Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Ecotec Question

klampy

Member
Joined
Sep 25, 2007
Messages
735
Reaction score
2
Points
18
Location
coffs harbour
Members Ride
Mazda E2000 V6 convert
its a bit of a grey area argument. of push vs suck....

theres two spacers. one goes in the runners, one goes in under the plenum lid.

now, my experience with mods is based on a VR but the principles are the same, i increased the size of my plenum. i lost torque down low. but picked up alot of power up high. so from what iv learned, longer runners shift your torque down the rev range, giving the appearance of having more down low. and the idea of the lid spacer, is to give a better distribution of air inside the chamber for less stagnant air meaning more free flowing air available to the runners when the cam opens the valves.

at the end of the day, a stock TB can only flow so much, but by adding the spacers your not changing the amount the engine ingests, your changing how it ingests it.

all i can say, is that my experience with the lower spacer (12mm) was a positive one. more torque and better economy.
 

MACE

Well-Known Member
Joined
Mar 30, 2008
Messages
3,185
Reaction score
93
Points
48
Don't go sticking any spacers on unless your fitting a larger throttle body. Fitting the spacer increases the volume of air that the plenum can hold. When you boot it, it will take longer for your plenum to fill up with air. Fitting a plenum spacer on its own will make your car less responsive to drive.

What size spacer do you have? Fitting any plenum spacer using a standard throttle body will dull throttle response. I suppose it depends on ones standard or expectations, however the 12mm plenum spacer is fine for NA engines running a standard or larger throttle body, while the 25mm item is recommended for boosted setups. It's more to do with the plenum spacer and not so much the manifold insulator given the significant difference in volumes between the two
 

Immortality

Can't live without smoky bacon!
Staff member
Joined
Apr 15, 2006
Messages
22,476
Reaction score
19,930
Points
113
Location
Sth Auck, NZ
Members Ride
HSV VS Senator, VX Calais II L67
For economy i'd go the MACE CAI, 25mm manifold spacer and 12mm plenum spacer. I have these on the missus VS and my long term fuel average has improved by at least 1litre per 100km's. runs better too :)


Umm. Yeah. Well, insulating benefits? You sure? Alot of people claim that the plenum stays pretty cool even after 1hour of driving with the manifold spacer in. I touched my Plenum and burnt my hand.

I think it comes down to the style of driving as well. I've noticed that if your stuck in traffic or doing lots of stop/start driving then the plenum does still get fairly warm, however after a decent stint on the open road the plenum cools down fairly well. luke warm would be a good description i guess. ambient temps may also have a effect. before the fitting of the spacers/insulators you could easily cook a egg on the plenum cover :D if the temps still bother you, fit a cooler thermostat. MACE sell them to suit the ecotec/L67
 

billy bob

Member
Joined
Nov 3, 2009
Messages
131
Reaction score
0
Points
18
Location
Canberra
Members Ride
VE S2 SV6
its a bit of a grey area argument. of push vs suck....

theres two spacers. one goes in the runners, one goes in under the plenum lid.

now, my experience with mods is based on a VR but the principles are the same, i increased the size of my plenum. i lost torque down low. but picked up alot of power up high. so from what iv learned, longer runners shift your torque down the rev range, giving the appearance of having more down low. and the idea of the lid spacer, is to give a better distribution of air inside the chamber for less stagnant air meaning more free flowing air available to the runners when the cam opens the valves.

at the end of the day, a stock TB can only flow so much, but by adding the spacers your not changing the amount the engine ingests, your changing how it ingests it.

all i can say, is that my experience with the lower spacer (12mm) was a positive one. more torque and better economy.

Do you have both spacers? If your just fitting the bottom one your mainly increasing the runner lenght without effecting plenum volume substantially. If going top and bottom I would go 24mm bottom and 12mm top with a 69mm throttle body.
 

klampy

Member
Joined
Sep 25, 2007
Messages
735
Reaction score
2
Points
18
Location
coffs harbour
Members Ride
Mazda E2000 V6 convert
Do you have both spacers? If your just fitting the bottom one your mainly increasing the runner lenght without effecting plenum volume substantially. If going top and bottom I would go 24mm bottom and 12mm top with a 69mm throttle body.

its not me in question here. and i took the one out of my wifes VX coz it was a VS spacer, PCV was in a different spot. and i noticed a big drop in power after it was removed. so with more cash, i would certainly not hesitate to buy another for her car.
 

ajvx01

Member
Joined
Dec 13, 2010
Messages
911
Reaction score
6
Points
18
Location
North east Adelaide
Members Ride
308 vc
if you listen to steve's advice the spacers DO work, i have both...
cai makes throttle responce alot better.
 
Top