45 replies to this topic

[andyroo]

Having read through the brilliant how-to guides over on z22se.co.uk, I decided to grind out and polish the lumpy bits in my throttle body. I didnt go the whole hog and replace the screws and flatten the spindle on the butterfly, but i did remove the crud and take off a fair bit of material. Using a lot of sandpaper and a lollipop shaped sanding drill bit, I smoothed out then polished the really lumpy bits into a smooth, mirror finish. Put it back on the car, ecu hunted around for idle for a bit, found it, and i went for a little drive. Let the car warm up and the ecu do its thing, then decided to open the taps. Wow! Im not one for placebo effect mods, this really did make such a difference! The way the revs raise and fall is so much smoother, the pick up is much more distinct from lower down the rev range where it would struggle before, it just seems to shoot off like a rocket at the slightest tickle of throttle! So thanks to Vocky and Co for doing the hard work and research, allowing me and other to follow in your footsteps.

[vocky]

surprising the difference it makes porting the throttle body

[andyroo]

surprising the difference it makes porting the throttle body

Especially since the inside of it was black when i took it off

Couldnt believe the shape as standard, the air going through must be really upset by the huge ridge! When i first started the car , it was idling at 2000rpm before quickly hunting around and settling down to 800 again, so the difference is very obviously definate!

Im no mechanical expert and i thought it was easy, it just takes a steady hand a bit of care. Taking my time saved my one and onyl throttle body, god know what idve done if i cocked it up

Cheers for the how-to Vocky!

[RCduck7]

What mm is the throttlebody now in comparison to a standard one? The key is to port it not to much as otherwise a standard VX will have an ECU error code.

[andyroo]

What mm is the throttlebody now in comparison to a standard one?
The key is to port it not to much as otherwise a standard VX will have an ECU error code.

God knows I just smoothed out the big ridges

Was definately worth it and easy too. Seeing as its free, and if you have a careful, patient hand, theres no reason not to do it! I think someone got an ECU error because they tweaked the butterfly too. If you stay away from it and the material it touches you shouldnt get and ECU error.

[p4cks]

Yeah, Markv got an error message as hiw was tweaked alot. I'll be porting my spare TB at the weekend.

[andyroo]

Yeah, Markv got an error message as hiw was tweaked alot. I'll be porting my spare TB at the weekend.

Good luck with it Take your time!

[rsg]

Sounds like a 'must do' when upgrading to the 2.4 manifold! Now, wheres my dremel.......

[oakmere]

Did mine a few weeks ago and I think it has made a big improvement and wouldn't be surprised if it increased power at points throughout the rev range. MarkV really went to town it wasn't the improvements to the butterfly that caused problems but the fact he removed the default position humps. I really wanted to remove these as they appear to be the biggest restriction to flow but suspected it would cause problems, one being if the TB fails it will probably tick over at 3000+ rpm not the safest. The default position of the butterfly is not closed as expected but at an angle of about 20 degrees from the horizontal and it is at this point that the TB wall bulges in to reduce flow. If you remove these bulges with a standard map you will get an error code. It is much easier to understand when you take the TB off and have a look at it. Unfortunately photographs don't show this clearly. Can someone draw a simple diagram and put it up here? The safest bet is to not remove any material where the butterfly sweeps the TB wall. I used a dremel with the sanding belts then 240, 1000 grade wet & dry, t-cut and finally polish. Hope this is of help Cheers Oakmere

[p4cks]

As I've said, it's a spare so I'll not be rushing at all. I'm quite enjoying this z22se mod malarky!

[drpau]

Another thing to put on my list then . Ive got to start gathering all the bits now for when the 2.4 manifold arrives, egr plate, and this corsa valve etc. Its amazing how taking a little bit off like you have done makes such a diffrerence.

[ChazUwe]

Hi guys this looks like something I might have a bash at, I can't find the how to guide over on z22se has anyone got a link??

[VIX]

Brave man! I know I've seen it, might be this one? (Try a search for "butterfly".)

PS Or maybe this:
http://www.z22se.co....light=butterfly

Edited by VIX, 23 October 2007 - 11:21 AM.

[andyroo]

This is only rough, but gives an idea of what is shaved off. Note that any areas in the path of the buttlerfly should NOT be touched. You can pivot the butterfly along its rotation as you go to make sure you dont make a mistake. I used some light sandpaper to mark as far in as i want to go and then kept to that mark. Solid lines show the tb as it is, the dashed ones show material to be removed (except the circle which is the rotation of the butterfly)

Please remember this is only a quick sketch and not entirely accurate.

Heres a good how to by Vocky: http://www.z22se.co....ghlight=porting

Attached Files

•  tb.JPG   22.69KB   2 downloads

Edited by andyroo, 23 October 2007 - 11:29 AM.

[vocky]

the porting creates a nice venturi effect

[markv]

Just a small FYI, removing the humps where the throttle plate is in idle position doesn't change the rpm when the car goes to limp mode. Had it happen, no change from what I've seen before, it runs between 1500-2000 rpm. Oh, and it would be interesting if the error code on my ECU was caused only by the changes to the butterfly valve. That would mean the valve is a HUGE restriction when opened Mark

[Crazyfrog (Fab)]

Just a small FYI, removing the humps where the throttle plate is in idle position doesn't change the rpm when the car goes to limp mode. Had it happen, no change from what I've seen before, it runs between 1500-2000 rpm.

Oh, and it would be interesting if the error code on my ECU was caused only by the changes to the butterfly valve. That would mean the valve is a HUGE restriction when opened

Mark

is it worth to do this mod !

[andyroo]

Just a small FYI, removing the humps where the throttle plate is in idle position doesn't change the rpm when the car goes to limp mode. Had it happen, no change from what I've seen before, it runs between 1500-2000 rpm.

Oh, and it would be interesting if the error code on my ECU was caused only by the changes to the butterfly valve. That would mean the valve is a HUGE restriction when opened

Mark

If your at that stage it would probably be better to add a ported 68mm tb instead, no? And for that cams, etc are recommended... Yours should be heading in that direction shouldnt it?

[rsg]

Wow! Im not one for placebo effect mods, this really did make such a difference! The way the revs raise and fall is so much smoother, the pick up is much more distinct from lower down the rev range where it would struggle before, it just seems to shoot off like a rocket at the slightest tickle of throttle!

So thanks to Vocky and Co for doing the hard work and research, allowing me and other to follow in your footsteps.

Andyroo, do you reckon there is any power increase or is it a pure drivability thing??

[andyroo]

Andyroo, do you reckon there is any power increase or is it a pure drivability thing??

I couldnt say about power increase without rr'ing it, it probably isnt much! What it does do is allow the engine to rev freely and smoothly and so you can get to the power more quickly. It also means gear changes are smoother, and power and torque seem better at lower revs too where the engine may normally be starved of oxygen. For the price (free!) and the amount of time taken to do it (1-2 hours) its a must-do. Its so easy as well, I was nervous but now I've done it I was wondering what the fuss was!

Its hard to explain the benefits, you'd have to do it and see. To try and put across how much more air the engine gets (the removal of the material allows more air in faster) idle was at 2000rpm until the ecu adjusted it back down to 800rpm. And more air means more fuel which means more power. With the 2.4 manifold which allows more air through the next stage of the intake process, its an ideal mod.

Just do it and stop asking questions!