GT35R on a 2JZ-GTE

[Norbie]

Everyone is ganging up on me.

OK fine, I'll install a trim pot! Bah, extra work.

[1JZ-Rolla]

bah, just crank the fuel pressure, at least it will be a good test of your system for leaks when it runs that pressure eventually on full boost anyways

[JustenGT8]

AFPR? just crank up fuel pressure.

Cranking up all the load points as a group by 30% is also pretty easy to get you ballpark

[CrUZida]

Everyone is ganging up on me.

OK fine, I'll install a trim pot! Bah, extra work.

What do you mean install a trim pot?

The ecu should have a -100%/+100% fuel trim feature.
Just bump it up to +50%

[Norbie]

I thought the trim feature used an external trim pot for adjustment, but maybe you can also do it via the laptop. I'll have to look into this.

Yes I have an AFPR, and I've already cranked it up to 60psi to check for leaks.

[CrUZida]

Well, the Microtech does it all on the laptop, so I'd hope to hell that the Haltech has that ability.

Trimpot may only be able to do +-5% for say cruising fuel economy?

[CrUZida]

Yes I have an AFPR, and I've already cranked it up to 60psi to check for leaks.

Also, 720cc + 50% increase in fuel pressure will not give 1000cc.

Going from 45psi to 60psi will take the injector from 720cc to about 830cc

If you want to go to 1000cc you'll need to increase the pressure to about 87psi

[thechuckster]

Everyone is ganging up on me.

... peer pressure FTW!!1!

[1JZ-Rolla]

Microtech does have an overall fuel "MixTrim" adjustment available through either the handset or laptop, but Haltech does not (on the older E6 models anyway)

For the Haltech you need to adjust each RPM load map, which can be done by selecting all load points and entering a percentage adjustment across that rev range only. From memory the shortcut is "Alt-P" to make a percentage increase or decrease (+ or - value).

If you choose to go this way, making a percentage change equal to the size difference in your injectors is a pretty rough adjustment, If I remember correctly, it will give too lean a mixture on vacuum, but you'll find out when you try since you have the wideband O2 meter.

Cheers
Phil

[edit] there is actually a quicker way, you don't need to do each RPM range individually, you can select all maps to adjust at once, I think its "Alt-R", then bump up a percentage change (Alt-P) to do the lot Microtech style.

[Norbie]

According to the E6K manual the external trim control can be used to adjust fuel up to +/- 50%, so perhaps that's the way to go. It will be much easier to turn a knob while watching the wideband meter as I drive than playing with a laptop.

[JustenGT8]

This is a dodge to get you to the tuner right? Just crank up the damn fuel pressure and baby it there...10 seconds work

[lojik]

The E6X does have the injector trim feature which can be used to trim each injector individually or as a group. Not sure about the E6K, however as you don't need individual injector control you can get away with the external trim.

Though perhaps its a good idea to lock the pot (wrap it in tape or something) once you've found the correct setting, you wouldn't want to accidentally bump it to super-lean at WOT would you....

[CrUZida]

This is a dodge to get you to the tuner right? Just crank up the damn fuel pressure and baby it there...10 seconds work

Did you see the pressure he'd have to crank it up to in order to achieve the equivalent of 1000cc ?

[CrUZida]

According to the E6K manual the external trim control can be used to adjust fuel up to +/- 50%, so perhaps that's the way to go. It will be much easier to turn a knob while watching the wideband meter as I drive than playing with a laptop.

Honestly Norbie, just increase all the values for injector pulse by 50%.
Your tuner is going to have to do this anyway, so time spent doing this at home is time (and thus money) saved with the car sitting on the dyno.

The external pot would not be the smartest move to make, and is something that could accidently do damage under bad circumstances.(as pointed out above)

[JustenGT8]

Did you see the pressure he'd have to crank it up to in order to achieve the equivalent of 1000cc ?

Yup i did but not an issue.

1) he doesn't have to get to the equiv of 1000cc. If he's just babying it to a dyno, as long as it's running there's no issue with how lean it runs...what a:f you reckon you're at when cruising ??? 16:1 is totally doable.

2) 60-70psi will be fine. I've run the GT8 at 70psi idle fuel pressure with no issues.

I'm definitely not saying this is a good idea for even a week of plodding around, but one 30km trip to the dyno will be fine.

I've already suggested doing the group load point richen but i'm assuming Norbie doesn't have the manual as he hasn't gone this way? if you do Norbs it's dead easy.

....either option will get you there