Mods Before A Dyno Tune

[Niran]

Hey Guys,

I am planning a list of mods before I get a full dyno tune done. Currently my 2004 WRX STI has got a full turbo back exhaust (custom made - bought the car with it on), not too happy with the exhaust tone and cabin resonance. Due to the car overboosting heaps, i got the boost pill drilled out slightly, just until i could save enough for a tune. I've also got a lot of wastegate chatter as well that I'm hoping to get rid of with the tune, and/or parts. I am planning to install the following before getting it tuned at Torque Performance:

1. GFB Mach 2 Recirc BOV

2. Grimmspeed 3-port Boost Solenoid

3. AdrenalinR Muffler - Try fix some of the in cabin resonance

3. K&N Typhoon short ram Intake and intake silence delete - Not sure if this is the best intake to get, any ideas?

4. Any aftermarket wastegate actuator to fix the wastegate chatter and provide better response - Not sure which one to get yet.

The plan is to get all of these parts, and install just before getting a tune done. What do you guys rekon?

Cheers.

[Marky]

1. GFB Mach 2 Recirc BOV - Don't bother, the stock ones hold fine

2. Grimmspeed 3-port Boost Solenoid - Good plan

3. AdrenalinR Muffler - Try fix some of the in cabin resonance - Sure why not though it isn't really dyno related

3. K&N Typhoon short ram Intake and intake silence delete - Not sure if this is the best intake to get, any ideas? - Leave the stock one there

4. Any aftermarket wastegate actuator to fix the wastegate chatter and provide better response - Not sure which one to get yet. - Are you sure that's actually a thing... I'm not

I'd add fuel pump and FMIC to the list

[chulozumo]

Rotational idle. DO IIIIIT.

[boon]

The stock intake is better than the short K&N one. Get an aftermarket panel filter if you really must.

When you put a 3-port on it completely negates the need for a different wastegate actuator, save that money for petrol & tyres.

[Andy_Mac]

Word on the street is removing the milk bottle/silencer from the bottom of the stock intake is good for better spool and more choo choo noises

[Niran]

 Marky']1. GFB Mach 2 Recirc BOV - Don't bother, the stock ones hold fine

2. Grimmspeed 3-port Boost Solenoid - Good plan

3. AdrenalinR Muffler - Try fix some of the in cabin resonance - Sure why not though it isn't really dyno related

3. K&N Typhoon short ram Intake and intake silence delete - Not sure if this is the best intake to get, any ideas? - Leave the stock one there

4. Any aftermarket wastegate actuator to fix the wastegate chatter and provide better response - Not sure which one to get yet. - Are you sure that's actually a thing... I'm not

I'd add fuel pump and FMIC to the list

[quote name='boon said:

The stock intake is better than the short K&N one. Get an aftermarket panel filter if you really must.

When you put a 3-port on it completely negates the need for a different wastegate actuator, save that money for petrol & tyres.

Awesome thanks for the feedback guys. So buying an after market intake isn't going to provide any benefit even with a tune?

Will leave the wastegate actuator alone.

Lastly, I wont have enough coin for a full FMIC kit and installation. You mentioned getting a fuel pump. How much benefit do think that will provide at this stage? Given my mods will only be, full exhaust, 3-port and panel filter. Also would you recommend getting anything else done before the tune that won't majorly break the bank?

[Munkvy]

A fuel pump won't do anything on it's own. However replacing a now 11 year old fuel pump is a safety aspect first and foremost. And a quality aftermarket fuel pump should allow you to run more fuel to the injectors, therefore potentially allowing the tuner to extract more power from the car.

I assume when you say full exhaust you have an aftermarket down pipe and no cat?

[boon]

To be honest, having been down this path, you have all the mods I'd bother doing at this stage. The difference between the power you'll make as-is and the power you'll make with another $4k spent is about 20kw.

When it comes to modding these cars, and I have done the whole shooting match in a very staged manner, is spend the bare minimum you can (basically a decent turbo back exhaust and nothing else) and get a reflash, this will net you maybe 200-210wkw, then if that's not enough save a whole lot up and do a much bigger turbo, 1000cc injectors and a FMIC which will get you the better part of 300wkw. Faffing around in the 230wkw area (aka trying to make power with the factory-sized turbo) costs a whole lot of money and doesn't provide a much bigger grin on your face than 210-odd.

