[B4RSTiwsnc]

what if a CEL comes on after you get the car protuned? when you reset the ECU on the AP will that delete the map? sorry for the dumb ?

[Digitalfiend]

Originally Posted by B4RSTiwsnc

what if a CEL comes on after you get the car protuned? when you reset the ECU on the AP will that delete the map? sorry for the dumb ?

No it doesn't. The base map is stored permanently in the ECU.

[GilMikalian]

What Digitalfriend said....just kidding, Digitalfiend When you get a pro-tune, you get a new map, just like the ones that came with the AP, except it's a tune ONLY for your car! So you can realtime it or reflash it to your heart's content.

[Digitalfiend]

Don't make me break out the ban hammer...

[twigg107]

Originally Posted by Digitalfiend

I would love to hear an explanation from a tuner on how to stop that by tuning. You might be able to minimize the effect, but I'm not sure you can tune it out.

From what Ive been told, instead of making the turbo spool up quickly (having the wastegate solenoid closed shut) you make boost come on slower (have the wastegate open sooner) which will yeld more control over boost creep. Its kinda hard to explain it.....

[hairlesswookiee]

dumb question, but i just bought an AP and will be getting an exhaust when they are available. how much does a Protune usually cost?? after spending the money on the AP i dont want to spend the same amount on the Protune.

[mofoSTI]

Originally Posted by GilMikalian

Did you get a Pro-tune on your '08? It would be interesting to compare/contrast your experience with mine since it seems to be one of the OP's concerns.

I have not yet, because I plan on doing headers and up pipe with my custom tune.

[twigg107]

Originally Posted by hairlesswookiee

dumb question, but i just bought an AP and will be getting an exhaust when they are available. how much does a Protune usually cost?? after spending the money on the AP i dont want to spend the same amount on the Protune.

Call tuners around your area and ask.... Also if your going to go stage 2 with a catted downpipe, I wouldnt even do a protune unless your car ran crappy. I drove my 05sti on stage 2 with off the shelf maps for almost 40k miles without one problem.

[hairlesswookiee]

^^cool thanks for the help. i plan on keeping it at stage 2 until i finish school and can afford the repairs if anything happens.

[GilMikalian]

Originally Posted by hairlesswookiee

dumb question, but i just bought an AP and will be getting an exhaust when they are available. how much does a Protune usually cost?? after spending the money on the AP i dont want to spend the same amount on the Protune.

About $450.

[Sinister redlines]

Alright I will try to explain this as best I can, I have tuned boost controllers for both IWG (fp green) and EWG (my gt35r) along with ported my old green.

You can tune alot of creep out and here's why: your boost soloniod runs on duty cycle (which is the how hard it holds the boost pressure away from the WG actuator diaphram). As the boost gets higher it will begin to overcome the soloniod and start to push the gate open in turn stabilize the boost PSI.

This table consists of a 2D map RPM over dutycycle, the higher the dutycycle the more it holds the gate closed making more boost along with a set boost target. Now most setups have this dutycycle set high on the lower RPM to help spool the turbo up as fast as it can BUT this can also cause it to overshoot the target as the wheel has a small amount of mass and once it starts to cook to a higher speed it can overspool. So you can lower the dutycycle on the lower rpm and raise it on the higher RPM and you get more control but only to a certain extent. Plus you will end up with a turbo that is slightly laggier (is that even a word?).

Now you have some understanding here is why IWG have some issues over EWG's. The internal gate on your stock turbo is at a perfect 90 degree turn in comparison to the exhuast flow. This causes the exhuast flow to shoot past the opening and not relieve the turbine from ramping up. So there are ways to help make an easier path for the exhuast "porting your wastgate" now to give you a situation I had with my car when I was still running my green. I was running meth and a espelir catback with a invidia catless dp. The boost was very controllable, thanks to a great tuner Tim Bailey. BUT I changed catbacks to a much more free flowing setup the invidia N1 race. This setup is so free flowing it had almost zero backpressure and caused MASSIVE overboost issues even with trying to slow the turbo down early in its boost range. So I ported the wastegate, basicly remove the turbo (I didnt because I put a header on at the same time and just cleaned out the shavings from below) and put a small champfer on that 90 degree turn where the wastegate is. It doesnt take much and be VERY carfull not to get carried away. Do a Search and you can find pretty good pics on how to do it. Then I retuned my boost controller and amazingly I was able to get the boost come on sooner and more contollably.

Now EWG are usually much bigger openings and they are usually desighed to be as a y in the up pipe so exhuast has a nice easy turn to get to the wastegate. This make fine tuning the gate a tremendous amount easier and can actually make more power due to better turbo control.

Hope that helps, and for those running the 08 STi Tim Bailey did most of the ots maps for COBB. Now theres a reason why these tunes have more potential after protuning. One is Tim had to be very conservative due to COBB liability for these tunes. Two every car has a different situation, catbacks (makes way more difference than you would think), DP's, headers, intake, even your location (some regions have higher ethanol content in thier gas 10%, 20% ect..) and of coarse your location to sae level..

Now the car has some logic in it to adjust for some of these senerios and thats why even after a protune you will notice the car still learns a little bit for minor changes like driving style and quality of fuel, ect.. BTW NEVER run cheap gas cause thats the first killer of powa...

[Digitalfiend]

Great explanation but what you are describing sounds more like a boost spike than boost creep. I had this with my '05 where I would overshoot my 19.5psi target and hit 21-22psi briefly and then it would settle down. This was extremely noticeable when I would floor it in 4th.

Being able to tune out a boost spike makes perfect sense as you described. Assuming a stock turbo and bcs, you can sacrifice a little spool up time to help reduce the chance of a spike by opening the wastegate earlier and this is exactly what my tuner did.

What I was referring to is boost creep where you floor it in a high gear and even though the wastegate is fully open, the boost is still increasing. So as you near the higher RPMs, the boost continues to build because the wastegate can't vent enough exhaust to control the turbine. This results in progressively building more boost as the RPMs increase, until eventually you hit fuel cut.

So, I think there are two issues - boost spikes, where you overshoot your target and then it settles back to appropriate levels and boost creep, where the boost continues uncontrollably until you hit fuel cut or backoff the gas.

Are you saying that you can eliminate boost creep with tuning? Even if you open the wastegate fully, earlier, eventually you end up at the point where you still can't get rid of the exhaust gas fast enough to control the turbo. Your WGDC is 0 and boost is continuing to increase...what more can you do to control that through tuning?

[Sinister redlines]

Yes they are two different situations. BUT I was talking about creep as I was tuned on the green for 21psi and after changing catbacks I would hit 21psi and then it would creep to 30psi if I would let it.. Now if your solonoid is at 0 duty cycle and you have backed the lower settings down and it continues then the only releif is porting or EWG..

You are correct as far as these both can be tuned out to a certain extent creep being the hardest. Boost spike is not as near detramental but something that still need to be watched and aleiviated if it can.

[Digitalfiend]

I didn't realize that you could tune out boost creep somewhat. Good to know.

[mofoSTI]

I have a coworker that is a creep. I wish I could tune him out.