Unofficial weight reduction thread

[Diablo360]

I absolutely disagree !!
The numbers listed by NSXsupra correspond very well with the numbers that I got for my own steel bumper beams.

What a lot of people forget is that when you have a large and/or long part in your hands, its weights will seem much larger than if you have the same part in a small compact form.
Perhaps next time someone lifts the front or rear beam of his car, he should immediately after lift the OEM Honda battery and then compare those weights.

Are you really that confident? I'm holding a 20lb dumbell right now and there is no way in hell that the steel rear bumper beam out of my car was this light. I would have left it in there if it was. I'll bet you $100 that the weight is closer to my predicted 45lb's than your 20lb's....... If you want i'll take the beam to the next SCA meet along with a scale and have others take pictures and serve as witnesses. Deal?

 

[MvM]

Are you really that confident? I'm holding a 20lb dumbell right now and there is no way in hell that the steel rear bumper beam out of my car was this light. I would have left it in there if it was. I'll bet you $100 that the weight is closer to my predicted 45lb's than your 20lb's....... If you want i'll take the beam to the next SCA meet along with a scale and have others take pictures and serve as witnesses. Deal?

:smile: :smile:
Posted by NSXSupra in this same thread:

Accuracy is the key. Rough estimates by hand is usually over estimate. Vance and Erick felt my wheel spacers, they guessed around 20~30lbs, but actually they only weight 12lbs on electronic scale.

I removed 12lbs worth of wheel adaptors/studs/lugs (weighted at postoffice). two 20mm F and two 35mm rear.

As far as the rear bumper beam is concerned, mine is made of steel.
I have a European NSX so maybe the beam is different from the US bumper beams but I doubt that very much. I've posted this before but perhaps a reminder is not a bad idea:

The rear bumper beam on my NSX weighs 7.4 kg (= 16.22lbs)
The left bumper mounting bracket is 0.582 kg (= 1.28 lbs)
The right bumper mounting bracket is 0.962 kg (= 2.12 lbs)

The total weight or my rear bumper, that is bumper beam, brackets, plastic foam, the painted bumper cover, license plate holder and 2002 lower valence including the mesh was 19.2 kg (= 42.33 lbs)

These are the brackets

Here is the car with just the rear bumper mounted on the car with the brackets.

And here is the complete rear bumper beam, ready to be bolted to the car.

It would be nice if someone could post a picture of the rear bumper beam off a US spec NSX.
It would be nice to know if they are any different although in reality, I would doubt it.

 

[nsxotic911]

BTW: I took out the Windshield wiper Motor last night and weight it. I was 1xx with the windshield wiper and 1xx - 10 without it. Not quite the 15 - 20 as previously estimated by others.

With the actual wipers, I think that's another 5 lbs, but I was too lazy to do it at the time..
I think it's one of the cool mods to do, and as others have said, it's really high up... you don't want that kind of weight screwing up your center of gravity.

On the center of gravity - I've asked this before, why does no one produce a Carbon Fibre roof top? Of course the steel/alluminum pieces inside the roof need to stay, but I see at least 10 lbs that could be saved.

There's gotta be a good reason, or someone has to just start doing it.

 

[95EagleAWD]

I'd totally spring for a Carbon roof, like the M3CSL and the M6.

 

[john@johnhudakracing]

I'm shooting for 2500lb's. Ambitious you think? I'll some time to do a complete write up on everything I have taken out, and/or replaced to make my car lightweight. Give me a few weeks.....

I would certainly hope so. Sounds like there is some more work to do. How's it going? All this talk about weigh reduction is making me hungry. :biggrin:

Have any of you added a roll cage yet? You have to remember to drop off enough to compensate for all the needed safety stuff that you have to add back on as well... or it's really not a fair comparison.

I pulled in this morning for a quick weigh to get a ball park where I ended up, stepped out... and the scale was undecided between 2600-2620. Forget the NSX-R.... that's on a top down late model T wet!! That's just about how much my gutted S weighs yet look at the size of this thing! I didn't gut mine time attack style either... for my purposes I am actually trying to sit mine toward over-built so it will last 8 hours!

In fairness, for comparison here their are also significant differences.

First, I have a robust roll cage, fire, etc... and all the safety equipment. That adds up to a lot right there. Further, I kept a lot of stuff I otherwise probably would not have otherwise on a standard build simply due to application/preference- bigger battery, power steering, driver cooling, cock pit adjustable everything, adjustable column, 4 way ABS, huge brakes, big tires, over-built cooling and oil systems, full aero kit with full belly pans, wheel liners, big ass wing, street exhaust, etc.... the shit adds up quick.