[Niran]

 boon said:

To be honest, having been down this path, you have all the mods I'd bother doing at this stage. The difference between the power you'll make as-is and the power you'll make with another $4k spent is about 20kw.

When it comes to modding these cars, and I have done the whole shooting match in a very staged manner, is spend the bare minimum you can (basically a decent turbo back exhaust and nothing else) and get a reflash, this will net you maybe 200-210wkw, then if that's not enough save a whole lot up and do a much bigger turbo, 1000cc injectors and a FMIC which will get you the better part of 300wkw. Faffing around in the 230wkw area (aka trying to make power with the factory-sized turbo) costs a whole lot of money and doesn't provide a much bigger grin on your face than 210-odd.

This is awesome info man, thanks heaps! I guess I am aiming for 230-240kw from my dyno tune (at Torque Performance) and need to figure out the best combo of parts to get there. I know another guy got his v8 STI tuned there with full TBE, K&N typhoon intake, grimmspeed 3-port and GFB recirc BOV. He netted 233kw atw.

So i was thinking, similar mods would give me a similar net power output. The things i have no idea about are if:

1. Adding a high flow fuel pump will add any value to achieving 230-240kw - Is the stock one capable of delivering up to this level?

2. Is replacing the intake with a dyno tune going to give me a power gain - So many mixed opinions on this!

3. Spend the $350 on an intake on something else with more power yield?

Again thanks again guys, really helpful.

[Niran]

 Munkvy said:

A fuel pump won't do anything on it's own. However replacing a now 11 year old fuel pump is a safety aspect first and foremost. And a quality aftermarket fuel pump should allow you to run more fuel to the injectors, therefore potentially allowing the tuner to extract more power from the car.

I assume when you say full exhaust you have an aftermarket down pipe and no cat?

Fair point there. I've got a full TBE so with down-pipe and no cat. All i have are the receipts from the previous owner which state (when he changed the whole exhaust) the replace part was: 'Subaru Twin Scroll Turbo Downpipe'. $350 worth

[calebwrx]

The standard fuel pump COULD deliver enough for 230kW, but it might not last long being worked that hard. Just spend the $300 on the pump instead of the intake hose, unless your current hose is damaged then it won't make much difference.

[D1Style]

 Niran said:

This is awesome info man, thanks heaps! I guess I am aiming for 230-240kw from my dyno tune (at Torque Performance) and need to figure out the best combo of parts to get there. I know another guy got his v8 STI tuned there with full TBE, K&N typhoon intake, grimmspeed 3-port and GFB recirc BOV. He netted 233kw atw.

So i was thinking, similar mods would give me a similar net power output. The things i have no idea about are if:

1. Adding a high flow fuel pump will add any value to achieving 230-240kw - Is the stock one capable of delivering up to this level?

2. Is replacing the intake with a dyno tune going to give me a power gain - So many mixed opinions on this!

3. Spend the $350 on an intake on something else with more power yield?

Again thanks again guys, really helpful.

Been through this with my current car.

The factory airbox is more than capable at your power level plus you wont get the heat soak factor like you would with the K&N. Just buy a high flow panel filter and chuck it in.

I would save the $350 on the intake and put it towards your tune or fuel pump.

With the fuel pump, you are future proofing your car and like what Munkvy said, it will allow the tuner to extract more power.

While you're at it get a set of 1 step colder plugs fitted too.

[rskikn]

no ones mentioned split fuel rails and an aftermarket reg to go with that fuel pump..

that was my first engine mod as we all know subaru's love to lean out.

[Koom]

 rskikn said:

no ones mentioned split fuel rails and an aftermarket reg to go with that fuel pump..

that was my first engine mod as we all know subaru's love to lean out.

I reckon thats more of an old sidefeed injector problem and I'm doubtful as to gaining any benefit from splitting the later top feed rails IMO. Same with factory fuel pressure reg. Unless the tuner wants to wind up the base pressure.

[rskikn]

i split them even running top feeds as i run twin external bosch pumps with there own lines one to each fuel rail then into twin port fuel reg. better to much fuel than to little. safe or sorry take yr pick lol.

[boon]

I did the maths on this somewhere, leaning out the 4th injector (on top feed rails) is a myth and splitting the fuel rails + adding an aftermarket fuel reg is 100% a waste of time and money on a modern Subaru.

