Duratec induction length

[Molecular--Bob]

Anyone know the induction length of the Duratec roller body setup? 

I want to get as close as I can with Jenvey parts to allow me to run a borrowed map until I can get it on the rolling road.

Ian B.

[AdamQ]

I don't know the answer to your question, but, as I'm sure many others do, I have Emerald maps for a couple of Duratecs with Jenveys if that's any help - happy to email them - say the word ...

Adam

[Molecular--Bob]

Hi Adam

I run a DTA S60 but have been given a map for an r300 spec engine on rollers as mapped by Northampton Motorsport, so trying to get a close match on the induction length to not mess up the fueling too much. 

 

Having said that, i would be interested in the emerald maps as i have the software and could manually transpose the numbers in the ignition tables. 

I will message you with an email address if that is ok.

Thanks

Ian

[dave_h34]

Trumpets are 100mm on mine if that helps.

[Molecular--Bob]

Hi Adam

Maps have landed, will take a look this evening

Thanks.

Dave, 

I am after the distance from the head to the end of the 100mm trumpet if you have it? 

Ian B.

[John Vine]

I've just measured the RBs on my R400D:

Trumpet = 100

Carbon backplate = 2

Rear of backplate to head (top edge of RB flange) = 87     This was tricky to measure accurately as the backplate gets in the way.

So, 189 in all,

JV

 

[Molecular--Bob]

Hi John

That number is perfect thanks, gives me something to aim at. I am expecting to have to mess with the fueling anyway, but if I can get close then I can use the DTA target AFR function / Data log to dial it in to the point where I will be able to do a short Rolling road session to get it spot on.

looks like I can get within ~6mm of this if I use the 118mm dcoe style bodies and the shortest air horns they do. 

[cr500dom]

Dont go dcoe bodies on a Duratec, Jenvey and AT power both do Direct to head bodies which are much better.

You want the butterfly as close to the head as possible too and DCOE bodies wont allow you to do that.

If you are trying to get close on maps, then you need the throttle position to be similar to the Roller Barrel position too or it doesnt work.

TBH you are better off fitting the right hardware, a lambda guage and mapping it on the road will get you close enough to not do any damage.

But I wouldnt comprimise the performance because of hardware just to save yourself an hours mapping.

[Molecular--Bob]

Its a case of using what I have to be honest, having said that I have 4 sets to choose from. I have 45 and 48 dcoe style bodies, with the Jenvey angled inlet, or a set sf tapered bodies with either 45 or 48mm plates. I am only aiming for 200ish hp so I think the 48s will be overkill as you can make 240hp on a Duratec with 45dcoe style bodies, and to some extent you loose low end driveability with the bigger throttle plates. 

I have a wide band and the ecu can log the output so I stand a chance of getting a decent map with the one I have as a starting point.

[Pendennis]

You don't lose low end drive ability with bigger throttle bodies, plates or whatever you want to call it 

[7 wonders of the world]

The centres on the DCOE style TB's are nigh on the same as the ports on a Duratec ISTR only 3mm out between cylinders 2-3 so the difference is negliable.

The butterfly position in relation to the head is dictated by the manifold length in the case of DCOE style TB's so don't discount using these based on the previous comment.

Also getting the butterfly as close to the head as possible is incorrect.

So long as your using the correct TB manifold and not a carb manifold you'll have no issues.

[cr500dom]

A number of years designing engines and induction systems including Throttle bodies means I stand by what I said regarding throttle position.

M-Bob, If you already have the Bodies then that's different.

The theory says you lose port velocity with a bigger diameter, (Which was always more of an issue with carbs) in practice its less of an issue.

I`d use the smallest bodies that will give you the power output you seek, but be aware, power is addictive.

If you go 48's I doubt you will lose any noticeable driveability over 45's but you will not be choking it at higher revs.

All in my humble opinion of course, you are free to use whichever internet wisdom you choose 

[Pendennis]

Well said.

Quite correct, in theory you lose velocity with bigger bores, although as you know it's relevant to flow rate of head, so what velocity suits 'his' head?

