Jump to content
SAU Community

Recommended Posts

When driving along on an open road in 2nd gear or above and i go full throttle, when the revs hit around the 5000+ mark the engine does not run as smoothly as before and begins to like missfire and the exhaust begins to backfire as if there is too much load or stress on the engine. Anyone know what this is? Some one said new irridium spark plugs would fix it? what are ur thoughts?

Thanks...

Link to comment
https://www.sau.com.au/forums/topic/17890-irridium-spark-plugs/
Share on other sites

The fancy iridium and platinum plugs are great for cars that are factory, and no forced induction. Greater service intervals and so forth.

For performance cars, standard plugs with the right gapping, and perhaps running a slightly colder plug does the trick.

A freind had a misfire just as he got on boost on his soarer, running 1 bar. While in the car you couldnt feel it or notice it, but on the dyno you could clearly see that was struggling at a particular point on the graph, and it was doing it almost all the time.

Gapped down to 0.8 and ran a colder plug, using standard NGKs, problem solved and t he car runs better. He has platinum plugs in there before, which were fairly new.

The iridium plug has a very small tip on the end of it, and its very fragile, expecially when exposed to the elements of high boost. Even a light detonation pulse with the front focused on the centre or starting out from the centre, could melt the tip or deform it in a way that the spark integrity is sacrificed.

9-10 second vl turbos run approiately speced standard NGKs with no problems.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Thanks Duncan! Yeah it's street use for me only. Maybe occasional track day. Any difference in noise when running with the two pumps? I would expect the lift pump to be more quiet than the main pump so hopefully not? And yes, unfortunately quite a big price difference to the simple hanger setup. Though I'm usually willing to trade money for better reliability and future-proofing. Buy once, cry once and all that. I'd be very happy to never have to deal with fuel pump / wiring issues again  
    • The old manifold was quite under the GTR strut brace.  The new manifold is quite [unknown] the GTR strut brace. The GTR strut brace was needed to clear the bonnet vents. The Old strut brace will almost certainly clear the new manifold, but not the bonnet vents. The old strut brace will almost certainly clear the new manifold, and the new bonnet without vents. But I am hoping the GTR strut brace clears the new manifold :p
    • On the bright side, at least you knew that it happened and remedied before anything happened. A friend of mine just took his Fiat 124 to a shop for an oil change and they didn't tighten the oil filter housing properly. 4.5 quarts spewed out and even after refilling + tightening the cap the engine has a tick now.
    • So, more pain. The FAST manifold is a little larger than the stocker. This is problematic because there really wasn't much clearance to begin with, so going from 'barely enough' well into 'no' is sad based on the external dimensions of the thing, even though where it bolts to the head is the same. Result is the fuel rails sit a good 25mm higher, and this is a bit of an issue with the wiring that runs behind the motor, and the fuel lines, and everything else. When pushing the manifold on, it required a huge amount of force to crush wiring looms to fit it, sensors like the MAP sensor are about 1mm from the firewall, and the FPR just has to bend ABS lines to be forced into place. After some brainstorming and some sad drinking, the loom for some reason ran from the grommet behind the ABS sensor, then to the driver side head, then back to the passenger side head. So all of this was pulled back and stripped, a few wires cut and rejoined, so that the 'branch' was now on the passenger side's head as below: Before you basically couldn't see anything behind the driver head. This is much improved! The MAP sensor is now pointing up (instead of at the firewall) Brackets have been made up for the rail. The rails are for a LS1, the manifold is designed around a LS2 as it's base. Which of course has slightly different bracketry and water pump clearance, hence the mods people need to do. Should be hopefully mounted tonight. I spent money on a new FPR that is slightly more compact than my Turbosmart FPR1200. The gauge has also been moved to the rail. There's also apparently an ORB to AN Union instead of the adapter, because the ~25mm of the current adapter is going to make the difference. Provided this all goes together and arrives today, it'll be the totally not stressful attempt to start it.
×
×
  • Create New...