DIY: Turbo the EJ25D

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[quote=lord flashheart]

Yeah the Emanage I figured would set me back like $600 I might have to check the first page again but how well does the stock fuel pump do at say 5 psi? If I decide I'd at least store the parts until I have about 95% of the parts ready to go.

i ran the stock fuel pump for 6 months with no issues.
but i would recommend an upgraded pump.
also in the winter if you plan on running 6psi
you will have to turn down the boost in winter because the air is more dense
so you get more air in and the injectors usually cant keep up.
if you are looking to do it on the cheap, you can get a rising rate fuel pressure regulator.
which turns up the fuel pressure to match the boost. the computer doesnt know the difference.
ive done that on some a couple Hondas, toyotas, chevys, and a subaru. they work if you want to
run just a little more boost.[/quote:1s1r043j]I know about the winter air but this is the first I heard of having to adjust for seasonal changes like this, if it's just a matter of finding injectors that will do fine in both winter and summer then it's no big deal to swap them out.

[anothernord]

You shouldn't have to be changing things just because of a change in temperature. That's ghetto and unnecessary if you have a properly-tuned setup. Air flow, no matter the temperature, is still mass flow.

[lord flashheart]

This is only If you don't have a way to tune it, and don't run an upgraded pump, you will be on 100% duty cylce, which is very hard on the injectors drivers. Believe it or not you can overload the ecu. You will know when you do it because your computer will shut down for a second when you go under boost and overload the injectors drivers.

[lord flashheart]

i was saying i bought a standalone for 800, but a stand alone will cause you to fail the OBD2 test. thats why i picked the 95. i get the OBD1 test.

[grayguy]

He should just buy my LINK ecu for $800 and forget this nonsense haha

[98legacygt22]

So do I have to mess with any kind of timing controller? I'm getting ej22t pistons and installing them and acl race bearings. I want to run 12-15psi and am also wondering if an safc will be able to run my car properly with that much boost.

[anothernord]

Engine management = fuel/timing control.

[98legacygt22]

Sweet, thanks. This thread is great, you guys always answer my questions no matter how dumb they may be.

[98legacygt22]

I'm getting more anxious by the day to have this done. Just ordered my ej22t pistons.

[grayguy]

My buddy blew up a 25d block w/ 22t heads on it last week, cracked a piston and bent a rod. When I asked him what he was using to tune the timing he smiled/laughed and replied "the knock sensor" lol!

So kids, don't depend on the stock knock sensor to figure it out haha

[Thomistopheles]

^ bwahahaha! Might as well have used the "let off when it pings" method

[98legacygt22]

What kind of blow off valve would you guys recommend? re-circulatory or just a regular BOV. I just need my head gaskets and head bolts and I will start putting it together! I also wonder if Gates makes a racing belt for the EJ25D and if I should use one.

[r3v_v3ng3]

Recirculating specially since the car uses maf senor

[lord flashheart]

One up on that^

Also if you use 22T pistons your compression will be dizmal witb 25D HEADS

[Garrison]

I always advocate recirculated, but if you want to sound rice go with bov, its not going to hurt anything - the time that the ecu is reading mega-rich levels (between shifts) is so short it isn't going to hurt anything. Probably will cause backfires though.

Flashheart:
Yeah, but you can run a lot more boost, so its a tossup. I tend to agree with you though that you shouldn't use 22T pistons with the 25D heads.

[98legacygt22]

Even if im at 7.5:1 I don't care but I doubt I will be, I'm thinking I'll be at around 7.8:1. I don't race so I don't need off the line power but I imagine with that low of a CR I will spool at a somewhat low rpm. I would much rather not sound like a ricer, so I will go with a re-circulatory.

[lord flashheart]

yes you can make up for it with boost, but you sacrifice some low end.
it takes fuel to make horsepower, you can calculate your max power based on your fuel injector size, number of injectors, type of fuel, BSFC, and duty cycle.

lets set the lag thing aside for now..

lets say you use the stock 280cc injectors, you are limited to roughly 210-220CHP depending on whos math your using.
now, if you do say 10:1 compression ratio, with 5lbs of boost, you will make roughly the same power as a 7.5:1CR on say 15lbs of boost.
your using the roughly the same amount of fuel (even tho real world, the BSFC is lower with a hi comp, low boost, in contrast to low comp high boost. but for all intended purposes, we will say they are the same).
so not everyone knows this but volumetric efficiency (VE) is directly related to compression ratio, which means the higher the compression ratio, the higher the VE, the higher the VE, the more air, the more air the more torque.
so at 5lbs you will probably make similar power numbers but the torque numbers are off the hook.
(ive actually done some experimenting with this.)
from my experience, ive seen, (these are rough numbers at the wheels)
same heads, cams, and roughly the same IAT, and ignition timing, just different shortblock.
a 8.5:1 2.5 on 11lbs of boost made 170ftlbs of tq and 160hp
a 9.9:1 2.5 on 5lbs of boost made 195ftlbs of tq and 160hp

we also experimented with a 2.2, and the results were more or less the same.

