Weight savings...

[longislandwrx]

My question is, if the 1800lb mark was established using factory running gear, how much do you think can be done to get that number even lower.


In case you guys dont know about this:

http://www.oakos.com/wrx/weights.htm

Oakos has some good deals btw on performance parts for wrx.
Well I lost my first post that had all my numbers in it, here's a quick rewrite.



Things that I plan on doing/parts I already have:


braille battery -14lbs
sparco/status seats -40lbs
sparco steering wheel -3 lbs
wheel and tire combo -20lbs
lightweight pulley -4lbs
header/uppipe combo -20lbs
driver crash diet -10lbs

anything I am missing?

[StatGSR]

well since we don't know what the 1800lb mark includes or excludes its hard to say. more or less it will be about the stuff that you don't install that saves you weight. talking about it like your stripping in down is kinda odd since you will be putting it together instead...

[07FIREBLADE]

Lol if u want to save weight just don't install everything. Since ur going to be building the car to begin with.

[apexanimal]

ac delete
ps delete
airbag delete
tgv delete
wiring harness (delete what's not used)
stock set belt delete (for 5pt harness)

lighter rotors (getting expensive but doable)

[longislandwrx]

ac delete
ps delete
airbag delete
tgv delete
wiring harness (delete what's not used)
lighter rotors (getting expensive but doable)

I cant imagine that power steering or ac would be part of the std kit unless you know otherwise?


stripping the harness will be a must considering what it looks like in the prototype. :eek:

tgvs is a good call, although I cant imagine it saves much weight.


the wilwood kit on the prototype looks like it has two piece rotors so will probably just go that way.

[riptide motorsport]

cheapest,,,,,,,,,,,,,,,,,,,,,,,,go on a diet!:cool:

[timmy318]

^I like it^!!!!!!! :P

[StatGSR]

cheapest,,,,,,,,,,,,,,,,,,,,,,,,go on a diet!:cool:

yeah right, healthy food is expensive as hell!

[Xusia]

Quite the contrary. Vegetables and fruit are cheap. Also, most people eat far more quantity than they should, so for most eating healthy means eating less. Bottom line, we feed a family of 2 adults, a half time 15-year old, and a 5 year old with very healthy food for less than $50/week. And that includes at least 1 lunch at a restaurant (usually a cheaper place though).

[longislandwrx]

cheapest,,,,,,,,,,,,,,,,,,,,,,,,go on a diet!:cool:


lol yeah I had that on there!

[JRL]

Quite the contrary. Vegetables and fruit are cheap. Also, most people eat far more quantity than they should, so for most eating healthy means eating less. Bottom line, we feed a family of 2 adults, a half time 15-year old, and a 5 year old with very healthy food for less than $50/week. And that includes at least 1 lunch at a restaurant (usually a cheaper place though).

I'd like to see your weekly menu - $50 is far less than we spend on the same number of eaters and we do coupons :D

[Xusia]

Sent you a PM.

[JRL]

Thanks - email sent

[carbon fiber]

i'm curious to see if the 818 hits the #'s or not. with most of the builders final weights on the gtm are north of 2500lbs., the 818 may be closer to 2000lbs. with a/c,stereo, sound deadning, etc. still very light.

[longislandwrx]

i'm curious to see if the 818 hits the #'s or not. with most of the builders final weights on the gtm are north of 2500lbs., the 818 may be closer to 2000lbs. with a/c,stereo, sound deadning, etc. still very light.




what do you think the frame will come in at... 375 lbs?

[PhyrraM]

Didn't someone from FFR state that the prototype chassis is currently 1500 pounds? This would include all the Subaru running gear, the complete harness, a fuel tank, battery, and at least 1 OEM seat (all based on FFR post/pictures). Essentially everything but the bodywork, lights, sheet panels (footwells, etc), and glass.

If it indeed weights 1500 now (I don't see it), 1800 pounds is going to be a challange when the rest is added.

[rjh2pd]

Sent you a PM.
Can you send me that too?!?!

