Advanced Weight Reduction Questions

[godzillarb]

S14 SE chassis. The car is driven on the street but is mainly used for grudge racing at the local drag strip (aka people who think their 80k Viper is fast).

For starters I did all the normal stuff like removing the interior, radio, a/c, heater, carpet, wiring, jack, spare, bumper support, airbags, sound deadening, titanium exhaust (ok ok, not normal), light wheels, coilovers, seats, ect.

The sunroof will be plugged soon along with getting a lighter hood. I know there are CF doors, but come on, $1600? I'd rather spend that on internals.

With that said, I've heard a couple guys talking about cutting out the metal supports in the doors. I think they're referring to the extra metal skin that's on the door. Does anyone have pictures of someone that has done this? The ability of the plastic door pieces going on is not an issue. Also, exactly what parts of the interior metal can be cut out... one guy said something about the metal in between body panels?

Without going to a CF trunk lid, what if any can be trimmed from the trunk?

If anyone has done this stuff pictures would be greatly appreciated.

My RB is a fatass :(

[Irukandji]

The lining on the inside of the trunk pretty much weighes NOTHING and will make your trunk super flimsy. I did it on my old car and I regretted it.

[johngriff]

Pointless.

Add more boost/power.

[godzillarb]

Pointless.

Add more boost/power.

That's coming as well.

However I'd like to have an edge over my main competition. This guy happens to have a boat load of money for modding his RB26 240sx, but is keeping full weight. If I can drop another 100lbs plus the ~270lbs that I've already pulled out, that might be enough. It's free performance, I'll take it.

[KA-T_240]

do a custom wiring harness motor and chassis. Thats if you feel capable of such thing.

[tt99ol]

put a skid pan across the whole bottom of the car and lose wind resistance, sheet metal is cheap

[Nismoknightska-t]

Pointless.

Add more boost/power.

+++++1


its all about the power

[S14DB]

get an S13 much lighter...

[cdlong]

Pointless.

Add more boost/power.

how does more power make help you turn or stop faster?

as for what to take out, it depends how hardcore you are. lightweight battery, switching to manual windows and mirrors, or aftermarket carbon mirrors. don't forget to take out all the wiring for the electronics you remove, a pain in the ass, but it adds up. for the doors, i think people are refering to the metal framework just behind the interior door panel. if you're really dedicated, you can remove the door panel, the interior framework, fix the window, and cover the opening with a sheet of aluminum.

[Kn1ves]

how does more power make help you turn or stop faster?


never knew turning was such an important factor in drag racing

[Addicted2Kouki]

^^^LOLOL!!


messagelength.

[IIIXziuR]

Lexan/Acrylic Glass maybe...especially on the windscreen and backlight. Even the 1/4 Glass

[g6civcx]

get an S13 much lighter...

+1. Base model coupe with no options. Sell your S14 if all you care about is drag.

If you're hardcore, there's a local guy (to me) selling a tubbed S14 set up for drag. Weighs nothing. PM me for link.

[02BRB20]

redo your wiring

[godzillarb]

do a custom wiring harness motor and chassis. Thats if you feel capable of such thing.

Mostly done, just a few odds and ends left.

get an S13 much lighter...

Like that's practical. Might as well just get a fox body.

The lexan glass and fixing the window, that would suck for a car that's still driven on the street.


So basically cutting metal out of the door isn't a popular modification haha. I think I'll just get some door diagrams and see which parts are necessary for the window mechanism.

[jobestudios]

Riveted lexan windows fuddawindoe, otherwise you pretty much gotta keep everything inside the door, whereas with lexan you could just chop everything out except the latch that keeps the door closed. Rivet a NACA duct in there if you want airflow to the cabin.

[cdlong]

never knew turning was such an important factor in drag racing

shit. i'm retarded. had that coming.

