Quarter times for 5eat

[2jz929]

I might put my wideband in the exhaust and checks afr's then to be sure. Stock engines typically run rich so I couldn't see there being a big issue.

Seems like these Subarus are a little behind in ecu compensation is that was the case. I've got a gt35, ported heads, cams, intake, intercooler and exhaust on my mazda with the stock ecu and it's fine.

[dr20t]

All factory ecu's are limited in their compensation capacity to closed loop

Unless mazda's run full time closed loop (I'm not familiar with them) then I would dare say your Mazda would be running lean on boost with those mods if untuned

In closed loop (feedback from 02 sensor(s) ), ecu will target stoich of 14.7:1. This is fine for most of the time unless you need more than 25% fuel adjustment (which for target afr of 14.7:1 means you can't be less than 11.5:1 or 17.9:1 uncompensated afr).

Basically with the Subaru ecu, once in positive boost you're in open loop. No adjustment there. So if your engine now flows 10% more air, then you're running 10% leaner than stock. That's fine if your open loop table at 14psi and 2.5+ load is set to 10:1 (to get to a safe 11.1:1 afr at that point). But you will find its still not optimised, and your ve will also be different requiring different cam and ignition timing

[dr20t]

You're right about most ecu's being rich too. But it depends on which load point etc. with increased airflow you may have entered unchartered territory for your ecu (resolution doesn't extend to that or may need different fuel and timing values)

[2jz929]

I put a 2jz in my Mazda.

Will chuck my wideband on check afr's on the liberty. Was going to put a mbc on it and wind it up to boost cut but this isn't meant to be good on the liberty either.

[dr20t]

Just picked up on your user name

Nice

I take it that its not an untuned, stock rom Mazda ecu though. Surely wouldve been tuned?

And mbc is also a bad idea for any late model Subaru.

32 bit ecu in our cars is fully tune able and has ecu controlled boost. Stock 2 port controller is sufficient and can be tuned. Big gains to be had in driveability, torque and a little more power on the stock setup with dump pipe once ecu is tuned.

[2jz929]

Yeah figured I'd can the mbc idea and just wait for tune.

The mazda is on the stock toyota ecu with stock injectors but only on 10psi at the moment. The porting/cams have made the idle lumpy but other then that it runs great. Very flexible ecu, will run 500rwhp just by putting in larger injectors and playing around with a safc on the MAP sensor.

[dr20t]

Difference is they're map (speed density) based, so have variability in their parameters

You can't crack a toyota ecu too, so "fooling" it into submission is generally the go

Good luck wth the tune

Mick

[2jz929]

Thanks.

Hoping to at least get into the mid 14's with a tune and dump. Is this realistic? Low 14's would be preferable.

[dr20t]

Thanks.

Hoping to at least get into the mid 14's with a tune and dump. Is this realistic? Low 14's would be preferable.

Definitely possible

Brake boost to 14.5psi, get 60 ft time to sub 2 seconds (easily possible) and off you go to a low 14 maybe even better

[2jz929]

That's alright. Might be worth putting up with the extra noise if the dump will make a noticeable difference once tuned.

[oldmate]

I ran a 14.9sec 1/4 with trap speed 93mph. Stock 05gt a/t. Ran again with TBE no tune(I know, my bad) no difference in time. I did get it e-tuned but wasn't right and went back to stock rom. Recently had it dyno tuned but needs some tweaking as fuel consumption is through the roof. LV has ranges at
0-5.59 5.6-9.99 10-39.99 40+
+7.1% -13.4% -7.9% -2.7%
Planning to get that sorted and a few other things then run it again and see what changes have made.

[2jz929]

Cheers. That's pretty much what I expected mph and time wise. Interesting the tbe didn't help your times. Will get a tatrix cable and find out why my boost is low.

[alexeiwoody]

I ran a 14.9sec 1/4 with trap speed 93mph. Stock 05gt a/t. Ran again with TBE no tune(I know, my bad) no difference in time. I did get it e-tuned but wasn't right and went back to stock rom. Recently had it dyno tuned but needs some tweaking as fuel consumption is through the roof. LV has ranges at
0-5.59 5.6-9.99 10-39.99 40+
+7.1% -13.4% -7.9% -2.7%
Planning to get that sorted and a few other things then run it again and see what changes have made.

Who did the tuning?

[oldmate]

I ran a 14.9sec 1/4 with trap speed 93mph. Stock 05gt a/t. Ran again with TBE no tune(I know, my bad) no difference in time. I did get it e-tuned but wasn't right and went back to stock rom. Recently had it dyno tuned but needs some tweaking as fuel consumption is through the roof. LV has ranges at
0-5.59 5.6-9.99 10-39.99 40+
+7.1% -13.4% -7.9% -2.7%
Planning to get that sorted and a few other things then run it again and see what changes have made.

Who did the tuning?

There's a guy in town here called forced. His specialty is fords but has done a few wrx /forester tunes. He had come highly recommended. I was kinda hesitant when he had to use my laptop and tactrix as he couldnt get his to work. Said he would road tune the problems out (not sure if at additional cost though, dyno was $750)

[Bugalugs]

Cool thread mate.

Thinking of taking my lightly modded 05gt wagon to Willowbank in first Friday of June for a run to see how it goes. Have dump, mufflers, high flow panel filter and tune is all that's been done performance wise. Will be first time on a strip! Out of interest, what's the best launch technique for the auto? Hold the brake on to build good revs (how high?) then release or I saw on YouTube some dude going up to 5k revs in neutral then popping it into Drive, looked a bit crazy the N to D method must be hard on the box?