gtmcoupe

Ladies and Gents

First post here from the UK

I run a Forged/sleeved B18C1 10:1 compression and a Direct port Nitrous Kit. I have been succesfully running approx a 100-120hp shots and getting impressive times last year, However when I went to using Two kits with an additional 50-60hp via a single fogger pre throttle body I came across a problem and melted three plugs and some reapirs to do over this winter.

I was running NGK plugs heat range 8, obviously retarding the timming etc.

I know there is a few Nitrous users on this bored that have run large shots of nitrous towards 200hp, Can anyone suggest what power levels certain plug heat ranges are suitable for as I plan to revisit two nitrous kits at this power level again later this year.

Thanks
Neil

gtmcoupe

Been searching through the forums, but still struggling to find Spark plug recomendations, found plenty on what size jets and other engine specs but not much on actual Spark plugs, i.e ngk BC8RES etc

I have some of my own ideas on which plugs might be suitable next but would like to see what actually works from peoples expriances.

for example a 190hp B18 with a 200Hp nitrous shot what plugs have been used for this combination.

Neil

K7-1Ktrevor

sweet setup, what did it run if you don't mind me asking?

4g hatch

if you search there is a huge nitrous thread in here that will help alot. if you can get in touch with cubish he could help you. i think you may have a fuel supply problem more than plugs. are you running race gas? if so some of them run a t of the fuel supply at the fuel rail and run a seperate inline fuel pump just for the nitrous fuel supply. BTW what times and traps where you running with the 120 shot?

civiconfire

the ngk 5671a-9 is the plug i have been using with my setup.

gtmcoupe

Thanks for the ideas but it is a fairly well sorted nitrous sytem now. I have a dedicated Fuel system for the nitrous, Dedicated Pump, Filter, Regulator. as experianced fuel supply problems in 2008 when I swapped to the direct port. Current thoughts are the earth strap is not getting its heat out fast enough and retracted plugs will be better suited.

In 2008 I was running projected plugs, and melted the earth straps on two plugs,

In 2009 I was running non projected plugs and revised fuel supply, now with a good supply of fuel I was actually needing to remove fuel and add nitrous to get the mix back. he approx 100-120 shot had been reliable and making consistant times.

The problem was when I turned on the second stage initially it worked fine in third, then in fourth it gave up.

the car for those interested

Mid engined Rear wheel drive B18C1 with my own choice of ratios, 100% street legal tires fastest run 11.54 @ 124.5 mph with the direct port kit. Its my summer daily driver clocking up lods of miles between work/track/home/shows.

Neil

gearhead16

when you had it on the dynod what did your af ratios look like it sounds way too lean ive been running a 150 direct port shot on my b16 with 14:1 compresson for a year and a 90 shot for 2 year on the same engine ive never had any problems i was using ngk BKR7E plugs with the 90 shot and now im using R5671A-10 NGK plugs. you may want too look down at your pistons too make sure you havent damaged them aswell and comsider retunning it.

gearhead16

my best time last year was an 11.30 at 126mph i had to get bigger slicks cause i was spinning till 1/3 of the way into 3rd gear

racebucket_eg

Cool car. If you wouldn't mind could you please list the components of your dedicated fuel system. I've searched & searched but can't find clear answers on this topic.... also could you help me out with this specific question I posted in the nitrous thread but couldn't get a clear answer.

1) How much psi of fuel are you sending to the fuel solenoid??

Thanks dude, you can pm me if you don't want to derail your thread.

gtmcoupe

No Dynos only tuned on the strip, looking over the datalogs, AFrs 12 tapering down to 11.5 over 6k-8k generally speaking, Now back to plugs.

Now a BKR7E is a projected plug heat range 7 this is the same plug I ran in 2008, until I had the first problem and just started to wind the wick up,

Now the R5671A-10 you mention is alot colder plug, heat range 10. I have not gone anywhere near that cold and confirms my thoughts that I should had gone colder. Now these plugs are non projected too which means the earth strap is short too helping to remove the heat from that. Does R5671A-10 have a normal style curved earth strap or a really short straight angled version I found conflictng info on the net.

Engine has been fully inspected and in need of new pistons and rebore due to a score. Pistons show no signs of det but one is damaged from spark plug bits, The plug was the failure and cause of my troubles.

Fuel system for the nitrous is using an In tank Pump I had, not as large as a walbro 255, but suffciant for my needs, to filter plumbed to the solenoid via -6 hose then a tee from the solenoid to the regulator, then back to tank. and is activated when the nitrous system is activated.

Neil