Technical 38mm TB is too small for my engine

[StoneNewt]

I don't think this is a throttle body problem. I've got a 47.5mm TB mounted on a modified P75 manifold. While on the rolling road holding the engine to a certain rpm to populate the load points it was noticed from around 4500 rpm up at WOT we were getting manifold vac that stabilised after a second or so.

 

[gazzaman2k]

is that a 43mm tricker TB? how much did it cost, and can i borrow it?

i traded 3 spi throttle bodies and some cash for it from tricker himself

id let you borrow it but its plumbled into my car now hence the pms yourve been receiveing lol, if i take it off ill loose my coolant

 

[arc]

I don't think this is a throttle body problem. I've got a 47.5mm TB mounted on a modified P75 manifold. While on the rolling road holding the engine to a certain rpm to populate the load points it was noticed from around 4500 rpm up at WOT we were getting manifold vac that stabilised after a second or so.

pants.. so it looks like a manifold design issue. BUT i still could do with a bigger TB. What is your TB from, and how is it mounted? How come you're never on MSN anymore?

i traded 3 spi throttle bodies and some cash for it from tricker himself

id let you borrow it but its plumbled into my car now hence the pms yourve been receiveing lol, if i take it off ill loose my coolant

oh yeah. doh. nevermind!

 

[bean]

is the 43mm tb just for mpi's?

nath

 

[StoneNewt]

pants.. so it looks like a manifold design issue. BUT i still could do with a bigger TB. What is your TB from, and how is it mounted? How come you're never on MSN anymore?

Not sure where my TB came from, it was a gift from my partner and a few friends. It was modified to use the standard fiat sensors/ICV. It uses an adaptor plate similar to the one J333EVO uses on his 1.4 16v.

To mount it the manifold had to be reamed out & also remember messing about with the original mountings to secure the spacer/adaptor as they didn't fit the new arrangement.

I've not been on MSN because now I'm fit I don't spend nearly as much time on the computer as I did before.

 

[TOZEVE]

Hi, I have a 1.1 SPI Cinquecento with a 38mm trottle body and the RPM is floting from 1000 to 1500.
I have just used the lower part from a Punto 75 trottle body.

Does any one soved or had this problem?

I tried the 42mm and the 38mm they have the same problem, floting from 1000 to 1500RPM at idle.

 

[fingers99]

It's nothing to do with the throttle body itself. Either an air leak or the Idle Air Control is dirty.