOJtpZST_WM and you'll get the window you want.

Like this one


Cheffy - 17/2/14 at 10:55 AM

quote:

(Quiet Cheffy before you start )



Daniel, you've seen my V8 build - I'm in no position to criticize anybody else's chassis for being overweight!

Mart.


rossnzwpi - 18/2/14 at 08:29 AM

Wow, what a great project! The Alfa V6 is a fabulous engine and the 12 valve version is torquey to boot. It may be a bit heavy but if you're after a sports car not a maximum lightweight, high power beast then that's OK. I had a 164 for a while with this engine and the tone under acceleration was spine tingling. What gearbox arrangement do you have? The ones I've read of are an adaptor plate to a Ford type 9 or a slice of Alfa front wheel drive bell housing mounted to a rear wheel drive box like the type 9. Some have used the Alfa 105 gearbox, or if you can find one the old Alfa 6 / Alfa 90 ZF box.
Looking forward to reading your build log
Cheers
Ross in NZ


scutter - 18/2/14 at 04:54 PM

Cheers Ross, A friend whom I brought the project from used to race a V6 alfa in Rwd and made up a bellhousing by welding a few alloy nuggets into a Cosworth T5 box. So it should be able to handle the torque.

Not the clearest picture, but it's hidden in here somewhere.

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I'll keep you all posted, Dan.