Sharing what you’ve just done. Not questions. No comments required.

[DarrenK]

Finally managed to get the tub to the painter over the weekend, borrowed one of the works vans and didn't break 40mph getting it there 😳 made it in one piece and now i can hopefully make some progress 

[Flying Carrot Steve]

18 hours ago, Davemk1 said:

For years my Westie has run the standard 7.5 gallon fuel tank and it worked fine. Eecently the race sanctioning body I run under (the SCCA) lowered the minimum weight for my class from 1420 lbs (with driver) to 1400 lbs. My car was 1425 with a minimum full load and figuring out a way to lower the car’s weight to the new minimum was one goal.

 

The other goal was to shift weight from the driver’s side to the passenger side (keeping in mind that I’m in the USA and so I sit on the left) to help even out the weight distribution. The idea was to cut down the fuel tank on the left side (reducing the amount of aluminum) and this would take about 3 lbs off the driver’s side of the tank. The other benefit was that I could maintain the same fuel depth in the tank (to help prevent fuel starve) with 1 gallon less fuel in it…and this reduces the weight by another 6 lbs. This means that this one modification reduced the weight of the car by 9 lbs and most of it coming from the driver’s side of the car.

 

The downside is of course that the tank is smaller. It now holds only 5.5 gallons so long range touring would be a pain in the ass but I’ve never used the car that way so that wasn’t a big issue for me the way it might be for others.

 

So - I cut off one end and welded a new end wall on. I also made a new pick-up sump that hangs well below the main part of the tank to help it not run dry during hard cornering. All this got welded together and reinstalled into the car. While I was at it I shifted both the low and high pressure fuel pumps to the right to help with weight distribution. In the end it worked as intended. This, and the relocation of the battery and lots of other small things, has made it so that despite the fact that my 185 lbs in on the left side of the car that the difference right-to-left is only 57 lbs.

 

I’m excited to race again in the spring but as I type this the snow is falling and the car is tucked away in my warm workshop.

 

 

Dave

Great job! I presume you've done all the usual weight saving tricks, lightweight LiFePo4 battery, carbon this, carbon that etc? I sometimes wish my tank was larger but so far at 5.5 UK gallons it has not been much of an issue

[Davemk1]

4 hours ago, Flying Carrot Steve said:

Great job! I presume you've done all the usual weight saving tricks, lightweight LiFePo4 battery, carbon this, carbon that etc? I sometimes wish my tank was larger but so far at 5.5 UK gallons it has not been much of an issue

Yes - I think I've picked all the low hanging fruit. I built the car in 2014 as a standard Mega S2000 and since then it's been a slow progression to a lower weight. During that time the car has shed 180 lbs to get down to it's current 1210 lbs (549 kg).

To take much more weight out it's going to require spending big money on carbon bodywork and right now that's not in my budget.

 

dave

[Flying Carrot Steve]

29 minutes ago, Davemk1 said:

Yes - I think I've picked all the low hanging fruit. I built the car in 2014 as a standard Mega S2000 and since then it's been a slow progression to a lower weight. During that time the car has shed 180 lbs to get down to it's current 1210 lbs (549 kg).

To take much more weight out it's going to require spending big money on carbon bodywork and right now that's not in my budget.

 

dave

549kgs is very impressive!  

[Dave Eastwood (Gadgetman) - Club Chairman]

17 hours ago, Flying Carrot Steve said:

549kgs is very impressive!  

 

On a Mega S2000 that's insanely good, for a car without lots of composites/exotic materials. (The drive train is really heavy! The gearbox alone weighs more than the SEiGHTS Rover gearbox!)

[Davemk1]

On 09/01/2024 at 03:11, Dave Eastwood (Gadgetman) - Club Chairman said:

 

On a Mega S2000 that's insanely good, for a car without lots of composites/exotic materials. (The drive train is really heavy! The gearbox alone weighs more than the SEiGHTS Rover gearbox!)

Even though I'm currently at the minimum weight for my race class I'd still love to reduce it further so that I can replace the lost weight with ballast where it will do me the most good.

 

There are two more plug-and-play places I can think of to pull out weight. One is replacing the stock Honda alternator (5.4 KG) with something much lighter. The problem is finding an alternator that will be happy at such high RPM's. So far I've had no luck there.

