v6 throttle body?

[col33]

I'm disappointed with my v6 Vectra, the throttle response is so poor compared to my SRI 140. You put the foot down, then wait a while for anything to happen!

Has anyone used an enlarged throttle body (64mm machined to 68mm) on their 2.5 V6, and if so, does it help cure the problem?

Just wondering if they are worth the money

[col33]

Sooo...no one tried one of these then?

[deegte]

I have my one enlarged on the cav its some job. Def get it done. Guy from ebay done my one I had his number but changed phone. He delt outside ebay I think allin end up costing about 60 quid. Barging if ya ask me.
Before


After

[col33]

Yeah, there's a guy on ebay doing it for around £80.
Any noticeable difference to performance Deegte?

Would be handy to know if it goes some way to improving throttle response on the V6...

[34ada]

dont expect much but with the v6 it's more a case of every little helps...

you could also maybe look at a lightened and balanced flywheel which will help with throttle response and a good service is always a good place to start.

the gearing on the vec v6 is quite long and can feel sluggish until she getts going! lol

[col33]

Don't really want to spend a fortune so just looking at the cheaper mods which may make a difference. Just converted to lpg so spent enough for now! :-)

[34ada]

yeah i no what you mean! lol

how do you find the lpg?...been looking at it myself but not sure how it will fit in with future plans

[Nemesis]

Flywheel is the issue here not the TB. The rotating mass of the engine is probably twice that of a X20XEV, hence the throttle response being poor

Long ratio box as well dont forget.

[elongmoss]

I do 68mm versions or 70mm enlargements for £50 usually with a weeks turn around

The 70mm require the coolant at the bottom to be diverted however but is better for
WOT type driving the 68mm is better for day to day use

[vectra640]

how much to enlarge the twin butterfly omega one

[col33]

yeah i no what you mean! lol

how do you find the lpg?...been looking at it myself but not sure how it will fit in with future plans

To be honest, I've been fitting the lpg kit over the past few weeks and am only now at the point where it's ready to stick the gas in and see how it works. Hope to be doing this sometime next weekend. I've spend about £800 on parts, but should recoup this within a year or two hopefully. It's a tricky business though on the V6, really difficult to find space for everything and many hours spent making brackets etc. Will let you know how it performs once it's done :-)

[col33]

I do 68mm versions or 70mm enlargements for £50 usually with a weeks turn around

The 70mm require the coolant at the bottom to be diverted however but is better for
WOT type driving the 68mm is better for day to day use

And in your experience, what difference will they make to the V6?

[col33]

Flywheel is the issue here not the TB. The rotating mass of the engine is probably twice that of a X20XEV, hence the throttle response being poor

Long ratio box as well dont forget.

I wonder why they used the same box throughout the V6 range instead of using a close ratio on the SRI/GSI
The smaller engined SRI's had the close ration box after all...

[Frisco]

Because a CR box wastes what the v6 is very good at and makes it really bad on fuel when you use it on the motorway. The F25 is too wide though.

Nemesis is right though, your problem isnt the TB.

[vectra640]

It's the near on 15kg flywheel and the long legged F23/25 box that's why I changed all of mine over when I rebuilt it, including the intake

[col33]

It's the near on 15kg flywheel and the long legged F23/25 box that's why I changed all of mine over when I rebuilt it, including the intake

What did you change over to?

[vectra640]

Mine has a F28 which I know is heavier than the others but has closer ratios than the F23/25 and the extra gear makes up for the weight, mine also runs 3.0 omega plenum, quad G cams and a straight through 3.5 inch stainless exhaust, lowered over 60mm, bilsteins all round, front mount oil cooler, air con removed blahdy blah

[Frisco]

I used an F20 with a F18wr 5th in it. I actually prefer it to an F28