Hi everybody. I am looking for advice on piggybacks vs reflashing the stock 04 WRX ECU for our PGT rally car.

We must run a 32mm restrictor at the turbo inlet.

The rules state we can run piggyback controllers, TT's & manual boost controllers. We can change boost, and fuel curves, but not timing(which makes no sense to me, due the the "learned" timing on the WRX's).

Next year it will "most likely" be legal to run relfashed ECU's, as currentlythe sanctioning body cant really test for them. More like Group N.

Anyway, I am old school (34 yrs old school to be exact), and grew up with carbs & American V8's, so I need something I can figure out, and that will also give me the most bang (well, torque really) for the buck.

Suggestions please?

Thanx
JC

From what i know. the Hydra seems to be the most user freindly currently. (www.elementtuning.com) Then again, when it comes to tuning and messing around with ECU's, i don't know how "Easy" any of it really is. Good luck.
-Eli

The hydra is a standalone though.... Are there any limits on the mods you can do? Water/alcohol injection could help the engine deal with a big turbo on the stock timing curve(if this is allowed). You could easily use a utec and just have the timing map be stock. The only problem is that when piggybacks remove fuel, they generally make the engine think there's less air going into the engine at a given point which makes the timing a little more advanced. Would this be ok since it's just a result of fuel tuning, or do you need something that tunes the fueling independently(like a reflash)? eh,

peace

SM-

A Hydra is not a piggy-back.

Your options go like this:

S-AFC and similar - fuel controller only. Since this is all you can change here, this is probably the easiest and cheapest way to go. Run an MBC for boost control.

UTEC - piggyback that lets you alter and/or force fuel, timing and boost. But you CAN select "ECU" throughout the timing map, and then you'll run only ECU timing. As a warning, this is a great way to blow up an engine if you are not careful, as the stock ECU stops listening to the knock sensor at ~5500rpm, and the UTEC does not offer knock correction on ECU timing.

XEDE, E-manage - piggybacks that also let you adjust the curves in the ECU.

Since you can't touch timing, you could just use an S-AFC for fuel leaning and an MBC or EBC for boost-control. You can add notable performance this way, and you would only spend about $400 total. However, I would probably want to buy a knock-detection system of some kind (knock-link, etc.) and a WbO2 sensor. Or, a unit that combines both, like a TXS tuna.

Sorry it took so long to respond(I've been traveling all day for work)-

So, what I need to do really is try to make up for the restrictor choking the air inlet by changing the fuel & boost curves. THe problem is, I need someone with experience using restrictors to help push me in the right direction on how to use these products I guess.

WHat's the max boost I can run on a stock WRX engine? 1.2bars? 18psi? I need help there too.

Who in the Detroit area does reflashes? Can the stock ECU be relfashed to make good use of the 32mm restrictor?

This is making my head hurt...

:)

The hydra is a standalone though.... Are there any limits on the mods you can do? Water/alcohol injection could help the engine deal with a big turbo on the stock timing curve(if this is allowed). You could easily use a utec and just have the timing map be stock. The only problem is that when piggybacks remove fuel, they generally make the engine think there's less air going into the engine at a given point which makes the timing a little more advanced. Would this be ok since it's just a result of fuel tuning, or do you need something that tunes the fueling independently(like a reflash)? eh,

peace

I cant run water injection, we run in PGT (PRoduction class) no mods to the motor at all, and we must run a 32mm restrictor. NO TIMING mods(at least this year).

hmmmm...

Sorry to jack the thread, but does that mean you can't switch out injectors or turbo? It would suck to run on stock turbo if ya had to go up against a evo.... What octane fuel do you use? That might limit the boost ya run.

peace

We dont see many Evo's in PGT. One day we will when someone with lotsa money steps in, but for now, the worst is one person with an STI. THe rest are WRX's & Talons & Eclipses.

Can run race fuel(110 Sunoco- from a specific vendor at the rally).

Stock turbo- although we *can* switch to an STI turbo (I think- kinda grey area)

I *think* we can switch to STI injectors, but no aftermkt turbos or injectors.

What I need is to at LEAST get back to stock numbers(preferably higher numbers) even though I am running the 32mm restrictor. If I could get 250hp with the HKS up & down pipes, 1 hi flow converter, no muffler, stock turbo, 110 octane, stock ecu timing control... THAT's what I need. Is it possible? Bueller?...

Sounds good, course I'm no expert. I dunno how much power you'd make with that restrictor and what not. Maybe it would be a good idea to get an extra o2 sensor and cat if you're gonna be running leaded gas? If you can put bigger injectors and a bigger turbo on(sti and ihi), you'd probably get a nice bump in power/torque......

peace

1 hi flow, near the rear, in place of the muffler.

You can, theoretically, get about 300 crank HP with a 32mm restrictor. PSA and Subie do better than that in WRC, just multiply out their torque numbers at mid-revs.

However, you've got to deal with the fact that you can't run enough boost to do that on the stock or STi turbos. Find out if you can upgrade turbos. If you can, get yourself into a vf35 (failing that, a 39, 29 or 34, I've ordered those three from best spool/least power to worst spool/best power) or something like that. If you can't, do what you can.

I safely ran 22.5psi on pump gas on my stock engine (since swapped out) for probably 5K miles on a GT30R, and 19-20psi on a vf34 before that. However, I had an FMIC, and better-than-stock turbos.

You don't need to switch injectors if you can run 110 octane fuel. You'll be able to run the boost pressures you want, safely, at 12.5:1 or close to it. You probably SHOULD switch fuel pumps, just because the stocker seems to bypass around 14psi over static.

You should use something to spot knock. The stock ECU ignores the knock sensor up high, so you need something to make sure you're not blowing the sucker up. I would also put in a 2-probe air temp sensor, before and after the intercooler. That way you can really effectively tune the car's boost and not just blow useless hot air.

With an upgraded turbo, even with the restrictor, I think you should have no real problems turning 260-270 safely, perhaps more. I'd definitely give you 280-290 if you could play with timing, but I think the ECU is going to adjust away from you if you're not very, very careful. That said, even with the stock turbo, I think you should have no problems getting 250 from this setup at the crank. A 32mm restrictor just isn't much of a limit at the power-levels you are looking at.

-Sean