With an IHI turbo you will never outflow the 565cc injectors so there is just no point in doing any of it.

I will add that I run 1600cc injectors in stock rails with the stock reg.

[rskikn]

I only run 800cc injectors haven't needed anything larger with my split rail system it currently runs 300kw on 95 octane.. u keep yr theory and ill stick to my old skool one

[boon]

 rskikn said:

I only run 800cc injectors haven't needed anything larger with my split rail system it currently runs 300kw on 95 octane.. u keep yr theory and ill stick to my old skool one

Why not stick to carburetion while your at it, **** those injector things.

Keep in mind that when you recommend someone do something completely pointless, you are wasting their time and money. Would you still do it if they could invoice you for the waste?

"Your advice was bad, here's a bill for $300"

[Koom]

 rskikn said:

i split them even running top feeds as i run twin external bosch pumps with there own lines one to each fuel rail then into twin port fuel reg. better to much fuel than to little. safe or sorry take yr pick lol.

That could create the situation where one pump dies and goes lean on two cylinders while the others run fine. Unless you add a leg to balance between the two sides. Or are you relying on the dead side being backfed via the dualport reg?

I wouldn't consider that safe at all personally.

[Niran]

I think from what I've read and what you guys are saying, its definitely a good idea to get an uprated new fuel pump to replace the old one. Stock STI injectors and fuel lines are fine for HP up to which the stock turbo can handle - works for me im aiming for 230-240kw

So the list will be:

1. Fuel pump - Walbro 342 fuel pump?

2. Grimmspeed 3-port Boost Solenoid

3. Intake silence delete and new panel filter

4. GFB recirc Mach 2 BOV

5. New spark plugs - a step colder

Rekon I'll need new ignition leads too? Anything else?

[rskikn]

http://rogerclarkmotorsport.co.uk/store/product/57-rcm-parallel-fuel-rail-kit-rcm-performance-fuel-regulator

you guys should email him and tell him his fuel systems are a waste of time. you know just cos hes wasting every ones time.

[Andy_Mac]

If you get the 3-port direct from grimmspeed when you get to ordering chuck BECAUSETHANKYOU in the coupon section to get 15% off, or BECAUSEGRIMMSPEED for 5%. Not sure if you can use both or just one. Worked out way cheaper through them than any NZ places could do for mine.

Sure you can get the standard MAC valve versions alot cheaper but you typically don't get any mounting brackets or a plug so have to cut it into the existing wires.

Edited December 2, 2015 by Andy_Mac

[Guest]

Buy one off a trucking firm they dont charge rfb tax.

[boon]

 rskikn']http://rogerclarkmotorsport.co.uk/store/product/57-rcm-parallel-fuel-rail-kit-rcm-performance-fuel-regulator

you guys should email him and tell him his fuel systems are a waste of time. you know just cos hes wasting every ones time.

That kit is designed to provide fueling for up to 1500hp.

Is the guy asking questions here trying to make 1500hp or is he trying to make 380hp?

In that case he should definitely have the heads and block o-ringed because that's safer than running a head gasket and we all know from years of internet rumours that Subarus love to blow head gaskets.

[quote name='Niran said:

I think from what I've read and what you guys are saying, its definitely a good idea to get an uprated new fuel pump to replace the old one. Stock STI injectors and fuel lines are fine for HP up to which the stock turbo can handle - works for me im aiming for 230-240kw

So the list will be:

1. Fuel pump - Walbro 342 fuel pump?

2. Grimmspeed 3-port Boost Solenoid

3. Intake silence delete and new panel filter

4. GFB recirc Mach 2 BOV

5. New spark plugs - a step colder

Rekon I'll need new ignition leads too? Anything else?

Walbro will be good, personally I'd buy the generic MAC valve that Grimmspeed puts their sticker on but as mentioned it means a little bit of wiring rather than a plug/play install.

The BOV won't do a single thing for you, the stock one works completely fine but I'm sure you can find some internet hero saying it leaks over 20psi.

Your car doesn't have leads - Coil-on-plug

If you make 240wkw either the dyno is made of lies or you have a unicorn motor.

Even 230 I would be pretty surprised by.

[chulozumo]

*Grabs popcorn*

I'm still voting for rotational idle.....