Gas tank weight

[Arizona Vipers]

Does anyone know what the factory fuel tank weighs? Thanks!

[TheMadMachinist]

Full or empty?

just kidding........

[SLP]

If no one chimes in, you might have luck asking online mopar parts sellers what the shipping weight is for it (part#5181528AD). I tried buying a hood liner once from one of the mopar parts sellers and they calculated it as $10 to ship but then I got a call and they said that their automatic shipping calculator didn't have the right item dimensions and that it would be $2xx to ship...So that tells me that they store dimensions/weights somewhere in their database.

[Arizona Vipers]

If no one chimes in, you might have luck asking online mopar parts sellers what the shipping weight is for it (part#5181528AD). I tried buying a hood liner once from one of the mopar parts sellers and they calculated it as $10 to ship but then I got a call and they said that their automatic shipping calculator didn't have the right item dimensions and that it would be $2xx to ship...So that tells me that they store dimensions/weights somewhere in their database.
yeah but you never know if they are including packaging etc. I think no matter what I'm going fuel cell, just so we can move it to the back of the car and lower. Moving 70lbs (with fuel) back two feet will be like running a lower wing setting without the added drag!

[Whitey]

:United_States:

[RedTanRT/10]

AZ, beyond the aero your thinking, the cell is a lot safer

[Martyb]

AZ, beyond the aero your thinking, the cell is a lot safer

This!

[ViperGeorge]

Certainly a fuel cell is safer. On the other hand there have been a number of serious Viper crashes and I have not seen one where the gas tank has ruptured. It is virtually behind the seat and if it ruptured it would mean the damage is catastrophic and you probably would already be dead. Now if you are moving the tank to the rear (think Ford Pinto) I would definitely put in a fuel cell. The existing tank is a composite I think (based on pictures I've seen) so I would think it is reasonably lite.

[Whiskey]

If you want to remove that fuel tank...you either have to take apart the body and trunk inner tub or...like me and cut it out. I had to cut out my fuel tank on my G3 (Gen3 to 5 is all the same for this). It was to repair a small hole from a rock or who knows what got up there and put a very small hole in the composite. It may have been a factory defect but nobody ever noticed.

[Arizona Vipers]

Certainly a fuel cell is safer. On the other hand there have been a number of serious Viper crashes and I have not seen one where the gas tank has ruptured. It is virtually behind the seat and if it ruptured it would mean the damage is catastrophic and you probably would already be dead. Now if you are moving the tank to the rear (think Ford Pinto) I would definitely put in a fuel cell. The existing tank is a composite I think (based on pictures I've seen) so I would think it is reasonably lite.

How is it safer? And overall, it's probably going to be less safe as it will be closer to the rear bumper.

[Arizona Vipers]

If you want to remove that fuel tank...you either have to take apart the body and trunk inner tub or...like me and cut it out. I had to cut out my fuel tank on my G3 (Gen3 to 5 is all the same for this). It was to repair a small hole from a rock or who knows what got up there and put a very small hole in the composite. It may have been a factory defect but nobody ever noticed.

Yeah we are cutting the tub out. Taking as much weight off as I can back there. I think the inner taillight assembly's are another 5 lbs, will just mount the bulbs an aluminium strip or something.

[Arizona Vipers]

13 lbs gone here so far. Will get closer to 30 lbs, just don't want to cut out too much until we figure out how to mount battery and fuel cell etc.
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Fuel cell will be nice and LOW. With the power of my car and the style I drive it, me getting back onto full throttle as soon as I can is what makes or breaks my lap times. I always run a different line than everyone I know, always trying to shorten the track to be able to get my car straight as soon as possible to mash the throttle. What's an apex? lol (That's not my skinny ass arm lol)

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[ViperGeorge]

How is it safer? And overall, it's probably going to be less safe as it will be closer to the rear bumper.

A fuel cell has an interior bladder that resists ruptures and punctures even if the case is damaged. The inner bladder is quite tough and unlike the OEM tank will flex when hit, it is not attached to the case but is free to move out of the way when hit. The OEM tank is hard composite and does not have the give that a fuel cell bladder has. In this regards a fuel cell has two levels of protection, the outer case and the inner bladder. However, even fuel cells will leak if hit hard enough or sometimes if the car goes upside down. Isn't that why they put them in the ACR-Xs? You need to have a shutoff and check valve so that if you were in an accident or if you flipped over the fuel pump would shut off so it doesn't continue to pump fuel in an accident.