[metalmaker12]

From the looks of it the 818 will be at or under 1800lbs, thats light enough for me, but as mentioned before

lightweight race seats
lightweight steering wheel
carbon fiber floor panels
light weight glass
carbon fiber intake manifold
all aluminum radiator
lightweight radiator fans
lightweight flywheel
lightweight wheels and tires
minus some liners etc etc

[PhyrraM]

From the looks of it the 818 will be at or under 1800lbs, thats light enough for me, but as mentioned before

lightweight race seats
lightweight steering wheel
carbon fiber floor panels
light weight glass
carbon fiber intake manifold
all aluminum radiator
lightweight radiator fans
lightweight flywheel
lightweight wheels and tires
minus some liners etc etc

FFRs stated goal was 1800 pounds for the base kit. I'm hoping it meets or beat that usung stock WRX parts. Leaving this list as over and above on the way from 1800 towards 1600.

[305mouse]

I have never seen a carbon fiber intake manifold for these engines. The newer models do use a molded plastic manifold which fits and has less heat transfer.

[longislandwrx]

From the looks of it the 818 will be at or under 1800lbs, thats light enough for me, but as mentioned before

lightweight race seats
lightweight steering wheel
carbon fiber floor panels
light weight glass
carbon fiber intake manifold
all aluminum radiator
lightweight radiator fans
lightweight flywheel
lightweight wheels and tires
minus some liners etc etc


good call on the flywheel, I forgot I already have a lightweight one... saves 12 lbs.

[Rasmus]

all aluminum radiator


The aftermarket all-aluminum radiators weigh more than the OEM one.


Stock RADIATOR bare (no cap, fans etc) 8.040 lbs
with water (aprox) 13.43 lbs
Koyo radiator bare...11.855 lbs
with water (aprox)...20.455 lbs

Data from this thread (http://forums.nasioc.com/forums/showthread.php?t=998086).

[Rasmus]

The lowest hanging fruit would be the OEM seats weighing in at 45 lb each. Which you could drop for a single Kirkey Aluminum job at 11 lb. Savings of 79 lb.

8486
The OEM headers are cast iron 25lb units and could be swapped for a two piece Stainless unit already available from the after market about 8lb. Savings of 17lb.

Next would be the stock steering wheel and it's air bag.

[Mechie3]

The plastic intake manifolds have the throttle body in a different location than the motors using the aluminum manifolds. You'd have to do a bit of work to make all the other bits fit. One guy (Greg McCance) it on his 2002 WRX with a 2007 Engine (runs in ESP for AX). He said it was too much work and probably wouldn't do it again if building another car.

[longislandwrx]

The aftermarket all aluminum radiators weigh more than the OEM one.

+1, especially considering the extra fluid capacity


seats/header/steering wheel have already been mentioned... lets get creative.


A magnus/godspeed/obx? sheet metal intake manifold claims to be half the weight of stock... should be good for several lbs when combined with TGV deletes.




as for minimal savings..

non weighted shiftknob
lightweight lug nuts

[305mouse]

The problem with those sheet metal intake manifolds is I haven;t heard of any good numbers from them. They look real nice, but if the flow is worse, it isn't worth the weight savings IMO.

[longislandwrx]

I've read that the gains have been decent 20hp or so, but not really until you are using a GT30 + turbo.

I would love to see someone put one with a smaller turbo and see what it looks like... would I pay $1000 for the magnus for 2 hp? no, but $300 for the knockoffs and to save a few lbs maybe.

[Rasmus]

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4670.jpg
TGV's, hardware, and gaskets: 2590 grams

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4671.jpg
Intake Manifold: 3404 grams I had to weight the three seperately because it maxed out my scale (>5kg). But altogether the OEM intake/tgv system weighs 5994 grams. Almost 6 kg.

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4696.jpg
Reduced mine to 4310 grams. Saved 1684 grams. Those are Grimmspeed phenolic spacers epoxied to the bottom.

