Nameless Downpipe: Official 5th Gen GT Install Thread

[nossy]

Where to start?

 

1. You do not set boost targets at 17.5psi from 1400rpm to redline. Setting unattainable boost targets at such low rpm just has Turbo Dynamics building up where you are so far below boost threshold it's laughable. That is what causes the run up to 8psi or so at 2k4rpm and then the slump at around 2k7rpm and then a slow rise that doesn't see peak until 4k0rpm. You should be running WGDC in the 80 or 90% range up to 2k4rpm or so and then tapering off as you approach the turbo's sweet spot at around 3k2rpm. As you are now you're running a flat 40% or so until 4k0rpm or so, which has spool delayed and uneven. You should be hitting 17psi at 3k2rpm and no later.

2. You do not ask the little VF-54 to do 17.5psi at redline, or really much after about 5k2rpm. Again, asking for more than the turbo can possibly do just loads TDi and TDp up to where it will mess up boost control in the next gear.

 

I'm glad I can't see the AFR or timing curves when boost control is that messed up.

 

The conspiracy theorist in me makes me suspect that Nameless was in cahoots with English racing to attempt some lame cover up of this overboosting issue. From what very quick investigation I've done it would appear that English does actually know how to tune cars properly, so the only way a tuning monstrosity like this makes sense is if they were purposely doing all they could to prevent overboosting, at the expense of everything else. Makes me wonder who the customer is here?

[Apexofthevortex]

The conspiracy theorist in me makes me suspect that Nameless was in cahoots with English racing to attempt some lame cover up of this overboosting issue. From what very quick investigation I've done it would appear that English does actually know how to tune cars properly, so the only way a tuning monstrosity like this makes sense is if they were purposely doing all they could to prevent overboosting, at the expense of everything else. Makes me wonder who the customer is here?

 

I don't think your theory is that outlandish. We already know nameless is more concerned with taking our money and saving face than actually helping their customers. The fact that they even gave El his car back with that half ass tune and half ass port and most likely charged him for it then just washed their hands of the whole situation is seriously unbelievable.

[FLlegacy]

Considering TA also seems to be working around the DP without much feedback tells me they are either complacent or just assume the customer just wants it to work.

 

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[nossy]

Considering TA also seems to be working around the DP without much feedback tells me they are either complacent or just assume the customer just wants it to work.

 

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If that's the case, these companies have some very interesting ideas on what it means for something to "work"

[BBPeik]

Is it just me or does 114 pages talking about this stupid downpipe pretty much sum up the problem. Pretty sure if it worked great, this thread would be a ton shorter.

[FLlegacy]

Is it just me or does 114 pages talking about this stupid downpipe pretty much sum up the problem. Pretty sure if it worked great, this thread would be a ton shorter.

Define "work" and "great"...

 

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[ripstik]

work: (of a machine or system) operate or function as intended, especially properly or effectively

 

great: of an extent, amount, or intensity considerably above the normal or average.

 

so did this DP operate or function as intended to an extent, amount or intensity considerably above the normal, its intention being to ELIMINATE overboost and boost creep? ...

[Sarang]

Guys I'm pretty sure his point was that it doesn't work great.

[ChrisCrash]

Im not sure if someone said it earlier but is anyone running a bov opposed to a bpv?

[jkenefake]

I run a hybrid valve with about 30-40% venting. I get the blow off sound with no ill effects.

[jojorios]

Would that happen to be the GFB one?

[Starks]

Hey here's a DP/tuning related question for you guys. I'm mulling over how I want to approach an immediate tune and future mods. (As of now I just have a bpv and DP)

 

I'm not anticipating going too crazy with future mods. Larger intercooler, maybe cams? Tops.

 

I'm looking to either in shop pro tune or etune. I'd like to go for a shop tune, they are more expensive but I'd hopefully leave feeling that they got every horse out of it that they could. In a couple of posts of logs with etunes there seemed to be a couple of questionable things going on from what I interpret. Also on that note I'd rather not pay 600+ a piece for 2 in-house sessions at who knows time period a part (considering I could find additional parts at a discount and purchase them sooner).

 

E tune and shop tune guys, how are you approaching your progress? Would the two methods of tuning be likely to build upon the last tuners maps?

 

 

 

 

 

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[BBPeik]

If you go to the same tuner for a shop or e tune they can build on their previous map. I am pretty sure the maps are proprietary, so if your e tuned through one company and then shop tuned through another they would have to start fresh. I have been happy with both e tunes that I have done. That being said though, I think I would feel a bit more comfortable with an in shop tune in the future. No real reason, just seems a much more thorough way to do it to me. I am thinking I will have mine dyno tuned after the trans is all set so I can get per gear tuning etc..

[FLlegacy]

If you go to the same tuner for a shop or e tune they can build on their previous map. I am pretty sure the maps are proprietary, so if your e tuned through one company and then shop tuned through another they would have to start fresh. I have been happy with both e tunes that I have done. That being said though, I think I would feel a bit more comfortable with an in shop tune in the future. No real reason, just seems a much more thorough way to do it to me. I am thinking I will have mine dyno tuned after the trans is all set so I can get per gear tuning etc..

