This may be a first but is it possible to convert my mpi seicento to spi? If so what parts do I need exactly?

I want to do this for the purpose of running a P75 inlet manifold as the sei inlet isn't really big enough, flow well enough or even fit exactly as it should.

I know the spi loom is good for the engine and the same for the ecu, I'm not worried about that. I'm interested in the car side of things...

From what I know so far I'm assuming I will need:

- SPI loom for the whole car
- ECU
- Codebox
- Key
- Speedo clocks + cable
- Rev counter to match (Not neccasary)
- SPI Radiator + fan?

Is there anything else I've missed? Is this even possible?

I doubt if the MPI mani is actually any worse than the P75. The P75 is MPI anyway.

So, you've got me puzzled.

Remember, if you don't change either the engine or the car, you have to meet MPI emissions. You can't do that with an SPI ECU.

fingers99 said:

I doubt if the MPI mani is actually any worse than the P75. The P75 is MPI anyway.

So, you've got me puzzled.

Remember, if you don't change either the engine or the car, you have to meet MPI emissions. You can't do that with an SPI ECU.

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I have some plans to swap things about a bit, emissions aren't a worry at the moment either.

A P75 inlet will fit properly, a plastic mpi one does not. It sits too high but does seal.

A ported and port matched P75 inlet that sits in the right position is a much better prospect... An SPI ecu and wiring is whats required to make it run the P75 inlet

Wouldn't a DET 3 be a better solution than to swapping to spi stuff I think there's even a wiring diagram on their website

Don't do this!You will never have the benefits of the MPI.I told you,i'm running the Punto 75 engine with Sei Mpi inlet and knock sensor.We found out the way to make the Sei Mpi Inlet Manifold to PERFECTLY seal up to the Punto 75 head.I can help you solve everything.Send me a PM and give me your facebook account or your skype so that i can tell you exactly what to do.The Sei inlet with the 40mm TB provides you ENOUGH air,don't go back to SPI technology....TRUST me!

P.s.

Guys,someone please tell me HOW to upload photos of my conversion.I don't want the approval stuff ,i just have my photos and i want to add them on my post...how can i do this?

The 75 manifold has the 4 injectors so are you thinking of running them from spi setup? What cylinder head do you have?

cc1 said:

The 75 manifold has the 4 injector holes so you must be thinking the 60 one?

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It's a P75 inlet with 4 injectors, I'm just doubting that a Sei mpi inlet with fit a ported 75 head, seal up and give anywhere near the power of a port matched P75 inlet on a ported 75 head.

However it may be the only real option since switching to spi is a huge hassle and quite a bit of spending to get all the parts required. That and I will lose my beloved OBD2 port.

Staying MPI is looking to be the only option....

The 75 manifold won't fit properly due to the servo take-off. The Palio one is better. TBH, I compared the plastic Seicento and metal Palio ones and they are pretty much the same size port wise. Even the GP Punto 1.4 manifold was the same, though it runs about a 44mm TB.
Changing the inlet manifold from plastic to the old type is a major hassle with all the pipes, wiring etc. I have the same problem with the GP engine in mine. Very big ports and slim valve stems. I bet the vacuum is more than a Dyson?

cc1 said:

The 75 manifold won't fit properly due to the servo take-off. The Palio one is better. TBH, I compared the plastic Seicento and metal Palio ones and they are pretty much the same size port wise. Even the GP Punto 1.4 manifold was the same, though it runs about a 44mm TB.

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I think I may have already asked you this but will a GP Punto inlet fit a 75 head and benefit from a larger TB or does the seicento look like it will flow better?

Anyway it seems I have a solution now thanks to Bimmermeister :slayer:

Cento186 said:

I think I may have already asked you this but will a GP Punto inlet fit a 75 head and benefit from a larger TB or does the seicento look like it will flow better?

Anyway it seems I have a solution now thanks to Bimmermeister :slayer:

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GP manifold is too big to fit. The Seicento one has short ducts but restricted on TB size to 39mm with out modification. The 75 TB is 38mm as opposed to the Seicento 36mm but the 866 Cam helps to boost intake time.

cc1 said:

GP manifold is too big to fit. The Seicento one has short ducts but restricted on TB size to 39mm with out modification. The 75 TB is 38mm as opposed to the Seicento 36mm but the 866 Cam helps to boost intake time.

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I shall certainly be staying with the seicento plastic mpi inlet then! I will get it bored out to 40mm so it matches my TB.

Of course, the other issue of fitting the P75 inlet mani (and presumably the Palio one) is that the injectors are a different impedence and longer than the Pico ones of the MPI (which could be gotten around by using more modern Bosch ones). Still, you can't easily run the modern ones on an SPI ECU.

fingers99 said:

Of course, the other issue of fitting the P75 inlet mani (and presumably the Palio one) is that the injectors are a different impedence and longer than the Pico ones of the MPI (which could be gotten around by using more modern Bosch ones). Still, you can't easily run the modern ones on an SPI ECU.

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The 8v Mpi cars are still in need of a definitive answer to the best off the shelf setup but a 40mm TB will provide the potential at least.

Bimmermeister said:

Don't do this!You will never have the benefits of the MPI.I told you,i'm running the Punto 75 engine with Sei Mpi inlet and knock sensor.We found out the way to make the Sei Mpi Inlet Manifold to PERFECTLY seal up to the Punto 75 head.I can help you solve everything.Send me a PM and give me your facebook account or your skype so that i can tell you exactly what to do.The Sei inlet with the 40mm TB provides you ENOUGH air,don't go back to SPI technology....TRUST me!

P.s.

Guys,someone please tell me HOW to upload photos of my conversion.I don't want the approval stuff ,i just have my photos and i want to add them on my post...how can i do this?

Click to expand...

Any particular reason why you can't just post how here for people in the future having the same problem, being that a search will no doubt now bring up this thread with all the mention of spi and mpi and p75 etc.... That afterall is the exact point of the forum, to share knowledge.

blu73 said:

Any particular reason why you can't just post how here for people in the future having the same problem, being that a search will no doubt now bring up this thread with all the mention of spi and mpi and p75 etc.... That afterall is the exact point of the forum, to share knowledge.

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Don't worry guys,i just wanted to have a live conversation with im in order to help better.I will write exactly what it need to be done.and i will open up a new Seicento Project Topic,because i have changed some more things on my car.!

Bimmermeister said:

Don't worry guys,i just wanted to have a live conversation with im in order to help better.I will write exactly what it need to be done.and i will open up a new Seicento Project Topic,because i have changed some more things on my car.!

Click to expand...

Good stuff.