And as you know high velocity means higher resistance pressure which may hinder efficiency. I'd of thought in theory your better off with lower air velocity.

I presume the butterfly being nearer the head encourages more air turbulence to enter as opposed less being further away, does that encourage more fuel/air mix saturation?

My 2L Duratec uses 50mm DTH Jenveys and they are ported, admittadly the head has had some work but FYI it drives as nice as my day to day Ford Focus.

[cr500dom]

Higher port velocity means greater cylinder filling in most situations, it would always be my preference to increase rather than decrease port velocities.

It also helps with fuel mixing and tumble. 

Butterfly closer to the head is better for transient response and drivability, this is difficult with a traditional DCOE style body because of the manifold required.

Direct to head allows you to position the butterfly much closer than a DCOE style.

50's on a 2.0L sounds like a serious motor ? 9000rpm ? and 250+ hp ?

[cr500dom]

Some engines just dont need big throttles, The sigma, we did an oval blade with an effective diameter of 42mm, which is fine for over 200hp

We built a set at 45mm for testing with a customer who was convinced they were strangling the motor at the top end.

It made no more power but lost torque everywhere else with teh larger throttles.

What made a much bigger difference was intake length, both on top end power and lower end torque.

Most ITB systems, even on 16V engines have intake lengths that are really too short.

My Sigma set of direct to head throttles have something like 180-190mm trumpet length behind the butterfly and my Zetec (On jenvey dcoe bodies as thats what was fitted) has probably 150mm post butterfly but has a longer intake tract because of the manifold.

This makes good power with only cams and rod bolts on a std Blacktop crate motor at 205hp but has 160lbs/ft of torque too with a really nice fat curve.

 

[Pendennis]

Hi, yes I didn't imply decrease velocity through the head, just implied if velocity through inlet section too high this may hinder head efficiency thus strangle capability.

yep mines a revver but torque and power is remarkably driveable throughout. No doubt I could of got same result with 48's but doubt the same with 45's.

[Molecular--Bob]

My choices are currently driven by expediency, and will probably go with the 45 sf set up as I have a shiny carbon air box for those, but if packaging wasn't an issue what sort of length of runner would you like to run on a stock 2.0 Duratec with high port head?

Interested in the throttle plate position question as I had a look at the SBD set up and it seems to put them a long way from the head, as does the Raceco direct to head setup. 

Always good to hear from people who actually know something learnt in the real world. 

[cr500dom]

Every engine is different, Id want to try a selection of different lengths on the dyno to get the optimum.

Port design and cam timing will have a bearing on what will work, too many variables without running a proper 1D simulation to get somewhere close.

Dave Walker (emerald) has adjustable length trumpets available, might be worth seeing if he does a set to suit your Bodies ?

As for throttle plate position, very often this is driven by packaging rather than what is optimum for the particular engine.

Also the Jenvey pattern tooling and casting process is somewhat modular, which often drives the spindle position.

 

[7 wonders of the world]

My point regarding throttle position is simply, every engine is different and the correct length for power and driveablilty can only be measure on a flow bench, and proved on the rollers - if as you say closest is best then TB's, either direct, single or other wise, could and would be mounted much closer to the head than they currently are.

You also need to consider what your wanting form the engine in terms of performance which affects this length and injector location - again no simple answer and many ways of achieving similar results, RB's with multi hole in head injectors or Seperate TB's with single hole Picos in the TB.

 

Dave Walker does have adjustable lengths inlets for 45's and possibly now 48's too, though the didn't the last time i was over there with one of my clients engines.

Theres nothing wrong with the DCOE pattern TB's as when coupled with the current Jenvey TB manifold they offer the same mounting angle and alignment as the direct to head, though you will need to be creative with spacers if you go over 48mm as this is the limit for porting the std 2.0/2,3 manifold.

Inducing too much turbulance too near the head can be counter productive as this backs up at the point the ports seperate which can effect the swirl - again playing on the flowbench shows all sorts of results, port size, shape and finish well thats a can of worms for another day.

Packaging true, which is possible one reason CC use RB's as compared with butterflys their performance is less effective during transient throttle.