[kognition]

CF doors are not needed, and in my opinion a waste of good money better spent elsewhere. We just finished our first round of parts for factory Scion's speed world challenge team. And we took doors that were 60lb's (weighed with no glass) and took them down to 21lb's! All the while keeping stock door frame and hinges. If you have ever seen CF doors at the track on a hot day, it's sad. Bad investment. I am under the gun right now to finish up our S14 for next weeks time attack finals, but the car comes back from paint tomorrow. I will do a photo included step by step write up for the forum on how to do this while maintaining excellent door integrity. There is a trick to it. I will tell you though, that your oem door skins are approx 10lb's each. I don't have enough
time to make door skin molds right now, but i will have those next month. This is going to knock the carbon fiber door crowd into the ground, permanently. :bow: I will subscribe to this thread, and post my link next week.


The sunroof will be plugged soon along with getting a lighter hood. I know there are CF doors, but come on, $1600? I'd rather spend that on internals.

With that said, I've heard a couple guys talking about cutting out the metal supports in the doors. I think they're referring to the extra metal skin that's on the door. Does anyone have pictures of someone that has done this? The ability of the plastic door pieces going on is not an issue. Also, exactly what parts of the interior metal can be cut out... one guy said something about the metal in between body panels?

Without going to a CF trunk lid, what if any can be trimmed from the trunk?

If anyone has done this stuff pictures would be greatly appreciated.

My RB is a fatass :(

[FaLKoN240]

Like that's practical. Might as well just get a fox body.

The lexan glass and fixing the window, that would suck for a car that's still driven on the street.


So basically cutting metal out of the door isn't a popular modification haha. I think I'll just get some door diagrams and see which parts are necessary for the window mechanism.

Removing any of the skeleton of your car that you drive on the street is stupid. That stuff isn't there to make your car extra heavy its for your safety.

The bars and metal you're removing take a lot of the initial blunt trauma so your body doesn't have to.

I'm sure stripping out all the amenities hasn't made your car that much more awesome to drive on the street either.

[!Zar!]

Why don't you re-gear your car instead.

[projectRDM]

My old S14 got down to 2530lbs, and that's without cutting sheetmetal except for the forward parts of the frame rails (where they stick out past the core support) and the front fenderwells. I also had all the OE sound deadening and a full interior. I could have shaved another 100 pounds had I been really serious. Redoing or making a custom wiring harness reduces a few pounds. Aluminum uprights, flywheel, driveshaft all do a little bit. I was even going to go as far as cutting out the spare tire well and laying a thin sheet of tin over the opening, though it would have created some drag back there.

[SILVIA_KIDs14.5]

Lexan/Acrylic Glass maybe...especially on the windscreen and backlight. Even the 1/4 Glass
Yeah agreed and you don't eve have to cut the glass peak performance already has it speced out for you. here's the website http://www.peak-performance.net/content/view/210/132/ hope it helps, also here is another site i stumbled across when i was looking to reductions http://www.importmodifications.com/240sxweightred.html looked legit and helpful

[Tops*]

My RB is a fatass :(

Are you a fat ass?

http://www.iateapie.net/images/brands/slimfastshake.jpg

Get some.

[mRclARK1]

Street driven = Leave it alone
Track Only = Tear it apart, strip it, and add even more power.

I drove a stripped car on the street for awhile... it sucks balls. lol

[godzillarb]

This is going to knock the carbon fiber door crowd into the ground, permanently. :bow: I will subscribe to this thread, and post my link next week.

Great, that's exactly what I was looking for.

Are you a fat ass?

http://www.iateapie.net/images/brands/slimfastshake.jpg

Get some.

Ahh classic Zilvia... and for your information, I'm not a fatass. I tip the scales right at about 150lbs.


I'm sure stripping out all the amenities hasn't made your car that much more awesome to drive on the street either.

Actually, I like it. I'd rather listen to the sound of a RB going through the gears than some asshole singing about his problems. The racing seats are a little stiff, but that's just fine with me.

[projectRDM]

hope it helps, also here is another site i stumbled across when i was looking to reductions http://www.importmodifications.com/240sxweightred.html looked legit and helpful

That shit is retarded. The rear seat combined does not weigh anywhere near 39lbs. Maybe if a small child is sitting in it.

[mRclARK1]

True that^^^ The actual seat part of it is pure foam in an S13. Weighs MAYBE 5-8lbs.

[godzillarb]

^^^ same in the s14, rear seats are light as hell.

