Dear Diary....

[NSFW]

I went looking for a place to do some hard 60-to-10 braking, but didn't find anything near where we did the install (Woodinville, not my turf). So I drove home gently, and drove gently to the Italian car show. And then I found a place where I could do 60-to-20 hard, repeatedly, without being rear-ended or pissing anyone off. I made lots of smoke. Girlfriend thought something was very, very wrong.

 

But in the four or five pulls I did between brake-smoking slowdowns, my engine knocked a lot. So much that IAM dropped a notch, and the car switched to the 'low octane' fuel table. I wasn't logging so I'm not sure what happened. 87 octane from a 92 pump at my last fill-up? Fuel pump? Fuel pressure regulator? I dialed it back to wastegate boost (10-12psi) and I'll run this tank out and re-fill with 92 from my usual gas station before I do anything else.

 

Hopefully it's an injector problem, because I have a set coming anyway. That seems unlikely though.

 

I just hope no damage was done. I don't think I've ever seen IAM drop before.

[easy19]

suby for dummies....IAM??

[dynamic80]

I though the mistyped and was saying I AM...

[dschultz]

Ignition Advance Multiplier

[NSFW]

Subaru uses two timing tables, a 'base timing' table and an 'advance' table. Total timing is base + advance.

 

Unless IAM drops to 0.5, then total timing is base + half advance.

Or IAM drops to zero, then total timing is just the base timing.

 

Base timing is probably safe for 87 octane, so the ECU can pull down IAM if you put in a tank of the wrong stuff.

 

It can also pull timing via "knock learning" and it used some of both last weekend, pulling about 3 degrees altogether.

[NSFW]

I dialed it back to wastegate boost (10-12psi) and I'll run this tank out and re-fill with 92 from my usual gas station before I do anything else.

 

I refilled yesterday and did some pulls, and go no knock with the fresh tank of gas. I didn't have time to get the boost turned all the way back up, so I'm not yet 100% certain it was just gas, but so far so good.

[Spoonwacker]

suby for dummies....IAM??

 

[RyanGT]

Happy Birthday NSFW! I think it's only appropriate that I post this in your diary!

[NSFW]

Awww, shucks.

[mpiotro]

T1 Racing Development fuel rail and Injector Dynamics injectors. I'm curious if you have received and or installed yeat and how much additional coin you spent to plumb in the rails. THX

[NSFW]

Haven't received them yet. I am planning to use ORB-to-5/16-barb fittings on the backs ($20/ea), with rubber hoses going to the pressure regulator and bulkhead, plus a single piece of teflon-lined braided line connecting the fronts. I forgot what the braided stuff cost, but you can price it out at anplumbing.com - speedflex hose and whatever fittings the speedflex requires, I forgot which now. I've been waiting for those injectors for too long.

[NSFW]

ID 1000s are installed, pretty much the way I described above. Details here:

 

http://legacygt.com/forums/showthread.php/nsfws-id-1000-injector-swap-139738.html

[legacyurabus]

awesome machine...subscribed

[NSFW]

Thanks.

[NSFW]

Over the last week or so, I have been experimenting with higher boost levels. Right around the time I reached 25psi, I started getting just a little bit of clutch slip. Only in 4th gear, and only at peak torque, but I did find the limit. I turned it down a bit, and I'm staying out of WOT in 4th, and I'm looking for a new clutch.

[Tracer-X]

Have you not don't your clutch yet? I thought you were doing it months ago, LOL.

[LittleBlueGT]

Over the last week or so, I have been experimenting with higher boost levels. Right around the time I reached 25psi, I started getting just a little bit of clutch slip. Only in 4th gear, and only at peak torque, but I did find the limit. I turned it down a bit, and I'm staying out of WOT in 4th, and I'm looking for a new clutch.

 

How much power on an airboy are we talking about?

 

I was good up to close to 380 wtq in thew winter before, then when I started hitting 360 in the summer months now (3-4 years old too) I am at the limit, or it is slightly worn, or both.

[NSFW]

Have you not done your clutch yet? I thought you were doing it months ago, LOL.

 

Yeah, well, the new clutch was almost strong enough.

 

The good news is, I now have reason to believe that this turbo likes more boost than most people give it.

 

I haven't done an Airboy dyno run since getting my turbo. I have to go a long ways to find a road that's both level enough and safe enough. I was planning to get a real dyno trip soon but that's off the table now, as I don't want to spend $100ish for a dyno session just to see my clutch slip. So, maybe I'll head to the edge of civilization one night, and do some Airboy dynos instead.

