Unofficial weight reduction thread

[MANIACura]

: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.

Ok you asked for it.....REAR Bumber beam off a 1991 US Spec NSX. I was curious to see exactly how much weight I could safely save by replacing my rear beam. Pictures for proof.....

Looks like the US version is heavier due to the Brackets in the license plate area.

OEM 1991 Rear Beam Steel - 23.7 Pounds

STMPO Aluminum Replacement Beam (Prototype) - 8.8 Pounds

Weight Saved - 14.9 Pounds (Not bad....pretty easy install)

Rear Beam on the scale.

23.7 pounds. I can see why Diablo thought it was heavier. It feels heavier.

STMPO prototype aluminum beam installed in bumper.

 

[John McCain Racing]

I have a STMPO Rear Beam on my NSX too. I plan to weigh again soon, but I'm guessing I'm right at 2800lbs. :biggrin:

 

[MvM]

Ok you asked for it.....REAR Bumber beam off a 1991 US Spec NSX. I was curious to see exactly how much weight I could safely save by replacing my rear beam. Pictures for proof.....
Looks like the US version is heavier due to the Brackets in the license plate area.

OEM 1991 Rear Beam Steel - 23.7 Pounds

STMPO Aluminum Replacement Beam (Prototype) - 8.8 Pounds

Weight Saved - 14.9 Pounds (Not bad....pretty easy install)

Wow, you are doing what I have been thinking about for some time. Excellent Work !! :smile:

First of all, you are probably right about the weight differences. Seems the US NSX has some extra brackets bolted or welded onto the bumper beam which the European NSX doesn't have.
Am wondering though why the brackets are there in the first place. The European license plate is much longer than the US one since our plates are bigger.
But it could also be due to differences in madatory impact protection laws.

What are the measurements of the alu beam you have been using. What material thickness are you using.
And last, of course, what does STMPO stands for??

 

[John McCain Racing]

Wow, you are doing what I have been thinking about for some time. Excellent Work !! :smile:

First of all, you are probably right about the weight differences. Seems the US NSX has some extra brackets bolted or welded onto the bumper beam which the European NSX doesn't have.
Am wondering though why the brackets are there in the first place. The European license plate is much longer than the US one since our plates are bigger.
But it could also be due to differences in madatory impact protection laws.

What are the measurements of the alu beam you have been using. What material thickness are you using.
And last, of course, what does STMPO stands for??

STMPO Race Products..... www.stmpo.com

 

[ChitownNSX]

I have always browsed at this thread and thought that you guys are all nuts... But Im starting to get it, Major Kudos to those that are really turning their X into a mean lean machine!

 

[MvM]

STMPO Race Products..... www.stmpo.com

Thanks for the link. I thought it maybe was some kind of special aluminum alloy .

 

[oscar_driver]

This should be renamed from:
"Unofficial weight reduction thread"
to
"Unofficial OCD weight reduction thread"

JK i love this... actually it was quite addictive to go page by page and see so much "ingenuity" from you guys .. amazing!
Good luck you all!
Oscar

 

[Floyd]

Ok you asked for it.....REAR Bumber beam off a 1991 US Spec NSX. I was curious to see exactly how much weight I could safely save by replacing my rear beam. Pictures for proof.....

Looks like the US version is heavier due to the Brackets in the license plate area.

OEM 1991 Rear Beam Steel - 23.7 Pounds

STMPO Aluminum Replacement Beam (Prototype) - 8.8 Pounds

Weight Saved - 14.9 Pounds (Not bad....pretty easy install)

Rear Beam on the scale.

23.7 pounds. I can see why Diablo thought it was heavier. It feels heavier.

STMPO prototype aluminum beam installed in bumper.

Look Out! Marla Streb is riding naked behind you

 

[MANIACura]

Look Out! Marla Streb is riding naked behind you

I was wondering how long it would take somebody to recognize Marla.

I have quite a few honeys on the wall......Jenny Stensland, Marla Streb and Paola Pezzo to name a few. Love fit women in bicycle shorts:biggrin:

 

[RagingAngel]

Re: Flip-up headlight skeletonization

The light unit itself was around 5# which is quite heavy. Old sealed beam units probably weighed around 1 to 1/2# at most (they call that progress?). I didn't want to break the seal just to get the weight, but the vertical glass protection lens looks REAL heavy.