[fromxtor]

Skinning the door:
http://www.mysportscar.com/andy/FA/512.jpg
http://www.mysportscar.com/andy/FA/513.jpg
http://www.mysportscar.com/andy/FA/514.jpg
http://www.mysportscar.com/andy/FA/515.jpg
http://www.mysportscar.com/andy/FA/516.jpg
http://www.mysportscar.com/andy/FA/517.jpg
http://www.mysportscar.com/andy/FA/518.jpg
http://www.mysportscar.com/andy/FA/519.jpg


Theres your door answer

[89dc240]

Does doing that to your door really reduce much weight?

[trsilvias13]

Get a sheet metal dash, aluminum or cf (if you have money) driveshaft.

[carnagexxxx]

I took out everything but the dash and the passenger seat (gotta haul the woman around). I have a '93 coupe. If you are thinking about removing weight from the rear of the car be careful of what you wish for. If you remove too much weight from the rear, the weight balance may get thrown off (especially with a heavier motor up front).

For drag racing you need to keep the rear tires from breaking traction. The less weight back there the more trouble you will have keeping the tires planted on the ground. I can tell you that with my car, I think the only thing that keeps me from breaking traction is the fact that my wing weighs like 4 billion pounds. I wanted to remove it before but after driving the stripped down car for awhile I noticed that the rear tires would break loose a tad easier than before. I felt that it would be worse if I removed more weight from the back.

Finally, if you are going to be doing some serious weight reduction by cutting metal, you should invest in a good roll cage. It will stiffen things up, keep you from getting inihilated by grandma when she side swipes you while adjusting her wig, and hell, most legit drag strips require one for cars that trip the clock fast enough.

SPEED AND WINNING SHOULD ALWAYS COME SECOND BEHIND SAFETY!

[PoorMans180SX]

Does doing that to your door really reduce much weight?

"To lose pounds in racing, count the ounces."

[godzillarb]

"To lose pounds in racing, count the ounces."

Yep... I know a guy that went through his entire car and cut off the excess threads from bolts, just to save a little extra weight. On his 67 Nova he claimed 10lbs if I remember correctly.

[Nikeboy355]

I got my S13 down to 2370 lbs. by getting rid of:

Full interior except driver seat, dash, center console, and door panels...
Heater, AC, radio, and underdash venting...

I still have to get rid of the sound deadoning and change to some carbon body panels... The goal is to knock out another 100 pounds...

http://photos.freshalloy.com/gallery/d/29591-1/2IMG_6217.jpg

[Kn1ves]

wouldnt spray painted cardboard be better... coulda just stopped at this step?

http://www.mysportscar.com/andy/FA/514.jpg

or better yet...

http://www.mysportscar.com/andy/FA/512.jpg

[KA24DESOneThree]

Gutted doors but full glass is hilarious.

Door glass in an S13 weighs 11 pounds per side.

[turtl631]

I got my S13 down to 2370 lbs. by getting rid of:

Full interior except driver seat, dash, center console, and door panels...
Heater, AC, radio, and underdash venting...


http://photos.freshalloy.com/gallery/d/29591-1/2IMG_6217.jpg

Are you saying you still have those things, or that you eliminated them?

2370 seems pretty light. I bet my S14 is damn porky, full interior, AC, KA, 4 point rollbar. I refuse to strip out my only car to gain some time at the track though.

[S14DB]

Like that's practical. Might as well just get a fox body.

The lexan glass and fixing the window, that would suck for a car that's still driven on the street.


So basically cutting metal out of the door isn't a popular modification haha. I think I'll just get some door diagrams and see which parts are necessary for the window mechanism.

So, cutting metal out of the doors is practical? You going to cut the crash bars out too?

S13 has less features which makes it a lot easier to strip down and still keep civil. If I were picking an drag chassis I would pick the S13 first.

[PoorMans180SX]

Gutted doors but full glass is hilarious.

Door glass in an S13 weighs 11 pounds per side.

When you don't have a blower motor, it helps to be able to roll down the windows.

Plus some people want windows that don't scratch from dust blowing across them.:bash: (aka lexan)

[PoorMans180SX]

http://photos.freshalloy.com/gallery/d/29591-1/2IMG_6217.jpg



Nikeboy, I love your car (minus the Sileighty part). Clean track car, nicely done. Yup.