[Mechie3]

Drill lots of holes in the tube frame. :D


If someone had design experience with cars, you could make billet aluminum uprights/hubs. I've designed some for my Fmod car, but have no experience in that area and don't feel comfortable doing it for a full size car.

Trim down the alternator/AC and power steering brackets to the minimum required to securely hold the pieces.

Ditch the GBOD (Green brackets of death/injector covers)

I ground off all of the heatshield mounting points on the OEM manifold and heat wrapped it. Saved a few pounds.

Not sure if the aluminum lateral links in the rear are lighter than the steel counterparts.

[longislandwrx]

Rasmus, great info and nice work ty... btw what thickness phenolics are you running 3s or 8s?

how many hours with the grinder did that take?

[Rasmus]

Thanks. Those are 3 mm spacers.

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4615.jpg

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4614.jpg

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4616.jpg


how many hours with the grinder did that take?
More than I'm willing to admit. I ground off all the unused bosses and tabs. Port matched every thing. Removed all the casting flashing both internal and external. Deleted the TGV system. Reduced the cross section of the TGV bodies section by adding epoxy in them so they'd be the same cross sectional area as the intake runners (didn't want the air slowing down and then speeding up one more time). Then I welded (GMAW) the TGV bodies to the intake manifold. Finish is media-blast, aluminum oxide, 80 grit.

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4744.jpg

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4745.jpg

[longislandwrx]

when you add your labor, still cheaper than a v8 manifold?

[Rasmus]

https://lh3.googleusercontent.com/-h6jQoOPr-1Q/TtcEAjGJTDI/AAAAAAAADrI/8W_UCd4GDog/s800/IMG_5310.JPG

Tough to decide. Apparently the hard part of getting the V8 (version eight) manifold is getting a hold of the fuel rails. USDM rails DO NOT bolt right up. I've read they can work with make-your-own spacers and longer bolts.

So say I could get the whole shebang, fuel rails and all, for $500? Valuing my time at a low low of $25 per hour, I would have been better off getting the V.8 STi Manifold. I had so much trial and error, and things that just went plain wrong. I had to remove and install my modified manifold and the original manifold 5 times before I got it right. I didn't know of anyone else that did what I did. I didn't have plans/pictures to follow. Getting the cross-sectional area of the TGV bodies to match the c.-s. area of the intake runners took up about 50% of my time.

[PhyrraM]

Maybe $25 would be charged shop rate, but the guy doing the work would be lucky to make $12.

Seems like if you were willing to go through some of the very minute details mentioned in this thread, the full bodied 818 wouldn't be as appealing as a more basic Atom type of car? Either way, all good ideas.

[longislandwrx]

using this as my baseline...

http://www.gruppe-s.com/parts/103/STI_Spec_C_TGV-less_Manifold_.php

includes required rail spacers, and pretty much the best deal around iirc. It would probably still require a few hours or work to port match the spacers/gaskets and clean up the runners.

Thanks again for the info!

[longislandwrx]

Seems like if you were willing to go through some of the very minute details mentioned in this thread, the full bodied 818 wouldn't be as appealing as a more basic Atom type of car? Either way, all good ideas.


The price point is still a factor... I already have my donor car, running about 330 whp. Adding the $9900 kit price and another $6-8k for the majority of these lightweight parts, getting the car down to 1675 lbs would make it even more appealing, both physically and to drive.

[bugeye_fever]

Who knows if the mods to the trans where taken into account in the target weight. If not there stands a good amount of weight lost.

[RCKSTR]

1800 lbs. is enough of a diet for me since my wrx is around 3200ish last time I was at the drag strip lol

[longislandwrx]

13270

just found these

http://fastwrx.com/tuincocotgvd.html

no need for phenolic spacers and priced right! check out that weight!