I'm wondering if there's any weight savings in the NA1 flip-ups from the halogen vs. the HID units?

Or perhaps, even if the HID units were lighter, the extra ballast/ignitors would bring their weight back up.

I suppose something like this is the only way without going full out NA2- Is this pictured one Marga Hills? Maybe those lamps retrofitted into the flip-up housing would work too?

 

[liftcontrol]

For me, no music compares to the symphony being played by the NSX engine behind me, so I removed the two door speakers and the one passesnger footwell speaker. Total weight savings: [14.5 x 2] + 15lbs = 44 lbs.:wink:

That in addition to eliminating many of the other things mentioned here has made a difference in the handling and acceleration.

 

[MANIACura]

For me, no music compares to the symphony being played by the NSX engine behind me, so I removed the two door speakers and the one passesnger footwell speaker. Total weight savings: [14.5 x 2] + 15lbs = 44 lbs.:wink:

That in addition to eliminating many of the other things mentioned here has made a difference in the handling and acceleration.

I don't know what kind of speakers you had in your NSX but just to avoid any confusion the OEM aren't nearly that heavy. OEM door speakers are 4.4 pounds each as is the footwell subwoofer. (4.4 + 4.4 + 4.4 ) = 13.2 lbs saved.

 

[MANIACura]

Decided to stop at the scales and see how much my 1991 Coupe weighs. This is how I drive it daily with the radar detector, glove box full, Ipod and whatever else. Literally took me five minutes. I was pleasantly surprised because you would never know that the weight is reduced by looking at the car. Still has stereo with two TV monitors and all the comfort items installed.2820 lbs. Not Bad.

In my opinion......not enough of these weigh slips are being posted.....way too much speculation going on here.

 

[nsxotic911]

Decided to stop at the scales and see how much my 1991 Coupe weighs. This is how I drive it daily with the radar detector, glove box full, Ipod and whatever else. Literally took me five minutes. I was pleasantly surprised because you would never know that the weight is reduced by looking at the car. Still has stereo with two TV monitors and all the comfort items installed.2820 lbs. Not Bad.

In my opinion......not enough of these weigh slips are being posted.....way too much speculation going on here.

That's very cool. That is pretty much S2k territory - at least the 'heavy' stock version - but with more hp/torque and wider car. Very cool.

 

[Greg Z]

That's very cool. That is pretty much S2k territory - at least the 'heavy' stock version - but with more hp/torque and wider car. Very cool.

Weighed mine a few months ago, but kinda forgot this thread. It was 2700 even. Me out of car and only 3-5 gall of gas. Full interior and stock wheels.

 

[Ojas]

In my opinion......not enough of these weigh slips are being posted.....way too much speculation going on here.

Thanks for posting your weight, but you didn't mention the amount of fuel in the tank. Starting from a full tank, you'll easily shed 100+ lbs. before even hitting "E". The fuel gauge has a very limited precision and between different NSXs, I've observed the readings varying greatly. For accurate comparisons between different weight reduction efforts, I think it only makes sense to weigh with a full tank.

 

[John McCain Racing]

Thanks for posting your weight, but you didn't mention the amount of fuel in the tank. Starting from a full tank, you'll easily shed 100+ lbs. before even hitting "E". The fuel gauge has a very limited precision and between different NSXs, I've observed the readings varying greatly. For accurate comparisons between different weight reduction efforts, I think it only makes sense to weigh with a full tank.

I agree. :biggrin: I'm going to try and take mine next week if possible. Like to get a weight before my Lovefab.

 

[MANIACura]

Thanks for posting your weight, but you didn't mention the amount of fuel in the tank. Starting from a full tank, you'll easily shed 100+ lbs. before even hitting "E". The fuel gauge has a very limited precision and between different NSXs, I've observed the readings varying greatly. For accurate comparisons between different weight reduction efforts, I think it only makes sense to weigh with a full tank.

What makes you think I didn't have a full tank? Earlier in this thread it was stated that we should all fill our tanks to keep this consistant so that's what I did. Lets keep the guess work out of this. I'm sick and tired of people posting how much their car weighs or how fast it'll go in the quarter mile without posting slips.

Now go fill up your NSX, get it weighed and post the freakin' slip.