This! And in your situation, the cams will definitely require a retune the upgraded intercooler not so much. You will also want to look into an upgraded fuel pump if you haven't already done that. I would also look toward an in shop tune as well, I would especially like a custom 6th gear tune for cruising and passing without downshifting, like more conservative timing in boost and a low boost limit 8 psi or so.

 

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[fahr_side]

If you go to the same tuner for a shop or e tune they can build on their previous map. I am pretty sure the maps are proprietary, so if your e tuned through one company and then shop tuned through another they would have to start fresh.

 

If you're on Cobb AP you can expect the maps are password protected and your new tuner will be starting over. The fact that you can easily protect your work is by far the biggest reason for the platform's popularity.

A few of us Opensource guys obfuscate our maps or tag them in various ways, though this only keeps the script kiddies out or allows you to quickly recognize a copy when you run across one. It's pretty funny when a car 'tuned' by a competitor shows up and it has one of your basemaps on it. Every tuner has their own style and when you have a large collection of proven maps you tend not to spend too much time trying to unravel the thinking behind a previous tune.

 

There's nothing wrong with e-tunes in and of themselves. The problems come when the customers can't make useful logs or take forever to go through the steps or resolve mechanical issues, or when tuners take on more projects than they can handle and become unresponsive. A good e-tune is better than a sloppy tune done at a shop. I've turned mostly to doing e-tunes now, simply because finding a reliable shop to do mechanical work for me in my area is impossible with my nearest reliable partner being 2.5h away and I'm moving further away, not closer.

 

This! And in your situation, the cams will definitely require a retune the upgraded intercooler not so much. You will also want to look into an upgraded fuel pump if you haven't already done that. I would also look toward an in shop tune as well, I would especially like a custom 6th gear tune for cruising and passing...

 

 

An upgraded intercooler on this car usually needs tuning for. The RacerX cooler for example has so much less flow resistance you will overboost and run into fuel cut after swapping it if the tune isn't adjusted.

 

It's not possible to limit boost to any level below base actuator pressure which is around 10psi, without limiting throttle angle. That's how i-mode works btw, by setting boost targets very low and allowing full throttle only at low rpm, limiting throttle angle at higher revs.

 

The stock exhaust cams are quite unique and require an unusual approach to AVCS mapping. Fit stock or high performance cams for the STi and you can use the usual EJ257 strategies.

Edited May 9, 2017 by fahr_side

[Ellesedil]

Is this amount of soot pretty normal for a new exhaust/less restrictive downpipe or does this also indicate a fuel-related tuning issue? It's only been 2 months.

 

Edited May 9, 2017 by Ellesedil

[fahr_side]

Any high-flow, low cell count metallic substrate cat is going to be less efficient than stock. If you're in boost a lot, and the gas is bypassing the cat by design, it's going to be worse since that's when your target AFRs are the lowest. Edited May 9, 2017 by fahr_side

[Starks]

All of the last couple of posts were super helpful. Thanks a lot for everyone's input. A lot of things I need to consider.

 

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[FLlegacy]

Is this amount of soot pretty normal for a new exhaust/less restrictive downpipe or does this also indicate a fuel-related tuning issue? It's only been 2 months.

 

My back bumper has been getting pretty dirty since my tune.

 

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[fahr_side]

So this took a little longer than planned. Such is life.

 

Here's a view into the throat after boring the wastegate port to 28mm. Just minor deburring afterward.

 

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33411_zpsmtbgtp5o.jpg

 

Porting begins...

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33441_zpsu0i316nh.jpg

 

Keep grinding...

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33451_zps1nn9oaai.jpg

 

This is about as far as you want to go from the throat side. Clean up from the dump side now.

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33481_zpsgpdkytpx.jpg

 

Small hole vs. big hole. Stock port is about 24mm diameter. We've gone to 28mm.

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33501_zps2spu8fo8.jpg

 

Stock vs. ported throat side.

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33511_zps8uvu44e1.jpg

 

34mm wastegate flapper welded to arm. Yes it still floats.

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33521_zpslqe914fl.jpg

 

The wastegate arm would hit a flat flange type dump pipe before the flapper edge does, just like the stock one.

 

http://i464.photobucket.com/albums/rr5/fahr_side/IMG_33531_zps7nx22apt.jpg

 

I'll update on results when the turbo is installed and I get to tuning the car.

 

And yes, I know my nails need trimming. Thanks. On it.

Edited May 11, 2017 by fahr_side

[BBPeik]

Awesome work. Thanks for the experiment and I can not wait to see the results.

[GTEASER]

Yes, very excited to see these results. Fingers crossed that this is a solution for the overboost. Maybe the NP DP's potential for good performance can be salvaged by this mod.

 

It seems like the bore was done a little off center of the original hole. What was the reason for that?

Edited May 11, 2017 by GTEASER

[fahr_side]

It seems like the bore was done a little off center of the original hole. What was the reason for that?

The flapper would foul the arm if it was any closer.

 

Note also this a TD05H-18G hybrid in VF-54 housings. The larger turbine already goes a long way toward curing boost creep.

Edited May 12, 2017 by fahr_side

[GTEASER]

The flapper would foul the arm if it was any closer.

 

That's what I suspected. Thank you.

[mcg_]

So this took a little longer than planned. Such is life.

 

I'm so thankful that you took this project up. I contacted a half-dozen different turbo shops to acquire a bigger flapper to do the same thing, and nobody was willing or had a larger flapper to sell me.