Technical Sei MPI throttle body enlargment - a guide/idea ;)

[randomizered]

Right, I've been messing around a lot recently with throttle bodies

I have 1368cc, 1242 16c, rover 48mm, 1008cc MPI.

I was just playing and have seen a fantastic potential upgrade for any mpi seicento owner. It's not a bolt on, but simple

The mpi sei inlet (may fit 75 head) has a metal TB bolted onto a plastic manifold.




Stock mpi butterfly (most restrictive part) is 35/36mm.

Inlet (in plastic) underneath this is 40-42mm.

A 1.2 16v metal throttle body (cheap and readily available) has a 42mm butterfly!

All the sensors are the same and all compatible with the 1.1 8v ECU...just plug and play I know as i did this with my sei ecu and 16v conversion.

The bolt pattern is NOT the same, but all you need to do is get some plastic or metal, drill a 42mm hole, drill holes right through to bolt this to the plastic manifold, and drill new holes to bolt the new TB to the plate.

No tapering of the metal etc needed, so anyone with a drill and file could do it

Here is a comparison of the two:




The opening of the 1.2 16v is 70mm, so i don't know it the stck airbox would fit, but its perfect for induction :slayer:




Just thought i'd post this up in case anyone fancies a bash ... I'd have already done it if i has a standard mpi sei, and i have all the parts needed lying about


Any comments?

Reckon Ronnie should give it a bash

Kristian

 

[fingers99]

Nice!

Any idea what TB the Punto 90 uses? That might be easier to sort out (going on a 75 inlet manifold on Blue) than the K series (and it would mean I don't have to identify and chase down K series sensors).

 

[Rosso83]

Looks good... any down sides from fitting the larger?

 

[randomizered]

If you go overly large, you get a slow air speed and can loose power.

This size change is not huge though, and matches the intake manifold, so i'd imagine it will give a nice little boost

Downside is stock airbox no longer fits (at least i don't think it will), and you have to make a sandwich plate, but other than that should be a cheap mod.

Look at the tricker throttle body rebores for the spi, similar thing really, but your just fitting a whole new body.

Kristian

 

[NUGGY]

i have fitted a 1242 16 valve TB to my 1242 punto 75 engine that's fitted to my sei sporting, i had a spacer plate made with 2 holes drilled straight through, this was bolted on to the existing spacer with counter sunk bolts (after the studs were removed) it then had 3 holes drilled and tapped to bolt the throttle body onto, the throttle cable mount was altered to fit and a sillicon hose with a 90 degree bend in was then connected to an enclosed filter induction kit, the car seems to pull better and has more top end (i've had the speedo off the clock)

 

[ronnieronson]

Reckon Ronnie should give it a bash

Kristian

 

[cojones]

If you wanna try that out on a stock 1.1MPI I offer myself, don't live too far away from you

 

[cc1]

I think feel a molestation of my 16v punto engine coming on.

 

[Steffen Jensen]

how about putting af 75er on your engine??
I have this in spare...

43mm throttle, new and made my Tricker from Denmark.

 

[arc]

the P75 manifold is crap though.

 

[Brooky]

how about four butterflies:slayer::slayer::slayer:

Look away now fingers99

 

[fingers99]

As art, it does it for me.

 

[allanhelen]

and as automotive porn that does it for me too :yum:

 

[+Speed++freak++]

Looks interesting project...wonder what kind of power gains you get after :yum:

 

[JAMES_89]

Presumably this would work on a mk2 punto 1.2 8v aswell. sounds like a good upgrade if it will because the tb atm is pretty small.

 

[fingers99]

I'll email tricker, see how big a 1.2 16v tb will go.

 

[afragmachine]

I think i understand how this concept is working but i've got a little questions. I have a seicento mpi with a supersprint outlet manifold, metalcat a custom made exhaust system, airbox and it has been chiptuned. Will this chiptuning give any problems when i'll fit a diverent inlet manifold and on what car is this manifold originalie fitted?

 

[warrior]

Sorry to re open a old post but

Did this work???

 

[randomizered]

I know at least one person has done it

 

[warrior]

all im worried about is the sensors the making of it is nt the problem