Weight

[david oleary]

HI GUYS
CAN WE TALK WEIGHT?????
So the conversion is done and we are going to start testing in a couple of weekends, BUT
the car is FAT!!! so the question is this,
for the guys who have converted FC to FB did you fine out that because the car was built for FC it is hard to get the weight down for FB ?
Does anyone one want to share what there cars weight is please?
Any idea on how to lighten it?
My West DSR was always 100 lbs overweight, nothing I could do but spend $20k for a carbon fiber body, (did not do that) just drove it.
thanks
dave

[Brandon Dixon]

I'd start with smaller brakes

[Northwind]

How fat are you talking?

I did a lot of work to get my car down. Many items were included to shave weight. If I know how many pounds you are over I may be able to help you prioritize what you may want to change.

[HayesCages]

I'd start with smaller brakes

Your mean.

[ghickman]

Dave
Getting down to minimum weight is the Holy Grail of any class, more so with the F1000 due to the low torque.

I can tell you from watching your build as it went along I could see it was going to be heavy.

I doubt that anyone that has done a conversion is going to tell you exactly what their car weighs. I do know that those that have done it have gone to great lengths to achieve it, ask Dan (northwind) about this. As I recall he built one of the lightest conversion cars built.

FAST WAY TO DROP WEIGHT:
Go to smaller calipers and rotors. I believe there could be 4 or 5 pounds per corner to shave off.

TRIPOD AXLES:
Get rid of those heavy FC halfshafts and convert to the small tripod FSAE ones that Taylor sells. That will most likely be the cheapest 9 lb loss (about $700)

You really have to look at the overall packaging on the car. Do you have redundant brackets, wiring, body work that might be repaired multiple times, or bodywork that is simply way too thick.

[JohnPaul]

I just shaved 40lbs off my cars overall weight by going on a diet. Didn't cost me anything

[Jasonrmbell]

JPaul nice dude I didn't realize you had 40 to drop lol

[JohnPaul]

I carry weight nicely...

[Brett Lane]

Get one of those small light weight batteries. There are more than one out there.

Also, maybe go to an aluminum floor if the one you have is steel.

[Jasonrmbell]

What's the weight of your car alone Dave

[sprocketmensch]

My car was ridiculously overweight at the start of the season. here is my approach:
Anti gravity Battery- saved 13 lbs
New Wheels JongBlood instead of OZ Aluminum about 20 lbs total
New diffuser from Gyrodynamics saved 9 lbs
SS header and shorter exhaust- about 6 lbs

Still looking at:
Lighter calipers and rotors - assume I can get another 2 lbs per corner
Lighter bodywork and floor - another 10 to 20 lbs available
removing full jabrock underfloor and replacing it with strips ??lbs
Going on a starvation diet before each race - no fun!

If I do everything I can get my car close to minimum weight provided I don't eat too many sweets.

[ghickman]

Man I feel bad for you guys, I've got 60lbs of ballast on my car and I can eat whatever I feel like.

Buy a Phoenix.

[Jasonrmbell]

That's a lot yikes I'm around 1015 -1025 I'm not trying to peel the last 15lbs. I'm good with it.

[ghickman]

That's a lot yikes I'm around 1015 -1025 I'm not trying to peel the last 15lbs. I'm good with it.

You can bet that the guys running in front of you are counting that 15 to 25 lbs. Ask JR or Brandon about that. Ballast with fuel and roll over the scales at 1006. Gotta push the limit. You just gave up a horse and a half.

I have a 3/16" thick steel plate bolted to the bottom of my car, as low as you can get it.

[Jasonrmbell]

I'm good Smalls. No worries

[JerryH]

The JDR has to carry lots of ballast........even with heavy ss floors We can meet wt with a 230 lb driver. Apparently so can the phoenix according to Gary. The Piper that Novak won the runoffs with a couple years back was always near the min crossing the scales. I don't know about the converted cars.....but some good ideas at dropping some pounds have already listed.....give it a try.

Jerry

[david oleary]

hi guys
any ideas in what the OZ wheels weight is 6" and 8"
I have 2 sets of the 3 piece youngblods now
can we save a lot by going to OZ?
dave

[Jasonrmbell]

We actually came across the scales at 1008 after the mid ohio race. Usually we come across at 1025 because we only have ran a half a lap lol.

[gcoffin]

Oz 6 are a few more ounces, Oz rears are a few more pounds, I use mine for my rains and inters.

[RSS]

Greg he has the same wheels i do so it might be the opposite direction weight wise. The jongbloeds made from lead shot not alum or mag

[Brett Lane]

I think my VD weighed about 1040 before WE went on a diet. The AP aluminum calipers, the light weight battery, and I am 10-15lbs lighter. We're close.

[Jnovak]

We weighed in at 1006 after the race at last years Runoffs. To bad we had throttle cable problems in the race.

[Frazer Mackay]

I guess first you need to quantify the components of the car and identify which are "heavy". Then asses how realistic modifications are to get weight out without compromising the integrity of the car.

The conversion looks awesome to me, I can't see a lot wrong with it. I think you are probably stuck with an overdesigned front end rather than your new rear end being the problem.

Only things I notice is the intermediate bulkhead has some lightweighting pockets to it but you could be more aggressive with them. The differential bearing housings also look solid alu in the photos, you could pocket out those. Also the rear wing supports could be pocketed. These are all aluminium though so weight gain versus the work involved may not be worth it.

It's been eluded to already with the talk of lighter wheels and brakes discs. Reducing rotating mass is a win win scenario. You reduce the overall car weight but also reduce the inertia of what the engine has to turn over. So savings in those areas would pay dividends in terms of overall lap time improvement.

Are the drive shafts solid? If so could you get them gun drilled? The material in the centre of a solid drive shaft is really doing sweet FA!!

[Frazer Mackay]

While I mention lightweight drive shafts here's a little anecdote you may like.

I once worked for a well known transmission company and we designed a new drive shaft for Indycar. It was beautiful. It incorporated the CV trilobes on both ends as one piece with the rest of the shaft. It was a feat of maching and really looked the dogs bollocks! We also applied that age old engineering adage of if we increase the diameter we can reduce the wall thickness and maintain strength whilst reducing weight. Less rotating mass - win WIN!!!

As proud as punch we arrived at Indianapolis with our one piece, super lightweight, super strong, LARGE diameter drive shafts. Do you think increasing drive shaft diameter at a track like Indianapolis helps????? Apparently there is another age old race car adage called DRAG?!?!!??! D'OH!!!!! I think we made the car 10mph slower.

It was good on the road courses though.

[ghickman]

Awesome post Frazer, I can appreciate how difficult that halfshaft must have been to machine.

When I first took my Taylor FSAE halfshafts out of the box my reaction was, "no way these will hold up". Well I've installed 3 sets of these now and they've got a total of 16 races on my personal ride.

The small tripods are holding up just fine, I was a bit worried about doing standing starts with them but so far so good. They weigh half of nothing compared to a Lobro CV.

This setup comes standard now on the new Phoenix F1000. We machine our own tripod drives so no conversion parts are needed, few parts less weight.

[mwizard]

I could not figure it out from the GCRs. Is it 1000lb with or with out driver?
Mark

[DanW]

1000lbs with driver.