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Old 08-19-2008, 08:30 PM   #426
Bad Noodle
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Quote:
Originally Posted by Clark Turner View Post
Please dont just add or remove advance to the cam map. You will have to retune the timing and AFR

Clark
Thanks clark. I was reading the thread (haven't finish it yet since it's 9 pages of technical discussion) but what gave me the idea was your results for the sti you tuned with meth and a stock axle back.

You said that you loaded a new avcs map and nothing else and got +20whp/wtq out of the car.
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Old 08-19-2008, 09:20 PM   #427
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Yes. But you need to retune the timing and fuel. You are changing the dynamic or running compression of the motor. Many people dont understand this and end up with a motor with a ton of carbon built up in it. Or they end up with a very gas hungry engine that wastes fuel.

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Old 08-19-2008, 11:07 PM   #428
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If you add AVCS timing, do you also (generally) add timing, or remove it? And what guides your choice of AFR, or changes to AFR?
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Old 08-19-2008, 11:11 PM   #429
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In essence, making power. It is alot easier on a good Dyno.

1. Tune stock - Finalised tune
2. Increase avcs in the affect area and watch the afr
3. Adjust the AFR if needed
4. Adjust timing and watch for knock.
5. Goto 2

Above is in simplicity. Changing AVCS will have effect on boost also.
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Old 08-20-2008, 12:05 AM   #430
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So you don't aim to change the AFR you started with, but rather you adjust the fueling table to maintain the AFR you started with?

Am I reading that correctly?
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Old 08-20-2008, 12:12 AM   #431
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It depends on your aims. Fuel affect ignition.

If you want to make power, then you start there after the avcs small change.

Honestly, a full review of the site highlights the changes or techniques you go through to tune AVCS.

Pay special attention to some of Clarke Turner respones, including others.
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Old 08-20-2008, 12:29 AM   #432
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Your going to need an accurate Dyno in order to tune. Do not make the mistake of tuning for manifold air pressure when tuning AVCS. Many tuners make this mistake. They reason that if they get faster spool up they are doing good. Never make this rookie mistake.

Clark
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Old 08-20-2008, 07:40 AM   #433
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Quote:
Originally Posted by Clark Turner View Post
Your going to need an accurate Dyno in order to tune. Do not make the mistake of tuning for manifold air pressure when tuning AVCS. Many tuners make this mistake. They reason that if they get faster spool up they are doing good. Never make this rookie mistake.

Clark
^^^ this guy is a rookie. look at his member number!



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Old 08-20-2008, 03:27 PM   #434
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Dont make me post with my AZscoobie account!

Clark
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Old 08-20-2008, 11:05 PM   #435
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Quote:
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^^^ this guy is a rookie. look at his member number!



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Old 08-23-2008, 01:55 PM   #436
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Quote:
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^^^ this guy is a rookie. look at his member number!



Clare Turner (aka AZscoobie) is no Rookie here

He is a very knowledgeable and intelligent guy. A person with a wealth of information. He and many others
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Old 08-23-2008, 04:11 PM   #437
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The point of the wink was to indicate sarcasm.

People need to learn to read emotes better.
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Old 08-23-2008, 05:40 PM   #438
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Just in case others miss that
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Old 08-24-2008, 05:26 PM   #439
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Originally Posted by west_minist View Post
Just in case others miss that
^^^^^^ This guy is a rookie because he think's that Ride doesn't know who Clark is.. =P
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Old 08-24-2008, 05:59 PM   #440
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You know, you are correct. We are all rookies here. All smiles

Back to the topics now

Last edited by west_minist; 08-26-2008 at 09:31 PM.
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Old 08-25-2008, 06:04 PM   #441
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If I learn everyday does that make me a rookie for life?

C
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Old 08-25-2008, 06:09 PM   #442
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Quote:
Originally Posted by Clark Turner View Post
If I learn everyday does that make me a rookie for life?

C
nope.

all it does is make you a little bit smarter every day.

edit: clark, you just get a ham license?
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Old 09-19-2008, 12:30 PM   #443
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bump for any more thoughts.....very good thread
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Old 09-22-2008, 11:43 PM   #444
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nope.

all it does is make you a little bit smarter every day.

edit: clark, you just get a ham license?

Yeah. I have had it for a few months. Going for my General next week and then my extra in a few months.

