Pinto N4b CAM change experiences?
Hello.
I own a sierra with the N4b engine, with cat and oxygen sensor, or lambdasond as we say in Sweden..
Calalyst is removed by previous owners.
The fuel injection on this engine use both air flow meter and a MAP-sensor as i understand?
How does this react to camshaft changes?
I have read trough the forum and dream about more power, altough I only use the car to drive to work..
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Mattias
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Re: Pinto N4b CAM change experiences?
badly! i think kent FR34 is ok, anything more will upset it
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Pit Crew
Re: Pinto N4b CAM change experiences?
I have driven a Pinto with that management with both a NH206 (quite close to the FR34) and a RL22 or something.
The NH206 was pretty much OK but the RL22 didn't run very nice - the biggest problem being the rev limiter stopping the fun just as it begun.
I would say an FR34 would work fine BUT the low power (105 bhp) is mostly from the lower compression in that engine. A cam swap without fixing the compression ratio will not do very much good.
The engine management is also rather adaptive so any changes you make to alter fuelling will gradually be reverted as the ECU learns that the engine runs richer than standard.
All in all, it is not the best base for tuning. Just swapping in a high compression Pinto with the earlier non-cat ECU (and adapted wiring harness!) would be the best way forward, if you can live with it being not not really legal in Sweden.
Gustaf
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Re: Pinto N4b CAM change experiences?
Are there no mechanical differences betwen the 115hp efi engine and the 100hp efi enginge except the compression ratio? And that is around half a point of difference? Is that worth the whole 15hp aside from the restriction in exhaust flow from the catalyst?
I am aware that the ECU will adjust the mixture at part throttle against the signals from the oxygen sensor, but that can be both positive and negative I guess.. At full throttle I guess it still runs against a fixed tuning map of som sort.
The KCFR30K, how does that compare to the fr34? They are both, as I understand it, listed to work with Ford EFI?
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Pit Crew
Re: Pinto N4b CAM change experiences?
The compression ratio (lower pistons) is the only mechanical difference in the engine itself, but the EFI system is a bit different (different mapping as well as some other sensors used). That combined makes up the power difference.
When I ran the cat management i always got the feeling that the ECU re-learnt the values and it had effect also on the non-lambda controlled areas. As an example, the ECU would detect a rich part-load situation, and pull fuelling all across the range, meaning that my "carefully" set full load mixture would lean out over time.
Swapping to another management system, or remapping the EEC-IV (but there are few tried and tested solutions for the Euro EEV-IVs) is the only viable long term solution IMO.
The FR30 has less duration and lower lift, so I would say it is marginally less likely to upset the EFI. But the NH206 I used is quoted at 281 degrees and worked fine...
Gustaf
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