Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: CharlieP on February 08, 2010, 01:25:55 PM

Title: FD- Butterfly removal!?
Post by: CharlieP on February 08, 2010, 01:25:55 PM
Hi all- I was talking to a guy who had a rex at brands hatch, and who works on them...Bansted somewhere.
 
Now, he mentioned something about removing one of the butterfly things in the throttle body, makes the car run better on choke, or something like that!?
 
Anyone else heard of this? I\'m curious to if it does do anything good..
Title: FD- Butterfly removal!?
Post by: Jovic82 on February 08, 2010, 01:34:10 PM
steve rivett?
Title: FD- Butterfly removal!?
Post by: CharlieP on February 08, 2010, 01:36:40 PM
Put your real car up! haha
 
Umm really cant remember his name, in his 50s I guess, had a son who had a red rex, very talkative
Title: FD- Butterfly removal!?
Post by: nuki on February 08, 2010, 01:51:34 PM
ye thats deffo steve. he rebuilds engines all day long every day. good fella.... and yes i have removed my butterflys. you can just remove the screws and take out the butterfly\'s or you can remove the butterflys and take out the main shaft that holds the butterfly\'s but that requires tapping the hole for a bolt to act as a plug on the side of the inlet near the bulkhead.
Title: FD- Butterfly removal!?
Post by: CharlieP on February 08, 2010, 02:01:45 PM
Ok...but what does it do exactly!?
Title: FD- Butterfly removal!?
Post by: turbotoaster on February 08, 2010, 02:08:37 PM
cleans airflow up to the engine, you want the easiest access to your engine, not for the air for to be flowing around a load of butterflies, he did mine when he rebuilt it, also ported the manifold to turn it from 3 holes into 2, see below

(http://img697.imageshack.us/img697/8619/throttlebody.jpg)
Title: FD- Butterfly removal!?
Post by: CharlieP on February 08, 2010, 03:48:32 PM
Ahhh..ok I get it...what are they there for to start with?!
Is it something to do with start up, early running?
Title: FD- Butterfly removal!?
Post by: turbotoaster on February 08, 2010, 04:13:33 PM
yeh to help with cold starts, as far as im aware they stay closed when the engine is warming up to stop alot of air entering the engine when its not warm enough.

It was to cover people who started it from cold then thrash it, they stayed closed so not alot of air could enter the engine, ie on through the primary ports, since none of us do that and drive sensibly until the engine is warm then its fine to remove them
Title: FD- Butterfly removal!?
Post by: CharlieP on February 08, 2010, 04:15:41 PM
Cool thanks, may well do that
Title: FD- Butterfly removal!?
Post by: SiH on February 08, 2010, 05:49:41 PM
Double throttle removal :)
The butterflies are there to stop you going full bore while the engine is warming up.

However, as Pip once sagely pointed out to me - anyone who does that on a cold engine needs to be shot anyways. :D

Basically, you need to take the UIM off the car, undo the screws that hold the throttle plates in (you\'ll prob need to drill them out) then withdraw the \'rod\' and remove all the associated gubbins :) (actuator on the side of the UIM, solenoid, vacuum lines etc)

Then you cover up the hole left by removal of the shaft - I just tapped the hole and wanged a bolt in, then sealed up with epoxy  :)
Title: FD- Butterfly removal!?
Post by: Jono FD3 on February 08, 2010, 09:12:01 PM
done this on mine.... all I have done for the moment mind is remove the butterflies themselves as I couldn\'t be arsed to pull the shaft out & have the faff of blocking up the throttle arm holes! not quite as effective as removing the lot, but on a street car you probably wouldn\'t notice a difference leaving the bar in!
So all you need to do is, throttle body off, undo the 4 screws and pull the round discs out... job done!
Title: FD- Butterfly removal!?
Post by: CharlieP on February 08, 2010, 09:39:07 PM
Ok...and the difference!?
Title: FD- Butterfly removal!?
Post by: Jono FD3 on February 08, 2010, 09:43:08 PM
difficult to say for me as I did loads at the same time along with a remap:

V-Mount
Turbo pipework
Down pipe
Decat
induction kit
Upped the boost

Jono
Title: FD- Butterfly removal!?
Post by: turbotoaster on February 08, 2010, 09:44:09 PM
it will just help flow better at higher rpm, since its a free mod you may aswell do it, give you something to do at weekend if your bored
Title: FD- Butterfly removal!?
Post by: chr007 on February 08, 2010, 10:43:27 PM
Here u go mate:

http://robrobinette.com/double_throttle.htm
Title: FD- Butterfly removal!?
Post by: AtomicRex on February 10, 2010, 03:49:17 PM
If you are planning on doing this...I will swap you one that has already done this....as I want ours back in again!
Title: FD- Butterfly removal!?
Post by: turbotoaster on February 10, 2010, 03:51:11 PM
how come, i thought yours was a racecar, what benefit would you recieve, or is this for another car...just interested in any positives of them apart from the obvious
Title: FD- Butterfly removal!?
Post by: AtomicRex on February 10, 2010, 03:55:20 PM
New plan :) ;)
Title: FD- Butterfly removal!?
Post by: nuki on February 10, 2010, 03:57:37 PM
atomic needs his back in! he cant help thrashing his car from cold :P only joking :D
Title: FD- Butterfly removal!?
Post by: turbotoaster on February 10, 2010, 03:59:57 PM
he must be going all european and decided to go ice racing in finland, lets have some of that -4c inlet charge!!
Title: FD- Butterfly removal!?
Post by: AtomicRex on February 10, 2010, 04:00:58 PM
Quote from: nuki;671508atomic wants to thrash his car from cold :P only joking :D

 
Too right!!  Just in case we get up late!
 
Once we have the new plan in place then I will say more....but at the moment I need new plenums:driving
Title: FD- Butterfly removal!?
Post by: CharlieP on February 10, 2010, 04:51:24 PM
Haha I would, but bit of a trek to get to you
Title: FD- Butterfly removal!?
Post by: AtomicRex on February 11, 2010, 07:35:52 AM
thats what the post is for??
 
Will only cost you at most a tenner to send it over to us...and you get a nice sparkly one in return!
Title: FD- Butterfly removal!?
Post by: CharlieP on February 11, 2010, 07:40:28 AM
Sparkly!? Mines been polished too!
Ok will see if I\'m free this weekend to get it off....not sure if I\'m going to Sweden yet..