What did you do to your Fiesta ST today ?

[SteveS]

Ever since changing to step colder ngk plugs I've been having misfires under full throttle. I gapped to .026(originally .030) and it's much improved but still misfiring a under wot. I'm in dizzy e30 tune. He suggested I gap to .028 which still wasn't enough. Should I go back to OEM plugs?

If step colder plugs cause misfires, yes, the answer is to go step hotter. The fascination with step colder plugs eludes me. It is not a magic formula for power. If, after your tune, the engine was running fine without preignition, and a plug check did not show signs of plug overheating, then there is absolutely no reason to change to colder plugs because the only expectation would be that you would have misfires, fouling, and eventual problems from unburned fuel.

 

[WolfDampf]

If step colder plugs cause misfires, yes, the answer is to go step hotter. The fascination with step colder plugs eludes me. It is not a magic formula for power. If, after your tune, the engine was running fine without preignition, and a plug check did not show signs of plug overheating, then there is absolutely no reason to change to colder plugs because the only expectation would be that you would have misfires, fouling, and eventual problems from unburned fuel.

I'll try my OEM plugs when I'm off Sunday and check what their gap is at. If I am correct a -1 octane adjust ratio means no knock? I've also never had negative ignition corrections with my OEM plugs. I do want dizzy to tune it up to the max when I get my revision tho. So I'll try tightening the gap to .024 as well, but if I'm tightening the gaps just to make the same power that sounds counterintuitive

 

[WolfDampf]

FYI if you're doing the focus coil conversion do not get denso coils. I thought denso was an "OEM supplier" so it would be fine. SVTdesignFab recommended Bosch and I should've done that. The connectors on the denso coils are straight which makes it a hassle to install as they make contact with the adapter plates. The Bosch coils are slanted up so you can connect them easy. I got some Bosch coils on the way and I'm guessing that it's going to fix my high rpm misfire issue as well

 

[Grsemky]

FYI if you're doing the focus coil conversion do not get denso coils. I thought denso was an "OEM supplier" so it would be fine. SVTdesignFab recommended Bosch and I should've done that. The connectors on the denso coils are straight which makes it a hassle to install as they make contact with the adapter plates. The Bosch coils are slanted up so you can connect them easy. I got some Bosch coils on the way and I'm guessing that it's going to fix my high rpm misfire issue as well

What did the coils run ya?

 

[WolfDampf]

What did the coils run ya?

That's the part that gets me mad 😂. When I ordered them the denso coils were 4$ cheaper per coil. Now the densos are 29$ and the Bosch are 24$

 

[Grsemky]

That's the part that gets me mad 😂. When I ordered them the denso coils were 4$ cheaper per coil. Now the densos are 29$ and the Bosch are 24$

Bastards

 

[M-Sport fan]

FYI if you're doing the focus coil conversion do not get denso coils. I thought denso was an "OEM supplier" so it would be fine. SVTdesignFab recommended Bosch and I should've done that. The connectors on the denso coils are straight which makes it a hassle to install as they make contact with the adapter plates. The Bosch coils are slanted up so you can connect them easy. I got some Bosch coils on the way and I'm guessing that it's going to fix my high rpm misfire issue as well

Are the Focus ST coils that much higher output than our OEM?

If not, what else would be the reason to swap to them?

 

[our guile]

New tires are on, RE71RS 205/50r15. They are downsized from the RT660s I ran last time which were 225/45r15. They should be able to hold most of the power with the diff, but I'm still expecting some wheel spin if I apply way to much in 2nd. Went less wide this time to try and see how it helps with response. If they just don't work out I'll probably just start looking at going flares so I can fit something much meatier.

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Are those the TD Classic Pro Race 1.2 wheels? I want TD wheels for my next set but am torn between them. Stock suspension?

 

[our guile]

Paid all my new-turbo money to shop to replace clutch and slave cylinder. Had to pay double labor (and two slave cylinders) because the first one (OEM Ford unit) failed spectacularly and bled out all over the bellhousing so shop had to redo the work. Mechanic certainly ate good that day.

This happened to me in September. All the money I'd saved for suspension mods went towards replacing the clutch and slave cylinder for the second time. God it was frustrating

 

[rallytaff]

This happened to me in September. All the money I'd saved for suspension mods went towards replacing the clutch and slave cylinder for the second time. God it was frustrating

Why did they charge you for a second time if they installed it?

 

[our guile]

Why did they charge you for a second time if they installed it?

No I meant that the slave cylinder failed on me a second time. The first time was in 2023, and the replacement failed in September.

 

[our guile]

Oil change with Pennzoil Ultra Platinum 5W-30, and transmission fluid change with Ravenol 75W-80 MTF2. Bought a titanium magnetic oil drain plug and Greddy magnetic transmission oil drain plug from Whoosh a while back and finally installed them too.

 

[WolfDampf]

Are the Focus ST coils that much higher output than our OEM?

If not, what else would be the reason to swap to them?

They have twice the windings so they can sustain higher voltage easier. It's not a necessary mod as our stock coils do fine. But when you start doing higher boost and sustained high rpm it can perform better and lasts longer for the same price or cheaper. It also can make your idle smoother although I haven't noticed this

 

[Downsy]

Been having intermittent issues with the purge valve for the last few months. Finally bit the dust on the way home the other day. Did the juryrigged replacement using a Motorcraft branded Bosch valve from Rock Auto and some 3/8ths tubing to splice in the new valve.