Rb25 Pinging

[elemenohpee]

Ok here's the story, i just got some bits and pieces bolted onto my engine and now when it was getting tuned the boost was wound up to 13psi and then if any more boost was put in or timing put in the engine started to ping.

The exact mods are:

FMIC, 3" turbo back exhaust, low mounted biago turbo (same size wheels as t03/04e but smaller housings), z32 AFM, z32 ECU with nistune, nismo 740cc SF injectors, catch can.

Original thoughts were that the cat converter in the exhaust may have been creating too much back pressure so the cat was removed and still the enging detonated at 13psi, second thought was that the rocker covers were being presurised so fitted a catch can and still engine detonated at 13psi.

Any thoughts or tips would be appreciated, but no stupid comments please.

Thanks all

[R34GT-t_07]

what type of FMIC do u have that could be causing problems, a friend of mine had similar problem as u and it turned out that the FMIC that he had was not up to the task of holding 250 at the rears and was making the engine ping do to lack of air-flow.

hope this helps.

[JonnoHR31]

if any more boost was put in or timing put in the engine started to ping.

was it pinging with very little timing or were you expecting to be able to smash as much timing in as you like with no knock?

[Dorifta]

pinging, detonation, knocking is caused by insufficient octane level or too much heat, dont go past the fuel, crack a line, one whiff will tell u if its premium, bad air fuel ratios, try adding more fuel to cool charge depending on ratios, heat soak, incorrectly positioned dyno fans or insufficient cool down betweeen runs.

Edited October 9, 2009 by Dorifta

[JonnoHR31]

or too much timing, the most likely cause in this case

[Dose Pipe Sutututu]

post up your timing maps, at least that will give us an idea

[Guilt-Toy]

Yeah good idea. Because every RB25 can handle the exact same amount of ignition timing. We will be able to find the problem by looking at the timing maps straight away.

post up your timing maps, at least that will give us an idea

[JonnoHR31]

isnt it 14.7 at full boooost?

[Dorifta]

or too much timing, the most likely cause in this case

I agree, but amount of timing u can run is directly related to octane rating of your fuel

[Cjmartz2k]

isnt it 14.7 at full boooost?

LOL, I hope you are joking.

[mad082]

what are the afr's doing when it's pinging?

some possible causes are:

you could have 1 cylinder that is leaning out so while the afr's are ok when taking from after the turbo are all fine, you could have 5 cylinders running rich and 1 running lean as anything and that is what is pinging. pull out your plugs and see what they look like and make sure they all look the same.

it could also be that your exhaust cam is a tooth out on the timing belt so while you think you are at 15 degrees, it is actually at 30 degrees or something like that.

what are your engine temps doing? if the cooling system isn't working that well then your engine temps cause be contributing to the pinging

[elemenohpee]

thanks for all the replies guys it gives me a few more roads to go down to stop the pinging.

R34GT-t_07 - my FMIC is a greddy kit but the pipe work isn't all that thick so it may be another thing.

I'll have to find the dyno print outs and see what the timing is doing, but if we put a heap of timing and pulled boost out it would ping and if we pulled timing out and put boost in we still got the exact same result.

[STATUS]

thanks for all the replies guys it gives me a few more roads to go down to stop the pinging.

R34GT-t_07 - my FMIC is a greddy kit but the pipe work isn't all that thick so it may be another thing.

I'll have to find the dyno print outs and see what the timing is doing, but if we put a heap of timing and pulled boost out it would ping and if we pulled timing out and put boost in we still got the exact same result.

weve run close to 400rwkw through the Greddy ls kit, so scrap that idea.

[JonnoHR31]

but if we put a heap of timing and pulled boost out it would ping and if we pulled timing out and put boost in we still got the exact same result.

all cars with your setup will do that on normal fuel when you push them to the limit. theres only something wrong if its pinging with very little timing or if its making stupidly low power

and if there isnt anything wrong and you get the same result either way then run with less boost and slightly more timing

[Guilt-Toy]

this thread is useless. take the car to a good nistune tuner. Go see Yavus at Unigroup Engineering.

[Cjmartz2k]

this thread is useless. take the car to a good nistune tuner.