Inlet manifold spacer?

[familyman]

Just a wee thought excercise:

in my old bogan V8 days, used to be talk of spacers made to go between carb and inlet manifold. Essentially this increased the size of plenum allowing for better throttle response (IIRC).

If one was to apply reasoning to EJ20t manifold, due to rather small volume by other standards, would some 1in (figure pulled from ass) help to alleviate lag?

Like I said before, this is just a random thought I had and I am fully open to being proven right or wrong.

Discuss away. (and let's assume we will deal with bonnet clearnce issues later)

[MercuryFree]

Isn't this partially what the airbox and intake setup is for? I know it's on the 'wrong' side of the throttle body, but I was under the impression that it served a similar purpose

[wrx_lou]

This was talked about breifly the other day. There was a reason this isnt feasable (sp) but I dont think it was really ellaborated on.

I think it could be due to the injectors being mounted at the bottem of the runners? By installing spacers you'd increase the distance the fuel needs to travel possibly causing improper ignition?

[familyman]

Good point re: injectors. Could be solved by tuning ecu to fire njectors earlier.

What about relocate spacer to throttle body? If throttle body is moved further down ic piping, additional volume could be added this way.

[familyman]

More importantly would there actually be any benefit in doing this?

Hope a physicist is reading this.

[wrx_lou]

I dont think thats something worth doing. If it was, then more people would do it. Its not hard to move the tb further down.

[familyman]

Another valid point. Maybe reason it so common in V8 dinosaurs is due to NA. Might be neglible in a boosted application just like head porting.

[Guest]

the gizmo thermal gaskets you can get are about 7mm in thickness, dont know if thats as thick as ur thinking?

-smurff

[wrx_lou]

Those are to stop heatsoak though right?

[Guest]

yea, used to be able to get them easy, pain to get now for subbys

but they still spacer the plenum

-smurff

[wrx_lou]

But they space it for a different purpose.

Hard to get? was going to get one for when i put my engine back togather. Is there anywhere that will still be able to get them? or a better alternative?

[Guest]

i belive you can order them from gizmo, i emailed them a few weeks ago with no reply

they do space for a different reason, but it will stell increase the volume of the plenum and will offset the injectors from the head, so same factors as spacers are involved.

-smurff

[wrx_lou]

Is the increased distance enough to warrent needing a tune?

[Guest]

havnt read it anywhere so dont know.

-smurff

[Guest itsgotgo]

Two very different kettles of fish.

If you are referring to the v8 as in windsor or chev.

They dont carry a spacer at the base of the manifold.

Unless fit a phenolic spacer under the carb.

Or if you mean like this http://s160.photobucket.com/albums/t161/blackxr6/?action=view&current=P2030004.jpg

The spacer is used to increase top end response.

If you want better low end response the best way to do this is to have the carbs on flat plane very close to the inlet and heads.

However your problem is lag,is this because of a big turbo?

I am far more at home with n/a cars,but i am sure sumone else will fill you in on the turbo side for lag.

If you get stuck,you can always add a 50hp shot of NOS FTW ;D

[familyman]

 itsgotgo said:

The spacer is used to increase top end response.

If you want better low end response the best way to do this is to have the carbs on flat plane very close to the inlet and heads.

However your problem is lag,is this because of a big turbo?

I am far more at home with n/a cars,but i am sure sumone else will fill you in on the turbo side for lag.

If you get stuck,you can always add a 50hp shot of NOS FTW ;D

yeah that what I meant. Perfect answer cheers dude. Ok. Rules out that thought.

So to further learning for me and others, why do aftermarket plenums always have extra capacity especially for monster horsepower drag cars?

[Munkvy]

Ive seen it mentioned on RSLC about using spacers under the manifold on BC/F5 manifolds to raise them enough to fit an under manifold intake in.

[Guest itsgotgo]

Depends on what you consider a monster drag car? 4cyl turbo,6cyl turbo v8 turbo,v8 bb scharged,top fuel ha ha.

The plenums are larger for the top end charge.

Although the ford in that picture runs 8,90 over the quarter.

It has monster heads,supercobra jet heads with over 30hrs of porting.

it needs to breathe,we did a comparison between the flat plane and 2x 1050cfm dominators over the 1/4 mile.

The 60ft times were awesome as a flat plane, but fell away in the top end 9.5 sec 1/4 due to lack of inlet size and volumetric efficiency.

The majority of resonable drag cars will also run a stall converter of 2.5k rpm or up 5krpm+

So when leaving the line they are allready flowing very well and only a few hundred rpm away from running towards the best efficiency for making instant power.

I hope this is as clear as mud ;D

[familyman]

Another awesome answer. Cheers dude. Is totally logical in hindsight with that whole launching at high revs thing.

Thanks heaps.

[Guest the_return_of_the_jedi]

wouldnt flipping the intake manifold and using a front mount intercooler also be a better solution?

ie: less distance for the air to travel?

just a thought..

[familyman]

Very valid point. Guess I just think too much outside the square. Like was stated earlier, IF it did help why doesn't everyone do it.

plus bonnet clearance would be a super pain in the butt

[Guest the_return_of_the_jedi]

 familyman said:

Very valid point. Guess I just think too much outside the square. Like was stated earlier, IF it did help why doesn't everyone do it.

plus bonnet clearance would be a super pain in the butt

bonnet clearance is fine. u get a flipped alternator bracket and the i/c pipe goes where the alternator used to sit

no probs for clearance?

[familyman]

Sorry. Was thinking clearance of 1in spacers. That would suck. But manifold flip sweet. Must get on to that one day

[Guest the_return_of_the_jedi]

 familyman said:

Sorry. Was thinking clearance of 1in spacers. That would suck. But manifold flip sweet. Must get on to that one day

do a search for flipped manifold on the CS search

here : http://www.clubsub.org.nz/forum/index.php?action=search