Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[export001]

on my vectra i have a courtenay sport enlarged tb from original 64mm to enlarged 69mm
can you get enlarged omega throttle bodies? i know there 54mm each is there room for these be enlarged or are the walls to thin?
has anyone done any mods with the omega inlet set up? i.e. port and polished it? enlarged the lower divider or are they best left alone?
many thanks
phil

[HockeyDave55]

I've also done this of another car and had great results 
I think it might be a case of making a jig, put it in a 4jaw and go for it..... Just make sure you have a backup!!!

[export001]

so it is possible to enlarge the tb's?? but by how much? how much gain did you get?

[RobG]

http://www.omegaowners.com/forum/index.php?topic=90624.0

[export001]

thank you i did use the search function but i didnt see that one

[Nick W]

I've also done this of another car and had great results 
I think it might be a case of making a jig, put it in a 4jaw and go for it..... Just make sure you have a backup!!!

Enlarging the hole is, as you say, that simple.
But, you do have to make a new butterfly, that fits the hole and the spindle, that also opens and closes reliably.
That is not as simple, and does require good engineering skills.
Plus, just how much are you going to gain just from an enlarged throtle body, especially when you consider the power that an LS1 75mm throttle body can provide.

[HockeyDave55]

I've also done this of another car and had great results 
I think it might be a case of making a jig, put it in a 4jaw and go for it..... Just make sure you have a backup!!!

Enlarging the hole is, as you say, that simple.
But, you do have to make a new butterfly, that fits the hole and the spindle, that also opens and closes reliably.
That is not as simple, and does require good engineering skills.
Plus, just how much are you going to gain just from an enlarged throtle body, especially when you consider the power that an LS1 75mm throttle body can provide.

Ok... With the car (not an Omega) I did a few years ago, iirc, it went from 58 to 65mm??? Before braking into the water jacket....
The butterflies also need a jig with an angled face where a piece of brass plate will be bolted using the same size and pitch fixings as used on the OE butterfly.
Then you can turn down the brass plate to the required OD....
It is easy but does require appropriate engineering skills.
If you don't have the skills, this is a very simple job for an engineering workshop to carry out given the correct dimensions.
As far as what you get from it, I couldn't say for this engine as I've not done one... YET....
All I know is the on the one I did, I saw a small increase (subjectively) in power and low down torque but more-over, it was much more responsive and a little better on fuel....

[HockeyDave55]

Then after doing the TB, you will also need to match the plenum to the TB bore....

[HockeyDave55]

http://www.omegaowners.com/forum/index.php?topic=90624.0

Having looked at this link, Thanks Rob I'm not about to put money you'd have much room to play, you might be able to ditch the o-rings, machine out and see how far you dare to go and fit a paper gasket??? Maybe???

[tigers_gonads]

I've noticed on some of these chaved up engines that most of the pipework has been replaced with smooth silicon pipeing of various colours.
Has anybody on here ever ripped out all the black plastic crap from the bagpipes and replaced it with this silicon stuff ?

Imo, its not so much the size of the throttle body.  Its more a case of getting the air to flow threw the bagpipe section more smoothly and with less turbulance.
If you could incorperate this with a mildly polished throttle body, I would say you would get some improvement in throttle responce 

[HockeyDave55]

I agree, a good polishing would go a long way, as would a complete clean up/de-coke of everything from the TB to the valves but I am lead to believe the "bag pipes" are crucial to how the engine runs.... Remove that and you take steps back.... I think if anyone wants to cuck a load of silicon, it would be for form over function, IMHO....

As for performance gains, I'm not sure??? Maybe another OOF member has done it??? Maybe one will??? 

[HockeyDave55]

Going back up to the OP,
one thing I have seen is a guy modding a throttle body so far the original Walls were machined out completely and new sleeves were fitted in...

[zirk]

Some Police, although rare, used enlarged throttle Bodies on the 3.0s, a few years back I run an enlarged TB, not heated, which was mirrored finished, with a Courtenay Chip with good results and surprisingly improved economy when driven in normal mode,

Only ever found one from an explod (by accident) which Ive still got kicking around somewhere, could measure the TB diameter if required when I get a spare 5 mins.

Chris.

[HockeyDave55]

Some Police, although rare, used enlarged throttle Bodies on the 3.0s, a few years back I run an enlarged TB, not heated, which was mirrored finished, with a Courtenay Chip with good results and surprisingly improved economy when driven in normal mode,

Only ever found one from an explod (by accident) which Ive still got kicking around somewhere, could measure the TB diameter if required when I get a spare 5 mins.

Chris.

A measurement would help but why was the coolant taken off?

[zirk]

Colder air in, as far as Im aware the heated TB is to avoid the Carb Icing Effect in colder cliemets.