Convert from '98 metal tank to '99+ plastic tank?
 

Looking at weight reduction, I read that the plastic is 18lbs lighter. What parts are needed to convert from a '98 F-body metal tank to a '99+ F-Body plastic tank? Any cons vs the metal tank?

Cons are the exhaust can melt it. Ask me how i know.

Always such an ominous statement! Though you DID live to tell about it, so a happier ending than what could have been!

I caught it early enough

No doubt! lol The result being BOTH you and the car are around to tell about it. Scary, though!

Melting

Was that with the heat shields still in place or removed?

Removed for a 4 inch pipe.

Jim Mueller your car must be awful light if you are looking to swap gas tanks. I'm under 3000lbs and still have the metal tank. Along with all the factory metal in the back, besides lightweight bumper support...

Is it really 18lbs lighter? Hard to believe that

Just because you want the comfort of interior that would keep the weight higher than yours doesn't mean that he can't want to save it in other places.

I agree that there are perhaps other ways to reduce the weight other than converting from a metal gas tank to the plastic one.

Looking at the mods - replacing sways bars from solid to hollow front and rear sway bars is one way.
Lighter wheels is another - big difference between the weight of a set of Centerlines that I used to own compared to the the heavy ZR1 wheels that I drive on now.

That said, it's always easy to spend other people's money with suggestions.

I am fully aware that people have different goals and different tolerances on weight reduction and what they can live with and without. I was just checking with him to make sure he has already crossed off the easier and more effective weight reductions.

Swapping gas tanks is not the hardest job but it is time consuming and if you have to drop a tank out of the donor car that doubles the time. I really question that it will save 18lbs. Maybe it will but would need to see proof to believe it. I would hate for him to swap tanks and whatever else for the swap required and only lose 5lbs lol. I've done some weight reductions that didn't add up to what I thought I was going to save based on the weight reduction sticky. Just saying

A good example of adding weight after making a lot of weight reduction mods is the torque arm and brackets - there is a big difference in the weight of most tunnel mount ta's in comparison to the flimsy stock ta.

I added a UMI - K member to loose weight on the front end, but lost all of the gains by adding a ProCharger, piping, silicone connectors, and the very heavy FMIC (26 X 12 X 4). You don't want to drop it your toes :)

Added a strut tower brace - more weight.
Added subframe connectors - more weight
Add lower control arm brackets - more weight

Heck - in my case I think I've added more weight to the car than I have lost -especially on the front of the car.

Not to offend anyone - but there is weight reduction often overlooked. I weighed 235 four years ago. I now weigh 175 and am keeping it off. That's 60 lbs less with me in the car.

My gas gauge has been inaccurate since 2010 when we installed the Racetronix kit. My tech said that if I'm swapping a lot of suspension (details below), it would be convenient to drop the tank to clean it and troubleshoot the fuel level concern. I'm not convinced that the "18lb" number is accurate either, but users on FRRAX (F-body road racing forum) commented the following, and if I'm already in there, it seems like a good time to consider the swap if I can have all the parts handy.

* "Big advantage to the plastic one is that you can run them empty on fuel and they won't starve, whereas my steel one starved at just under half a tank. That right there is a ~45lb advantage. Seeing as I run a full tank currently to avoid that issue it would make more like a 65-70lb advantage."
* "The plastic tanks are worth the swap just because of fuel starvation issues. I’ve literally run my car to empty out on the track. I wasn’t paying attention and forgot to refuel and the damn thing never sputtered once until it was completely empty. "

The mod list is seeing significant changes in the next few months. Converting to Penske DA coilovers (saving ~11lbs per front corner and ~14lbs per rear corner), F14 wheels (saving ~3lbs per wheel), hollow sway bars (~15lbs front, ~5lbs rear). Not going to an aftermarket k-member because there isn't one qualified for HPDE duty which includes a skid plate, but I might look into UMI front A-arms. Also converting from rear steel tubular LCA's to tubular aluminum, saving about 3.5lbs. I'm also planning to switch to a lighter clutch which will hopefully save another ~15lbs. I know the hood is heavy but I don't want pin-ons, and I don't like seeing the fiberglass/CF pattern underneath paint...unless that can be overcome? Don't want to switch to a lightweight battery or relocate it to the rear since it's a daily driver, or switch to a lightweight bumper support, lose the air bags or lose the door bars for the same reason.

Yeah, I've lost about 25lbs in the last 7 weeks, hoping I can stay on the train. :)

No suspension has to be dropped/removed to remove a gas tank. Only need the exhaust and their heat shields out of the way. :eyes: I pulled one just a week ago so.......

https://ls1tech.com/forums/fueling-i...-write-up.html

Here's a link to a guy who did the swap.

That link says it's the same weight with more capacity. If you put a Holley Hydromat in the current one you could get a way with running the tank lower on gas without issue. Here is the scale of the sending unit from my tune, it is 40-240ohms.

https://cimg5.ibsrv.net/gimg/ls1tech...e08a121fe7.jpg

The light weight battery isn't really that bad for a daily driver. The lithium battery has less capacity, so if you drive it every day the only way it's an issue is if you leave the lights on or if you need to set in the car charging your laptop while using it for long periods. I have a plan to reduce the price of those batteries and still work great. The motorcycle batteries don't cost that much at all, but will die in about a year starting the motor. So, if you get 6 Dell cell sized 350-400mF super capacitors and run them together it should be good to go. The capacitors can start the car alone as they put out current way better than a battery, but can only set for so long before they will need a charge which the motorcycle battery will provide. This would save about 25 to 30 pounds for $350-$400.

I think starting capacitors are going to be the real (AKA main)deal sooner than you expect.

Do our cars have a low gas light?

The already are and I'm shocked a battery company doesn't already sell this hybrid idea.

It won't hurt, so I'll call battery tender and see if they will make one so we can just by it and bolt it in.