[98legacygt22]

Yeah you are right, I figure with the lower compression I take a lesser chance at bending or breaking something.

[anothernord]

Low compression ratios suck. Also, from a thermodynamics, the efficiency of the engine is directly related to the CR. If I were to do it again, I would build another high compression 2.5.

[Garrison]

Low compression ratios suck. Also, from a thermodynamics, the efficiency of the engine is directly related to the CR. If I were to do it again, I would build another high compression 2.5.

You're talking 9.5:1 with 7-9psi boost?

[98legacygt22]

What's your guys thought on the AEM F/IC - 6? I see there is also the AEM F/IC - 8 but the differences only seem to be stuff I probably don't need for tuning anyway.

[lord flashheart]

We did a 1.3 liter with12.5:1 on 18lbs of boost and it made like 430whp

[r3v_v3ng3]

Low compression ratios suck. Also, from a thermodynamics, the efficiency of the engine is directly related to the CR. If I were to do it again, I would build another high compression 2.5.

You're talking 9.5:1 with 7-9psi boost?

High compression and boost is nothing unusual. I would rather prefer it as well, it just gives you a little room to mess up. Its all in the tuning. They do this alot on the honda crowd (which i've done before). I did a turbo gsr with a 10.1 compression on 12 lbs of boost. Others had jackson racing supercharged a type r (11:1 comp) on a 9 lbs of boost (which is alot of heat).

We did a 1.3 liter with12.5:1 on 18lbs of boost and it made like 430whp

sounds like an rx7

[Garrison]

[quote=r3v_v3ng3]
High compression and boost is nothing unusual. I would rather prefer it as well, it just gives you a little room to mess up. Its all in the tuning. They do this alot on the honda crowd (which i've done before). I did a turbo gsr with a 10.1 compression on 12 lbs of boost. Others had jackson racing supercharged a type r (11:1 comp) on a 9 lbs of boost (which is alot of heat).

We did a 1.3 liter with12.5:1 on 18lbs of boost and it made like 430whp

sounds like an rx7[/quote:1ygchqul]

Yeah, I was thinking something similar, the only downside to trying it on the EJ25d is the weaksauce rods and pistons. If you could figure out a way to get new equipment in there without blowing your wallet, you'd do okay; but I think that's why the phase 2 ej22 bottom-end is such an attractive option. The engine doesn't cost much and a refresh is cheap.


I was thinking the same thing
Love me some Wankel!

[lord flashheart]

The 99 "8 bolt" EJ25D uses a rear thrust and 52mm journals so u could put STI rods in it. The 48mm cranks break all the time, but the 52mm cranks are good for much more power.

The 1.3 was a hybusa. It was in a salt flat speed record car, and acording to the rules rotorys displacement is doubled because from an engineering stand point each cylinder fires twice per revolution so technically they say is a 2.6 instead of a 1.3 liter.

[lord flashheart]

The 99 "8 bolt" EJ25D uses a rear thrust and 52mm journals so u could put STI rods in it. The 48mm cranks break all the time, but the 52mm cranks are good for much more power.

The 1.3 was a hybusa. It was in a salt flat speed record car, and acording to the rules rotorys displacement is doubled because from an engineering stand point each cylinder fires twice as offen per revolution so technically they say is a 2.6 instead of a 1.3 liter.

[Garrison]

So you're recommending sti rods and pistons for a 99 EJ25D build?

[lord flashheart]

No, i was just pointing out tht the STi internals will work in the 99 EJ25D. He mentioned that the 25d rods are weak and was talking about ways to get stronger rods and pistons in it.

[Garrison]

That was me. So if you aren't advocating using sti pistons with the rods you mentioned, what are you suggesting?

[grayguy]

Here is some pics of the "knock sensor tuned" 25d/22t combo haha.