The old metal type gas tanks would readily rupture if hit especially since they were often installed under the trunk floor in the rear of the car. The more modern composite tanks are probably less prone to rupture but I would image they could still crack open if hit hard enough. Depending on where you were to mount the fuel cell it may be more safe or less safe than the OEM tank. I would think a cell mounted where the OEM tank is would be more safe. One mounted in the trunk, low down, might not be.

[ViperSRT]

Moving the fuel weight further back will increase the polar moment of inertia and worsen handling capability. It may indeed improve rear weight bias and rear traction, but does so with a decrease in front weight bias and front traction, while increasing turning forces. Lower is not always better if it includes an increase in the polar moment. Somewhat doubtful this will improve lap times.

[Arizona Vipers]

Moving the fuel weight further back will increase the polar moment of inertia and worsen handling capability. It may indeed improve rear weight bias and rear traction, but does so with a decrease in front weight bias and front traction, while increasing turning forces. Lower is not always better if it includes an increase in the polar moment. Somewhat doubtful this will improve lap times.

Tell that to Porsche. They blow away the ACR at the 'Ring with a 500hp car with 58% rear weight bias.

[sadil]

Can you take as many photos as possible of the modification. I was planning on eventually doing some aero mods and modifying the rear tub area for a new splitter design. Would be nice to see more photos of what it looks when you start cutting stuff up. As with everything else Arizona does, I’m SUB’d lol

[Arizona Vipers]

Can you take as many photos as possible of the modification. I was planning on eventually doing some aero mods and modifying the rear tub area for a new splitter design. Would be nice to see more photos of what it looks when you start cutting stuff up. As with everything else Arizona does, I’m SUB’d lol

Will do! What do you mean by "modifying the rear tub area for a new splitter design"?

[ViperSRT]

Tell that to Porsche. They blow away the ACR at the 'Ring with a 500hp car with 58% rear weight bias.

And a lower polar moment of inertia for the Porsche. Big difference between axle weight distribution and polar inertia. Which is why mid engine layout provides the best performance when the mid layout has most of the weight between the axles.

[kriskyk]

Tell that to Porsche. They blow away the ACR at the 'Ring with a 500hp car with 58% rear weight bias.

Umm because DCT, 9000 RPMs and weight

[Arizona Vipers]

Umm because DCT, 9000 RPMs and weight

Are you saying mid/rear engine cars with rear weight bias have zero advantage on the track?

[kriskyk]

Are you saying mid/rear engine cars with rear weight bias have zero advantage on the track?

No, just that the Porsche results at the ring are a sum of the engineering and efforts and not just the rear weight bias

[Arizona Vipers]

No, just that the Porsche results at the ring are a sum of the engineering and efforts and not just the rear weight bias

Agreed. If you have tracked side by side with GT3's for years like I have, how fast the come off of slow corners is scary, they just walk away from you like you are standing still. Very depressing when they are in a slower class even.

[Back In Black]

My Gen 4 tank shell is around 20 lbs. A Comp Coupe cell with bladder is about 40lbs.

[Arizona Vipers]

My Gen 4 tank shell is around 20 lbs. A Comp Coupe cell with bladder is about 40lbs.

Well there's my answer, no fuel cell for me :smilielol:
How much does your car weigh no fuel?

[Back In Black]

Well there's my answer, no fuel cell for me :smilielol:
How much does your car weigh no fuel?

That's a large cell though. 26 gallons. I'm right at 3200 empty.

[Arizona Vipers]

That's a large cell though. 26 gallons. I'm right at 3200 empty.

aaah, ok. I'm going with just 10. really want 7, but looks like they don't make those FIA FT3

[RedTanRT/10]

My Gen 4 tank shell is around 20 lbs. A Comp Coupe cell with bladder is about 40lbs.

AZ, I do not know my cell weight it is from Fuel Safe. Keep in
Mind the CC and x cells are 100 liters, 26 gallons. Stock Viper is 15 gallon?

Look at the ATL site. They offer a Light Weight version, and a low as 5 gallons. The 8 gallon should work for what you do. I know it

[Arizona Vipers]

Ok, well I got my answer. Looks like I will be keeping the factory fuel tank. As with everything on these Gen 5's, it's extremely light:

Fuel tank 7.5 lbs
Pump cap .7 lbs
upper strap .3 lbs
Lower strap .4 lbs
Fuel filler tube .6 lbs
Fuel pump 3.9 lbs

[Arizona Vipers]

I wish it worked like this

Not doing it anyway, fuel cell will add too much weight unfortunately. All the FIA FT3 10 gallons are way heavier than 7.5 lbs

[ACR Steve]

Agree with what SRT said

You cant compare characteristics of a rear engine car like Porsche to a front engine car. The key is to keep your weight as close to 50/50 , as low as suspension geometry allows and between the axles preferably as close to center as possible . Dont move the fuel cell back

[Arizona Vipers]

Agree with what SRT said

You cant compare characteristics of a rear engine car like Porsche to a front engine car. The key is to keep your weight as close to 50/50 , as low as suspension geometry allows and between the axles preferably as close to center as possible . Dont move the fuel cell back

Dodge went through hell and back to get the Gen 5 to a rear weight bias, 49/51, so did AMG with the GTR 46/54, both are extremely fast track cars.