[Roc]

The lining on the inside of the trunk pretty much weighes NOTHING and will make your trunk super flimsy. I did it on my old car and I regretted it. spot weld the inside of your trunk to stiffen it up..

[godzillarb]

So, cutting metal out of the doors is practical? You going to cut the crash bars out too?

S13 has less features which makes it a lot easier to strip down and still keep civil. If I were picking an drag chassis I would pick the S13 first.

The reason going to an S13 at this point wouldn't be practical is because I'd have to swap over a mountain of parts, some of which wouldn't even fit. My S14 also has a minitub and 50mm fenders molded, I'd really rather not lose that time/money.

The crash bars stay, I'm not suicidal.

[S14DB]

Are you even close to 11.49?

[godzillarb]

Are you even close to 11.49?

As in 11.49 seconds in the 1/4? I've never run at a 1/4 track, so I can't say for sure. My fuel injectors finally showed up along with some other goodies so it's finally time to get a good tune. From comparable dynos, my setup should make 470-500whp.

[SR240DET]

replace all nuts and bolts with titanium hardware, i saw this on some supra forum like 4 -5 years ago he saved roughly 100-300 pounds, i cant remember it was a long time ago.

[godzillarb]

replace all nuts and bolts with titanium hardware, i saw this on some supra forum like 4 -5 years ago he saved roughly 100-300 pounds, i cant remember it was a long time ago.

Hey Panda Mark! I saw you on some of the local forums a long time ago, we might have even met at one point. How's the car?

[Tops*]

Ahh classic Zilvia... and for your information, I'm not a fatass. I tip the scales right at about 150lbs.

Heh, I'm 150 too.

Those stripped and sheeted doors are looking REALLY nice.

Anyway, 16.3 ---> 14.3 Sentra SE.

http://www.sportcompactcarweb.com/features/0208_technical_assistance_program/index.html

Enjoy.

[SR240DET]

Hey Panda Mark! I saw you on some of the local forums a long time ago, we might have even met at one point. How's the car?

haha didnt realize you were from destin, i dont usually run into too many locals on this forum, is your name mark?

[johngriff]

My S14 also has a minitub and 50mm fenders molded

MOLDED?!!?!?!

And your worried about stripping weight?

PIX of Car PLX.

[racepar1]

If you really wanna get your car super light don't think in pounds, think in ounces (as was already stated in this thread). Gut the fuck out of EVERYTHING that is not structural. Remove ALL unused wiring. Get carbon EVERYTHING. It is VERY expensive and VERY time consuming doing these final steps to reduce weight, but it will be rewarding. However don't expect to lower your ET by a second or anything like that, in the end you are probably only gunna see a few 10ths difference. This kind of weight reduction is much more noticeable in a road race or autocross set-up. Also don't expect your car to be liveable on the street. If you take these final steps plan on the only street time for the car to be to and from the track, and that is only if you can't afford a truck and trailer.

[godzillarb]

haha didnt realize you were from destin, i dont usually run into too many locals on this forum, is your name mark?

Yep, my name is Mark as well. I think it was a couple years ago at the commons when I met you at that random 240 meet haha.

MOLDED?!!?!?!

And your worried about stripping weight?

PIX of Car PLX.

http://i72.photobucket.com/albums/i170/tdi520/240sx/14.jpg
http://i72.photobucket.com/albums/i170/tdi520/240sx/112.jpg
http://i72.photobucket.com/albums/i170/tdi520/240sx/130.jpg

[sideview_180sx]

umm.........aside from SMRacing. Some of the fastest 240sx are in s14 chassis. Duy is 1JZ running [email protected] or something. Hybridynamics and Mazworx are all kicking ass against supras. Setup your suspension first and dial it in. No point in getting the car lighter if you don't have it dialed in first.

[S14DB]

I would weld the differential and look at changing the ratio.

[godzillarb]

I would weld the differential and look at changing the ratio.

I'm running a full 6x1 R33 rear end (besides the subframe) with SLP solid bushings and tilt spacers. I can't remember if these LSDs are normally 2way from the factory or not, but this one definitely is. I might consider changing the ratio later, but for now it seems just fine.