 

However that's complicated by the fact that my boost control gets progressively worse as I go above 20psi. This is using the MBC alone. I've emailed ATP to see if they make an actuator with a stiffer spring, as I think that would probably solve the problem. It spikes, which takes me into super-conservative timing, which costs a ton of power, and then it gets strong again.

 

Here's a bunch of wiggly lines to illustrate...

 

That's time on the X-axis. The boost curve is the one that's shaped like a boost curve with a spike at peak boost. The timing curve is the one with the negative spike at the same time. RPM is the diagonal line that climbs to the right. Notice that it gets steep as boost approaches the peak, then flattens after timing gets retarded.

 

The line that crosses the X-axis is "AFR error" and the line above it that looks slightly similar in shape is AFR.

[NSFW]

On second thought... that RPM blip is probably actually just the first sign of my clutch slipping.

[LittleBlueGT]

On second thought... that RPM blip is probably actually just the first sign of my clutch slipping.

 

Any chance of putting up a graph with numbers on the axis?

 

What clutch are you thinking of? Staying with bullly stage4 PP? I am in the same boat as you.

[NSFW]

If I stay 5MT I'll probably get a Bully stage 3 or 4.

But I'm thinking real hard about going 6MT + Exedy Twin.

That's a lot of money though. Tough call.

 

That graph came from the spreadsheet I posted the other day to my RomRaider tuning thread. If you download that, you can slice-and-dice the data any way you want.

 

Go to the 'calculated' page, select the filter on the 'pull' column, and make sure only #20 or #24 is selected (I think that's #20 above), and then go to the 'time' page, and you'll see the image above. The other pages in the spreadsheet have plots with meaningful axes, like boost over RPM (in psi), AFR error over RPM (in percent) and so on.

 

I'll create a thread for that spreadsheet to RR's Utilities forum after a couple more tweaks. It needs an AFR over RPM plot, for example.

[LittleBlueGT]

If I stay 5MT I'll probably get a Bully stage 3 or 4.

But I'm thinking real hard about going 6MT + Exedy Twin.

That's a lot of money though. Tough call.

 

That graph came from the spreadsheet I posted the other day to my RomRaider tuning thread. If you download that, you can slice-and-dice the data any way you want.

 

Go to the 'calculated' page, select the filter on the 'pull' column, and make sure only #20 or #24 is selected (I think that's #20 above), and then go to the 'time' page, and you'll see the image above. The other pages in the spreadsheet have plots with meaningful axes, like boost over RPM (in psi), AFR error over RPM (in percent) and so on.

 

I'll create a thread for that spreadsheet to RR's Utilities forum after a couple more tweaks. It needs an AFR over RPM plot, for example.

 

I am not sure about the stage3 or 4 clutch. Not sure if I will like it for daily duty. In reality, I can just turn down the boost a bit, run the same peak whp, but less mid rpm wtq.

[LittleBlueGT]

I've emailed ATP to see if they make an actuator with a stiffer spring, as I think that would probably solve the problem. It spikes, which takes me into super-conservative timing, which costs a ton of power, and then it gets strong again.

 

I wanted to add my experience with this.

 

My actuator on my 68HTA opens at about 6 or 7 psi. Pretty low I know. When I ran with a MBC (either in hybrid mode, or pure MBC, with as short a line as possible) it started to spike at boost levels above about 19 psi or so. Exactly the same as yours. (I did not have this problem with EWG and MBC)

 

I found that in just a few pulls I was able to dial in boost with a 3-port solenoid. It spools just as fast as the MBC, and does not spike.

 

It really isn't that hard.

 

This is the way I tune boost now:

 

Create WGDC tables with about a 10 point spread (I change this later), starting at about 20%. I just keep adding about 5% across the board until I see what boost levels the turbo seems to naturally want to hit. Once I see where the turbo likes to be, I use that to create my boost targets, and adjust from there. With your turbo, peak boost will probably be at 26 psi to run 22 psi at red-line, so obviously if you don't want that now (clutch...) you will need to run more WGDC in the upper rpms. I find that I relax the td pro and int a bit.

 

Once boost tuning is done, I then message WGDCs and td values to tweak the response. I like to get things pretty close at about the 68F mark, then only adjust the comp tables after that to keep things good for the high and low IAT areas.

 

If you are considering alky (or even just water) injection, then having the lower value spring is an essential part of the fail-safe IMO.

[NSFW]

I compared to some earlier logs, and I think the boost spike in the recent logs was caused by the clutch slip.

 

Thanks for the tips though. I've been putting off BCS tuning for a while, but it was going to be the next step after those high-boost experiments with the MBC.

[SubyDude555]

But I'm thinking real hard about going 6MT + Exedy Twin.

 

Now that's what Im talking about Nate Ganbatte Kudasai!