 

[Ojas]

What makes you think I didn't have a full tank?

Matt, it's not that I thought you didn't - I just didn't know (since there's not a complete list of your mods posted here). Even though John@Microsoft suggested this early on, not all weights posted afterwards were measured with full tanks.

So, it was not an accusation - just seeking clarification.

Now go fill up your NSX, get it weighed and post the freakin' slip.

That's fine, but let's also list the mods performed to achieve the measured weight.

 

[Tanto2]

The real accuracy on these public scales (no matter what they say) is about 5%. Thats nearly 150#. Weigh the stuff you take off, and subtract from 3010 or whatever you start with.

 

[john@johnhudakracing]

The real accuracy on these public scales (no matter what they say) is about 5%. Thats nearly 150#. Weigh the stuff you take off, and subtract from 3010 or whatever you start with.

Where exactly did you get that figure from?

For starters, unless it is restricted to weigh-in-motion (rare).... most all modern truck weigh stations now use electronic load cells, not the older mechanical levers for their stationary scales which were widely known to be less accurate decades ago.

Now, the most common electronic load cells are rated at 3000 lbs (note that the U.S. Certificate typically rates it at 5000 lbs when used in a multiple cell system).

If you want to know the real accuracy- you need divide the calibrated capacity of the scale by the maximum displayed divisions, and you will get the worst case accuracy of the given weighing system.

As an example, if three 5000 lb load cells are used in a system, and the scale is calibrated for 10000 lb capacity, the calibrated capacity would be calculated for a 10,000 lb public scale.

If it is showing 10lb increments on the digital board- then divide by 1000 displayed divisions, or 10lbs. Thus, the actual resolution would only be 1% of calibrated capacity.

Now, in practice, our vehicles weigh far less than semi trailers, which helps (like a speed-o less is more here). Further, if​

you use a public truck scale for a passenger vehicle, you have to remember that you are only using a half the total number of load cells. Thus, the accuracy is actually twice as high for you than it would be for a semi truck. Further, if in doubt you can even double check the results by using the opposing axle load cell or even the other lane for redundancy.​

To the common question- why the displayed higher resolution. Legally the scales are required by the bureau to have their resolution intentionally limited as they are used in trade. Say ~1% of calibrated capacity or 10-20-30lbs increments for a 3000lb road car would be fairly common. The scales are actually more capable than this, they simply choose to set them up this way.

All certified public scales are checked periodically during calibration / re-certification by using a weight cart which is designed to place a large amount of known mass to be concentrated over a relatively small area of load receiving element. Most pass this inspection.


Bottom line-

My experience is that while they will not give you lb for lb accuracy like a good set of race scales- they are more than sufficient to give you the gist. Chances are if you are performance deficient, twenty lbs isn't your primary problem.

In fact, many race competition rules will allow for a sheet from a certified public scale to be used in lieu of an official weigh when alternate equipment is unavailable.

So, I could only conclude that if it's good enough for club racing, then it should be good enough for street posing or for a weight reduction thread.

My 0.2

 

[Danny@5star]

This thread has been very useful in giving me ideas as to where n what to do for additional weight reduction. Here is a list of what Ive removed/replaced and I'm also posting a copy of the scale sheet as a reference. I have a 2003 NSX-T. Hope this gives other members an idea of how much they should be weighing in!

Items removed:
CD changer in trunk
Tool set in trunk
All carpeting from trunk (stripped)
Complete Antenna motor
Spare Tire & bracket
Wiper motor & wipers
Small sun visors:biggrin:
Rear tow hooks

Items Replaced:
Cantrell Exhaust
Cantrell Headers
Test Pipes

Regards,

Danny

 

[Danny@5star]

Forgot to mention that this was with about 1/4 tank of gas and obviously without me in the car!

 

[oscar_driver]

Forgot to mention that this was with about 1/4 tank of gas and obviously without me in the car!

Danny, please come this Friday to the towers:
http://www.nsxprime.com/forums/showthread.php?t=119489
I hope you can make it!
Oscar

 

[Cornfed NSX]

Has anyone thought about replacing the targa top with a carbon fibre unit? or on the hardtops cutting the roof and replacing it with a carbon sheet ala E90 M3 and spoon civic? Would bring the center of gravity down alot and im sure you wouldn't loose too much rigidity if done right.