What's More Cost Effective. Less weight or More engine.

[Garrick Clark]

Hi Guys.
Right so my 67 turbo bug.
I've got to the point were my engine runs good, The box has some strength and it drives relatively good.

I only drive it on the street, But i'm looking for ways to get more excelleration off the lights.

This bug is all steel , all glass,T bars, stripped interior and 2 standard seats with harnesses.

So where  would i spend the money. For a street car only i do wonder if the cost of getting lighter panels is worth the money. I did read that getting the vehicle 10lb less  is 1hp gained, so the price of loosing 100lb to get  10 hp could get expensive and NOT cost effective.

I run at 1 bar boost. I dont see this as a high boost level really
so maybe i've aswered my own question put More boost into it, Im sure this turbo will do 1.5 bar without going pop.

[Erlend / bug66]

I would want the weight.

More power is “easy”  

[leec]

Maybe use the Wallace drag race calculator and play around with different power to weight ratios and see what happens to the ET.

Lee

[Garrick Clark]

Ok Thanks Guys.
My set up has been difficult to get this far. It might be easy (ish) if I had fuel injection , but a single blow through carb is quiet hard, I only no the old school way of doing things. No EC you for me.

I'll have a look at the wallace site.

[richie]

More boost/hp wont necessarily equal more acceleration but less weight will and will be more kind to your engine/gearbox etc as well

[Garrick Clark]

Ok didn't think of it like that.
I'll take to the weigh bridge and get it weighed.
What's your guess on what it weighs now.
All steel.
All glass.
No rear valance or engine lid.
Stripped interior. JUST 2 standard front seats.
T bars on front
Rear discs. (must be double weight of a rear drum set up).
Copy BRM wheels
no spare
Type 4 engine.
Turbo.
No cage.

Thanks.

[richie]

Ok didn't think of it like that.
I'll take to the weigh bridge and get it weighed.
What's your guess on what it weighs now.
All steel.
All glass.
No rear valance or engine lid.
Stripped interior. JUST 2 standard front seats.
T bars on front
Rear discs. (must be double weight of a rear drum set up).
Copy BRM wheels
no spare
Type 4 engine.
Turbo.
No cage.

Thanks.

1870lbs with you in it

[dragvw2180]

The 1966 bug street car I own now weighs 1800 w/o me in it , this is a 2387 turbo car . When I had this engine in my old race car I wanted to pick up some E/T so I removed 125 lbs off the total weight of the car , car went from 6.41 to a 6.35 , bummed me out, LOL . Mike McCarthy

[Erlend / bug66]

More boost/hp wont necessarily equal more acceleration but less weight will and will be more kind to your engine/gearbox etc as well

Any advice on a minimum weight with a car going let's say 140mph? Or doesn't it matter?

[Garrick Clark]

Mike , this is what I'm worried about, spending money on light weight seats/lexan windows/battery etc , doing hours of work drilling parts etc and not getting a performance increase to match the money/labour effort. I'm not trying to get low times down the strip. I just want to feel  the improvements while street driving. If I chuck a couple more thousand  at it I want to feel it in terms of acceleration. Not interested in top end really.

After spending a couple more thou on light weight panels/seats/windows etc and feeling that the car isn't  quicker I'd be pretty disappointed.
 

[richie]

More boost/hp wont necessarily equal more acceleration but less weight will and will be more kind to your engine/gearbox etc as well

Any advice on a minimum weight with a car going let's say 140mph? Or doesn't it matter?

Weight in right place is much more important, but lightest car I know that has gone 8.90s@149mph was 1600lb

[Erlend / bug66]

More boost/hp wont necessarily equal more acceleration but less weight will and will be more kind to your engine/gearbox etc as well

Any advice on a minimum weight with a car going let's say 140mph? Or doesn't it matter?

Weight in right place is much more important, but lightest car I know that has gone 8.90s@149mph was 1600lb

Thanks,

Yup, moving weight to balance the car is needed.

1600lbs is 725kg for those of us using a logical measuring system 

[Garrick Clark]

So who can do or who has the balancing equipment to balance our vee dubs and why is it so important.

[richie]

So who can do or who has the balancing equipment to balance our vee dubs and why is it so important.

Typically we add weight to rear of car and easiest place to loose it is from front, so you end up with a tail happy car you cant steer

We do our own and have our own scales but any decent road race or rally prep type shop should have access to them, and most drag race chassis shops will have them

[DaveN]

Maybe use the Wallace drag race calculator and play around with different power to weight ratios and see what happens to the ET.

Lee

Have you used this? How accurate was it?

[leec]

I have Dave, I found it surprisingly close to my cars best ET

Lee

[DaveN]

Cool! I have heard about it but have never used it as I don’t have any accurate information about my cars weight and power output,etc.

[leec]

I only used it after I had the oval weighed at the local scrap yard (had to tell them despite appearance I wasn't scrapping it!)
As the original post asked, I then worked out how much quicker the car would go if  I saved a certain weight.
Lee

[Garrick Clark]

Just been on the Wallace ET calc.
If i loose 300lb the ET goes down  . 61 of a second.

So from my set up..  loosing 300lb in weight i'd have to change what on my bug. thats alot of weight for very little gain.

Theres probably an amount of hp increase that will beat that. Which 1 is cheaper.

Just waying up my options. I'm only a streeter anyway.

[DaveN]

Replace the glass windows that will probably be the cheapest/ biggest weight saver.

[Garrick Clark]

Ok thanks Dave. So is there anyone on the lounge making window kits for use with standard rubbers.

[DaveN]

Buy a sheet and cut your own. Use your old glass as a template.

[andy198712]

Buy a sheet and cut your own. Use your old glass as a template.

whats it like to cut? tape it and slow saw speed like acrylic or?

[leec]

I'm sure I did mine with a wood blade. Make sure you buy the coated/scratch resistant stuff

Lee

[DaveN]

Buy a sheet and cut your own. Use your old glass as a template.

whats it like to cut? tape it and slow saw speed like acrylic or?

Easy, I used a jigsaw, the polycarbonate had a protective film on it so I drew straight on that.

I wouldn’t use a wood blade as it’s likely to chip, you might get away with using one if it’s a reverse cut blade. I think I used a finer toothed metal blade or a progressive blade.

Marguard polycarbonate is the type Lee is referring to.

[andy198712]

Buy a sheet and cut your own. Use your old glass as a template.

whats it like to cut? tape it and slow saw speed like acrylic or?

Easy, I used a jigsaw, the polycarbonate had a protective film on it so I drew straight on that.

I wouldn’t use a wood blade as it’s likely to chip, you might get away with using one if it’s a reverse cut blade. I think I used a finer toothed metal blade or a progressive blade.

Marguard polycarbonate is the type Lee is referring to.

yeah metal blade will be nice with it.
do you use stock seals with it?

looks about the cheapest place on the car to loose weight other then running less fuel and no spare tyre.... and eating less 

[DaveN]

I Put some masking tape on the base of my jigsaw too so it doesn’t scratch and blow any debris out the way while cutting.

I used the original window rubbers that came with my car, I think marguard polycarbonate comes in 6mm thickness I’m not sure what thickness vw glass is.

[leec]

I was sure it was a wood blade   

I did do it 10 years ago though.....

Lee

[Neil Davies]

Direct Plastics in Sheffield do Margard polycarbonate in various thicknesses. They're used to supplying race car folk too.

[Garrick Clark]

Nice 1 Neil.
I'll be ringing them next week.
How hard is  rear screen to fit what with it being curved. i take it most people leave the front screen alone.