 

The other place I can remove real weight is with a carbon nose, engine cover, and scuttle. It looks like I could drop about 9kg there but the cost is very high. The parts themselves are not cheap and then the crating and shipping from Germany to the western USA nearly doubles the cost.

 

If I were to spend the money on the carbon bodywork that would allow me to reduce the overall weight by 9kg and then I would add it back with ballast on the far outside of the passenger floor. So in effect the money would be spent on shifting the weight to the passenger side and not actually reducing the weight. It's hard to know how much that would change the corner-weighting and if in the end it would be worth the money.

 

That said...if I suddenly have some long lost uncle die and leave me a pile of money I'll buy the carbon....it can't hurt!

 

dave

[LoneWolf]

13 minutes ago, Davemk1 said:

Even though I'm currently at the minimum weight for my race class I'd still love to reduce it further so that I can replace the lost weight with ballast where it will do me the most good.

 

There are two more plug-and-play places I can think of to pull out weight. One is replacing the stock Honda alternator (5.4 KG) with something much lighter. The problem is finding an alternator that will be happy at such high RPM's. So far I've had no luck there.

 

The other place I can remove real weight is with a carbon nose, engine cover, and scuttle. It looks like I could drop about 9kg there but the cost is very high. The parts themselves are not cheap and then the crating and shipping from Germany to the western USA nearly doubles the cost.

 

If I were to spend the money on the carbon bodywork that would allow me to reduce the overall weight by 9kg and then I would add it back with ballast on the far outside of the passenger floor. So in effect the money would be spent on shifting the weight to the passenger side and not actually reducing the weight. It's hard to know how much that would change the corner-weighting and if in the end it would be worth the money.

 

That said...if I suddenly have some long lost uncle die and leave me a pile of money I'll buy the carbon....it can't hurt!

 

dave

I've got a small Denso alternator which weight around 2kg. You can adjust the rpm by changing the alternator pulley.

The S2000 gearbox is actually quite heavy and not specifically geared for a light car. I've seen some custom bellhousings to mate the F20C to the Type9, which is quite light in comparison (my full aluminium SPC Type9 is surprisingly light, probably less than 30kg, I can grab it quite easily alone, while it was pretty heavy with the iron case).

I don't see other areas where you can lose a substantial amount of weight. Carbon stuff is, as you say, mostly cosmetic for the money you pay for it.

[Davemk1]

7 hours ago, LoneWolf said:

I've got a small Denso alternator which weight around 2kg. You can adjust the rpm by changing the alternator pulley.

The S2000 gearbox is actually quite heavy and not specifically geared for a light car. I've seen some custom bellhousings to mate the F20C to the Type9, which is quite light in comparison (my full aluminium SPC Type9 is surprisingly light, probably less than 30kg, I can grab it quite easily alone, while it was pretty heavy with the iron case).

I don't see other areas where you can lose a substantial amount of weight. Carbon stuff is, as you say, mostly cosmetic for the money you pay for it.

Thanks for the reply.

 

Are you running the Denso alternator on an S2000? My concern was that if you needed to gear it down to keep from spinning it too quickly that it might not charge well since it would be spinning so slowly most of the time. Have you had any issues?

 

Interesting idea on the Ford gear box. The Type9 box is not at all common in the USA and they seem to be hard to come by. I love the gearing of the S2000 box. With the rear diff and tire size I have the perfect 63 mph at 9000 rpms in 2nd gear.

 

dave

[Man On The Clapham Omnibus]

My son had an S2000 and the gearbox was the best gearbox for driving experience that I have ever driven! I wouldn't change it for a type 9 or any other if I had the choice.

[LoneWolf]

Not saying the S2000 gearbox is bad, I know it's one of the best based on the gear change feeling, just the gearing isn't the best for a very light car, plus it is quite heavy. I guess there is a reason why someone got to make a custom bellhousing to change it.

But as @Davemk1 is saying, it is good for him so probably not worth the weight saving.

[LoneWolf]

8 hours ago, Davemk1 said:

Are you running the Denso alternator on an S2000? My concern was that if you needed to gear it down to keep from spinning it too quickly that it might not charge well since it would be spinning so slowly most of the time. Have you had any issues?

My car is still in rebuild, but I plan to rev the engine to 8500rpm. Not S2000. If you do not overspin the alternator often I don't think you'll have problems really. If your budget allows, you can look at the WOSP stuff which is very nice.

