Ex-Finesse

Afternoon all..

I have a 2045cc zetec being built, and we will be using a Weber Alpha throttle body kit.

It will be installed in a mk6 escort, which will see lots of use on the track next year. Main objective with the engine is a smooth power band from 4000 to 7500, not just a peak power figure.

I have the complete 40mm throttle body kit which is sold for the 1.8 zetec. 45mm throttle bodies are sold for the 2.0 zetec.

I hope the smaller TBs will give a smoother power curve, and more torque in the mid-range due to higher air velocity.

I was just wondering if anyone has used 40mm bodies on a similiar engine, or knows of the effect of changing sizes of throttle bodies?

Any help would be class..

Johnny Knoxville

I mate of mine was told not to bother with the Alpha management with a turbo engine. Ian Howell use that management the first time he ever did a zetec turbo and he had nothing but bother so i've been told.

Ex-Finesse

It's not going to be a turbo engine! Staying N/A

I'm heavily against N/A zetec tuning given the small torque gains unles you spend mega money... but I managed to buy my mates car at a silly low price, which had a mega 1.8 on this throttle body kit!

Basic spec:

Forged pistons, 11:1CR
Shotpeened rods
Balanced crank
Aluminium flywheel
Well ported head, with solid lifters and uprated valve springs
Rev limit in the region of 7600rpm

Had a thought earlier; what size are bike carbs / bodies? Haven't heard problems with them maxxing out at high revs!?

Mike C

iTrader: (1)

should be good on the track next year, just watch out for obstacles such as slow-moving Lambos this time

NUTS RuS

iTrader: (35)

As your not after ultimate high power it should be fine on 40mm, would possibly make a little more on 45's but thats not your oblective is it.

7600 isn't high revs. My engine peaks at 9000+ on similar

Ex-Finesse

That was exaclty my thought process.. just wanted some other opinions in case I was talking B/S LOL!!

What's your spec? I'm not actually sure what a safe limit for shotpeened rods would be, but I think standard ones are risky above 7500?

It made peak power @ 6500 on a 1.8 with hydraulic lifters, so I hope changing to solids will shift that up a bit. Peak around 7000 would be my ideal

NUTS RuS

iTrader: (35)

It's not a Ford engine mate the bottom end is all but completely standard. Sod all that Ford tuning lark.... way too costly

Ex-Finesse

Amen..

Does anyone have experience of using an aluminium flywheel on a zetec? I looked into this alot.

I know it's going to take away ease-of-driving, especially pulling away, but I'm happy to sacrifice that. Far from a daily car..

Apparently it'll also handle the harshness of a paddle clutch better, too?

Cheers..

neilm

What you want my friend are these !

Titan Roller Barrels, The 40mm ones flow the same air as a 43mm throttle body as there is no restriction when they are on full throttle...



They arent the cheapest things in the world....

40mm is really too small for a 2.0, especially when you are looking at a tuned 2.0

But the 40mm Barrels may give you what you want.

They are new to the market but I do re-sell them. E-mail / PM me if you want further details, price etc

What I can say, in a recent test on a 2.0 Duratec they gave 8BHP more than the equivilant throttle bodies and a tad more torque.


And for all the doubters, check last months Classic Ford with Colin Mcraes Ultimate MkII Escort in...... what was on his Millington motor ?.... WEBER ALPHA !!! If its good enough for Colin.. its good enough for me

Ex-Finesse

Those do indeed look rather sexual...

As said, no harm in just finding out prices..

You really beleive 40mm are too small?

neilm

They sound rather sexual as well apparently


I can only go off what Dave Colledge at Retro Ford tells me and our mutual customer who runs 45's on his Anglia with a 2.0 in it.

sambo170588

link for zetec throttle bodies please????

It's Czech Mate

Out of fucking nowhere!!!??

and seeing as you asked so nicely NOT........google it!

sambo170588

mondeo man junction 27 put ure money were ure motuh is and race me bitch

It's Czech Mate

I'll meet you there at 3am tonight...i'll be in a silver mondeo estate with a surprise

OldDan

"Butterflies, barrels or slides?



20 years ago, carburettors and mechanical fuel injection were the only choice to fuel a racing car engine. Selection of air valve type was simple and, apparently, carved in stone: carburettors used butterflies and injection used slide throttles. Motor Bikes and their history are a special case but what follows is true for any performance 4-stroke petrol engine.
With the advent of electronic fuel injection and a more adventurous (better funded) approach from the leading engine designers, it was discovered that butterflies, whilst sometimes (but not always) giving slightly less power than slides, inevitably gave better lap times. The explanation was simple; butterflies give more progressive throttle control, improved transient conditions and aid mixture quality throughout the RPM range.

As a result of these discoveries most (possibly all) of the leading car race engine manufacturers switched to using butterflies. Lap times continued to tumble, but there was a problem brewing for the future.

As peak RPM increased year by year, the required induction system length reduced. At the same time, the ideal butterfly to valve distance ( see FAQ's, positioning) increased. Over about 15,000 rpm, the ideal butterfly position falls outside the induction system - clearly useless. Enter the barrel.

The barrel has some, but not all of the attributes of a butterfly. Opening is reasonable progressive and, like the butterfly, it is easily packaged. The great advantage is that it can be made as a continuation of the port shape, regardless of profile (slides would overlap), and thus be placed near or even in the cylinder head, allowing for a very short system to suit the 18,000+ RPM which is now common. Any compromises (poor idle control, tendency to stick, poor flow vector control, etc.) were once believed to be offset by the sheer power available at these RPM although once again, most (possibly all) of the leading car race engine manufacturers (e.g. F1) had switched back to using butterflies by 2006. It follows that barrels on a sub 15,000 RPM engine will suffer from the compromises without gaining the possible benefits. **

The main advantage of the barrel - maintenance of port profile - can be obtained by using fully profiled butterflies. These are made to precisely fit the port profile and are shaped in cross-section to achieve the required characteristics; minimum drag, controlled turbulence or whatever else best suits the application. This is now the preferred solution for top-end engines used in Formula 1, World Super Bikes and some sports-racing engines. Jenvey Dynamics supply these for specific applications since they must be designed to suit the engine and cylinder head used.

In summary;
Butterflies are best wherever they can be used. Jenvey Dynamics have a design and make service for engine - specific profiled butterfly bodies.
Barrels are suitable only for engines running at over 15,000 RPM and must be designed to suit a particular engine type. Jenvey Dynamics have a design and make service for engine - specific barrel bodies.
Slide throttles are best reserved for classics, if the rules prohibit a change.

** In a back-to-backcomparison, using a Rover K series engine in race trim, Jenvey road - going butterfly bodies were found to give significantly more power at all RPM when tested against barrels (not ours!). Full race butterfly bodies would further increase the margin. Whilst the power improvements are unlikely to be found in all engine types, the performance gains almost certainly will.

Mar07"