5efe turboing q's

[Linz]

im a bit stuck building this motor as im tryin 2 get the comperssion down 2 around 8:1 and id rater not go 2 forged pistions any ideas ? any1 done 1? ps. rods have been nitrated+shot peened+crack tested and crank shot peened and polished and using a .6 Trd head gasket

[Jebus]

Using a .6mm headgasket is a bad start, get something over 1mm.

[Linz]

toyota or TRD dnt make a thicker 1 aye

[Jebus]

:O Is that standard thickness?? Sorry im not familiar with a 5EFE.

[matt dunn]

A thicker gasket would be a good start


why do you want to go that low anyway?

[Linz]

mainly so i can run around 10-14psi safley thats all im using a starlet gt head (complete) i just dnt want the bottom end falling apart aye

[CozmoNz]

use 4efte rods and pistons?

4efte = 74 x 77.4
5efe = 74 x 87

[Linz]

i looked into that aye cause the 5e block is 1.5mm taller than than the 4e so the rods wod b way 2 short and the pistons have diffrent pin heights

[CozmoNz]

use 4efte bottem end? so a complete 4efte , they are getting cheap.

[Jebus]

Would be better using a block and crank assy designed for boost in the first place. Surely the strength of the 4EFTE would outweigh the extra displacment of the 5EFE??

[Linz]

i was after more cc = less boost needed 4 good power = less stress on motor + more torque

[CozmoNz]

so use your stock compression ratio, with low boost, that works...

save your pennys, buy a 4efte bottom end, save up, buy forgies, etc, then wind up the boost and blow the 5e to hell and rebuild

[Jebus]

Yeh I agree with Cozmo, run lower boost with standard comp. Other wise youll needa run more boost to make up the power if ya had a lower comp ratio. If ya get my drift?

[matt dunn]

basically power is made by the cylinder pressure.

If you run high comp and low boost the pressure created is the same as lower comp and high boost.

The only difference is the high boost low comp way stresses turbos and pipe work etc more,
and you can get slightly more power when running huge boost due to the sheer volume of fuel and air you can cram into the cylinder for the same cylinder pressure,
however you do loose driveablility, off boost response and create lag.

Matt

[CozmoNz]

you using a cynos?



could just do that... but put a 3sgte in instead of a 3sge .

[Linz]

its a starlet gt im just tryin 2 get a less stressd motor im not keen on forgies 4 what they do 2 the bores

[loose_unit]

Dont use the TRD headgasket, the stock headgasket is 1.1mm so straight away you will be over the 9.4:1 stock compression.

In all honesty you are better to run it as a stock engine, just make sure that you get it really well tuned on a link or similar, it should handle 10-14 psi easy if the tune is right.

You can use 4efte pistons, you just have to use the stock rods, the compression will be approx 8.9:1 with the fte pistons.

[Linz]

cheers guys gives me something 2 ponder over

[evil_si]

its a starlet gt im just tryin 2 get a less stressd motor im not keen on forgies 4 what they do 2 the bores

as in what?
forged pistons wont do anything to the bores that normal pistons wont.

[Stu-]

Why do you want the compression that low? Mid to low 9's is fine for turbo as long as the tune is good. 4efte pistons in place of the 5efe units is the common conversion and brings the compression ratio down a touch. Thought about the use of o ringing and a stock 1.1mm head gasket? Some minor head work will also reduce the comp ratio if your worried and also reduce any hot spots in the combustion area of the head. 10-14psi is nothing on a stock 5efe. As long as the fueling is up to spec it will be reliable at those levels. If you stand 4e and 5e rods next to each other the only difference is the length. They share the same widths and one isn't considerably stronger than the other.

I'm running a 5efe turbo in my EP71 and its running fine.