[JeromeS13]

If anyone is curious, this is what 16 lbs of wiring harness removal looks like. From my '06 WRX donor. Honestly, I'm not sure it's worth the hassle... I'm just hoping it starts!! haha

http://i157.photobucket.com/albums/t43/JeromeS13/IMG_20130628_230055_zpsedd656dc.jpg (http://s157.photobucket.com/user/JeromeS13/media/IMG_20130628_230055_zpsedd656dc.jpg.html)

[Frank818]

braille battery -14lbs

If weight is your thing, I think you can get a Shorai battery for 4.19lbs.
Apparently this one fits, although Shorai doesn't seem to officially support batteries for cars.

http://www.shoraipower.com/Products/batteries/LFX27A3-BS12.html

[Silvertop]

If weight is your thing, I think you can get a Shorai battery for 4.19lbs.
Apparently this one fits, although Shorai doesn't seem to officially support batteries for cars.

http://www.shoraipower.com/Products/batteries/LFX27A3-BS12.html

I'm all for saving weight. The question for me in battery selection is how light I can go while maintaining a decent degree of reserve power -- cold crank rating, etc. The 20 or 30 pounds I save may not be very important when I'm stranded in a McDonald's parking lot in Podunk 500 miles from home...

[longislandwrx]

The 20 or 30 pounds I save may not be very important when I'm stranded in a McDonald's parking lot in Podunk 500 miles from home...

Easier to push for the bump start

[wleehendrick]

I'm taking a little different approach to weight 'savings'. My goal isn't to reduce the weight below 818kg, but how do I add comfort and refinement with minimum weight and cost addition... i.e. lightweight, moderately priced upgrades (in the same spirit as the 818 itself). For example:

I'm really leaning towards Corbeau FX1-Pro seats. They're not as light as a c.f. bucket, but pretty light at 19lbs each, and supposedly quite comfortable for a harness capable shell bucket, and affordable.

I want a storage bin under the rear hatch. Reportedly, there will be a tray over the tranny, but I want a fitted compartment. More Al panels with carpet, perhaps?

I want to add sound deadening, carpet the interior body panels and upholster the door panels. Dynamat is heavy, what are all the alternatives?

I will install a stereo, but have a good plan there... a single DIN digital media head unit, small digital switching power amp (probably an Alpine KTP-445A), 5 1/4" component speakers, and a low-profile powered sub-woofer, like a Soundstream USB-8A. This should give good sound in an open top 818, yet be affordable, unobtrusive and not add too much weight.

[bnr32jason]

I want to add sound deadening, carpet the interior body panels and upholster the door panels. Dynamat is heavy, what are all the alternatives?

My little project that I'm working on now, a 1992 Honda Civic CX hatchback had very little sound deadening from the factory so after some research I went with FatMat. It's cheaper than Dynamat by quite a bit, works very well, and 100sqft of the stuff was only 31lbs according to the shipping weight.

[Frank818]

You did the whole car with 100? Had any left?

[AZPete]

I like EZ Cool because I used it to insulate my FFR roadster and it drastically reduced the heat and sound, yet is very light weight and easy to install. It's 3/16" foam with aluminum facing and gives up to 13 R-value. I bought two 4' x 10' rolls for the roadster and had enough left over to do the trunk, splash guards and double in the footboxes. The 40 sq. ft. roll weighs less than 2 lbs. Maybe one roll will do the 818, maybe 2 rolls (2 - 4 lbs.). Before I bought it, I clamped their test sample in a vice overnight and it recovered its thickness and then I tried to burn it and it won't sustain a flame. I'll use it in my 818, for sure.
http://www.lobucrod.com/faq.html

Pete

[wleehendrick]

Thanks for the insulation recommendation guys! I'm not too worried about heat in the cockpit of the 818; some thermal insulation on the firewall would be a good idea, but I wouldn't think it would be needed in most areas, unlike in the roadster where you have V8 headers inches from your feet! My main concern is to keep the road noise down from the Al panels. From the reading I've done (and my understanding of thermodynamics and acoustics) I would think that EZCool would be ideal on the firewall, but for damping the resonance of the AL panels, some mass is needed, like FatMat (and then carpet).

I don't want to go overboard and add too much weight, but as I mentioned, make a reasonable civilized cockpit with a few key additions.