[WizardBlack]

1. Pull the dash. Remove the framework behind it. Remove the tack welded tabs on the firewall that are behind it that you don't use. Install an aluminum dash and autometer gauges with small toggle switches. Use an aftermarket steering column.
2. Remove your quarter glass windows and the seam sealer behind it. Install triangles of carbon fiber in their place with sections of 6mm I.D. aluminum tube as spacers to space them out flush with the quarter glass.
3. Tubular suspension (if you haven't)
4. Aluminum propshaft
5. If your car audio and other items are out, pull the associated chassis wiring, antennae, relays, fuses, etc.


Want real weight loss? Skip the S13 240SX and get a stripped 240Z. :-)

Hope something in there helps.

Mark

[KA-T_240]

the fastest 240 in the states is a white s13 KA-T that ran 7.9X at Atco this year.

Other then that car and 1 or 2 others, most the sub 10sec. 240s are s14(Duy, Ivan, Mazwork are the main examples)

[sideview_180sx]

the fastest 240 in the states is a white s13 KA-T that ran 7.9X at Atco this year.

Other then that car and 1 or 2 others, most the sub 10sec. 240s are s14(Duy, Ivan, Mazwork are the main examples)

the KA-T s13 is known as SM Racing on FA.

[Rayne]

I got my S13 down to 2370 lbs. by getting rid of:

Full interior except driver seat, dash, center console, and door panels...
Heater, AC, radio, and underdash venting...

I still have to get rid of the sound deadoning and change to some carbon body panels... The goal is to knock out another 100 pounds...



Pull the dash out and remove all of the old vinyl and padding. I managed to pull at least pound or two off of the dash alone. You can pull a few more ounces off the dash if you trim off the excess plastic around the vents, glove box and center console mounting points.

[Koopa Troopa]

Remove the trunk latch and hood latch and switch to pins to hold them down...

[projectdrifter]

I am under the gun right now to finish up our S14 for next weeks time attack finals, but the car comes back from paint tomorrow. I will do a photo included step by step write up for the forum on how to do this while maintaining excellent door integrity. There is a trick to it. I will tell you though, that your oem door skins are approx 10lb's each. I don't have enough
time to make door skin molds right now, but i will have those next month. This is going to knock the carbon fiber door crowd into the ground, permanently. :bow: I will subscribe to this thread, and post my link next week.

i cant wait to hear more read more about putting my s14 on a diet.:ughug: plus one rep for kognition

[chuy]

I have no rep but id love to add to his as well

[drftwerks]

back on topic

spool instead of full diff, and wiring harness strip

[tre]

http://filebox.vt.edu/users/kshiring/photos/boost-funny.jpg

who cares how much it weighs. I'd rather rock people in a fully loaded down car :P

[Bizzytony]

Haha looks good so far, if you are pulling out the dash there is a small rectangle weight on the back of your firewall. It has no use nissan just put it there. Im not lying. haha my 2 cents.

[kognition]

Here's some advanced weight reduction for ya. 6lb carbon roof. Booya :bigok:
If you see me in your rearview this weekend, it's allready too late for you.
http://kognitiondesign.com/carbon-roof.jpg

[jskateborders]

Theres always the option of driver weight loss.
Lean Boleme anyone?

[cdlong]

Here's some advanced weight reduction for ya. 6lb carbon roof. Booya :bigok:
If you see me in your rearview this weekend, it's allready too late for you.

wow.

did you ever weigh that chunk of the roof?

[kognition]

Yes, without the sunroof system, it was 50lbs. So add another 25lb's for the sunroof system, and the total weight was 75lb's minus 6lb's for the new roof. It would be a 69 lb total weight drop.

wow.

did you ever weigh that chunk of the roof?

[yokotas13]

and off the top of the car which is even better!

[kognition]

Yup, the benefits of the lowered CG is likely bigger than the actual weight reduction itself.

and off the top of the car which is even better!

[kouki_s14]

i want close up shots! and a price please....

[kognition]

It is a little rough looking, because i did not have time to prep the mold like i would normally in order to do a vacuum bagging. This was a wet layup just to get a roof on the car for this weekend. And it was still 6lbs. But i did learn a few things with this one that i will make changes for on future ones. But it is rigid, 2 layers of 20oz. 5 harness satin weave. Price is TBD

i want close up shots! and a price please....

