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2litre Zetec max power at what RPM?
will121 - 23/7/08 at 12:20 PM

ive also got a 2litre zetec silver top engine in a Fiesta, it has been on a rolling road and produced 127bhp @6000rpm, ive since initally removed the cat and now fitted a tubular manifold and had it back on the Rolling road, its increased max power to 133bhp but reduced the peak to 5200rpm making it slower overall, is removal of the cat effected the back pressure and shifted the peak revs or am i missing something cant believe its slower by removing it!
Has any one else got details of their zetec on a rolling road removed their cat with simular effect?

nitram38 - 23/7/08 at 12:38 PM

I think that your tubular manifold change has more to do with your peak power change.
Different configurations of 4-2-1 and 4-1 and pipe lengths will affect this.

[Edited on 23/7/2008 by nitram38]

Dusty - 23/7/08 at 12:43 PM

My last session shows max power at 6230. Doesn't have a cat.
I suspect you have made quite a significant change to the exhaust system. You need to make the same level of changes to the rest of the breathing system, induction, head and cam to release the power that has gone 'missing'.

JAG - 23/7/08 at 12:47 PM

How is 133bhp slower than 127bhp?

You now have more power but at a slightly lower engine speed. More torque at lower rpm - not slower exactly just different. Perhaps a lower top speed (only maybe depends on gear ratios) but better acceleration.

will121 - 23/7/08 at 01:20 PM

quote:
Originally posted by JAG
How is 133bhp slower than 127bhp?

You now have more power but at a slightly lower engine speed. More torque at lower rpm - not slower exactly just different. Perhaps a lower top speed (only maybe depends on gear ratios) but better acceleration.


As you say its better mid range acceleration but slower max speed, half way down the straight at Snetterton tops out at 110mph at about 5200rpm where power now tails off quite sharply where as before may have took a bit longer to get there but would have nearly pulled 120mph

JAG - 23/7/08 at 01:40 PM

I can see what you're saying but find it difficult to believe that 5bhp has made a difference of 10mph at 110mph.

As the others have suggested; you need to improve the induction side of the engine in the same way that you have improved the exhaust side. This should lead to keeping the current imcrease in power whilst adding that extra top end that you want.

What sort of induction are you using? If it's the standard stuff then a set of bike throttle bodies and an ECU will help

big_wasa - 23/7/08 at 03:13 PM

are you still using the lambada sensor in your new manifold ?

the_fbi - 23/7/08 at 07:30 PM

You need to up your rolling radius to change your gearing to take advantage of your increased torque lower down.

On a twisty circuit you'll be faster now than you were, on a long straight'y circuit you'll be slower till you up your rolling radius.

Best value for money change would be to add throttle bodies or bike carbs which will be partially offset by the saving in new tyres (& possibly wheels too) and give you more power all round, especially where you've just "lost" it.

Presuming you're running EEC-IV, and have the budget, then megasquirt with the EEC-IV adaptor board + a set of bike throttle bodies would be easy to implement and save chopping looms around if you ever wanted to go back to the EEC-IV. You should be looking at an easy 30bhp from that.

[Edited on 23/7/08 by the_fbi]

will121 - 23/7/08 at 08:46 PM

quote:
Originally posted by big_wasa
are you still using the lambada sensor in your new manifold ?

Yes just fitted a new Lambda sensor as well its got approx 0.8v output when warmed but doesnt seem to make that much differance when unpluged

[Edited on 23/7/08 by will121]

will121 - 23/7/08 at 08:49 PM

quote:
Originally posted by the_fbi
You need to up your rolling radius to change your gearing to take advantage of your increased torque lower down.

On a twisty circuit you'll be faster now than you were, on a long straight'y circuit you'll be slower till you up your rolling radius.

Best value for money change would be to add throttle bodies or bike carbs which will be partially offset by the saving in new tyres (& possibly wheels too) and give you more power all round, especially where you've just "lost" it.

Presuming you're running EEC-V, and have the budget, then megasquirt with the EEC-V adaptor board + a set of bike throttle bodies would be easy to implement and save chopping looms around if you ever wanted to go back to the EEC-V. You should be looking at an easy 30bhp from that.


and was looking at upping to 50 profile tyres from 45 to make the most of the lower peak but difficult as limited wheel arch space, its running standard RS1800/2litres management at mo is the megasquirt adaptor board more of a plug and play?

big_wasa - 23/7/08 at 09:24 PM

quote:
Originally posted by will121
quote:
Originally posted by big_wasa
are you still using the lambada sensor in your new manifold ?

Yes just fitted a new Lambda sensor as well its got approx 0.8v output when warmed but doesnt seem to make that much differance when unpluged

[Edited on 23/7/08 by will121]



engine should run closed loop when warm . So there should be a differance when unpluged, have you looked for any fault codes.

Again I asume you are using the eec-iv ?

the_fbi - 23/7/08 at 09:27 PM

quote:
Originally posted by will121
its running standard RS1800/2litres management at mo is the megasquirt adaptor board more of a plug and play?

Firstly just let me correct my EEC-V statement, I meant EEC-IV, V was way way later (no idea what my fingers were typing!)

Was the engine initially a 1.8 or was it always a 2L? The 2L MAF is larger than the 1.8's and worth fitting (if it was a 1.8 engine).

Whilst its the same bhp, I can't see any benefit of running the RS1800 ECU instead of the 2L's proper one unless there's some immobiliser reason? The RS and the 2L don't run the same FPR/injectors etc do they?

The Megasquirt adaptor board is for an EEC-IV, which would have been in a 2L Mondeo silvertop. If you've got a 60 pin EEC-IV (as per http://www.auto-diagnostics.info/ford_eec_iv ) then the adaptor board will simply plug into the loom and to a Megasquirt and away you go. Even on your current injector/inlet setup.

Then again, thats just being lazy, there are plenty of people on here who can talk you through making your own loom/connections without buying the adaptor board.

http://www.mtechautomotive.co.uk/FordEEC.htm

[Edited on 23/7/08 by the_fbi]