Individual Throttle Bodies and Improved Airflow

[oab_au]

Originally Posted by Dessertrunner

Okay I get your point Harvey but I still think it is worth doing the excerise as regards individual throttle bodies. As to if I use the top manifold I will see. I need to decide if I am going to use ram pipes or not.
Any way sounds like there is a lot of negitive as to the whole thing so I will not bother keeping you guys updated with posting.
Tony

Woo hang on there Tony.
We are all in the same boat, trying to get this engine to put out some real power in the higher rev range.

The writing was on the wall, when Matt did his engine, he did all that he could do as far as cams, duration and lift, and light weight solid lifters. It should have revved HARD, and put out the power that he was looking for.

When it came to seeing what the results were, it would not put out torque up the rev range. As I told him then, it was the standard inlet/exhaust manifolds that were hold the torque peak down to the resonate, 4800/5000 rpm. As the rules prevented him from modifying them, there was nothing he could do, to bring the torque peak, up the rev range.

What you are looking at, can be done, but it would take a lot of work, a lot of money, and if it was designed to length, it may do the job. The inlets would have to bend over the top to get the length in, then there has to be air cleaners, and trying to get cold air to them.

The same result can be got by modifing the standard inlet, and doing a set of short headers, all tuned to the higher rev range.

Harvey.

[Dessertrunner]

Harvey haven't heard from Matt lately but the rules I am racing under will allow for extrators so I will fit them. When we talked about the issue of cams at the start of my build I figured we need to do somthing about the inlet and exhaust flow so thats the plan.
When you see what happened to Rally Bob's intake under vacum it is hard to not come to the conclusion that that engine was starving for air inspite of all the understanding that the throttle body is big enough.
The plan is to buy them with a plan figured out how to get them ontop of the existing injector manifolds and look at what is above as we go. I have asked about 90 degree bends on the ram pipes or what ever else may be aviable.
Attached is two photos of manifolds we are dealing with.


Tony

[Dessertrunner]

Okay a bit of an update,
Got the quote for the throttle bodies and it is $525 Aust per bank so for 6 uints its $1,050. To this I still need the linkage and the return spring with stopper.
I measured the inlet size on the injector manifold and its 45mm so the plan to use the 45mm throttle bodies is correct.
Tony

[AppStateSVX]

Originally Posted by oab_au

The engine in good standard trim, will achieve 106% Volumetric Efficiency. That is it will get 583cc of air in the cylinder, there is not much that will get more air in there, other than forced induction. Increasing the intake area will not make the cylinder draw more air in. I have seen a VE of 110% in simulation, that equates to 605cc of air. This is about all that we can achieve in the way of increasing the torque.
What we can do is to ensure that the engine can still induct the same amount of air, at a higher rpm in the shorter time. Longer duration cams will only help if the resonate rpm is raised to allow the cams to keep filling the cylinder, at the higher rpm, it will produce the HP that is needed.

As we can't increase the air pressure acting on the outside of the cylinder, we can increase the negative air pressure inside the cylinder to increase the flow. If the inlet, and exhaust tracts are shortened to resonate at the same higher rpm, the exhaust will provide a strong start to the inlet flow, and the inlet will cause a strong negative pressure inside the cylinder to induct the air.

Harvey.

i dunno how i missed this post earlier, but it's golden

great info.

[legacyau]

I reckon the noise it will make will be worth every cent spent on it I remember a guy using twin downdraft webbers on an ea81 to great effect, it made a good noise too!.

Tony are you going to use individual sock aircleaners on each TB ?

cam

[dynomatt]

Subscribed for updates...

[Dessertrunner]

Its worth having a look at this setup on another forum. Here is the link and one photo.
http://forums.nasioc.com/forums/show....php?t=1175829

[subbieatnz]

Originally Posted by Dessertrunner

Its worth having a look at this setup on another forum. Here is the link and one photo.
http://forums.nasioc.com/forums/show....php?t=1175829

Thats a nice set up

[SilverSpear]

Originally Posted by subbieatnz

Thats a crazy set up

Fixed ...

[longassname]

If you end up with solid works files for needed parts and want to send them to me I can run them through solid cam and let you know what it will cost to make them.

[Dessertrunner]

This is the current kit being suggested looks impressive. This is for 4 cyclinder but we would have 3 each side.

Tony

[svxfiles]

Originally Posted by Dessertrunner

This is the current kit being suggested looks impressive. This is for 4 cyclinder but we would have 3 each side.

Tony

THAT just made my pants shorter!


They look AWESOME!!!!!

[subbieatnz]

Damn thats looks so nice clean and smiple

[Dessertrunner]

As I see it now the ram pipes may work but I am concerned about the engine getting hot air from the engine bay. For that reason I am going to give a different approach a try. Where the throttle are now I was going to built an airfilter box and force feed the air through a bonnet scoop. In that was any pressure loss by still having the manifold may to a degree be overcome by forcing the air into the intake and the individual throttle bodies. I am also hoping to be able to raise the manifold by 20mm.
I have positioned two standard aircleaners to show what I mean in this photo. Would like to here if we anyone thinks I can get the 20mm under the bonnet.

Tony

[RallyBob]

Originally Posted by Dessertrunner

As I see it now the ram pipes may work but I am concerned about the engine getting hot air from the engine bay. For that reason I am going to give a different approach a try. Where the throttle are now I was going to built an airfilter box and force feed the air through a bonnet scoop. In that was any pressure loss by still having the manifold may to a degree be overcome by forcing the air into the intake and the individual throttle bodies. I am also hoping to be able to raise the manifold by 20mm.
I have positioned two standard aircleaners to show what I mean in this photo. Would like to here if we anyone thinks I can get the 20mm under the bonnet.

Tony

FWIW, on Jack's 318 whp EG33-powered Impreza, the car was first dynoed with no outside forced air (cooling fan was off), and then it was dynoed with the fan on (60 mph wind speed). Something like 35 whp difference! That's with the cold air box I fabricated getting outside air from the OEM hood scoop.