[all stock]

nice kognition, looks beautiful. how is it going to attach to the rest of the sheet metal car?
i just worry because cf is brittle and can shatter. don't wanna get impaled by cf in a rollover. i like the rollcage.

to the OP, you can drill out seat/radio brackets. there's quite a few useless ones you can drill the spot welds out of.

[UNITEDMASTER]

Nice work there Mike, its about time haha,J/K. I know your real busy with the bread & butter. Now , just let me know when we can do a wet layup for my coupe hahaha J/K but Im serious. I still need to send you those pics . Again nice work, Whats your total weight at now

[kognition]

Thank's here to A.J. (United Master) for providing me with the spare roof clip to do this project with. Please give him rep, as he made a great effort to get this roof to me.
A.J. , i honestly have not had alot of time to scale the car but i would bet we are around 2, 200 lb's somewhere. Doing the Nissan tuner shootout in Jan, so i will probably do some more weight reduction before that. Still waiting on your pics. :2f2f:

Nice work there Mike, its about time haha,J/K. I know your real busy with the bread & butter. Now , just let me know when we can do a wet layup for my coupe hahaha J/K but Im serious. I still need to send you those pics . Again nice work, Whats your total weight at now

[kognition]

No it's fine as far as flexing goes because the weave is only going in two axis and not three. A third axis would give you a stiffness that would likely be subjected to stress from chassis flex. Which could cause that kind of stress in the part. We used a 2 part urethane that we use for bonding aluminum honeycomb core to laminates. So it has a very strong bond with the desired flexibility in it. We clamped the pillars with spring clamps overnite while the adhesive cures.

nice kognition, looks beautiful. how is it going to attach to the rest of the sheet metal car?
i just worry because cf is brittle and can shatter. don't wanna get impaled by cf in a rollover. i like the rollcage.

to the OP, you can drill out seat/radio brackets. there's quite a few useless ones you can drill the spot welds out of.

[PoorMans180SX]

Awesome. So freakin awesome.

[cdlong]

wait, did you cut out the rear parcel shelf too? it looks like you can see the strut tower in that pic.

[Rayne]

wait, did you cut out the rear parcel shelf too? it looks like you can see the strut tower in that pic.

The parcel shelf is removed. Look how far back the cage goes into the trunk.

[sl4ck3r]

power steering!

[projectdrifter]

yummmm very sexy top. thats a ton of weight gone.

[kognition]

The new roof held up like a champ with zero problems whatsoever. I was very impressed with response during acceleration and coming out of turns with it. No weird sounds or cracking noises. We bonded the roof pillars with our urethane 2 part adhesive. We use this adhesive to bond the honeycomb to laminates for our race splitters. Extremely happy with the results. Because this was a wet layup, i am removing it in order to put a vacuum bagged version onto the car. We got major props this weekend for the roof. Major. :bigok:
http://kognitiondesign.com/laguna-seca-1.jpg

[S14DB]

So, when is the full CF S14 Shell coming out?

[Tearlessj]

So, when is the full CF S14 Shell coming out?
That would be fucking sweet.

[projectdrifter]

yes a cf shell would be ohhh so pimp. to bad i could never afford one.

[kognition]

We just weighed the S14 today before scalling it, 2,227lb's with the new roof replacement. I have easily another 100lb's to remove from it. :2f2f:
http://kognitiondesign.com/s14-scales-nov-07.jpg

[Addicted2Kouki]

to the OP....^^^pay attention... thats REAL advanced weight loss.

[projectdrifter]

so whats the mod on the doors to shave some weight without going cf.. im still waiting.

[kognition]

Happy New Year! :w00t:
This is an involved mod article. And it does require that a mold be made for the door skins of your specific model. As i work on the door skin molds for the S14, i am thinking that i will try to have this writeup published in Modified this Spring.
But if you would like an idea of what is involved, you can read my Scion article online over at Modified.com CLICK HERE (http://www.modified.com/sportculture/tcracecar_week3.html) to read that with pics.
so whats the mod on the doors to shave some weight without going cf.. im still waiting.