Last, relatively... I still have all the trimmings (non-essentials like more stock wiring than I should, latches, the stock dash, some trim for cosmetics I could easily throw off, etc...) just to keep it a little more civil.

So basically, yeah If you guys are going to play hard ball I could just ditch all that stuff and drop 200lbs tomorrow... and see 2400 or less pretty easy. But for now you know this feels pretty good, I think I'm at least in range as I'll have to carry ballast anyway. If you think about it.. I added all that shit this year and I still lost 60+lbs !!! Not bad, but you know...

... I think next year that maybe it is time for John Stage II?

Polycarbonate wind screen, tilton pedal set, new A arms, little more use of bagged carbon.... some time to pick up some new blades for the sawzall on the way home... don't worry we'll see what we can do about these slow nsx-t's. :wink:

BTW: I took out the Windshield wiper Motor last night and weight it. I was 1xx with the windshield wiper and 1xx - 10 without it. Not quite the 15 - 20 as previously estimated by others.

With the actual wipers, I think that's another 5 lbs, but I was too lazy to do it at the time..
I think it's one of the cool mods to do, and as others have said, it's really high up... you don't want that kind of weight screwing up your center of gravity.

On the center of gravity - I've asked this before, why does no one produce a Carbon Fibre roof top? Of course the steel/alluminum pieces inside the roof need to stay, but I see at least 10 lbs that could be saved.

There's gotta be a good reason, or someone has to just start doing it.

Paul, it would be very expensive as it is a structual and very significant safety item. Some of the SCCA guys use a gentleman I know out of California which makes a 6 layer vacuum infusion carbon plug for some models sun-roofs. If you have to ask about the price.... :wink:

 

[yellow-scorpion]

how much weight saving is there if the rear glass hatch is replaced with the sos rear lexan hatch? Has anyone here had any problems installing or maintaining these LH?

 

[nsxotic911]

how much weight saving is there if the rear glass hatch is replaced with the sos rear lexan hatch? Has anyone here had any problems installing or maintaining these LH?

About 12 - 15 lbs is what has been quoted before. I almost went for one, but I was informed/concerned that it can't be tinted.. which I wanted. Too bad... :frown:

John - At about 500 lbs heavier, you make me feel obese. No Roll Cage though Dave's Roll Bar coming in soon (today/tomorrow)

 

[john@johnhudakracing]

how much weight saving is there if the rear glass hatch is replaced with the sos rear lexan hatch? Has anyone here had any problems installing or maintaining these LH?

Significant more than the numbers, as it sits so high on the vehicle. Location is important for CG and PMI.
http://daliracing.com/v666-5/catalog/index_browse_part.cfm?focus=1180

I haven't had mine long, but maintainability with these is usually ok from what I've heard. Obviously they scratch easily, so over time they will likely start to look a little ratty. They may also sag from the heat, especially if you are running hot. Maybe more so on the race thickness.

As far as bang for the buck, the best savings come from deleting the lock, hatch rail and struts entirely and just using hood pins with the lightest thing you can throw on that does the job.

I plan to use some release wax on my stock glass piece to lift a CFRP one as a spare this winter.

John - At about 500 lbs heavier, you make me feel obese. No Roll Cage though Dave's Roll Bar coming in soon (today/tomorrow)

That's ok, you got boost. :wink:

 

[nsxotic911]

That's ok, you got boost. :wink:

Yeah, I guess that makes me cooler
I'm telling you, get boost and it will be night n' day....
Then there's no way I can say "haha I'm 'faster' "

 

[yellow-scorpion]

Thank you John for your reply, very insightfull. How much weight saving is in the lock, hatch rail and struts? This might be worthy mod I think.

 

[john@johnhudakracing]

Thank you John for your reply, very insightfull. How much weight saving is in the lock, hatch rail and struts? This might be worthy mod I think.

Best guesstimate would be that the hatch rail itself might be 4.5 lbs or so. Maybe if you put every little thing (struts, lock, support, security switch, wiring, etc...) in a pile you'd have that extra 5.5-6.0 lbs or so. Minimal.

Is what it is.

Pins are always a good idea, but yeah as far as the latches/struts on hatches, trunks, hoods.... I'd say think about it before going ape with it. It makes inspecting and working in the engine bay a PITA.

