Question is not specifically for LO or HO, more about the connections/sensors on the manifolds.
1-On my LD9 plastic manifold, i can only count 1 (one) vacuum line going from the 2.4 throttle body, to the manifold, the hose is 4"-6" long. I tried to feel under the manifold to find another connection but i couldn't.
Are there other connections
?
2- lets say there are 9 holes on the 2.3L manifold,
a)1 for the throttle body,
b) 4 for each intake port,
c)1 ~1/16"-1/8" vacuum 'nipple',
d) 1 ~1/8"-1/4" vacuum nipple,
e)and a plug in of some sort
f)some other hole, for a hose
>picture of manifolds taken from i think quad4forums.com or j-body.org, in some post about HO manifolds and differences to LO
Now here is my question, do theholes c), e), and f) have any purpose
? I thought one(letter e?) was Intake air temperature? but if i retain the bung in my intake piping? will this still be needed
?
what about c) the small nipple thing? and f)? any purpose or could those be filled in and smoothed down
?
letter d) i know would be the little vacuum line going to the Throttle body
?
Am I missing anything
?
Lastly,
are the runners on the LO manifold the same length and shape as the runners on the HO manifold. I always read about the difference being the plenum, how the HO has much more volume. Runners=same
? they look similar? just looking for a rough answer here..
Thanks
Ryan
AND I hate to thread jack, BUT I would also like to know about the performance difference between these 2 manifolds. Is their a large difference ?
My Cav
I give up...
i'm buying a VW those people love trees, so they should love eachother too... "Andy"
Ok, I'll clear this up for you eventhough if you read the *Updated* 2.3 HO Intake Manifold and TB install guide it will tell you everything you need to know about the swap.
(C) is where you will hook up the line coming off of your fuel rail.
(E) this is not needed on the 2.4 keep the original sensor in it or use a pipe plug to keep it closed off.
(F) is for the EGR vavle, if you plan on using a EGR Block-off plate you will not need this either. But if you use the EGR adapter that is going around like I did you will need it.
(D) is for your MAP sensor, you will bolt your MAP sensor to one of the bolt holes above it and plug in the vaccum line to the nipple on the Manifold.
And the diffirence between the LO and the HO as far as I know is the size of the plenum, the runners are the same size and lenght.
If you still don't understand and need pictures here is the
URL for the Updated Guide. Have fun
.
In the planning stage for an all American TRD Cavalier.
c = FPR
d = MAP
e = IAT
f = vacuum for black box that you always see sitting atop of the quad4...it sucks in all the oil vapors from the timing and crankcase....if you dont need it just cap it off
as far as the differnces..its just the plenum..runners are the same...IMHO all you need for the 2.4 is the LO manifold..if you can get it to rev higher or you get bigger cams you could possibly benifit from the HO
hope i helped you out and let me know if i missed anything
The diffirence as far as I know from searching and reading other posts.... Is that the HO brings in more air, the more air means the more fuel the computer injects to make more power. But recently I read on this page in a diffirent thread that there is a possiblility of the LO giving you better low rpm TQ. Because it does not bring in as much air created a bottle neck in the runners going to the head. The HO brings in larger amounts of air creating a bottle neck causing you to lose TQ on your take off and in lower RPMs. So with the HO you will get more HP after about 5,000RPMs but have less TQ. Nobody that I know of has done a before and after on the HO but somebody did with the LO and they got in the neighborhood of 11hp gain from the LO but lost about 5LB TQ. Not sure where at in the RPM range they lost HP or gained it compared to the TQ lv they did not post their Dyno charts. So, I'm guessing with the HO you will get more HP and probably less TQ compared to the LO and stock intake manifold. Oh and by the way the dyno results were also with a bigger TB.
In the planning stage for an all American TRD Cavalier.
the 2.4 is closer to a 2.3 LO than it is the HO....and the reason the HO has the bigger plenum is because it has bigger valves and revs higher..therefore actually utilizing the manifold properly....if the 2.3 LO didnt need the bigger manifold what makes you think the 2.4 does?..my theory still stands,if your 2.4 is N/A the LO manifold should be best for your application.....wait..what were we talking about again?
In theory I agree with scott, the 2.4 does have the smaller cams, valves, ect... And the fact that the plenum is smaller so making the bottle neck effect smaller. I went with the HO because later I do plan on going big with the 086 Head and the HO Cams.
In the planning stage for an all American TRD Cavalier.
Thanks guys for the help.
One last question
the vacuum line for the fpr, c) in my diagram, comes off the fuel rail line. On the stock 2.4L throttle body, there is a fitting for this line? If the 2.4L throttle body is being retained, and bored, is this 'nipple' still necessary? seems as if it wouldn't be needed right?
Ryan
Hmm..... Well, I do eventually plan on going the supercharged route. BUT that is a year off as of now, I do have the hybrid cam swap as well.......
My Cav
I give up...
i'm buying a VW those people love trees, so they should love eachother too... "Andy"
if your not using ANY nipple simply cap it off
ok its 45mm bolts with the spacer??...and wat do u use to cap them off?....so u would cap off both that fuel nipple and the F hole.....and for E where would u get the plug to put here.....
you scratch my ride IMA EAT YO CHILDREN
if you go to autozone( or the like ) they all carry these rubber covers in a bunch of differnt sizes..if youve ever seen the little rubber nipple covers on brake caliber bleeder valves? there kinda like that..but they make them much bigger
..or..if the nipple isn't being used...simply yank it..and fill it with some al. weld