[Arizona Vipers]

Your already fast why are you thinking of big structural and weight distribution changes? Have you tried everything else already no change in lap times??

That's my hobby, making my car faster. Slowly just keep taking out weight. I'm leaving the factory fuel tank now though, can't find anything lighter. Car is about 2899 now with the cage. Want to get to 2799. For the record the fuel evap is 5.5 lbs alone!

[ViperGeorge]

That's my hobby, making my car faster. Slowly just keep taking out weight. I'm leaving the factory fuel tank now though, can't find anything lighter. Car is about 2899 now with the cage. Want to get to 2799. For the record the fuel evap is 5.5 lbs alone!

Wow, 2899!!! Maybe you could hire a racing horse jockey to drive the car. That might get you close to your goal. :lol2:

[catwood]

Wow, 2899!!! Maybe you could hire a racing horse jockey to drive the car. That might get you close to your goal. :lol2:

no...they weigh like 130#....he's shooting for zero

[ACR Steve]

"Dodge went through hell and back to get the Gen 5 to a rear weight bias, 49/51, "

That was so they could get as close to 50/50 as they can . By the way I show them at Weight Distribution (front / rear) (percentage) 49.6 / 50.4 thats basically 50/50 in my book


If you are in a power to weight class why not just add some power . Its a lot easier and safer then trying to get lighter then you are

[Arizona Vipers]

Easier to add more power than 803whp to lose weight? Please tell me how! Is there some secret shop I don't know about? How much can they get me? 900? 1000? I already lost 40 lbs this week alone, 2799 here we come.

[Arizona Vipers]

Coming from a crew chief and race engineer point of view. You always want less weight no matter what, "every o.z. counts". Less weight = less mass to move and less mass to slow down and the benefits down the line from less weight. More HP is a good thing if you can use it in your application. Road course racing more HP then you can use effectively will cause a multitude of problems. 3.6:1 ( approx) power to weight ratio, with lots of tire.....You got plenty on the table to work with

Yeah that's why those pesky Cup cars are so fast with just 500hp. When you're 2500 lbs, you're getting near prototype weight territory. It's hard to make a 3,000 lb car brake and corner like a 2500 lb car.

[Arizona Vipers]

little tweaks and some fine tuning and you will get those cup cars

Yeah that Cup Car that got me a few weeks ago, I beat him at Chuckwalla last weekend. Got him by over 2.5+ seconds both directions. I wasn't caught with old tires this time :D

[Arizona Vipers]

Moved battery inward and lower (Not a huge difference as the battery is an 8 lb Doug Shelby lithium, but every bit helps)

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[kriskyk]

Nice! Any chance you can share a zoomed out picture of the trunk?

[Arizona Vipers]

Nice! Any chance you can share a zoomed out picture of the trunk?

Here you go!

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[kriskyk]

That's phenomenal!

[Arizona Vipers]

Another 45 lbs gone!

42198

[ViperGeorge]

With all the stuff you've taken out what holds the car together?

[sadil]

Hey hey, don’t throw any of the parts out. Send over what you don’t want!

[Arizona Vipers]

With all the stuff you've taken out what holds the car together?

Roll cage and duct tape and super glue :smilielol:
What's funny is when people look at the car they think it's stock, not gutted. It looks 100% stock from the outside and when they peek in the full dash etc is still there.
For example, we cut out the rear tail light housings from the inside and used LED strip tape for the lights. So the tail lights still look and operate like 100% stock, but that saved 6.5 lbs alone, and that's at the extreme rear of the car. We have done countless sneaky things like this.

[serpent]

Az, have you gone to a carbon drive shaft? Also, is the rear hatch window heavy? I wonder if lexan will drop some weight too.

[Arizona Vipers]

Az, have you gone to a carbon drive shaft? Also, is the rear hatch window heavy? I wonder if lexan will drop some weight too.

The carbon shaft is heavier than the factory shaft. Custom titanium is an option, but we are talking $15K to save 2-3 pounds. The rear glass is paper thin, it probably weighs 4 lbs.