I've looked around a few sites for possible gap sizes for the BPR7ES plugs I need to replace in my 03 EVO 8. On one site I found someone gapped theirs at .25, and someone else on that same page mentioned gapping theirs at .26. Another person had his at .29. I'm guessing this may be due to his setup (mods).

I previously had someone else do this for me, but I haven't received a response from him yet.

Current mods:
FPGreen
Injen intake with upper and lower hard pipes
TurboXS BOV
Megan downpipe
HKS exhaust
(will be getting 800cc or more injectors soon)

Thanks, any help would be appreciated.

 

0.025 is fairly narrow - but realistically you are not going to physically be able to tell the difference between 0.025 and 0.026 - the human hand is not going to have the resolution of a thousandth of an inch.

0.029 will give you a better spark but only if your ignition can support that gap based on the boost pressure you are running.

(Keep in mind spark plug gaps are in hundredths of an inch, 0.25 as you mentioned is a full quarter of an inch and not an actual gap)

 

thank you for the clarification, it was one of those "be careful what you read on the internet" i guess.

I believe i'm running at stock psi. I'lll be in desperate need of a tune after I get my hands on a set of new/larger injectors.

 

I get misfires when I gap over .25 on the 7s. But my motor is 9:1 so that may be it.

 

Start off big. Id say start at .029 and if you get any misfires then go down to .025. I have ran down to .023 before to prevent spark blow-out. But thats only from crappy ignition.

 

Thanks for the info guys. I appreciate the insight.

 

i currently run .022 on my evo 8 with stock ignition, and i ran bpr8es with my stock turbo gaped at .025 and i never had problem

 

I thought i replied to the PM you sent me. YOu should start the gap at .024. Drive it and see if you get a miss fire during a pull. That should be a good gap. If you get a misfire set it down to .022.

 

^ No prob, I figured you might be busy. I wasn't going to hound you for it. Thanks for the info.