Spark Plug Heat Range

[Largekid]

Alrighty, quick motor specs:RB25 bored .80 overP&P HeadPFC w/ commander and datalogitT70 @22lbs680cc injectorsand all supporting mods otherwise

When we were tuning this weekend, once I put it on 22lbs, its started to buck a bit and miss...we figured the plugs had gone, because they were just standard copper NGKs (BKR6's) and it was super fat all over the place before we started. We drove home, I went and changed the plugs to a BKR5 because I thought that was a heat range colder....well its hotter...and ran like dog ****. So I'm wondering what the higher HP RBs/Z32TTs are running for plugs, and if I should look into a BKR7 or just stick w/ the BKR6s? I dont want iridiums because they made my car run very bad too, so far i've had good success w/ the coppers, just running rich is killing them. Also, do you think I should lower my gap a bit? .8mm right now...TIA

[s13point5]

.8mm should be fine. try NGK BCPR7ES (autozone part number is 3330 i believe). ive always suggested copper plugs in turbo motors.

[Largekid]

so you think I may have been missing w/ the 6's? I assume that that model # is for the basic coppers? When I went to AZ the other day, they only had the VPower coppers in stock, and not for my engine. Do they stock that #3330? I'll deff give them a try.

[nissandrftr88]

I run r5671a-9 which are 9's.Stock # 5238.Advance here always has about 30 in stock

[Carl H]

x2 on the bcpr7es @ .8mm gap ngk pn 3330.

[PorkChopExpress]

I did the same thing ngk made there heat ranges the other way around to mess with ya.

[Largekid]

sweet, that settles it! Now to get them in, finish some tuning, and start yanking ppls ****! Maybe even a 11sec pass

[Carl H]

if i can boost 22psi on the 3330's with a rich 11.3:1 full boost afr then you can definately blow thru your mixture with your external coil setup.

[Shocker]

x2 on the bcpr7es @ .8mm gap ngk pn 3330.

Its what I run, also my buddy with with the 720fwhp DSM as well.

[BoostFab]

as i have said it before, and say it again; ngk 3330 (bcpr7es) 7 heat range is the way to go for any boost level

[Largekid]

if i can boost 22psi on the 3330's with a rich 11.3:1 full boost afr then you can definately blow thru your mixture with your external coil setup.

blow thru as in blow the spark out, or have strong spark thru-out? I order them today thru NAPA, going to pick them up after work. They are a Saab plug...weird, but if thats what I need, then thats what I'll take. I'm going to race a S-Trim cobra tonight, so we will see if they hold up to some good boost levels.

[SullivanRacing06]

i run

so you think I may have been missing w/ the 6's? I assume that that model # is for the basic coppers? When I went to AZ the other day, they only had the VPower coppers in stock, and not for my engine. Do they stock that #3330? I'll deff give them a try.

ngkr bkr7e copper plugs at a .045 gap in my 26 with the splitfire coils, the ngkr # is 6097, 1.78 a pop, never have had probs with them

[rb25drag]

Has anyone else tried my AcDelco #4 plug?

Seems like im the only one on here running this plug.

[matafied]

Has anyone else tried my AcDelco #4 plug?

Seems like im the only one on here running this plug.

Thats all i have ever Ran

[moso240]

rb20 would be the same plug correct? (pn 3330)

[s13point5]

rb20 would be the same plug correct? (pn 3330)

correct

[Largekid]

well, put them in, .8mm gap, was running ok on the street...still a bit rich cruising so I think the plugs were getting some carbon buildup on them...went out and raced the cobra, started @ 4k in 3rd...not sure of speed (~60ish maybe) pulled even thru 3rd, started to pull 1-1/2 cars thru 4th...breaking up real bad in the top end Not sure if its tune or the plugs...but it was bad, and pissing me off. Atleast I know that my car is a good 11sec car...maybe 11.7ish? breaking up, hah.

