loosing weight

loosing weight

Author
Discussion

monaco

Original Poster:

219 posts

283 months

Friday 20th September 2002
quotequote all
No question about getting a cage made up by just anyone, I would rather just have a proper rear roll bar than make a mock up full cage, I understand that an official full cage has been made for an S at some point, but haven't had the time to investigate who made it yet.

On the subject of wheels, If the wheels were changed for wider ones e.g. 8x15, and you fitted lower profile tyres which then intentionally decreased the rolling dia. I know this would change the gearing, but do you think that it would significantly change the 0-60 and top speed ??

If so I could live with a drop in top speed on most tracks ( never get a straight long enough !!) if I could get better acceleration through the lower gears.

Just a thought.

Paceracing

729 posts

267 months

Friday 20th September 2002
quotequote all
quote:


On the subject of wheels, If the wheels were changed for wider ones e.g. 8x15, and you fitted lower profile tyres which then intentionally decreased the rolling dia. I know this would change the gearing, but do you think that it would significantly change the 0-60 and top speed ??

If so I could live with a drop in top speed on most tracks ( never get a straight long enough !!) if I could get better acceleration through the lower gears.

Just a thought.


If the rolling radius remains the same, then the gearing and hence top speed / 0-60 times will be unnafected. A smaller rolling radius will accelerate quicker, whilst a larger rolling radius will increase top speed. Bear in mind that tyre width should ideally be within 1" to 1.5" of the wheel rim width for optimum handling.

Jas.

P.S. Even though it is possible to calculate rolling radius, by adding wheel rim diameter to tyre wall height, (x 2) it is not as accurate as measuring by rolling along the ground and measuring 1 revolution.
Sorry to get so technical, it's a bit of a minefield which needs a lot of thought!

GreenV8S

30,224 posts

285 months

Friday 20th September 2002
quotequote all
quote:

P.S. Even though it is possible to calculate rolling radius, by adding wheel rim diameter to tyre wall height, (x 2) it is not as accurate as measuring by rolling along the ground and measuring 1 revolution.
Sorry to get so technical, it's a bit of a minefield which needs a lot of thought!



[anorak]
If you're getting technical, that would be the rolling diameter?
[/anorak]

Paceracing

729 posts

267 months

Friday 20th September 2002
quotequote all
Peter,
How can a diameter roll?
Come to that, how can a radius roll?
The only thing I know is that I like a chocolate roll!

Jas.
P.S. I suppose it must be a rolling circumference!

shpub

8,507 posts

273 months

Friday 20th September 2002
quotequote all
BTW don't forget to tank into account the growth in the tyre height due to centrifugal force (centripdal reaction to be more accurate) which will vary as it is dependent on the rotational speed.

Alternative you can get in, belt up and drive the thing...

As for S roll cages, Tower View/Rollcentre have roll bars and that might be a good starting point for a cage.

Steve

GreenV8S

30,224 posts

285 months

Wednesday 25th September 2002
quotequote all
Anyone care to hazard a guess what the bonnet weighs? (Just weighed mine, need to sit down for a rest.) Free smiley to the closest answer.

Cheers,
Peter Humphries (and a green V8S)

shpub

8,507 posts

273 months

Wednesday 25th September 2002
quotequote all
47.45 KG unpainted.

Paceracing

729 posts

267 months

Thursday 26th September 2002
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quote:

Anyone care to hazard a guess what the bonnet weighs? (Just weighed mine, need to sit down for a rest.) Free smiley to the closest answer.

Cheers,
Peter Humphries (and a green V8S)


Peter,
I know that the original bonnet is very heavy, I have had mine made out of fibreglass, like they do on race cars.

Jas.

P.S. I would agree with Steve, my guess is around 50Kgs.

monaco

Original Poster:

219 posts

283 months

Thursday 26th September 2002
quotequote all
Does anyone do light weight body panels ?? bonnet etc.

Paceracing

729 posts

267 months

Thursday 26th September 2002
quotequote all
I looked into this one a year or so ago.
TVR themselves wanted me to re-mortgage my house, and so I spoke to a local fibreglass repair man who used to work for Reynard F1. He wanted £1,500 for a lightweight bonnet, but told me I could keep the moulds that would need to be made to produce it. After a bit of thought, I guessed that I could knock out cheap bonnets for around £600 apiece until I figured that TVR might send some heavy lawyers down as I would be infringing upon their rights to the design. Hence the project never even got off the ground!

Jas.

shpub

8,507 posts

273 months

Thursday 26th September 2002
quotequote all
quote:

Does anyone do light weight body panels ?? bonnet etc.



Tower View have done a bonnet, bumper and front spoiler/splitter for the 520 which weighed 4 kg total.

They have many of the moulds. It is not cheap though but you may be able to recover a lot by selling the original.

Steve
www.tvrbooks.co.uk

PS 47.45 KG unpainted. This is for the V8S bonnet with no grill or metal work but flattened prior to painting.

PPS Where's my smiley?

>> Edited by shpub on Thursday 26th September 09:50

GreenV8S

30,224 posts

285 months

Thursday 26th September 2002
quotequote all
quote:

I figured that TVR might send some heavy lawyers down as I would be infringing upon their rights to the design. Hence the project never even got off the ground!



Other TVR specialist body shops seem to be able to make their own body panels, presumably without any legal trouble?

Paceracing

729 posts

267 months

Thursday 26th September 2002
quotequote all
Peter,
Interesting to read both yours and Steve's comments.
Maybe there is some kind of get-out clause for manufacturing your own TVR designed panels. As I said before, one of the main reasons I didn't take it further was that I was under the impression that TVR owned the rights to manufacture, supply, reproduce, etc... and I would be breaking the law.
Anyone from the legal profession care to comment?

Jas.

monaco

Original Poster:

219 posts

283 months

Friday 27th September 2002
quotequote all
O'dear I'm back again !!

OK so where's the best place to get a light weight gell battery from and how much am I going to pay for this huge weight saving??
I need a new battery for this project as the S has been sat in the garage for two years doing nothing and the battery is about dead, so might as well get a gell one if I have to replace it.

shpub

8,507 posts

273 months

Friday 27th September 2002
quotequote all
Rally Design.
Red Top 20
About £70

Steve

monaco

Original Poster:

219 posts

283 months

Friday 27th September 2002
quotequote all
Cheers Steve

I have had a look a rally designs website, all looks good.

I am assuming that the red top 20 is the model to go for ?? with regards to the 2.8 S1

Many Thanks.

shpub

8,507 posts

273 months

Saturday 28th September 2002
quotequote all
I use two in parallel on the 520 as this gives me plenty of capacity for the road driving. Remove one for the track. Gives me a spare and one is more than capable of turning over the 520 so should have no problem with a 2.8i.

They like being battery conditioned or disconnected when used though. They don't like small current drain though. e.g. an alarm.

Steve