Aftermarket injectors

foreverpsycotic

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Jul 16, 2006
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SupraClaou said:
For 450 whp you don't need a fuel rail,fuel pump(assuming you have a walbro or a mk4 pump) or an AFPR ,but you are near their limit!
They are limited to about 480-490 whp.

BUT for 450 whp, the 440cc high impedance injectors from JDM 2JZGTE
Aristo or Supra are not enough.You'll need something like 620cc for 100%
safety on fuel issues.

However, 550s should be able to support 400whp. I might cheap out, get 550s and use meth as I don't want to run race gas (prices are too damn high).
 

annoyingrob

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SupraClaou said:
For 450 whp you don't need a fuel rail,fuel pump(assuming you have a walbro or a mk4 pump) or an AFPR ,but you are near their limit!
They are limited to about 480-490 whp.
Yeah, you are pretty close to the limit.

My stock(ish) fuel pump making 400whp on my 1JZ was running my 800cc injectors around 85% duty cycle at 7500rpm just because it couldn't flow enough fuel. So yeah, it will flow 400whp, but it's at its limit.

FWIW, my 1JZ on stock twins ran 96% duty cycle at 315whp on stock injectors at 7500rpm too. Not sure if that was a fuel flow, or an injector flow limit though.
 

Ronald

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Oct 16, 2007
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That's cool,

so just an injector upgrade to get up in the 400's range - but can skip the second fuel pump (I do have an mkiv pump in there) and afpr.

If that's the case, is there any point in going standalone at all?

I guess I don't understand how the engine management works in a Supra. On the wrx's with addition of larger injectors, you need to go with a piggyback that is capable of manipulating not only the boost, but fuel and timing as well.

Why is this not necessary on a Supra. It seems like you can just add fcd and boost control via an S-afc and be good to go... (for moderate hp increases at least). Doesn't S-afc only control boost settings... Or can you adjust fueling with it as well?
 

OneJoeZee

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AFC has nothing to do with boost at all...

If you want your car to run with any kind of decent AFRs, you need a piggy back or better to compensate for larger injectors.
 

SupraClaou

Supramania Contributor
Sep 1, 2006
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OneJoeZee said:
AFC has nothing to do with boost at all...

If you want your car to run with any kind of decent AFRs, you need a piggy back or better to compensate for larger injectors.

Exactly. You just need bigger injectors.No second thought on that!
The stock 1jz's - 2jz's(JDM) and 7m's 440cc are limited to about
400-420 hp (350whp),and almost nobody runs them so high at their limit.
Simply, the cost of some bigger injectors is nothing compared to an engine
rebuilt due to lean conditions on A/F .

Export (USA,Europe) 550cc injectors can hold up to 480 hp,that's true!
The other stock fuel parts of the fuel system will handle up to 550 hp
without any problems on the 2jzgte.Even the pulsation dampener,which
is located before the fuel rail does a descent jub on the 500 hp+ mark :icon_bigg
I don't know why someguys install AFRP and take away the fuel pulsation
dampener :icon_mad:

AND the only other thing you need after the bigger injectors is a fuel
computer, a piggyback like S-AFC will do fine!
 

Ronald

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Oct 16, 2007
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SupraClaou said:
Exactly. You just need bigger injectors.No second thought on that!
The stock 1jz's - 2jz's(JDM) and 7m's 440cc are limited to about
400-420 hp (350whp),and almost nobody runs them so high at their limit.
Simply, the cost of some bigger injectors is nothing compared to an engine
rebuilt due to lean conditions on A/F .

Export (USA,Europe) 550cc injectors can hold up to 480 hp,that's true!
The other stock fuel parts of the fuel system will handle up to 550 hp
without any problems on the 2jzgte.Even the pulsation dampener,which
is located before the fuel rail does a descent jub on the 500 hp+ mark :icon_bigg
I don't know why someguys install AFRP and take away the fuel pulsation
dampener :icon_mad:

AND the only other thing you need after the bigger injectors is a fuel
computer, a piggyback like S-AFC will do fine!

Ok thank you, I get it now. AFC is not a boost controller, but a fuel controller... makes more sense now - I was missing that link. For some reason i had in my head it was more of an electronic boost controller. I know peops use them heavily in this arena, and I think in DSM world too? I just don't know much about them (i know i know, READ UP!). WRXs aren't great with a AFC, I think probably cuz timing reduction is needed on wrx to keep it from denotating at higher boost levels. So most folks go with a more advanced piggyback for the wrx platform that controls timing as well.

thanks again, I'm learning new stuff by the day!

So on a side note -- Am I being to agressive running 13psi on a T67 turbo on the stock JDM 2jzgte fuel system, aside from also using mkiv fuel pump? I need to get an EGT or wideband in soon so I can monitor this --- last thing I want to do is blow this bad boy up!

