Spark Plugs for Rotrex Supercharger

[phaznet]

Hey all,

I recently installed the Rotrex c15-60 supercharger kit from Power Enterprise.

Yesterday I installed a set of NGK BRK7EIX spark plugs after reading that with S/C applications people recommend going with a colder spark plug and a narrower spark plug gap. Afterwards I got a CEL that read misfires in all cylinders (along with knocking), so I took the NGKs out (they were covered in carbon deposits) and replaced them with the stock Densos. However, since I have reinstalled the old spark plugs I find that the acceleration is a bit sluggish and there's still a bit of knocking, but no misfires.

Can anyone advise what I should do next?

[WeeYari]

Are you running a higher octane fuel now? S/C doesn't like 87.

Sent from my Elite_5_5_Octa using Tapatalk

[phaznet]

Are you running a higher octane fuel now? S/C doesn't like 87.

Sent from my Elite_5_5_Octa using Tapatalk

Yes I am running 94 octane atm

[Tima122]

Ставь 7-ки

[phaznet]

Ставь 7-ки

Google translate: Bet 7

I don't know what you mean, sorry :frown:

[atomic_hoji]

:eek: d00d you can't just casually post "I installed a rotrex..." like that - thread on install and setup needed asap! lol

My suggestion was going to be add a degree colder plugs, but clearly that wasn't working for you... Are you all setup to monitor air-fuel, fuel trims, etc..? Possible spark is fine and you're leaning way out?

-- Adam

[phaznet]

:eek: d00d you can't just casually post "I installed a rotrex..." like that - thread on install and setup needed asap! lol

My suggestion was going to be add a degree colder plugs, but clearly that wasn't working for you... Are you all setup to monitor air-fuel, fuel trims, etc..? Possible spark is fine and you're leaning way out?

-- Adam

My bad I should have posted an install thread...:tongue:

I went two degrees colder. I read somewhere that they recommend a spark plug with a heat rating of 7. Maybe I should try the 6? In that case should I go with the OEM gap of 0.044, or should I go narrower?

I do have a CEL that's showing 2 codes:

P2195 - Oxygen Air/Fuel Sensor Signal Stuck Lean Bank 1 Sensor 1
P0171 - Air/Fuel Mixture System Lean Bank 1


Other than the occasional knocking the car is running fine.

[SirDigby]

what are you using for fuel management?

[phaznet]

I believe its the Split Second PSC1-001 Programmable Signal Calibrator, but I haven't tinkered with it yet...

[Fluxtasy]

I'm also using NGK's BKR7EIX on a NA setup. Thai modders swear by this plugs over Denso. I'm not sure if my minor issues are due to this plugs; rough starts during morning & slight engine knocking at low rpms.

[atomic_hoji]

Hmm.. I'm by no means an expert, but from what I've read 2 temps cooler and tighten up the plug gap is the way to go.

Those are definitely the OBD2 codes I'd expect if you're running too lean. P0171 I'm familiar with, the P2195 I had to look-up, but it sounds like you're leaning out to the point that the ECM can't compensate. Not knowing how you're fuel management is setup with the Signal Calibrator I don't know what to say other than give her more fuel! :biggrin:

In all seriousness, you're running really lean, so my guess is add fuel and get closer to stoich. and then see if the cooler plugs work for you.

Ideas that come to mind..
Does the Power Enterprise kit come pre-mapped? Any chance the map got cleared / defaulted?
Kit came with bigger injectors? Injectors and everything all installed? (i.e. not mid-install and 'trying it out')
Connections all good (and correct) to interrupt the signals to the ECM?

-- Adam

[Bluevitz-rs]

you don't need colder plugs unless you're making about 100hp over stock or it's a dedicated race car. Colder plugs with just foul up because they're not getting to operating temps to burn away carbon deposits as the stock heat range is designed for.

Figure out your AFR before messing with anything else. If you're getting knock, you're running lean.

[phaznet]

Does the Power Enterprise kit come pre-mapped? Any chance the map got cleared / defaulted?
Yes, it comes pre-mapped. I don't know if it was cleared or not.
Kit came with bigger injectors? Injectors and everything all installed? (i.e. not mid-install and 'trying it out')
Yes, the kit came with (used) 1ZZ injectors, and they were installed. The only thing I haven't done is solder the connections to the ECU (in case I messed something up).
Connections all good (and correct) to interrupt the signals to the ECM?
Yes, I verified again today and all the connections are solid and going to where they need to.
And you're all right, I'm running very lean. I checked AFR and it showed a Lambda value of 1.20, so 17.6.

[atomic_hoji]

Hmm.. I think I'd dive into the tune to be honest. I've never heard of the Split Second PSC1-001 Programmable Signal Calibrator, so no idea how easy / difficult it is to play with or what it uses for software, but it's probably the best place to start delving into. See what you can do to push some more fuel and get out of this lean condition.

p.s. not trying to be pedantic, just trying to get an idea of your setup to see what I can throw out for ideas.. :thumbsup:

Keep us posted what you get into!

-- Adam

[SirDigby]

where is your fuel pressure? is it a return system?
can you check the duty cycle of your injectors?
can you check the spray pattern of injectors? used parts my have set around for a wile and varnished up.
you have a fuel issue somewhere. i would guess it's ECU...

[atomic_hoji]

Any luck with your lean condition? Curious to know how you made out if you've had a chance to look at it..

-- Adam

[phaznet]

Thanks for the responses everyone :)

I connected to the piggyback ECU via Split Second's R4 software and verified that it was working properly and had fuel maps loaded.
The AFR reading stays fixed at 18.12/1. I'm wondering if it's normal that the piggyback ecu forces the AFR sensor to read lean.
Other than that the car and supercharger seem to run fine; I only get a knock on engine startup.

[phaznet]

I think the problem might be with the o2/AFR sensor because it only shows an AFR (measured) value of 18.12, regardless of throttle input. The commanded AFR value, however, does oscillate.
Or, is the piggyback messing with the o2 sensor signal to force it into open loop?

Short term fuel trims are sitting around +20% at idle!

Still, I think i'm going to bring it to a tuner to have a look.

[atomic_hoji]

:thumbsup:

Glad you made a bit of progress. Getting it checked by a tuner is probably worth a bit invested to avoid long term issues..

Keep us posted!
-- Adam

[CrankyOldMan]

Have you done a leak check? My Blitz kit would get really unhappy if there was a leak in the intake side. Grab a can of brake cleaner, spray a little bit at a time around the intake parts. If the engine surges, you've got a leak in that area.

[phaznet]

Yes I've performed a leak test, actually 3 or 4 times!