Spark plugs???

[genius]

Up until about 2 days ago, I was running 10 psi. When I originally upped the boost, I changed out the plugs with NGK, one step colder... can't remember the exact stock number.

Over this past weekend, I decided to turn down the boost to 8 psi because I don't have forged internals and cannot afford a new block in the unlikely event of detonation. Besides that, I was getting alot of fuel cut because of the cold temps and the JoeP FCD although improved things, still was not effective in cold weather.

My question is, now that I am down to 8, should I change the spark plugs back to stock heat range? Is being "too cold" bad?

Also, I am having hardpipes shipped in, what kind of performance improvement should I expect from them if any? Rumor has it, my boost would stay high instead of tapering off, is there truth to that?

All opinions are greatly appreciated.

 

[madmerv]

A colder plug will cool off quicker and is typically used in situations of continuous high RPM. The standard plug (hotter) will burn off deposits easier and quicker which is more desireable in typical driving conditoins. That said, with todays clean engines and cleaner fuels, it probably doesn't matter which you use. Personally, I would go back to the standard plugs...less chance of fouling a plug.

 

[Puckpimp71]

With the turbohoses kit I have on, my peak boost has bumped up from about 6.5psi to 7psi. Before hardpipes my boost would be almost down to 3psi by 6000 rpms.

 

[dirtysouth_msp]

With the turbohoses kit I have on, my peak boost has bumped up from about 6.5psi to 7psi. Before hardpipes my boost would be almost down to 3psi by 6000 rpms.

Looking to get same hardpipe kit. Are you saying that you hold 7 PSI all the way to redline? If so, hell yeah. Another thing, were your stock pipes cracked or something? 3 PSI at 6000 rpms seems pretty low.

Later

 

[Brian MP5T]

Leave them. They will not hurt anything...Next time you change, swap them for stock...

 

[genius]

Thanks guys, I am installing the hardpipes and leaving the plugs for now.

 

[Brian MP5T]

Sweet!

 

[Puckpimp71]

Pipes weren't cracked... You won't hold 7 all the way to redline, either. Now it drops to about 5psi instead of 3 or 4.

 

[Brian MP5T]

Wtf?

 

[genius]

Pipes weren't cracked... You won't hold 7 all the way to redline, either. Now it drops to about 5psi instead of 3 or 4.

Check your fittings, I replaced just the lower I/C pipe and I am holding a constant 8psi... I did notice something wierd though, after I installed the pipes, I had to readjust the MBC up by 1.5 psi... Maybe I bumped it when I was taking the car apart. Maybe before the adjustment was compensating for the leak... I dunno, doesn't make sense... I would have understood if I had to bring it down, but I had to take it up?!?

Anyways, I built my own pipes, here is the thread with pics...
http://www.msprotege.com/forum/showthread.php?t=95413

 

[dirtysouth_msp]

Pipes weren't cracked... You won't hold 7 all the way to redline, either. Now it drops to about 5psi instead of 3 or 4.

My car only drops to about 5 1/4 psi with stock pipes. WTF?

 

[genius]

update...

Over the last few days, I noticed an increase in backfire and random popping noises at idle. I checked the plugs and they were sooty as hell. So I put the old plugs back in and it idles much smoother now.

I guess cold plugs are only good if you are going to run high boost routinely, or if you routinely drive hard...

 

[madmerv]

Over the last few days, I noticed an increase in backfire and random popping noises at idle. I checked the plugs and they were sooty as hell. So I put the old plugs back in and it idles much smoother now.

I guess cold plugs are only good if you are going to run high boost routinely, or if you routinely drive hard...

As I mentioned earlier, the colder plugs NEED continuous high RPM to stay clean. Even a stock MSP runs rich so needs the hotter plug to keep them from fouling out. I'm seriously thinking of trying one step hotter than OEM now that I've seen what the plugs look like......unless I can find a way to lean the mixture out a point or two.