The Synapse Syncronic I've heard nothing but good things about... I'm seriously considering getting one. I noticed a pretty significant difference between recirc and VTA with the GReddy RS BOV. Throttle response suffered, and I had boost lag compared to recirc. Thats in addition to the huge explosions every time I took my foot off the throttle.

 

I'm still running the std leading and trailing plugs but with summer heating up I think it is probably wise to run a cooler plugs.

what are the pros on cons of the various spark plug configurations?

I could just run all trailing plugs as I have a spare set. this seems like there
is a risk of having the trailing plugs fire out of sequence since mazda thought a cooler trailing plug is necessary.

or I can run FD plugs for leading and trailing. this set-up needs spacers but I have no idea of how to find and setup the spacers?

the other problem I may have is poor compression on the rear rotar that makes my car hard to start. I have read that cooler plugs may make the car harder to start.

anyone like to give some advise?

 

/\ yeah - my car takes about an extra 0.5sec to start with the colder plugs in .
FWIW the spacers (on the trailing) are just precautionary as there is not actually any interferance without them - contrary to popular belief . If you can get the crush washer off another plug somehow - that would be sufficient to allow plenty of clearance .

 

"Popular belief"?
Are you gonna make me have to dig up the pictures again?
The plug is 2mm longer than the hole you are screwing it into.
It doesn't "interfere". It distorts the housing.

 

so what do I use as spacers?

 

Here we go, again.......

If you're gonna use colder plugs use the BUR9EQPs on the leading side and the RE9B-Ts on the trailing side. Simple as that and MM has been doing it for a long time.... sans "spacers".

It is when one uses the BUR9s on the trailing side where spacers become necessary, which is pointless as the OEM Iridium plugs are already 9s.

If you have a set of "H.O." ignition coils use nothing less than Platinum plugs as the coppers will quickly be destroyed by LS, Yukon, and MSD coils.

 

We have had this argument before and nothing has changed .
Hole depth to shoulder = 21.2
plug thread length to crush washer ,when crushed = 20.5 (21.5 to shoulder)

0.7mm clearance - bit close for comfort so an extra crush washer is all that is required .

When you learn how to use your vernier calipers get back to me .

 

thanks Charles

excuse my ignorance, what's "H.O." ignition coils? in another thread of yours If I remember correctly BUR9EQPs are platinum so there doesn't seem like anything to worry about?

 

No problem, Jarl.
H.O.= "high output".
The "P" in "BUR9EQP" means Platinum. NGK also offers a "BUR9EQ". Big difference so check the box before you buy 'em.

 

Charles - what kind of plug life are you seeing on the BUR9EQPs in people running 10+ psi? My car runs great with a new set but they don't stay new for too long.

 

/\ I ran mine for about 12000 miles but I went a little too long as they were quite badly rounded . I would say 10000 miles max .

 

When you do the same, you will be quite dismayed.
The "hole" isn't the issue.
The curvature is.
The "mating" surface (which shouldn't be mating) is comprised of two different shapes.
I already posted the borescope pics to explain the proper caliper technique.

With Yukon coils and copper plugs at 9+ PSI, you will only get 5k - 7k of useful, full performance miles.

I've actually destroyed a new set of copper plugs in one track weekend. (Not detonation.)

 

The hole is harder to measure admittedly - 20 yrs of engineering did teach me a few small things - how to measure stuff for one . The depth you are interested in is the depth at which the outside diameter of the plug would interfere.
The plug is very easy to measure however and the fact that you could not do that right leaves me pondering about your effort .
BTW ayone who has a plug and thinks they know how to measure stuff should do it and then chime in here - cuz MM can't seem to get it right .

The final test of course is to get an old housing . Look in the hole with a torch and you should see a dark carbon stain at the bottom .
Then screw in a plug , tighten it up good , then remove it . If there was interferance you should see a bright 'witness' mark at the bottom of the hole . Such a mark was absent when I did this proving ,to me anyway, that there is no interferance.

 

Sounds like good advice.
my 12000 was not exceptionally hard out however so 10k would be a good max. for people who mostly drive on the street and do lots of cruise mileage .

 

Excellent. My car has been running great on new plugs but I eat a set every 6k at 12.8 peak psi. As for shimming, I didn't think the 12 dollars I spent on enough shim washers for the life of the car wad worth thinking about. The housing is al no?

Edit: Ah crud - my last set of plugs were platinum.

 

Pretty sure I Just broke past the 350whp barrier - Think i maxed out the injectors though (280+380+480)

 

U need to hit up kgparts for some bigger ones.

 

/\ was thinking i would just put the yellows in place of the reds ... ???

 

You are destined to do things the hard way huh? HAHA; kgparts will make them bigger, balance them and tell you exactly what they flow - makes tuning way way way easier since it takes the injectors out of the equation.

 

i'll see if i can find someone local to do it .....


BTW if i tell you how i did it you would poke me in the eye with a soldering iron so don't ask ........

 

you must be flowing tons of air...what is your g/s looking like now? are you pushing in excess of 14psi?

 

I am sure I would; probably welded the wastegate shut or something.......:sho cking:

HAHA

 

I know its around 350 because i saw 30g/s (at a higher ambient temp) more airflow than what i saw on the dyno when it made 325 .

My airflow is 360g/s which does not seem that high compared to others on here but maf scaling has a bit to do with that .....
Not sure of the psi - it's about 10psi at 7500

 

So around 350whp at 10psi? WOW!!!

 

well - not quite .
I've noticed that you get much better whp if your pressure is decaying from a higher level than if you are at a set pressure right to the redline .
Not to mention that the 10psi was a rough approximation - not a logged variable ....