What's a reasonable EGT for this car on WOT... 775 celcious at the entry of downpipe? Or can you say what temp not to exceed? Wideband not really in my budget right now, but EGT is less expensive and at least somewhat decent to monitor for lean conditions before I get setup for dynotune.

Anyone every modify the stock injectors to flow better? People in the suby world are hacking up stock 450's from regular WRX's (non-STi's) to flow over 700cc's reliably. And they are checking out on bench flow tests as well -- All for less than half the cost of new injectors. I guess that is technically like playing russian roulet though, if an injector were to fail, probably could be catastrophic. Or maybe not? No fuel, no burn, no burn - no BOOM. I guess if it were to fail to provide 'enough' fuel it could be catastrophic.
 
Last edited:

foreverpsycotic

Back in the game!
Jul 16, 2006
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SupraClaou said:
Export (USA,Europe) 550cc injectors can hold up to 480 hp,that's true!
The other stock fuel parts of the fuel system will handle up to 550 hp
without any problems on the 2jzgte.

Awesome, I was just about to ask this question. Looks like I might be hitting 450 on pump (maybe a little more seeing how I'm going to be running alchy+water)
 

SupraClaou

Supramania Contributor
Sep 1, 2006
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Ronald said:
Ok thank you, I get it now. AFC is not a boost controller, but a fuel controller... makes more sense now - I was missing that link. For some reason i had in my head it was more of an electronic boost controller. I know peops use them heavily in this arena, and I think in DSM world too? I just don't know much about them (i know i know, READ UP!). WRXs aren't great with a AFC, I think probably cuz timing reduction is needed on wrx to keep it from denotating at higher boost levels. So most folks go with a more advanced piggyback for the wrx platform that controls timing as well.

thanks again, I'm learning new stuff by the day!

So on a side note -- Am I being to agressive running 13psi on a T67 turbo on the stock JDM 2jzgte fuel system, aside from also using mkiv fuel pump? I need to get an EGT or wideband in soon so I can monitor this --- last thing I want to do is blow this bad boy up!

What's a reasonable EGT for this car on WOT... 775 celcious at the entry of downpipe? Or can you say what temp not to exceed? Wideband not really in my budget right now, but EGT is less expensive and at least somewhat decent to monitor for lean conditions before I get setup for dynotune.

Anyone every modify the stock injectors to flow better? People in the suby world are hacking up stock 450's from regular WRX's (non-STi's) to flow over 700cc's reliably. And they are checking out on bench flow tests as well -- All for less than half the cost of new injectors. I guess that is technically like playing russian roulet though, if an injector were to fail, probably could be catastrophic. Or maybe not? No fuel, no burn, no burn - no BOOM. I guess if it were to fail to provide 'enough' fuel it could be catastrophic.

Don't know much about WRX tuning,timing,etc.,but one think is for sure:
The TCCS ecu,timing and ignition system on supras (specially on jz motors)
is something else!! You see,the basic fuel calculation system in the tccs ecu
is working very hard to keep up with increased performance and higher boost.

13 psi on T67 turbo and stock fuel system isn't agressive.But you should't
go higher without some tuning.But even with correct tuning you can't
go over 15 psi,cause you'll need bigger injectors and A/F tuning.

775 celcious EGT on the dp is ok,but you get close to the limit which is
about 900 celcious on the exhaust manifold!
I think the EGT difference between manifold and dp is about 70'celcious
more on the ex.manifold.Anyway just watch the A/F don't go over 12-1
and run to lean.Better be rich then lean.Some ponnies will go,but the
engine will stay in one piece :biglaugh: :biglaugh:
 

SupraClaou

Supramania Contributor
Sep 1, 2006
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Ronald said:
Anyone every modify the stock injectors to flow better? People in the suby world are hacking up stock 450's from regular WRX's (non-STi's) to flow over 700cc's reliably. And they are checking out on bench flow tests as well -- All for less than half the cost of new injectors. I guess that is technically like playing russian roulet though, if an injector were to fail, probably could be catastrophic. Or maybe not? No fuel, no burn, no burn - no BOOM. I guess if it were to fail to provide 'enough' fuel it could be catastrophic.

Modify a downpipe or custom IC pipes...YES.
But never modify stock injectors to squize a little bit more
flow out of them :nono: Save some money and after some time
you'll put bigger ones.Thats the correct path to follow :icon_bigg
 

Ronald

New Member
Oct 16, 2007
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Cleveland OH
Thanks SupraClaou,

I appreciate all the info!

Agree smarter just to get upgrade injectors. I went that route on the wrx, despite guys were hacking their stock injectors... seemed too risky to me.

So I'll go 1. fix the speedometer 2. seal up the firewall or plumb the external wastegate (sick of fumes in the cockpit) 3. install the power steering rack 4. get fuel injectors, Apexi Neo, FMIC, and dyno tune.

Thanks again! :icon_bigg