I am getting ready to go and get my car dyno broke in, and tuned, and I am trying to decide if I should get a 1 step colder spark plug.

I have the following mods but basically I am aiming for 300+ rwhp
-11:1 comp pistons
-full length headers, hks knock off exhaust
-K&N typhoon intake and plenum spacer
-JWT C8 (272) cams (with springs and retainers)

I have a hard time believing I won't make 300 hp, but wanted to know the community's thoughts on what spark plug to run

 

I've tried them and believe it hurt the performance. Its quick to foul plugs if there is anything not ideal going on. Also, if you noticed the "Hot" stock plug is actually pretty cold already. I'd say stay with the stock range until you see reason to change.

 

id stay stock, unless you plan to use nitrous

 

tuning shop said the same thing, I am awaiting a part and then finally getting dyno'd and I can drive it home!

 

congrats, post results!

 

results here?

 

I don't have results I am willing to post yet, the tune I have I am very disappointed by and I need to go back and get it fixed. I did make power to 7k, but they stopped it there... I am very confident there is more power to be had with a higher red line. Also, it stalls and has bad spots in the tune just about 2k rpm...

 

ok, fair enough, sounds like it just needs some more tuning time. but you think the power will continue to increase after 7krpm?

 

The guy who tuned my car I was really unimpressed with... he was on the phone with the good guy trying to figure what to do most of the time... The car made 287hp at 7k rpm, the dyno graph did not have a down curve. I am not saying it will make power until 9k rpm lol, but I think it has a few hundred rpm of power left at least. Enough to hopefully make it into the 295+ hopefully. I have upgraded to a bigger intake since then and I am hoping it helps too.

 

i think the bigger intakes make the tuners job more difficult, but if he knows what he is doing, they can make power i think, i dont think im going with a bigger intake, or even an aftermarket one at that

 

Consider modd'ing the lower plenum or replacing it with a rev up version. I'm thinking as it is... it will be out of lungs at 7000. I too had a plot that had no downward movement at 6800 but as soon as they pushed to 7000 we started sloping and also notice manifold pressure increase (as in power stealing negative presure). Also remember, depending on the type of dyno it may not be an accurate reflection of the powerband at redline. I believe Dyno Packs always show an upward jump at the end of the run... just the way they work, and that could fool some people in to thinking they are still making power.

 

so you started seeing vacuum at 7000? isnt that needed for the pcv system?

 

I ported the lower manifold, lightly ported the lower plenum, did something kinda cool with the upper and mirror polished the TB and removed the casting marks and such. I want to get back in there and port more, but we will see, they are going to call me to schedule a round 3 at the dyno to finish this once and for all.

 

As for my PCV system, I have been putting off doing work to it

 

im still not 100% on what i want to do with that either.

hope you get it all ironed out, 3rd time's the charm

 

ran colder plugs as i was planning on nitrous before i blew it up NA haha..
did not run great on colder plugs for sure, so plus one on that one.


OP.. 287 at the wheels on the mods you have mentioned is pretty darn good NA.. id blame pistons and those cams on giving you any power at all IMHO....most cars are like 225-240 whp w bolt ons.. so bumping the compression up to a small degree and running the cams made a pretty bigg diff... didnt mention what youre tuning with... or i just missed it.. ECU mgmnt? Osiris etc?

all said n done, i also agree getting a good tuner will get you where you need to be, at least near where you want to be.

 

Ya, I stuck with stock plugs

I made 269hp on intake, spacer, porting, long tube headers and knock off hks exhaust. all that really changed is .020 over, 11:1 comp pistons, JWT C8 cams and springs. not even 20hp for all that, lol.

As for tuning.... I am going through Osiris, actually getting tuned by Uprev themselves in Autsin.

 

As for the PCV, I am thinking that I will probably plug the vacuum port on the intake manifold, run a tube from the intake vacuum port, to a catch can, then run one to a Y and have one go the the pcv valve and the other to the port on the back of the drivers side valve cover

 

how did you blow it up?

 

threw a rod bearing and ruined the crank from it.. couldnt polish it out..... and always had religious oil changes and good filters too.. Used a cobb and had the timing advanced as well.. colder plugs, misfires at 2 degrees closer to TDC.. equals more torque on the rod and bearings etc.. and if it was ready to go, well.. it went.


dunno, i have that affect on engines.. i appear to blow them up.

had 2 engines in my first suburban, had two in my z32, and now my first one in my Z33 at 104k miles.