John Eales triple throttle body plenum?
Discussion
chattign to paul at Austec, he was suggesting gettign a double as triple was overkill and sortign out all induction issues fully to aspirate the car well [over and above the new induction pipe that I have.
Dunno if that usefully applies to everyone, but he said that would provide bbetter overall benefit to me.
[500 fairly soprted]
J
Dunno if that usefully applies to everyone, but he said that would provide bbetter overall benefit to me.
[500 fairly soprted]
J
Paul is indeed correct - the triple supplies too much air for all but the wildest engines (5.3 with race and and heads will be OK)
The twin flows slightly more than a bored out single but measure the size - the butterfly is not 71 or 73 mm - then change that first.
Also - add the magna parva insulator plate - at < £50 it's well worth it !
The twin flows slightly more than a bored out single but measure the size - the butterfly is not 71 or 73 mm - then change that first.
Also - add the magna parva insulator plate - at < £50 it's well worth it !
Edited by rev-erend on Monday 4th December 13:53
rev-erend said:
Paul is indeed correct - the triple supplies too much air for all but the wildest engines (5.3 with race and and heads will be OK)
The twin flows slightly more than a bored out single but measure the size - the butterfly is not 71 or 73 mm - then change that first.
Also - add the magna parva insulator plate - at < £50 it's well worth it !
Totally agree with the Magna Parva plate. I fitted one during my rebuild and I am surprised at how effective it is. Not only does the plenum not get hot along with the engine, it actually seems to be colder than ambient.The twin flows slightly more than a bored out single but measure the size - the butterfly is not 71 or 73 mm - then change that first.
Also - add the magna parva insulator plate - at < £50 it's well worth it !
john Eales is the only source i am aware of,that sells his tripple plenum.I honestly don't know how they would behave on a std engine,but i would assume that if it is mapped correctly,then you would just get a great improvement in throttle response as well as a little bit more bhp,i honestly cant see any negative affects,but i'm no expert.
When comparing throttle size area of a twin Vs a large single,it is important to remember that the improvement in performance not only comes from the amount of air that the new throttles will allow to flow,but also the distribution of this air into the plenum area.For instance a twin plenum with slightly less throttle area than a large singe,can still work better as it allows air into the plenum in a more even manner,for want of a better description.This is why the tripple works so well,it not only allows a great amount of air,but the inlet can take the air more evenly,without having to suck it from a single center throttle,so its more direct going into the engine.
Hope that my explanation makes sense,i'm crap with words!
The last paragraph above,is how it was explained to me by my fave expert(or at least i think thats how he explained it
)
When comparing throttle size area of a twin Vs a large single,it is important to remember that the improvement in performance not only comes from the amount of air that the new throttles will allow to flow,but also the distribution of this air into the plenum area.For instance a twin plenum with slightly less throttle area than a large singe,can still work better as it allows air into the plenum in a more even manner,for want of a better description.This is why the tripple works so well,it not only allows a great amount of air,but the inlet can take the air more evenly,without having to suck it from a single center throttle,so its more direct going into the engine.
Hope that my explanation makes sense,i'm crap with words!
The last paragraph above,is how it was explained to me by my fave expert(or at least i think thats how he explained it
) Edited by mongoose on Monday 4th December 20:10
I was looking at a very nice siamese plenum on ebay a couple of days ago, and wondered about this. It had standard 64mm throttles, but I figured even they would potentially flow more than a single 72mm throttle - and they could be bored out. You would expect the left side of the engine to suffer a little on a standard single throttle plenum as the airflow has to get past the first bank of trumpets, which must starve that side of the engine a little at least? With twin throttles, in theory, you get a more even airflow to both banks of trumpets.
I'm not sure, but you might see even better airflow if you put a divider down between the banks to ensure each bank was fed from its own throttle body - less eddies in the plenum to disrupt airflow.
I was seriously tempted (it was a lovely bit of kit) but decided against it on matrimonial grounds, plus I couldn't work out how I'd get the ECU to cope with two AFM's, which would probably have meant moving to Megasquirt or similar.
I'm regretting not bidding already, it would have been an interesting project!
I'm not sure, but you might see even better airflow if you put a divider down between the banks to ensure each bank was fed from its own throttle body - less eddies in the plenum to disrupt airflow.
I was seriously tempted (it was a lovely bit of kit) but decided against it on matrimonial grounds, plus I couldn't work out how I'd get the ECU to cope with two AFM's, which would probably have meant moving to Megasquirt or similar.
I'm regretting not bidding already, it would have been an interesting project!
Why does the Magna Parva insulator have an effect on engine performance? Is it because it keeps the heat in the block/inlet manifold? Surely it can't have any significant temperature effect on the incoming air when on the move?
I would appreciate it if some engine guru could enlighten me.
Ricardo
I would appreciate it if some engine guru could enlighten me.
Ricardo
Cool air : more power!
Phil, turbulent air gives a better mixed charge - where it should be turbulent ???? Personally I think JE probably knows best, with the V8 weakness on the outer cylinders, a triple could probably be flowed to better match the inlet specifications. Agreed tho siamese symetry seems nice - but v8 is not really symetrical.
