420A Spark gap?

[Inkdlyfe]

So after taken off my turbo and what no going back to non turbo ecu and injectors should I keep the spark gap .28 or open it ?? It's still built internals tho .50 over sized wisco pistons what PSI should I put the fuel to and the spark plug gap to ?

 

[Zero6391]

0.50 is the gap for the 420a with the stock compression ratio and fuel pressure needs to be at 50 psi

 

[Zero6391]

do you know if its still a 9.5:1 compression ratio or is it lowered? sometimes when people go turbo they lower the compression ratio to run more boost

 

[gofer]

0.28" is over 1/4" of an inch, I'd recommend tightening up your spark plug gap to something like .050" on a NA 420A motor, which is 1/20".

Stock fuel pressure should be controlled by the stock fpr that came on your N/T DSM. An aftermarket regulator rises 1:1 since it's for a turbo application, the stock 420A fpr doesn't.

 

[Inkdlyfe]

Honestly don't know about the comp ... But I was hitting 18 lbs no problem and there wisco pistons .50 over so open it to .50 and run 50 psi?

 

[Inkdlyfe]

I'm pretty sure the stock reg is taken out I have a reg on my firewall

 

[gofer]

Honestly don't know about the comp ... But I was hitting 18 lbs no problem and there wisco pistons .50 over so open it to .50 and run 50 psi?

NO. Gap them to .050"

The bore of the cylinder doesn't matter, he's asking what the compression ratio is on the pistons.

I'm pretty sure the stock reg is taken out I have a reg on my firewall

I know the stock regulator is removed, the one that you've got is for a turbo application and it rises 1:1 with boost pressure. If you're no longer running a turbo then you should install the stock fpr and run it since it will set base fuel pressure to what it should be and it won't rise 1:1.

 

[Inkdlyfe]

How exactly would I find out the compression on the pistons ?... And do I need to put the org reg in ?? With out knowing my comp should I still do .50 gap

 

[Eddie Tsi]

How exactly would I find out the compression on the pistons ?... And do I need to put the org reg in ?? With out knowing my comp should I still do .50 gap

I maybe wrong but I doubt that you can gap your spark plug to 1/2"

 

[Inkdlyfe]

My bad people I mentioned .028 not .28 ! I just put it to .050 and pumped it up to 50spi

 

[Inkdlyfe]

So i got a question about gap of the plugs I know i asked about what size it should be before BUT I have a question about it . So right now I'm waiting on my new inner cooler pipe to come so im n.a right now BUT I'm fully build still .50 over pistons 8.8.1 low compression bigger valves and rods etc everything is still build but im not turbo and have stock injectors with about 50 psi of fuel. Now should I make the plugs .028 like i do when I'm turbo or put them to stock spark gap not being turbo but im still built ? Trying to figure out cuz it's stuttering at high rpms like 5k plus cruising around 5k I'm reading 12.6-13.6 on my AFR all depends how long I hold it before shifting and idle is about 14.9 also has a minor back fire too, i read i night be running too rich and it's falling on its face I have new plug and new wires and I tested my coil pack and it's good. But my plugs are tapped at about .035 with no cel also. Should i change my fuel psi? Change my spark gap?

 

[spyderdrifter]

I would put the gap at stock for now. Also, if you have no turbo hooked up, which essentially increases your compression, your car will almost go nowhere. Read here: http://www.dsmtuners.com/threads/can-i-run-low-compression-pistions-in-a-non-turbo-engine.199337/

And here's some more great info: http://dsportmag.com/the-tech/boost...igh-boost-levels-and-high-compression-ratios/

 

[Inkdlyfe]

Makes sense just figured it would be good question to be asked thanksss

 

[boostdawd]

What type of plugs are u running and how much boost?

 

[spyderdrifter]

He would have zero boost since he said the turbo isn't installed yet.

 

[codydsm1]

He would have zero boost since he said the turbo isn't installed yet.

good catch ! Go NGK all the way Turbo or not. gap to stock for now due to lower comp pistons with no turbo