4a piston question

[trikzlane]

i am building a na 4age using a 7rib bottom end and a bigport head, what i was thinking is i was goin to get gze pistons so that i have the option to turbo it later on, but i want to know will i lose power cause of the drop in the CR, in term should i just get smallport pistons and worry about the turbo build when it comes.

any help would be great, thanks

[jaz_ae86]

Smallport/20v pistons for NA and then run turbo with smallport/20v piston using boost in APPROPRIATE amounts.

With the GZE pistons it would be WORSE than a early bigport, but very strong. Early bigports at least have low inertia to account for the lower compression.

Also, use the smallport head!

[sun_moon]

agreed. smallport is a far superior engine in stock for and to about 200hp.

[Matt-AE86]

Use smallport pistons. Replaced to GZE when boost time comes.

[reecegze]

Use the gze block with .8 head gasket then when boost comes it comes on harder and ull have the pistons to support boost. Wina

[--Redwork--]

^^^ + shave the block and head to raise the comp more... High comp turbo motors are the in thing now... Just started my turbo gze build and I'll be shaving head block and may use a thinner gasket aswell... get it up around 9.5:1 maybe abit more. Undecided ATM.
And use Small port head.!!!..

[sundee]

Low comp + Big boost fails - higher comp + less boost wins always imo

[reecegze]

I agree raising the comp is the best thing you'll Eva do to your 4a turbo. Aslong as you got the right a/f ratios and good amount of boost you'll superceed the low c/r 4agte running 17psi.

Head gasket is the easier option but might aswell do a small skim.
I have plans for mine if it fails soon, raise the 8 0:1 c/r to atleast 9 0 :1 for more response with less boost.

[--Redwork--]

Yup.. Much more driable combo.. And the good guys are macking it work with very little power loss over and Low comp higher boost setups..

I'm seen some 2j's in the sate running 40psi and 12:1 comp... thats fucking insane.. The majic of methanol goes a fair ways to making that work though.

[marvis]

What they said.