Quad bodies and superchargers

[Paul Smith]

Ok I'm after your opinions, can anyone see a benefit of having a supercharger on quad throttlebodies over a supercharger from a single throttlebody. I am obviously arguing for but some good points have been raised as to why it would not be any more effective or why would it be more effective?

Thoughts and reasons

thanks

Paul

 

[frank]

i think any gains would be very small personally paul, the factory,s tend to fit either one or the other, and not both eh

 

[Paul Smith]

Why don't they fit both?

 

[will930]

Well all the boost will still be the same just more direct with the quads

 

[frank]

Why don't they fit both?

high cost and low gain i would guess ?

 

[Paul Smith]

I was thinking the single body would be pressurised by the charger and when that opens it draws in the forced air, now if there were 4 sucking the same equal amounts (4 times as much as one) of air then it would need a greater amount of pressure till it hits the engines top performing capacity?

 

[frank]

I was thinking the single body would be pressurised by the charger and when that opens it draws in the forced air, now if there were 4 sucking the same equal amounts (4 times as much as one) of air then it would need a greater amount of pressure till it hits the engines top performing capacity?

the quads dont suck 4 times more air than a single t/b @ x rpm tho eh paul, one single t/b is a bit more restrictive than 4 slightly smaller t/b,s sure, but thats less relevant if you,re boosting

 

[Low Rider]

OEM's use plenums and single TB's because it's cheaper, simpler, allows the use of a MAF or MAP sensor setup which is much more forgiving for changes. Also plenums are suited for mid range power, which most road cars are all about.

Multiple throttles are more complicated & expensive and need more work to set them up and balance them. Using TPS load I think can make the tune more vulnerable to variations in the engine. Two big advantages of quads would be that they can tame wild cams and give a much better tickover. They also have a much larger intake area, which is key for efficiency. These are good to have but are only a real benefit if you want to push for big power.

For your setup, you'd be better off with a single throttlebody and a custom plenum which offers some improvement over the stock item. You however can still make good power on the OEM item and run your stock brake servo, which maybe a bonus for you...

 

[frank]

I was thinking the single body would be pressurised by the charger and when that opens it draws in the forced air, now if there were 4 sucking the same equal amounts (4 times as much as one) of air then it would need a greater amount of pressure till it hits the engines top performing capacity?

and bear in mind your quads are only sucking in air one at a time paul (while the other 3 are doing nothing)
whereas the single t/b is sucking 4 times, one after the other (akin to a constant flow)

 

[superls]

i cant see any benefit of quad bodies and a charger unless you are going for ultimate power, as the factor of single body restriction in NA is overcome with the positive pressure on the charger side of the throttle bode in a boosted setup.

 

[airmike]

Nissan sunny GTi-R has quad TB's and a turbocharger.

 

[Antony]

bmw, volvo, rb26dett etc etc, all use throttle body's and forced induction. its a more acurate way of feeding each cylinder individually. plus the charge air will be distributed evenly throughout the cylinders as each is only open at one time, whereas with a single TB and plenum, the charge air effectively slows down in the plenum before entering the cylinders. simple fluid dynamics there... but i digress slightly.

its more of an advantage if you want to run huuge bhp figures or if you struggle with flow rates of plenums, manifolds and throttle body's.... but i dont think a cg13 will benifit at all from this setup.....