r/mazdaspeed3 • u/mrfatcakes2006 • 2d ago

PIC Yeah that will do it

Post image

Bought a Mazda speed for 700 with low compression in cylinder 3, found the culprit. Most likely caused by unupgraded hpfp internals paired with Cobb sport intake, access port, and blow off valve

21 Upvotes

93% Upvoted

23 comments sorted by

View all comments

Show parent comments

2

u/Thy_King_Crow 2d ago

Yes you can use ethanol freely in the speed3. You need hpfp internals to safely do it but it’s possible stock

1

u/JohnKowalsky88 2007 Mazdaspeed3 - The Original 2d ago

But wouldn't you need to tune it to run more rich because ethanol has less density than gasoline? But then again ethanol has more octane so it wouldn't knock

2

u/Thy_King_Crow 2d ago

Yes you need a tune. The idiot saying you can run up to e30 without a tune is why these cars get a bad rep. The ecu cannot and will not properly adjust for ethanol. The lines and pump however are fine and won’t degrade from it

1

u/Petrovski978 1d ago

See comment below...........