Help!!! acceleration problem power increase at 7500rpm
 

Help!!! acceleration problem:icon5: power increase at 7500rpm:icon5:

Only had my 04 231hp RX8 for about 2 months and never even noticed a problem until watching some videos on youtube etc and other rx8's accelerating. It can only be described as having even power right the way through to 7500rpm and then a real power surge/ powerband right through to redline in every gear. (very similar to Honda's Type-R engine) Thought this was normal as not had an RX8 before :/ Now startiing to wonder if it is really underpowered and only getting full power at 7500rpm???
Coil packs, plugs etc changed only 2000miles ago. No engine management lights or anything?? Car is on 04 plate, 52kmiles and FSH. Please help guys - new to this :dunno: thanks

Apologies if i have posted this in the wrong section or has been discussed before but spent hours trying to find a similar problem but to no avail !

Could be closed loop vs open loop. If your ECU is staying in closed loop for some reason, and you are hitting an ECU kick-over point where it forces you into open loop, it could do this. Would only really be a problem if the front O2 sensor isn't reading normally, making you too rich or too lean until it hits open loop for the better open loop table.

Do you have any way of reading ODB2 data? Can you see if the kick happens when the ECU goes from closed loop to open loop?

Thanks for the help, will look into this. So I take it there shouldn't be any sudden surges of power after 7500rpm to redline and should actually just be smooth power right the way through? Thanks again!

How would i know whether the ecu is in open/closed loop? or how would i test the 02 sensor?
Thanks

Correct, no surge at all. Maybe a faint extra gentle push from the variable intake valve opening, but not something you would write home about.


You will have to get or borrow an ODB2 data reader that can watch live engine data, specifically the fuel system status, while you drive. A passenger helps alot here.

It's hard to test the O2 sensor, since most places rely on the CEL ("if you don't have a CEL, it's fine!") but it can indeed fail and start giving bad readings without throwing a CEL. Unfortunately, replacing it is usually the only way of confirming it as bad when you don't have a CEL.