I mean, if you are still streeting it... and you want to pull in to quick take a peek or tweak something- it is a little unwieldy to be pulling full hatches, trunks, hoods, etc.. off without a pit crew.

Faster, but... probably best left for trailer/off-road only than weekend track day car or club racer. :wink:

 

[nsxsupra]

That ABSOLUTELY has to be the aluminum weight. Jason, you personally held my steel rear bumper beam. No way it only weights 20lb's. I've seen figures somewhere else where they state 45ish lb's, which seems more accurate......

Simo,

Sorry, been really busy lately. I no longer have time to do most of the things I used to enjoy:frown: .

I got the info off the Japanese NSX owner's site a while ago. I do not claim that is 100% accurate. Item with size always felt heavier than it actually is. For example, I took 4 of my wheel adaptors, put it in a bag, and had Vance and Erick felt it a few month ago. Without telling them the actual weight that I got off the post office scale, they both guessed ~30lbs. The actual weight is 12lbs total. The size and amount of space the item takes up can give an illusion that the item may weight more than its actual weight. The key to weight reduction is accuracy. If you felt you are absolutely sure, the answer is a few blocks away at the Garden Grove post office.

My guess were approximately 35~40lbs when I felt it. If you like to weight it. You can take the bumper beam to post office and use their scale, you do not have to wait in line.

BTW: I took out the Windshield wiper Motor last night and weight it. I was 1xx with the windshield wiper and 1xx - 10 without it. Not quite the 15 - 20 as previously estimated by others.

The weight also includes washer fluids resovior + washer fluids.:smile:

 

[robfenn]

Our NSX currently weighs around 2850lbs, so it's interesting to see people are comfortably lighter. However, we do have a hefty rollcage.

The dash currently remains but there is nothing really left of the interior, no aircon, no door bits (a couple of motors still there though), no airbags, no soundproofing, plastic firewall instead of glass. Race seats and steering wheel are in. There is plenty of wiring that could probably be removed, but will be left in place as i'm too scared of something going wrong...!

Parts wise, we have a carbon bonnet and spoiler. There is a race battery too, but then there are additional Type R strengthening bits which must outweigh some of the advantage.

We have a full AP Racing brake kit, lighter discs i imagine but then they are much bigger than OEM and ditto with the calipers.

Looking back on the thread our Nitron 3-ways must weigh less than stock items comfortably. The wheels however are bigger and wider, and were built for strength so undoubtedly heavier.

Since race season has finished we are going to do some easier jobs, like get rid of the electric motors and replace windows and rear hatch with lexan. We are just going to get a straight forward mould of the hatch, as the SoS is a bit 'pretty' and unnecessary for race use IMO.

A more serious mod is the wheels, which will be Dymag magnesiums. Should save a ton of weight, being unsprung is a bonus.

I'd love to see the car down to 2600lbs.... are there any obvious other things i haven't thought of?

 

[nsxotic911]

IRT to the rear bumper - what is the effect on handling? Given it's a good bit of weight that far out, I imagine it could affect it significantly, one that you could feel.

Thoughts?

Also - at what point is the car "totaled" in a rear end collision... versus stock 5 MPH in comparison to... 35 MPH? Does the "foam" raise the limit by a significant amount? (eg > 5 MPH) EG: I'm trying to evalute the risk for a street car. I've been in more times when people got close to hitting me then I can count, however, with being diligent at your soroundings, I've been fortunate to avoid pretty much all off them. However, I'm concerned that if I'm sitting in traffic and the guy's brakes behind me fail to work.. or he's just going way too fast, all the honking, repeated brake lights might not stop him...

 

[L8apex32]

We get off topic if we start talking, again, about safety and insurance issues. But, briefly, "totaling" is an insurance term for when the cost to fix the car is more than [or near to] the value of the car once fixed." In other words, "totaled" means "not worth fixing". If this happens, the insurance company will give you a check for the approx value of your car. They get owernship of the damaged car.

Bumpers (bumper beams) help prevent major damage. They can often be replaced for a reasonable price. Bumper (bumper beams) are in important safety item. Full discussion of these concepts probably deserve its own thread.

 

[Tanto2]

R eng cover weight vs DF CF unit?

