...as far as i can see my EEC4 cover is the same width as the 4x4 one.

4x4 = 460bhp

EEC4 = 520plus bhp

So the xtra power is gained from the bigger elbow on the EEC4...quite obvious!....SO it seems the elbow size is the restricting factor....so how does putting a spacer on have any difference in bhp capability to a 2wd/4x4 cover?

 

It dont but it looks Bling & people ask silly questions about it.

 

Who says it does?

 

You'd be surprised Mike!!!Alledgedly its about the space between cover and trumpets But i have kinda proved otherwise surely?

 

Mike why argue , no one has ever thought about these things before, then a DIY genius comes along & re-writes the rules. Hes a clever bugger.

 

Rod.....i dont understand

Mike is asking WHO says plenum spacers work...i am saying some people in the tuning business...i say how can this be with my first post proving it cant be the distance between trumpet and cover it must be the elbow.

 

i thought it was common knowledge that the elbow was the restrictive part.

so you could put a 50mm plenum spacer on and it still wouldnt flow any more air

 

aint the plenum design for torque/responce though and not just about the air flow


or is that a N/A car thing


just asking btw,,,,,as im clearly not a one to discuss this

 

can you put a eec 4 front cover on a big turbo back or do you have to change the whole thing ?


Dave.

 

Harvey once told Ian that spacers make very little difference in his experience Phil

 

i've never said that they increase power - i thought that their purpose is to even the flow between cylinders by having them suck from a larger volume.

 

Is that a no then

 

no it's a yes

 

ginge, it is... but when youre talking about peak BHP, all you're interested in is getting as much air in as possible

 

I think the spacers make that worse - if you look at the standard set up, most of the air goes under the trumpets for 2 and 3, evening the flow out a bit. With a spacer, the flow goes directly into the trumpets for 2 and 3.

 

Well it was a well respected tuner on HERE that told me a 10mm spacer would make the 4x4 plenum cover a 500 plus BHPer ...Other lesser tuners also.

So Ryan less of the asthough i am dumb ..i am just goin by tuners advice which i have worked out to be total bollocks

Not good...not good at all.

Stu,Karl???????Explain???

 

On a 2wd plenum I guess it´ll have some effect. Otherwise, why make it bigger on the 4x4?

A bigger plenum with the same restrictive inlet elbow might work in theory because you will have less pressuredrop in the plenum on a intake stroke because you have more air in the plenum. Don´t really think real life testing will show any significant gains tho..
Another thing is the "tuning" of the plenum. By altering plenum volume you also alter the pressurewaves created in the plenum by the inletvalves opening and closing. The main idea is to find the volme that will use the shockwave created by one cylinders inletvalve closing to reach the next inletvalve opening, and assist cylinder filling in the rpm range you need it.