Hi everyone

I've been reading everyday about how people build their car or make custom parts , lots of them (or us) dedicate important amount of personal time to develop pieces of art that are proven to be better for our vehicle.

When the product succeed and pass the "forum test" it's usually being commercialize.

I'm no engineer , nor a fuel specialist
Simply another Fd guy trying to figure out something..

In 1995 Mazda made the Rx-7 SP for the Eastern Creek event
The car came with some major update (weight saving parts) Ex; Recaro Seats or CF intake box etc etc
But one of the most interesting part that I found was
The Carbon Fiber 110L Fuel Tank.

Being a major upgrade compare to any FD or FD3S (76L)
Why no one didn't attempts to make a replica of it ?
Is there any good reason no one has tried it ?
Wouldn't it be an attractive option to lots of us?

With all the wishes to make a better FD/FD3S world
and push an Artist to work :P

Any information/inputs are welcome.

 

The reasons I wouldn't personally have one on my car is because I find that the FD is quite sensitive to weight. I remember I had my car tuned to about 350whp and I had a 250lbs friend and I did a pull and it felt like a stock FD. I know that's on the extreme side, but the extra weight in fuel wouldn't mean much to me.

The second reason I wouldn't personally, is because I would cry every time I had to fill up at the pump (more than I do already).

Believe me when I say this, but I've certainly thought of doing this modification as it would make my highway driving more relaxed when I'm driving through the province with a gas station too far apart from each other, but it's not that high of a priority for me.

 

Well, I have never wished for a bigger fuel tank in the FD, but I do auto-x/solo sprint races not endurance racing.

I would rather have a smaller tank so I can run less fuel with less slosh.

I would be very interested if someone designed a fuel cell that fit in the rear seat/rear bin area of the FD to centralize the mass of the fuel tank for better handling (like the RX-8).

I wouldn't mind if the fill was accessed by opening the passenger door and sliding the seat forward.

I wouldn't mind if it had a carbon fiber cover *bling*.

If someone built this relocated fuel cell, you could run both the standard tank and the relocated tank to meet your fuel capacity requirements.

 

Here is a pic of the RX-7 SP race car fuel filler.

RX-7 SP road cars probably used the standard fill since the SP CF tank itself appears to fit in the stock location without intruding into the hatch.



SMB exhausts in Australia (who made the SP exhaust) might know where you can get an SP tank made from the original molds- they still have this note on their website regarding the CF intake/intercooler pieces.


Note:

Dyno shows figures from Mazda RX-7 fitted with SPcomponetry ( intercooler, carbon fibre duct work, exhaust, and chip). We can supply all the components.

 

No need for a replica, I doubt he visits anymore, but Carbon Man on here is the bloke who originally made the SP tanks...and he still does - if you have the dosh. They're very handy for longer events so you're not pitting every 30 minutes. He also did an earlier stock carbon lined version for Bathurst, made from 2 fuel tanks.

The motorsport tank does still have provision for conventional fill, the dry-breaks were simply bonded onto the top. Big difference v the street version, it has 4 compartments plus ball valves linking them all to the fuel pump well. The street versions occasionally come up for sale 2nd hand, sold a couple over here myself.

 

L-Spec ; lol I admit that having a 200+ pounds passenger
makes a different

Fuelling up here is not that bad at 68c/L
The bad thing...it's winter for the next 4months

Mathematically speaking 36L of Fuel would approximately
weight 57pound , witch is not that bad
Even thought taken out 60pounds of our cars seems harder to do.

Racing speaking (endurance) where every lap
And every moment spend at the pit stop is crucial
It's logic that a 110L tank would mean more time on the track/less at the pit stop

BlueTII:
Having a bigger tank wouldn't aloud to run more time on track without fuel surge?
as It usually occur a 5/8 of the 76L stock tank
5/8 of the 110L tank would mathematically be more
(In theory that fuel surge occur at the same time)

Wouldn't the bigger fuel tank bring more option to install
an in-tank FST(fuel surge tank) ?

I do agree with you on the weight balancing about fuel cell that would fit in the rear (didn't some one did that already?)

And also agree money wise that CF tank would probably cost a pretty penny over other type of material

I'm looking at the option in America
I did in fact find who was responsible for making the parts for the Rx7 SP
A gentleman name; Ian Pollard
witch as a company name Pollard Product Pty Ltd
Referring to his website still makes SP parts...
I don't see the tank but I assume would be able to
make one...for another pretty penny...

I'm simply interested in people's opinion in why or why not
The 110L tank is an good/bad upgrade

 

Does anyone have a pic of the tank? I am assuming it is just deeper.

I dont think it would be to hard to extend the stock tank by cutting it in half and welding in a strip of steel a couple inches wide to make the thank larger. Then just need to extend the fuel pickup and fab something to lower the tank straps.

 

There is an extra inspection port on the rhs of the tank. I'm pretty sure carbon man did have a pic with all the bits together in the dim dark distant past.

Tank depth was extended by 55mm, going by the spacers required on the straps, but yeah, people have increased the capacity of stock tanks. One thing requiring care is the use of floor jacks at the rear!

Here's a few pics of the top of a tank that crashed in the 12hr after a couple of decades storage, showing a few loose ball valves and dry breaks -

 

how much these go for?

 

the tank cost @ 10k

 

The "street" one I thought was around $AUD4.5, wouldn't have thought the extra baffling would, add 5.5 more?

Best to contact Ian if you were interested, last contact I had for him was ppollard at bigpond dot net dot au, his website seems down this morning.

Can report it seems E85 safe.