Power Loss After Splitfires & Changing Plugs

[brentos]

Hi guys,

Car: R33 GTS-T S2.

mods: 3" dump. 3.5"catback exhaust. Catco high flow cat. FMIC. Pod. Exedy heavy duty clutch.

A week ago I was getting the dreaded mis-fire problems in particular after 5000rpm when hitting higher boost. I have now changed the coils to Splitfires. I also changed the spark plugs to BCP6ES-11's and gapped them down to about .8mm. (the plugs previously were Autolite 1.1mm and had burnt tips).

This stopped the misfiring and the car runs and idles fine.

Now i noticed after changing this the car doesn't boost as high and doesn't have as much of a kick back. note the car seems to be fine on the lower revs but doesn't pull as hard when boosting up when higher revs.

My question is.

Have I gapped the plugs too close for what mods i currently have and the very little rwkw my car is actually pulling?

Is it worth while factory reseting the ECU to loose any maps and get the A:F ratios back to normal?

is my car running too rich?

Thanks.

[R 2 THE J]

It'll be running rich man.

I did this too. your fuel is getting burnt better but also your O2 sensor will be reading a lot clearer.

It will show up as Rich...best to reset ECU. Or get a tune!

[Proximity Motorsport]

next time go the 7s for the plugs too, and buy the already gapped at 0.8mm is easily done. I also agree, reset ecu

[R31Nismoid]

Are you saying its not making the same amount of boost?

What is the boost set too?

Does it feel lazy in the mid range and then come good? If so, thats R&R, stock ECU issue with too much airflow

It'll be running rich man.

I did this too. your fuel is getting burnt better but also your O2 sensor will be reading a lot clearer.

It will show up as Rich...best to reset ECU. Or get a tune!

O2 has NOTHING to do with it under load. The stock ECU takes no reference from it.

I think you've posted about O2's being the problem a few times now... So ensure you understand under load the O2 counts for nothing.

Its for cruise only.

[R31Nismoid]

next time go the 7s for the plugs too, and buy the already gapped at 0.8mm is easily done. I also agree, reset ecu

0.7mm you mean as a gap?

Most certainly not. With brand new splitfires and a correctly working ignition on a stocker turbo you should be able to open the gap to 0.9-1.0

I was only running 0.8mm when over 300rwkw/20psi

[brentos]

It'll be running rich man.

I did this too. your fuel is getting burnt better but also your O2 sensor will be reading a lot clearer.

It will show up as Rich...best to reset ECU. Or get a tune!

Cool. Thanks for the fast response man.

Well I was probably trying to avoid a tune at this stage, at least until I can afford a PFC and there was a couple of other minor mods I wanted to do too.

I will try factory resetting the ECU on the weekend.

So I guess I just unplug the battery and pump the brakes or turn on the lights to drain any excess power and let it sit for a hr or so?

Do these ECU's map itself on your driving style? So over driving it for a certain ammount of time it maps itself, is that true?

R 2 THE J When you had your rich problems did the fact reset of ECU have a good affect or at the end of the day will I HAVE to get a tune?

Cheers.

[Merli]

0.7mm you mean as a gap?

Most certainly not. With brand new splitfires and a correctly working ignition on a stocker turbo you should be able to open the gap to 0.9-1.0

I was only running 0.8mm when over 300rwkw/20psi

He was referring to 7's heat range for the plugs dude...

[R31Nismoid]

oic -

still i reckon you can use a better gap than 0.8 for a stock setup and a working igniton system

[paulr33]

check the simple obvious stuff

given youve been in the engine bay messing around with hoses, pipes and crap to get to the plugs and coils

its likely youve left something off, ie leaving off a vacuum hose, will result in unlimited boost, which will result in R&R and the car will run like ass

so check the obvious, check all hoses etc, check what boost pressure you are actually getting too

[brentos]

Are you saying its not making the same amount of boost?

What is the boost set too?

Does it feel lazy in the mid range and then come good? If so, thats R&R, stock ECU issue with too much airflow

O2 has NOTHING to do with it under load. The stock ECU takes no reference from it.

I think you've posted about O2's being the problem a few times now... So ensure you understand under load the O2 counts for nothing.

Its for cruise only.

Thanks for your reply.

Well I am only basing these assumptions of power loss on feel, as I do not have any before and after dyno results to compare.

I didn't physically up the boost with a boost controller but as soon as i got my FMIC, pod + exhaust the flow just seemed better I guess - and the boost was hitting around 11psi generally and in cooler weather, sometimes 12ish.

