Anyone know where the increased fuel capacity came from the s5?
Straps are different so logically it seems from the depth. Anyone happen to have their s5 apart and can measure the depth of their tank?

 

Rob.I think I know where you are going here,so I hope you don't mind if I add into the thread.

I think another question too that could be asked is whether the Sender/pump units are the same height and can they be interchanged if you want say a S4 car with an s5 tank.(the connectors are different but can the S4 unit be used on the s5 tank for instance).

 

The S5 fuel/bulkhead is longer than the S4's, and won't interchange.
Sorry Rob, I have no tanks to measure, but I do remember the mismatch I ran into trying to swap the fuel pumps by just interchanging the assemblies and would say that depth is the biggest difference between the two series tanks.

 

Someone is possibly making new fuel pump hangers im sure the lids the same and the depth is different. Wasnt aware the connectors were different too. Ill search around later try to find some pictures.

 

I have a new S5 tank in my garage. I'll try to get some measurements this weekend.

 

great, and I have my s4 tank out of the car as well.

Thanks

 

the connector on the shock tower is the same, but the connector on the actual sender unit is different s4 and s5.

 

it looks like you re-use your stock sender, so people will be able to use their s5 or s4 sender, plug to the vehicle harness the same- sounds like it would work they would just need to compensate for fuel tank depth difference

 

I took photos in two locations. The first depth was about 10 5/8" and the second was right at 11". See the pics below. If you need anything more specific, just let me know.

First measurement:





Second measurement:

 

If you need measurements of a stock S5 fuel pump hanger, mine will be coming out in the next couple weeks, time permitting.

 

Geez, that is one clean looking gas tank.

 

Indeed it is. My use of the word new was no exaggeration. It will be installed in my car soon, along with a new pump and level sender.

 

I hope you only use period correct JDM fuel.

 

Absolutely. I will have it shipped in one 55 gallon drum at a time.

 

Thanks jerry, ill measure mine tomorrow if i pick it up from the radiator shop

 

I have an s5 expanded capacity in my s4. (did not even know they made them bigger until I went to hang it up). I can confirm that I am running the S4 sending unit from my Base in the S5 tank and thus far no issues under heave cornering etc.

I have pictures of the straps with a measuring tape somewhere.... if you need to see the difference.

 

If my fuzzy memory serves me right, the capacity increase in 1989 and 1990, then went back down in 1991.

 

'91 same 18.5.

Fuel Tank FC0242110A
Product Fitment/Applications
Mazda RX-7 1989, 1990, 1991, 1992

 

Im not so sure if you are running an stock s4 fuel pump in a s5 tank you can suck all the gas out? you ever run it empty and see how much to fill?


This was all in attempt to get CJ Motorsports to make us a fuel pump carrier like the FD unit they make. I cant find anyone with a car local to them or a fuel tank local to them. I am trying to purchase a cheap tank to send to them to fit.
Meanwhile I have all my bulkhead fittins and plumbing figured out for the stock carrier and even figured out how im going to run heavier wiring through the top of the pump carrier ( no im not running a wire and slobbering sealant all over it ) I found fuel safe cable glands. I would still have preferred to run a whole new unit like they sell. Worst case when its all up and running I can pull it out over the winter and cut a new lid and swap everything over