Technical Seicent SPI injectors

[Sporty_5_Seicento]

Hi guys/girls

Right, have been reading through a few posts on here but cant quite make out what I need to do. I've read that once the SPI sei reaches near 80bhp it can no longer provide the fuel needed to increase the bhp further? Mods i am currently running on my sei spi engine are as follows:

- Complete supersprint manifold, centre and rear sections.
- 1mm skimmed from head and ported on both inlet and exhaust to 31mm circular on exhaust to match supersprint and cant member on inlet side but matched to inlet manifold.
- Flowed inlet manifold.
- Metal 0.44mm head gasket combined with head skim taking cr to 12:1
(loves shell optimax)
- 4.5Kg lightweight flywheel (skimmed as far to outside as possible to reduce turning affect)
- Punto 75 (866) cams
- 40mm tb
- Gsr Induction
- May possibly fit vernier pulley an correct the valve timing on the rr day too.

When you get to high revs 4500 - 7100 the engine seems to sream a bit as though more feul is required. Im going to possibly get it remmaped and rr'ed on the 3rd of Feb but would like to sort this out first to give the best results? Can someone point me in the right direction as to possible injectors I would need and other parts to allow more fuel into the system.

Many Thanks
Matthew

 

[Brooky]

- Punto 75 (866) cams

You'll only have one.

I you wont need to uprate the injector yet,trust me

Altho mine aint running that higher cr, its always been fine for fuel,plugs always come out looking perfect and with the occasional flames out of me exhaust...well that tells me theres plenty of fuel

 

[Brooky]

and there are no known replacement injectors that have a higher flow rate

 

[fingers99]

At least do a plug chop on it before going further/worrying. Use new plugs! IIRC, the fuel pressure on the Spi is adjustable, but that really needs to be done on the RR with a wide range lambda (at least) available.

 

[randomizered]

The Cinq/Sei spi injector is a Magneti Marelli part number 213170623605.

The Fiat Seicento Workshop manual states the following specification:

Static Capacity: 465cm3/min
Dynamic Capacity: 103 cm3/min

Winding resistance: 1.75 ohm +- 5% @ 20 degrees celcius

cm3/min is the same as cc/min

Using the calculator here: http://www.megamanual.com/v22manual/minj.htm

54bhp requires 334cc/min.....the stock spi injector won't be driven at 100% PWM though, it will have a lot of head room.

Driving at 100% the injector should be capable of 75 bhp maximum, although i have heard others say its capable of more.

Anyways....all you need to do is find a low resistance injector with a flow greater than the standard one in the same package, and all should be ok. I'm sure there are some out there

Do you have a picture of the spi injector? Is it like the sei manual shows? a bottom fed injector?



Kristian