Mazda Miata + Opel Ascona = Asconiata?

Regarding fuel supply:

Gravity feed to an external pump will work fine. I'd go with AN10 if possible for your feed to the pump.

Based on the tank design, a swirl pot/surge tank would be a great idea. Since the tank is wide and relatively flat, anything around a quarter tank of fuel or less will be prone to fuel starvation. A small surge tank with a pre-pump would alieviate any concers. The pre-pump could be located in the surge tank (submerged) or you could feed the surge tank with an electric carburator pump.

For your throttle cable, I'd hit the junkyard first with a rough end-to-end length in mind. Failing there, maybe a bike shop could swage some lead cable ends on where you need them?

Motorcycle shops can hook you up with custom cables.

An AN6 line will feed 400+ hp at EFI pressures. It'll be big enough. Running AN10 to the pump is a little extreme, but it's not going to do any harm. The suction line on the Miata tank is something like 5/16", which is an AN5 equivalent. Personally, I'd cut open the top of the tank and submerge a pump inside. Quieter.

One way to avoid starvation problems is to plumb the return line so it drops into a little sump in the tank. You can put that sump in when you drop in the submerged pump.

A factory wiring diagram will make your life much easier. Your black/black/blue/white combo sounds like a four-wire O2 sensor. The blue/yellow is indeed the PS load sensor.

I would rather keep the car above 1/4 tank than all the cutting that seems required of a surge tank. I rarely drive below that line anyways since I don’t really trust the sending unit all that much.

besides I can always add that later, I’ve got enough fabrication on my plate as is LOL

Fo the throttle cable I now gotta hunt down a shop willing to make a custom cable. I plan on going to the yard tomorrow, hopefully I can find something that’ll work with minimal effort

External surge tanks don't require any cutting. You use a low pressure pump to feed the surge tank (with a return) and the surge tank feeds the high pressure pump.

I'd start by looking for MX5 cables if you can find one. You know it'll fit the throttle body!

In reply to Keith Tanner :

thanks to the comments you and mezzanine made i looked up the fuel surge tanks and watched this video from reat st performance. the guy went over several different types of fuel delivery set ups and the noise of an external pump isnt what im going after.

im googling universal internal fuel pump options now, if you know an easy button im all ears lol. would it be an issue if i just grabbed a generic internal fuel pump from a car at the junkyard and modified the housings to potentially fit my car?

What about a return style crown vic fuel pump? speaking of, before i send someone back home to grab this for me... is the ring on the fuel tank removable? i think the pump will work fine in my tank, considering both stand upright

also, found a throttle cable on ebay-k for 5 euro + ship. messaged seller to buy it lol.

so, for better or worse, i bought the pump. ill end up capping the OG fuel dump on the tank and cutting a hole to fit the new one. my challenge will be getting the pump to seal against the tank, current plan is to bend any of the curves out with a hammer and 2x4. beyond that ill just cut all of the extraneous wires out and try out my riv-nut idea

it seemed like a good idea and a decent multiple birds one stone situation. its a fuel pump that'll fit inside because both the ascona and vic have vertical tanks, a return style fitting already attached and a high pressure fuel pump. what could go wrong?

Looks like a good option as long as it fits and you can seal it. Fuel is tough to seal, it gets through almost everywhere.

In reply to Keith Tanner :

even copious amounts of silicone?

Any particular reason why you don't want to use the sending unit from a factory fuel injected Ascona? The Manta and Ascona A in the US were all fuel injected for 75, and the B models were in Europe. 

In reply to oldopelguy :

ill be honest, i didnt even think about it. every classic opel out here ive laid eyes on has been carburetted so i figured they would all be low pressure, mechanical or electrical conversion kits. lesson learned, that said as far as pro vs cons...

Pro Vic Pump

1. Part availability in the States will be super easy/cheap
2. No need to fab a return spigot
3. Internal Pump for Noise
4. Has that weird sock thing at the bottom to lessen the fuel starvation
5. Potential to look bitchin'

Con Vic Pump

1. Part availability in Europe sucks 
2. Fabing up a plate and sealing the thing will be a decent amount of work

Pro Opel Pump

1. Part availability in Europe is decent
2. Easy install
3.  Less fab for fuel return spigot
4. OEM look maintained
5. Interchangeability for aftermarket fuel pumps is probably pretty good

Con Opel Pump

1.  Part availability in the States is unknown, doubtful Autozone carries them
2. External, noise may be an issue depending on whats bought
3. Fuel starvation more likely to be a thing?

At the moment, I think ill stick with the Vic pump since its already purchased. If i change my mind later, ill likely jump on the idea you brought up 

TurboFocus said:

In reply to Keith Tanner :

even copious amounts of silicone?

Particularly not silicone, as gasoline will dissolve it. You'll need a gasoline-rated sealant.

In reply to Keith Tanner :

ah, thanks! ill get something like this then

would y'all recommend that i try and adapt the car to be hydraulic clutch or adapt the throwout bearing fork thing to be cable operated?

The Miata clutch pedal is a standalone unit that should be relatively easy to bolt in, I'd be tempted to do that. It's easier than trying to make a high-load cable work and it'll be super-easy to live with afterwards.