TBH I haven't checked what boost it is hitting since the splitfires and plugs.

Yeh I guess it feels lazy.

Its just when I flat stick it and at around 4500rpm when the boost used to push it to redline fairly quickly, it just now seems slower reaching redline and doesn't feel like the turbo is spooling as well as before.

Sorry if I am bad at explaining these things, I am still learning.

[R31Nismoid]

I wouldnt be suprised if the factory ECU is having a bit of a fit now the car is running better...

Try backing the boost off to 10psi (easy check), if it feels like it pulls nicely (ie, no worse than it currently is, and possibly better) then its the ECU

If not, perhaps its a mechanic visit if you're not upto checking all things like connections, AFM/AFM plugs and so on

[SiR_RB]

corect me if im wrong but shouldnt the copper plug code be BCPR6ES-1.1 gapped to 0.8?

sounds like R&R, turn boost down to 10psi or less

[brentos]

Cheers guys.

Currently I am not running any boost controller so the boost automaticly jumps up to 11 or 12, depends.

To control and/or lower the boost in order to test, I will have to purchase and install some sort of Boost controller yes? Manual ones OK for this check?

I will be trying the reset of ECU tomorrow when it is light too.

Sir_RB - the plugs I got say on the box BCP6ES-11 but i gapped 'em myself to .8mm.

I hope I got the right ones lol, I am sure i read a recommendation of those sparkplugs somewhere on this forum. It might have been the BCPR6ES-1.1 that was I was after and I was given the wrong ones. I dunno.

[TiTAN]

the ignition system with the stock turbo and brand new coils should be able to run 1.1mm plug gaps perfectly, there should be no need at all to gap them down to 0.8mm.

Yes, a manual T piece style boost controller will be fine for testing. my $22 manual boost controller holds boost fine to redline.

Edited May 5, 2009 by TiTAN

[brentos]

Awesome. I did the factory reset of the stock ECU tonight (only for 5 mins because my alarm went off as it must have a little battery in the alarm that sets it off if the 12v batt is removed). Anyhow after that the car doesn't seem to be running as rich and has that nice lil kickback and responsiveness again when hitting boost up on the higher end of rev range.

[Daz305]

BCPR6ES are these the same spark plugs for a 98 r34 gtt? and with fmic, turbo back exhaust, pod filter, and 10 psi wat should i have em gapped at? i am lookin at gettn more power but i asume they'd need to b changed again b4 then anyway...

[exXU1]

Sir_RB - the plugs I got say on the box BCP6ES-11 but i gapped 'em myself to .8mm.

Wrong plugs - should be resistor BCPR6ES and if that's just a typo, are you sure the car simply is not so surgy as before (i assume you changed the coil pacs because it was misfirring?)It may just feel smoother now or you have a lead to your plugs ass about. 0.9mm is correct at these stock settings.

[brentos]

Sir_RB - the plugs I got say on the box BCP6ES-11 but i gapped 'em myself to .8mm.

Wrong plugs - should be resistor BCPR6ES and if that's just a typo, are you sure the car simply is not so surgy as before (i assume you changed the coil pacs because it was misfirring?)It may just feel smoother now or you have a lead to your plugs ass about. 0.9mm is correct at these stock settings.

Yeah I changed the coils because it was missing and the plugs because the ones in there had burnt tips and was time for a change.

I read about getting the BCP6ES-11 plugs on another part of this forum somewhere, so that is what I got. They only cost me $25 all up so it's no biggy if they need changing again I suppose.

But yes, they definately say 'BCP6ES-11' on the spark plug boxes.

Is it crucial they I get the BCPR6ES plugs? What part does the resistor play anyway?

Yeah it might just not be as surgy, like it is probably just smoother throughout the rev range.

Na, there is no lead to my plugs its just coils into plugs.

Cheers.

[exXU1]

Yeah I changed the coils because it was missing and the plugs because the ones in there had burnt tips and was time for a change.

I read about getting the BCP6ES-11 plugs on another part of this forum somewhere, so that is what I got. They only cost me $25 all up so it's no biggy if they need changing again I suppose.

But yes, they definately say 'BCP6ES-11' on the spark plug boxes.

Is it crucial they I get the BCPR6ES plugs?YES What part does the resistor play anyway?

Yeah it might just not be as surgy, like it is probably just smoother throughout the rev range.

Na, there is no lead to my plugs its just coils into plugs.

Cheers.