[rb25drag]

Well since your at the Plug testing stage try the AcDelco's. My car use to break up ALOT up top with the NGK's, Since I went to the AcDelco's I have not had a problem. Just a Suggestion, Im running 13PSI on them and they seem Great, Before with the Ngk's I was not able to go above 7PSI. Im also Stock coils.

[Largekid]

Well since your at the Plug testing stage try the AcDelco's. My car use to break up ALOT up top with the NGK's, Since I went to the AcDelco's I have not had a problem. Just a Suggestion, Im running 13PSI on them and they seem Great, Before with the Ngk's I was not able to go above 7PSI. Im also Stock coils.

I can give them a try for sure...i'm running 22lbs but I also have a full MSD IGN setup...whats the model # of the AC Delcos? #4? are you at .8mm gap too

[rb25drag]

Ya AcDelco #4's. I am running .8mm gap. Let me know how they do!! SO far i stand by them.

[rtautoworks]

NGK BCPR7ES they seem to work the best

[cdorhout]

You might also try pulling some timing back at those high rpm cells where it starts to buck. I went through many heat ranges of plugs before I figured out I was running too much timing up top. That was with the factory PFC ignition tune.I run NGK BKR6E11 plugs at 26psi now.

[Carl H]

slightly off topic but cdorhout how much timing are you running at say 22 psi, im currently at 22* with no knocking and 11:1 afrs.

[cdorhout]

Well, last year before my rebuild I was at 18*

This last weekend, we tuned at 26psi and I keep increasing the timing until 21*. No knock yet, but I assume I'm getting close.

I think I've added enough timing though, I'll probably start pulling a little fuel at WOT instead now to get the tune just right. I think we were getting 11:1 or so on AFRs. This was on 92 octane and 82 degrees outside.

[Largekid]

Well, last year before my rebuild I was at 18*

This last weekend, we tuned at 26psi and I keep increasing the timing until 21*. No knock yet, but I assume I'm getting close.

I think I've added enough timing though, I'll probably start pulling a little fuel at WOT instead now to get the tune just right. I think we were getting 11:1 or so on AFRs. This was on 92 octane and 82 degrees outside.

thats good to know! I'm going to get w/ my tuner on thurs I think for another session. We will look at the timing in the upper RPM ranges for sure.

[Carl H]

it seems that rb engines require alot of timing to make power, at 18* my car felt like complete hell at 14psi, at 14psi its at 24* and feels good.my timing is as follows 14psi - 24*, 18psi - 23*, 22psi - 22*.no knock and pulls clean, now if i could only figure out why it goes rich on tipin.

[Largekid]

Hey Carl and cdorhout, are you guys both using PFC Datalogit? If so, i'd like to compare your guys tune logs to what i'm working w/. We have found out so far that the RB is a different breed when it comes to tuning, lol. I'd be interested to see where my timing is throughout my powerband for sure. Could you email them to me? [email protected]

[cdorhout]

I can, but I warn you I'm not done tuning it. It's in limbo between last year's higher compression stock internals and this years lower compression internals.I"ll try to remember to get it off my tuning laptop tonight after work and send it to you. ...along with a waiver for you to sign that says i'm not liable if that tune blows your motor up.

[Carl H]

i HAD a pfc (rb25 on a 20) but one of the coil drivers died on it...so im back on a full tuned stock ecu and works better than the pfc.i'd be interested in your pfc maps cdorhout too if you dont mind emailing them to me as well, we'll be fitting a z32 or rb20 ecu to the neo car i did not too long ago and will proly go with a 3076r as well for power with good response.

[Largekid]

I can, but I warn you I'm not done tuning it. It's in limbo between last year's higher compression stock internals and this years lower compression internals.I"ll try to remember to get it off my tuning laptop tonight after work and send it to you. ...along with a waiver for you to sign that says i'm not liable if that tune blows your motor up.

haha, i wont be running your tune i just want to compare ours side by side to see fuel and timing etx. if we can my old tune to your old tune, maybe we can make some sense and get a good tune from the two