Dave
Phil, turbulent air gives a better mixed charge - where it should be turbulent ???? Personally I think JE probably knows best, with the V8 weakness on the outer cylinders, a triple could probably be flowed to better match the inlet specifications. Agreed tho siamese symetry seems nice - but v8 is not really symetrical.
Dave
Ideally the insulator would be between the inlet manifold and the heads, keeping the charge as cool as possible as long as possible before it hits the cylinder. That would also keep the injectors and fuel rail cooler. In practice that would mean skimming the manifold, so not nearly as cost effective as just insulating the plenum. People use silicone inlet hoses, and/or heat wrap around the filter-to-AFM hose for the same reason, to keep the incoming air as cool as possible. Given how cool my plenum now runs I suspect the charge wouldn't get much cooler with those mods, so I'm happy with the standard inlet hoses (other than for cosmetic reasons!). I'm in no rush now to get a carbon fibre plenum either.
Not convinced on the turbulence argument Dave! People spend a lot of time adding radiused trumpets to minimise turbulence and get maximum airflow, and siamesed throttle bodies fit with that. The main job of the plenum is to smooth out the airflow and help create an equal intake area for each trumpet. The injectors squirt into the manifold; turbulence upstream of the injectors can do nothing other than slow down airflow. A smooth laminar flow is the objective until fuel is introduced, at which point turbulence then becomes the priority. The optimum for power is of course one throttle body per cylinder, with as straight a flow into the manifolds as possible (which 'bike throttle bodies achieve).
Another consideration is the conical diffuser, which helps prevent pressure loss. Bored out throttle bodies already compromise this, increasing the entry size to the diffuser relative to the exit, so two smaller throttle bodies with more optimised angle of expansion in the diffuser would minimise pressure loss/maximise flow.
Even if your power output doesn't justify multiple throttle bodies (and not many will) I'd expect better throttle response, and as you say they look cool!
Not convinced on the turbulence argument Dave! People spend a lot of time adding radiused trumpets to minimise turbulence and get maximum airflow, and siamesed throttle bodies fit with that. The main job of the plenum is to smooth out the airflow and help create an equal intake area for each trumpet. The injectors squirt into the manifold; turbulence upstream of the injectors can do nothing other than slow down airflow. A smooth laminar flow is the objective until fuel is introduced, at which point turbulence then becomes the priority. The optimum for power is of course one throttle body per cylinder, with as straight a flow into the manifolds as possible (which 'bike throttle bodies achieve).
Another consideration is the conical diffuser, which helps prevent pressure loss. Bored out throttle bodies already compromise this, increasing the entry size to the diffuser relative to the exit, so two smaller throttle bodies with more optimised angle of expansion in the diffuser would minimise pressure loss/maximise flow.
Even if your power output doesn't justify multiple throttle bodies (and not many will) I'd expect better throttle response, and as you say they look cool!
Edited by victormeldrew on Tuesday 5th December 02:25
I had the second prototype of the John Eales triple throttle and it was a big improvement over the big single throttle body I had before. It does help smooth out the response etc. It is a good piece of kit. As for flowing too much air... more air... more fuel... bigger bang... more power. A bit simplistic but it is a good general principle.
BTW why not talk to John to see what he says. Very helpful guy.
BTW why not talk to John to see what he says. Very helpful guy.
spend said:
Cool air : more power!
Phil, turbulent air gives a better mixed charge - where it should be turbulent ???? Personally I think JE probably knows best, with the V8 weakness on the outer cylinders, a triple could probably be flowed to better match the inlet specifications. Agreed tho siamese symetry seems nice - but v8 is not really symetrical.
Dave
Phil, turbulent air gives a better mixed charge - where it should be turbulent ???? Personally I think JE probably knows best, with the V8 weakness on the outer cylinders, a triple could probably be flowed to better match the inlet specifications. Agreed tho siamese symetry seems nice - but v8 is not really symetrical.
Dave
I would have thought Laminar air flow would be more desirable rather than turbulent as regards to better air intake efficiency to the plenum me thinks
and indeed colder the charge the betterrev-erend said:
Paul is indeed correct - the triple supplies too much air for all but the wildest engines (5.3 with race and and heads will be OK)
The twin flows slightly more than a bored out single but measure the size - the butterfly is not 71 or 73 mm - then change that first.
Also - add the magna parva insulator plate - at < £50 it's well worth it !
The twin flows slightly more than a bored out single but measure the size - the butterfly is not 71 or 73 mm - then change that first.
Also - add the magna parva insulator plate - at < £50 it's well worth it !
Edited by rev-erend on Monday 4th December 13:53
Paul recommended the triple to me ? On a standard engine but together with new injectors and airflow meter, remap, etc. IIRC he said the gain was not that much over the twin plenum but it smoothed the airflow out slightly more and was even less restrictive.
Pasco said:
I would have thought Laminar air flow would be more desirable rather than turbulent as regards to better air intake efficiency to the plenum me thinks and indeed colder the charge the better
and indeed colder the charge the betterI'm just making the point that you also need the air & petrol well mixed for a powerful charge.
Dave
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