Clark
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Old 11-04-2008, 02:00 AM   #445
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Hi Guys,
Mark here from sunny Oz and I'm hoping you might be able to give me a pointer as to my current line of thinking with the tune yes its AVCS related. This thread is a good read BTW
I have a fairly heavily modified 04STI with a sleeved 2.5 running CPs Pauters, EDM/AUS ported heads stock STI cams with a GT35R and Autronic SM4. We've recently exchanged its previous 3082R (with a weeny T31 turbine) for a 3582R with a custom rotated setup . I've recently ditched all the previous tunes (for various reasons) and decided to do it ourselves. I can handle fuel and timing but AVCS is a whole other chapter especially for my recently aquired abilites and I'd like to learn. I have a good friend with a Mainline which I can use for free and we spent hours sorting the fueling and timing (using the dyno min-timing-best torque feature and its fantastic down low but on boost I am having issues with compressor surge, I had this with both turbo setups. At say 4500 up to 5500 above 22~23 psi I get surge coming on boost. To test this I modified the boost map to avoid this region capped it at 22 psi then stepped to 26psi afterward and it worked very well - but its sucks of course. Now the thing is I stupidly didn't even think of cams during the last build so I'm running the stock AUS/EDM STI cams in mildly ported Aus spec STI heads with JUN retainers and springs -
I'm limited to what I can do to some extent. I look at the compressor map and I can see whats going on. My next step is to play with AVCS in that region and lower to see what can be obtained but I see that there are always two sides to a story. I may think I've sorted the surge at the expense of spool ? Yes ? Am I wasting my time with the stock cams ?
I could probably sort this out for myself just through trial and error and I will but I thought I'd just run it by you guys who have been through this many many times obviously. - watching those AFRs of course

Cheers

Mark

Sydney, AU

Last edited by parso_rex; 11-04-2008 at 02:07 AM.
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Old 11-04-2008, 02:10 AM   #446
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Give me specs of the system. What turbine? What compressor cover. What size hot and cold Ic pipes and what intercooler core. Your making a huge mistake trying to tune around a surge issue. You will probably not be happy until you fix the blockage. This is likely your turbine or intercooler setup and not the motor or Cams.

Simple pressure tests of the turbine pressure, compressor outlet pressure and Manifold pressure, will show you exactly what the limitations are.

Clark
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Old 11-04-2008, 02:21 AM   #447
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Quote:
Originally Posted by Clark Turner View Post
Give me specs of the system. What turbine? What compressor cover. What size hot and cold Ic pipes and what intercooler core. Your making a huge mistake trying to tune around a surge issue. You will probably not be happy until you fix the blockage. This is likely your turbine or intercooler setup and not the motor or Cams.

Simple pressure tests of the turbine pressure, compressor outlet pressure and Manifold pressure, will show you exactly what the limitations are.

Clark
whoops I left out that info , yes I need to get a couple of sensors to measure EGTs and back pressure thats on my parts list
but for the rest of it
8:1 comp
standard .7 AR comp cover (and .82 turbine obviously from above) V-band
I'm running the intake pipework off an APS front mount kit but I can't recall the sizing off hand. The FMIC is a hyperflow 'monster' its massive in core size and very low pressure drop - bit of lag though. I don't think I have seen larger surely that could not be an issue.....could it ?
I'll get hold of some more factual info
I hope your right about the mechanical side of things

I might have to take this out of the AVCS thread I guess but the reason why I'm thinking AVCS now is that along with the head specs its the only thing that hasn't changed apart from the FMIC. I have tried two exhausts two completley different turbo setups three tuners including myself LOL. motor internal changed too . All with the same issue. What fun !!


Cheers

Mark

Last edited by parso_rex; 11-04-2008 at 02:31 AM. Reason: adding more info
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Old 11-04-2008, 12:21 PM   #448
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The APS pipes are decent on the one side but way to small on the other. Do a few pulls and then touch that APS pipe. It likely burn you. A simple test of pressure at the turbo and at the manifold will tell the story.

The Surge is likely due to the setup and not the tuning.

With the AVCS, You can control the dynamic or running compression of the motor. You might want to try taking some cam away during that area to see if it helps. But I strongly suggest you change the turbo setup to stop the mechanical surge.

A great addition would be the Anti surge or Ported shroud compressor cover. TIAL makes one that I run. THis will likely CURE the issue and give you a much wider power band. Garrett has some and companies like Turbonetics and PTE have them also. I tend to lik the ones that are cast and not the ones that are drilled.

Clark
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Old 11-04-2008, 08:25 PM   #449
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Thanks Clark I really appreciate the advice. Perhaps I've been going about this the wrong way.
I basically just used a crude process of elimination and yes I even tried using the much larger Hyperflow pipework I think 70mm on the inlet side of things. My thought was that since the power continued to rise smoothly after the region of surge that it wasn't a restriction as such. Having said that it does drop off a bit too early for my liking round or less than 6K rpm although much better than the T31 3082R setup of old. I assumed this was cam related, perhaps this is where my inexperience shows.
I will source a new comp cover as its the proper way to go about things and cheap in the grand scheme of things. It can only improve things anyway
Now if only our dollar was as strong as it was 2 months ago lol. I'll have a quick look at the ATPs site as I know they can deliver to Aus

Thanks again,
Mark
dyno run

Last edited by parso_rex; 11-04-2008 at 11:33 PM. Reason: Added link
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Old 11-04-2008, 11:20 PM   #450
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Cool man.. Try the compressor cover.. if it still surges, You can then try to manipulate the cams a bit. But your better off by putting the compressor back in the range its happy with before altering the cam timing.

If all else fails, You might need to ramp boost up. I do this on some cars that tend to surge. If you control the boost a bit below the surge line, you can make up for the power with timing and cam adjustment. People are shocked at some of these power bands because the boost holds low then rises and the trq curve looks very flat.

Cya

Clark
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