Duratec Fuel Pump

[BruceBe]

For those of you running external regulators, are they vacuum-referenced? In most setups I've seen, the vacuum port is just left open to atmosphere.

Leave it open to atmosphere.

[BruceBe]

Current Caterham fuel systems are electronically regulated. The large sender assembly in new tanks anticipates the presence of the regulator module. We would need to do a bit of digging, but it's possible that the pre-2015 sender (still large diameter) would utilize a standard external regulator, thus allowing you to use one of the newer large-sender tanks. CSR and older Caterham sender configurations are problematic, as the sender unit is unobtainium. If you had an older standard tank, we could provide an uprated pump for that, which would basically just install into the sender.

-Bruce

[dallasdude]

Leave it open to atmosphere.

If you are running ITB's you don't have much choice since you don't have much of a vacuum source. If you have a throttle body, hook it up to intake vacuum, it will reduce fuel pressure slightly at idle and make injector sizing less of an issue. You can be a little large and still have some latitude at idle.

[Ferrino]

Thanks all. I've decided to go with the "early/pre-2015" Sigma/Duratec setup that Caterham uses and appears to have served them well. This employs a Ford fuel pump & sender combo, which is internally regulated (not electronically, like the later design) and return-less. I will then use the OEM return-less Ford fuel rail to suit.

[BruceBe]

If you are running ITB's you don't have much choice since you don't have much of a vacuum source. If you have a throttle body, hook it up to intake vacuum, it will reduce fuel pressure slightly at idle and make injector sizing less of an issue. You can be a little large and still have some latitude at idle.

Careful with that, especially with track cars. If you don't have full control over the engine management, and are over-fueling through larger injectors and/or elevated fuel pressure, do the homework and instrumented testing (e.g. wide-band) before scaling fuel pressure. We've seen failures associated with the accumulation of momentary lean conditions during tip-in/tip-out, and part throttle (higher vacuum).

FWIW,
-Bruce

[Lucky-7]

Hi, I recently finished building my 2018 280S so I checked the parts lists. According to my list, the fuel pump for both the Sigma and Duratec are the same. Stock Code # 36T004A Bin # OD1 that's how it's shown on my parts list, if it's not the actual number I'm sure someone at Caterham can get it for you.

Hope this helps.

[BruceBe]

As a Caterham dealer, we can source the assembly. Ferrino is on the right track.

-Bruce