Anyone know actual weights on either a real R engine cover or a DF CF mech unit? I have a 2# CF full cover I had made locally, would like to get some more sound into the cabin, but I don't want to add any OZ's. TIA

 

[socalx]

real r engine cover is 2 lbs

 

[socalx]

MVM-- on my na2 nsx the rear bumper beam is totally different from yours. it is made out of square aluminum, versus your pressed steel. unfortunatly i don't have a picture. it is still very heavy though.

:smile: :smile:
Posted by NSXSupra in this same thread:



As far as the rear bumper beam is concerned, mine is made of steel.
I have a European NSX so maybe the beam is different from the US bumper beams but I doubt that very much. I've posted this before but perhaps a reminder is not a bad idea:

The rear bumper beam on my NSX weighs 7.4 kg (= 16.22lbs)
The left bumper mounting bracket is 0.582 kg (= 1.28 lbs)
The right bumper mounting bracket is 0.962 kg (= 2.12 lbs)

The total weight or my rear bumper, that is bumper beam, brackets, plastic foam, the painted bumper cover, license plate holder and 2002 lower valence including the mesh was 19.2 kg (= 42.33 lbs)

These are the brackets

Here is the car with just the rear bumper mounted on the car with the brackets.

And here is the complete rear bumper beam, ready to be bolted to the car.

It would be nice if someone could post a picture of the rear bumper beam off a US spec NSX.
It would be nice to know if they are any different although in reality, I would doubt it.

 

[MvM]

MVM-- on my na2 nsx the rear bumper beam is totally different from yours. it is made out of square aluminum, versus your pressed steel. unfortunatly i don't have a picture. it is still very heavy though.

I know, the NA2 NSX (from 1997 onwards) has a rear bumper beam made of aluminum instead of steel.
However, whereas the steel bumper beam uses relatively thin material, the aluminum in the 1997+ beam is probably thicker, so the differences in actual weight is problem not that much.

If you have a chance to put it on a scale, however, that would be great.
First of all for me so I can update my Excel sheet with all kinds of NSX-weights and also to put an end to the long discussion about perceived weights versus actual weights in this thread.

 

[Q]

I've had my front beam and rear beam out of my car for various reasons and have weighed them both. They are 20 lbs per piece. They are the steel beams.

 

[L8apex32]

Jason, do you think it's possible to have a 12.00 second NA car? Maybe 2400lb's would do it. That would be pretty hardcore though. I think I can do 2600 and still have all of the interior (minus the stereo), and heat/ac.

For a stock NA1 engine (242 rwhp), you'll need to be down, roughly, to 2690 lbs WITH driver to get in the 12s.

With NA1 and I/H/E power (265 rwhp), you'll need to be 2950 with driver.

These are ball park estimates.

 

[nsxotic911]

For a stock NA1 engine (242 rwhp), you'll need to be down, roughly, to 2690 lbs WITH driver to get in the 12s.

With NA1 and I/H/E power (265 rwhp), you'll need to be 2950 with driver.

These are ball park estimates.

That seems... very aggresive, well, unrealistic.

Without the most preferable conditions (tires, traction, skill, launch..), and at least some, no, a lot more HP and less weight.... it's just not going to happen.

This site has 2950 + 265RWHP @ ~13.0. http://www.tunercalcs.com/

@ A very aggressive 2600 lbs (WITH driver) and 265 RWHP, it would indicate a ~12.4.
I'm hoping to be about 3200 lbs with driver, maybe 3100 lbs.. @ at 375 RWHP, if I can pull low 12's, I'll be happy..

 

[john@johnhudakracing]

Thoughts?

Also - at what point is the car "totaled" in a rear end collision... versus stock 5 MPH in comparison to... 35 MPH? Does the "foam" raise the limit by a significant amount? (eg > 5 MPH) EG: I'm trying to evalute the risk for a street car.

Hmm, thoughts.

Paul, maybe 'upgrading' to an iron one with integrated parachute? Another idea is that I learned last night that on the space shuttle they keep high explosives on-board so, in the event of an emergency, it's crew expendable to protect people on the ground.

That's all I have at the moment. :biggrin:

j/k ... still tagging along this weekend?

 

[nsxotic911]

Alright guys, I took out my front bumper beam on a 98T I weight it and it weighed... (maybe this has already been posted..) 13 lbs.With the brackets and bolts is another 2 or so lbs..

So there you have it, not that much. Rear bumper TBD.

 

[Tanto2]

Slownsxt- was your front bumper beam steel? or alum? Thanks