7afte build questions

[96celica]

hey guys wats up
right now i'm gathering all my parts for my 7afte project and i'm completely building the motor so if i do it might as well do it right the first time...
i've already located forged rods for my motor and i'm defenitly going with those but i'm in need of pistons....
stock CR is 9.5:1 and that just won't do either

now before i go on let make this clear no i will not make a 7agte or use 4agze pistons
that and 4agze pistons aren't a good idea anyways cause of the rediculously high CR
that it will create in a stock 7afe block

what i was thinking is that i'm boring my motor .40(82mm)
so that i can use http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW these pistons

well i pretty much plan to bore it 1mm anyways to get rid of any ovaling and imperfections that may have happened....

no with those pistons and still a cr of 9.5:1 could i use a 1mm or less headgakset to lower my compression (4age headgasket of course) to about 8.5:1 idealy?

that and if i use those pistons and a thicker headgasket would i run into trouble boosting up to 12-15psi max?

[Pineapple]

Get custom piston and don't use thinker HG. Thick gasket is easier to get blow out.

[96celica]

yea i know thicker is always weaker but 1mm shouldn't be an issue

but anybody know of pistons?

[toyotaspeed90]

if you want a motor that will hold, use a 4agze block. period.

there's a local mr2 with a stock ae101 gze longblock and bigport head with t25 dyno'ing 240whp and 220wtq..... a 7afte won't make anywhere near those numbers reliably at all without a ton of work... it's just smarter to build it right the first time.

[corolla_racer]

I think you can use the 4agze pistons in it......I'm going to rebuilt my 7afe soon to....

[Dr Tweak]

Originally Posted by 96celica

hey guys wats up
right now i'm gathering all my parts for my 7afte project and i'm completely building the motor so if i do it might as well do it right the first time...
i've already located forged rods for my motor and i'm defenitly going with those but i'm in need of pistons....
stock CR is 9.5:1 and that just won't do either

now before i go on let make this clear no i will not make a 7agte or use 4agze pistons
that and 4agze pistons aren't a good idea anyways cause of the rediculously high CR
that it will create in a stock 7afe block

what i was thinking is that i'm boring my motor .40(82mm)
so that i can use http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW these pistons

well i pretty much plan to bore it 1mm anyways to get rid of any ovaling and imperfections that may have happened....

no with those pistons and still a cr of 9.5:1 could i use a 1mm or less headgakset to lower my compression (4age headgasket of course) to about 8.5:1 idealy?

that and if i use those pistons and a thicker headgasket would i run into trouble boosting up to 12-15psi max?

You are correct about the 4AGZE pistons. However, using a thicker head gasket is a very bad idea especially with a turbo. The reason why is it basically eliminates the quench (or "squish") area around the pistons, causing even worse detonation than if you used a higher compression ratio. The correct solution is to use CUSTOM pistons, or build a 7AGTE with 4AGZE pistons, which you said you won't do.

-Doc

[96celica]

yea thats the only thing i was worried about is that squish......

"I think you can use the 4agze pistons in it......I'm going to rebuilt my 7afe soon to...."
don't use them you get a cr of 11.X:1 its just horrible

"there's a local mr2 with a stock ae101 gze longblock and bigport head with t25 dyno'ing 240whp and 220wtq..... a 7afte won't make anywhere near those numbers reliably at all without a ton of work... it's just smarter to build it right the first time."
i can come close believe me i'm using a T3 turbo to start, equal length manifold, nice intercooler, forged rods, bored 1mm, 2.5bar map, hks ssqv bov, dual stage MBC, 440cc injectors, s-afc2, supra fuel pump...ect..
that should easily crest the 200whp mark with about 10psi...
i believe NIK on his 7afte stock internals and stock injectors ran up to 180-190whp under 10psi.....
i see no reason why the 7afe couldn't go T and go up to 220whp between 12-15psi

[toyotaspeed90]

someone is lying to you.... 200cc/min or under injectors won't run a turbo engine up to 180-190psi....... they would be peaking their threshold......

[96celica]

seen the dyno chart its not a lie......
but yes it did peak

thats why i'm covering my ass with 440cc injectors if i can figure out if they will fit or not
cause they are RC universal fit top feeds

[corolla_racer]

So what type of pistons are you going to use then????...........

[96celica]

after dicussion with a few people and lots of thought

i'm going with the 4agze pistons
http://www.toyhookup.com/store/Scrip...dCategory=3302
(these in a stock 7afe block give a cr from 10.8:1 - 11.02:1)

along with
http://www.toyhookup.com/store/Scrip...idproduct=1179

note the fact that the pistons are 82mm (1mm overbore)
and the 2mm HG i am confident will hold up i mean after all it is designed to be on a boosted application thus proving a low enough CR to boost saftly and forged