High compression 4e?

Fatman

Fatman

Member +
You're looking for a td04-13g - they're original equipment on 91-94 lancer GSR's and are routinely thrown away by the mitsi guys as they're "tiny"

Reducing the exhaust housing will result in theoretically less performance potential, in the real world it's not going to matter, it will still easily out perform a CT9/CT9 Hybrid.

There does exist an even smaller version, the td04-9b. I couldn't accurately comment on spool but I would say it would be very early. Possibly would struggle to out flow a CT9.
 
Fatman

Fatman

Member +
billybob said:
dish pistons and a .6trd gasket brings the compression back to standerd engine comp:):):)
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There are many types of dished pistons, judging from Teds compression results it is significantly LOWER than standard. My stock 4e-fte on a fresh bottom end was 180psi+ across all four.
 
billybob

billybob

Untrusted Seller
Fatman said:
There are many types of dished pistons, judging from Teds compression results it is significantly LOWER than standard. My stock 4e-fte on a fresh bottom end was 180psi+ across all four.
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there wiseco ones so it would be standred comp with his gasket
 
Fatman

Fatman

Member +
Well, based on his compression results it's significantly lower. Doesn't matter if it's supposed to be the same, from observation it is not.
 
clarkytrd

clarkytrd

Member +
what is the stock compression ration on the 4efte??

and what will it be raised to with:

wiseco 74.5mm 10cc dished pistons
zep 1.2mm metal head gasket

Thanks for the help
 
G

gorganl2000

Lifer
well they are a number of ways to increase the stock 4efte compression---u can run a thinner h/gasket and/or flat/dome pistons...

u can probably raise the compression a little and maybe still be safe on the 4efte

BUT a full standalone will be best if u plan to go this route

i think 8.2 - 9.0 range on the 4efte should be ok for a nice daily drive car and should help spool up on a td04

PS - @ clarkytrd ..stock compression is 8.2
 
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J25GTi

J25GTi

Lifer
gorganl2000 said:
well they are a number of ways to increase the stock 4efte compression---u can run a thinner h/gasket and/or flat/domes pistons...

u can probably raise the compression a little and maybe still be safe on the 4efte

BUT a full standalone will be best if u plan to go this route

i think 8.2 - 9.0 range on the 4efte should be ok for a nice daily drive car and should help spool up on a td04
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Im going to be either using a megasquirt, or an Emerald, so no worries there.

Im searching for a TD04-13g, up the compression to 9.1-1 and see how we fare up!
 
clarkytrd

clarkytrd

Member +
how do i calculate compression ratio??

stock is 8:20:1 correct??

what will it be with the parts i listed above?
 
H

hkspower

Member +
Fatman said:
Impossible to say what sort of boost will be achievable without knowing what CR you're aiming for and how you're getting it.

I'll be running 1 bar or so on a 9.8:1 5e-fhe using water injection, it's been done before with excellent results. Water/meth injection is very valuable for keeping det at bay on high compression turbo builds.

If you want your turbo to spool earlier you need to look into optimising every aspect of the engine. Bigger exhaust will give better spool, decent intake, good manifold. Timing and fuel can also make a big difference in where a turbo will come in. I don't think you're going to get a td04 on full song by 3k even with everything perfect.
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hi mate ... any info about using water injection any fedbeak when using it ..
 
Ted

Ted

Member +
Fatman said:
Hate to rain on your parade but 160psi is less than the tired 20 year old 190,000km 4e-fte that I just pulled out of my GT measured at. Dished pistons are for lowering the effective compression ratio, a trd head gasket will raise it, but not enough to counter the difference from the pistons. You were certainly running below stock compression ratio.
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im not comparing my engine with a stock one, why would that be usefull. most forged engines run 1.2mm to 2mm metal head gaskets. thats the comparison, your missing the point.
 
Phil

Phil

Super Moderator
clarkytrd said:
what is the stock compression ration on the 4efte??

and what will it be raised to with:

wiseco 74.5mm 10cc dished pistons
zep 1.2mm metal head gasket

Thanks for the help
Click to expand...

it will not be raised at all quite the opposite.

Phil
 
W

weakboy2

Member +
yeah if you take into account a decent head skim and the decking of the block, it will in theory be near stock.

Dont forget though... the stock engine isnt a high compression engine to start with.
 
Fatman

Fatman

Member +
ted said:
you will never get a td04 spooling down there on a 4e. my engine has dished pistons and a 0.6mm trd head gasket. its pretty lively off boost must say. we recently mapped it at 1.5 bar on a vf24(bigger than a td04) and detonation wasnt an issue(it was at 1.6!) so plenty of scope for running a td04 at at least 1.5 on a high compression engine.

on a compression test my engine was 160psi across the board
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You state here 1.5 bar will be fine on a high compression engine, despite your example being of a LOW compression engine? I don't understand what you're trying to say here.

The thread is about HIGHER than stock compression, yours is LOWER and therefore irrelevant, unless I'm missing something crucial?

For those that are a little confused on the way compression is altered, a thicker head gasket will result in LOWER compression, dished pistons will result in LOWER compression. Combine the two and you will end up significantly lower than stock and will be sacrificing quite a bit of response and drive ability while gaining the ability to run a bit more boost before limited by fuel quality. Stock head gasket (once torqued down) is 1mm, thus the TRD 0.6mm head gasket will raise compression a bit.

As weakboy2 stated, a skim of the head (done to ensure a flat mating surface) will remove a small amount of material, this will also increase the effective compression ratio. Likewise removing material from the block will achieve the same thing.

A stock 4e-fte in good condition @ 8.2cr should see 180+ PSI on a compression test, a stock 5e-fhe @ 9.8cr will give you more like 210psi. This isn't exact, figures will vary slightly depending on temperatures, tester and your particular engine - they are primarily used as an indicator of compression ratio and engine condition. Over time as valves/rings wear the compression tester figure will drop, as long as each cylinder remains within a 5% tolerance of each other it's nothing to be concerned with.
 
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