I just got my mini mania 15% reduction pulley. I would like to get colder plugs for it because I understand they can prevent pre-detonation, but i dont want to drop 70$ or iridium plugs. First, are colder plugs necessary? Second, do colder plugs help performance? Lastly, are there plugs out there that do not cost 70$ for a set, and prevent pre-detonation?

Thank you for your time,
Chris Howard

 

Actually some vendors are dead set against colder plugs and say that the stock are just fine (DMH). I know many folks that are running 15% with stock plugs and have no problems. Personally I don't recommed it as the stock head is really not designed for them (they sit further in).

 

The fellas at Lucky Dog Garage were adamant that the stock plugs are just fine...at least for what you're doing.

 

Yep, LDG share the same thoughts.

 

Thanks for the help guys...

 

As I mentioned in another thread, I have a modified head, exhaust header, cam, injectors, bleh, bleh, bleh and am running stock plugs. Never had an issue with detonation or degraded performance because of the stock plugs.

I'm not entirely sure why people always suggest colder plugs with just a pulley as the pulley doesn't really alter the engine operation too dramatically in ways that would require colder plugs.

 

I will talk with Randy Webb about this on Tuesday when he does my 15% Webb Motorsports Pulley install and Denso Iridium IK22 plug swap. As far as I understand it..just because you cannot audibly hear detonation/pinging...it doesnt mean the knock sensor in the engine isnt. Which in turn retards timing. Of course here in Colorado we have $hitty gas 91 octane and 10% ethanol...so might be part of it. Of course increasing boost does increase intake temps as the hotter compressed gas doesnt cool down as much as the compressed air with a stock pulley.

 

While that can be true I have also had my car dyno tuned (and it will be re-tuned now that the clutch has been replaced) which essentially pushes the car at 100% load all through the RPM range. If it was pulling timing because of detonation it would have been pretty obvious in the resulting data gathered. Of course there wasn't a thing showing timing being pulled.

But then again all cars are behave differently. I chose not to waste my money on colder range plugs because they were pretty obviously not necessary.

However, if you really do want to go colder plug you could always get the JCW plugs which are one heat range colder than the stock MCS plugs. That way you don't have any issue with gap or plugs that thread into the chamber too far.

 

When the European Car Web were doing their MCS project, they found that the colder plug actually gained some HP due to detonation and timing retardation to prevent the detonation. For $60 of colder Iridiums & even cheaper for platinum tips, don't compromise.

 

While I certainly respect John at LDG and Don at DMH's opinions, at least at altitude and with 91 octane fuel (which the guys on the East Coast don't have the pleasure of playing with), we certainly see improvements with the colder heat range. We have seen gains with the Denso, the NGK (both Iridiums and JCW) as well as the really bad Champions over the stock NGKs. That said, I don't think the colder heat range plug is a necessary change, but it is nice to have.

I agree that if you have good fuel available, and there is no detonation perceived using good data, then they are a waste of money.

I hope that helps!
Randy

 

What is $70 for 4 plugs? I used to race motorcycles with guys that used plugs that cost $110 each; 4 required.

Depending on where you live (hot climate or high altitude), the drive (bumper to bumper commute or wide open high speed), and available octane (<93), cooler plugs are necessary.

 

For a great price on the JCWs go here:

http://www.ngk.com/results_cross.asp...r7equp&x=0&y=0

This is where I got mine.

 

I asked the same question when eric from Helix was installing my 17% and he said colder range spark plugs were not needed

 

Slightly off topid
i live in new york and there are no issues finding 93 octane fuel

 

I paid $40.00 for my Denso K22 iridiums...$70.00?

 

$70 does seem a bit high

 

It was CAN $ 60 for NGK Iridiums (colder) here in Canada way back in 2004 but it should be cheaper in the US. We pay premium here plus 14% sales tax! Exchange rate at that time was 1.25 but now 1.05 (Can $ : US $).

 

I went one range colder with NGKs and the car idles noticably smoother.

 

Not sure where you are looking for your irridium plugs, but Minicarparts.net has a set of 4 for 37.95 +s/h.

 

I just payed thirty and change for the standard temp ngk iridiums from Napa. If you do change them be sure to torque them!

 

And I'll do the same shipped to your door for the one colder range NGK BKR7-EIX Iridiums.