306xsi throttle body

Malachy · Post by **Malachy** » Sat Sep 16, 2006 8:53 am

just fitted one to my car (off my old engine) the butterfly is A LOT bigger havent measured yet will do later, the main reason for me doing this was that i wanted stepper motor idle control, the stock turbo throttle body does nto allow this (only allows pwm solenoid)

you have to re route the throttle cable to connect to it but no big deal, for stock ecu users, you can remove the plastic take off for the idle solenoid and put that inlace of the stepper motor (it fits i have tried) just use that, you willneed to blank off an internal hole that feeds the stepper though but that wont be that hard, i would expect its definatly worth it considering the tb butterfly has probably about 150%-175% as much area.

reason i am doing this is that Ms2extra has been released in beta this now means i will soon be able to use ms2 resolution (alot betterthan ms1) and run the extras like launch control/flat shift/boost control/ that normal ms2 does nto have. ms2 supports stepper control and ms1 does not i have been having problems getting the engine to idle well on warmup, once up to temp however it was fine, this should fix my problems

Post by **Welly** » Sat Sep 16, 2006 9:17 am

Not sure if I've missed something, but are you using the 306Cab now? you know like all up and running?

I want to know how it's going chappy????

Malachy · Post by **Malachy** » Sat Sep 16, 2006 9:23 am

yep its running, was using it for amont just takenit off road again to "tweak" a few things. was going to convert to 16v turbo but funds are nto allowing at the moment

Foxy · Post by **Foxy** » Sat Sep 16, 2006 9:25 am

Hmmmmm interesting..... wouldnt a 205 GTi throttle body be more suitable?

Cam gets fitted today, cant wait for the extra power.

Malachy · Post by **Malachy** » Sat Sep 16, 2006 9:44 am

205 gti throttle is same size as turbo, also has an on/off tps not a potentionometer needed for the ecu. i also dont think it mountsthe same way onto the manifold (you need one that uses 3 allen keys)

Foxy · Post by **Foxy** » Sat Sep 16, 2006 9:58 am

So the XSi one is almost a straight swap?

I think I shall look into this!

Malachy · Post by **Malachy** » Sat Sep 16, 2006 10:55 am

almost you have to run the throttlecable to underneeth and to the side,, you will also have to blank off a hole internally on the tb as its a feed for the stepper. then just put your plastic idle solenoid flange on, and you will be away

to blank off the hole i would just use liquid metal etc. its about 1mm and is visable in the top of the throttle body.

i did notneed to do this as i plan on running with the stepper

Malachy · Post by **Malachy** » Sun Sep 17, 2006 5:13 pm

been wiring up the stepper up today and got that sorted

idle is 1000rpm on warmup and 850 rpm oafter:)
very happy

Malachy · Post by **Malachy** » Mon Sep 18, 2006 5:44 pm

anyways i have been having fun with my car,now ms2 extra is in alpha i have decided to switch back to the ms2 cpu for the better resolution.And also i wanted stepper motor control ms1 does not do this.
MS2 makes it much easier to tune aswell can tune spark by 0.1 of a degree and fueling by 0.001ms so you can get it spot on. it also has a very nice Auto mixture control where you set your afr's in a table much like a fuel table you then drive about loading the engine (driving with the brakes on!!!)holding the engine on load sites andit autotunes the fueling map values to that afr and burns it to the ecu for you. spot on huh

this is very similar to closed loop running which ms1 does but closed loop you have a delay as its after the fact it adjusts,this is no good for acelerating since its constantly chasing the fuel table for the afr.

so basically using automatic mixture control drive about fking your brakes for abit and you have a perfectly mapped fuel map:)