Technical qucik tb question

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Technical qucik tb question

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quick tb question

will a tb of a mk 1 punto 1.2 16v be a straight swap for my seicento? it looks exactly the same where you bolt it on. thanks
 
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Re: quick tb question

No. The pattern is the same (3 bolts and etc.) but the 16v one is larger in all dimensions. One approach might be to take a saw to the 16v inlet manifold and bond the bit where it fits to the 8v MPI inlet mani.

But, to take full advantage of the bigger TB, my guess is that the ECU would need a remap.
 
If i'm honest a bigger Throttlebody is pointless unless your swapping for a 1.2 8V, even then the biggest I would go is 36mm to retain some acceleration.

Anything bigger starts to cause issues with throttle bogging and low down power begins to dissipate. In other words you lose the ability to accelerate away quicker.

However, if your boosting IE. turbo, then 40mm is the way to go.

Also proven with the 1.6 throttlebody on the 1.2 16v conversion. Hit the throttle and you had nothing up to around 3500rpm. No good if you need to accelerate in a hurry.

Thanks

X
 
I still think it might work with a remap.

With carbs the story is always that you loose if you go too large -- you'll tend to loose out on pick up and bottom end, because carbs work with vacuum signal (and on more sophisticated carbs, an accelerator pump to help out when the signal is weak) and nothing more.

People are getting away with absurdly large ITBs on Zetecs (54mm!) without ill effects but to gain you need porting, valves, exhaust mani, cam to suit and a custom map. Somewhere in PPC Dave Walker does a write up (and looses a bet that the 54mm ITBs would be too big.)

The 16v 1.4 FIRE engines seem fine with a single 48mm Dell'Orto (ex K series) but I think J333EVO is running a slightly larger Ford TB. These are all with stock internals, but better exhaust manis and aftermarket ECUs (= remap).

It's strange that the SPI cars react so well to a 40mm TB, but they do!

Without a remap and a better exhaust mani I doubt you'd see much, although the P75, IIRC, uses a 38mm TB. (Exhaust mani is certainly better than the later MPI cars, although I suspect that the inlet mani isn't quite as good.)
 
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