Knock retard on FD

[Ricco_04]

Generally speaking, most people on here would say to get a re-mappable ECU asap with a full de-cat and Apexi PFC being the weapon of choice at the mo.

[bnaellis]

Thanks Brian, thats helpfull stuff!

Btw, \'normal\' cars have the same setup with a piezoelectric microphone stuck on the engine which listens for the sound of knock, but can sometimes be fooled by other noises too! :rolleyes:

I\'m going to look at a rx7 over the weekend which has a full decat exhaust running a stock ECU (i think) - should i be worried?

Cheers, Paul.

If the car is sound and your happy with it, buy it but don\'t give it wot until you get a standalone ecu fitted and mapped.

[vxer]

Is there a ECU on the level of quality and price with the APC which does have active knock retard?

I\'m wary of not having that feature...  :eek

Those with the PFC, do you get it mapped on 95 or 98 octane?

Cheers, Paul.

[Ricco_04]

I will get mine mapped for 98RON.  My car will take 95RON being UK but as I always use the good stuff then I may as well take the advantages of it too  :mmmm

[vxer]

I will get mine mapped for 98RON.  My car will take 95RON being UK but as I always use the good stuff then I may as well take the advantages of it too  :mmmm

I was just thinking if theres no knock retard on the PFC and you get it mapped for 98, what happens if you are unable to find 98 one day when you need to fill up? You\'d have to be very careful otherwise you risk frying the engine!  :2eek

Ta, Paul.

[Ricco_04]

As long as you try to lay off the boost then you should be ok.  You could always keep a bottle of booster juce behind the seat should this happen.

[vxer]

As long as you try to lay off the boost then you should be ok.  You could always keep a bottle of booster juce behind the seat should this happen.

If you got it mapped for 95 would it be able to adjust for the better if you put 98 in? I\'m guessing not...

Ta, Paul.

[rx7veilside]

map to 98 and keep one bottle of booster for emergency..off boost will be no problem will lower octane

[shaunwil]

You will probably find that the tuner won\'t tune it too lean. They will always have a safety limit where you to get a bad batch of fuel (even with 98 ron) and the knock reading is higher it won\'t kill the engine as easily.

Shaun

[20B_boy]

You\'ll probably have broken an apex seal before your ecu retards the ignition

[andyrose]

i ran my import type R (with induction & exhaust mods) for 2 years on the std ECU and i must admit the i used 95 and 98 octane fuel.
I never abused the car (except a regular once a week WOT).
Maybe i have been lucky (touch wood) my engine is still in one piece and compression is still very high.
i fitted an apexi PFC, ran it on th base map and found it was running nice and rich (popping on overrun and off throttle) then had it mapped (by one of the reputabel companys) and i\'ve noticed my knock levels are alot higher now and when i have gone WOT my heat light flashes with occasional fuel cut (as it feels like it bogs down), so i\'m resetting to the base map cause i\'m worried about it going pop.
I have been lucky....................alot of others havn\'t.........be careful

[20B_boy]

i\'ve noticed my knock levels are alot higher now and when i have gone WOT my heat light flashes with occasional fuel cut

The \'knock\' level on the commander and heat light goin I wouldnt have necessarily said was a big deal (I get huge readings and lots of flashing flogging it round the nurburgring - but theres no audible detonation and never is on the numerous times te car is on the dyno; besides it wouldve **** it self long ago if the readings were \'proper\') BUT - theres no reason that you should be hitting any kind of cut...

Speak to whomever mapped it dude, and get it back there to get checked out. I wouldnt necessarily reset it, unless you can save the map first with datalogit (which I assume u dont own). Just use gentle throttle esp around peak torque in th emean time

[andyrose]

cheers for the info 20B boy
my mapper did ask what i wanted it set up for. i told him everthing except going pop. it was mapped (injectors maxing out @ top end) so boost was turned down to suit but even then my mapper said \'its ok for occassional bursts but nothing too prolonged\'.
on the drive home (3hr trip) it was ok in short burts but now i can\'t even do that without it \'bogging down\'.
Your right i don\'t own a datalogit and as i\'m in the middle of the \'fens\' i\'m kinda stuck with regard to dyno/mappers so reset to base it will be (until i buy an uprated pump & injectors then its going to be mapped again)
don\'t worry i always drive with gentle throttle (girls blouse me)

[vxer]

...was running nice and rich (popping on overrun and off throttle)

I\'m gonna pull you up on this (i\'ve heard a couple of other ppl say that as well) :

On the overrun unused fuel is dumped into the exhaust which causes the pop. Its nothing to do with you running rich or lean, it simply that the engine doesn\'t need to burn the fuel because you\'ve lifted off, so it goes into the exhaust.

Can an expert confirm..?  :confused:

Cheers, Paul.

[rx7veilside]

it does make a difference whether car is running rich or lean..a properly mapped car not really pop on overun as amount of unused fuel is small..but a car that is running rich on lift off will have more fuel left to throw out the exhaust which will ignite on the way..