[Rob Hunter - Club Secretary]

8 hours ago, Davemk1 said:

Thanks for the reply.

 

Are you running the Denso alternator on an S2000? My concern was that if you needed to gear it down to keep from spinning it too quickly that it might not charge well since it would be spinning so slowly most of the time. Have you had any issues?

 

Interesting idea on the Ford gear box. The Type9 box is not at all common in the USA and they seem to be hard to come by. I love the gearing of the S2000 box. With the rear diff and tire size I have the perfect 63 mph at 9000 rpms in 2nd gear.

 

dave

 

Gearbox wise I would be thinking about the MX5/Miata gearbox rather than a Type 9 as they're more plentiful. A number of companies (like MK Sportscars) are doing adapter plates for the K20 so I'm sure an F20 adapter would be possible.

 

What battery are you running? I've been running the Jack Webb Motorsport LifePo4 lithium that weighs about 1.6kg.

[Si.Dalziel]

17 hours ago, Davemk1 said:

Even though I'm currently at the minimum weight for my race class I'd still love to reduce it further so that I can replace the lost weight with ballast where it will do me the most good.

 

There are two more plug-and-play places I can think of to pull out weight. One is replacing the stock Honda alternator (5.4 KG) with something much lighter. The problem is finding an alternator that will be happy at such high RPM's. So far I've had no luck there.

 

The other place I can remove real weight is with a carbon nose, engine cover, and scuttle. It looks like I could drop about 9kg there but the cost is very high. The parts themselves are not cheap and then the crating and shipping from Germany to the western USA nearly doubles the cost.

 

If I were to spend the money on the carbon bodywork that would allow me to reduce the overall weight by 9kg and then I would add it back with ballast on the far outside of the passenger floor. So in effect the money would be spent on shifting the weight to the passenger side and not actually reducing the weight. It's hard to know how much that would change the corner-weighting and if in the end it would be worth the money.

 

That said...if I suddenly have some long lost uncle die and leave me a pile of money I'll buy the carbon....it can't hurt!

 

dave

Alternator wise. Have a look at my build thread.

I also got rid of the tensioner and extra pulleys.

 

[Ian Kinder (Bagpuss) - Joint Peak District AO]

12 hours ago, Davemk1 said:

Thanks for the reply.

 

Are you running the Denso alternator on an S2000? My concern was that if you needed to gear it down to keep from spinning it too quickly that it might not charge well since it would be spinning so slowly most of the time. Have you had any issues?

 

Interesting idea on the Ford gear box. The Type9 box is not at all common in the USA and they seem to be hard to come by. I love the gearing of the S2000 box. With the rear diff and tire size I have the perfect 63 mph at 9000 rpms in 2nd gear.

 

dave

Hi @Davemk1 I built my S2000 with a small denso type Alternator in 2016 and I've covered circa 32,000 miles since then. It's not been plain sailing, but I'd still recommend you doing the same. Details in my build thread here- Bagpuss build thread

 

If I was to do it again, I'd do the same again.

 

As a fellow S2000 user, regular visits to the 9000rpm redline are made by me. I chose the alternator pulley size to ensure the alternator doesn't seen north of 18000 rpm. Charging at the 1100 rpm idle isn't a problem.

 

My first alternator was a e-bay special and didn't last too long (the charge warning light started to flicker above 5000 rpm)

 

I replaced this with Denso branded item from GBS Cars and that's been fine ever since. I did have a concern last spring with a noise sometimes, so I took it off and took it to an alternator specialist and they confirmed the bearings to be fine and tested it electrical as fine too (free of charge as well).

 

I then used a laser light to align the pulley correcly with the 4 groove belt to the crank pulley and it's been quiet every since.

 

From my build thread, you'll see there has been some 'evolution' of brakets and tests of different types of tensioners.

 

My current large alloy bottom bracket and upper steel bracket have been fine. Though I did have the bottom alternator hole bushed so it didn't rock on the bolt. The two bolt fixing syem isn't ideal. I'd prefer 3.

 

Given you do much lower mileage than me, I'm sure you'll be fine.

 

Drop me a PM if you wish to have a call and talk any of this through.

 

Best regards,

Ian

 

[David Oxfordshire]

Bit embarrassing this one. Whilst waiting for the new Westfield to come out and weighing up options I've bought an MK Indy that needed some TLC.

 

Interesting comparing it to a Westfield.....🙂