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Turbo buffs: figure this out!

 
Old 11-12-2001, 02:23 AM
  #1  
David J. Harrington
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Post Turbo buffs: figure this out!

Okay, I have a very interesting situation:

I just put in a Garrett T04E-54 turbo. I am running the stock air-flow-meter, fuel pressure regulator(2.5bar), huntley chips, and stock injectors(as far as I know).

I knew that this turbo would pull WAY more air than my fuel system was ready for, so I had my boost set very low initially. Everything was fine on the A/F meter, nice and rich, no knock or pings. So, I upped the boost little by little, checking the boost gauges(aftermarket and stock), A/F meter, and listening very carefully.

I got up to 17 psi, and am having NO problems!!! I have no idea why. The car is incredibly faster than before. First and second will spin with full throttle while moving.

I am not quite sure why I am not running lean. My fuel pressure is around 36psi at idle(from rail mounted fuel pressure gauge).

I live at 5000ft ASL and am guessing that the less dense air is helping prevent a lean condition, but I can't believe it is allowing 17psi!

Help me figure this out,
Dave
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Old 11-12-2001, 09:21 AM
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Ski
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Aren't you already running about 7psi more at idle than the stock setting of 2 bar(29.4psi)? Is your AFPR a rising rate one?

Have you played with the switch setting on the DME at all? There was recent link here about the rotary setting for the DME,,timing and fuel. And your sure the injectors are stock?

I think you may just have everything working well together, from DME, KLR, O2 sensor, injectors, etc. As you and I have discussed upgrades(deepwater.com) I have continued my information quest before upgrading to the SFR garrett or Kokeln from LR. This has led to information that you can run 15-17 psi without larger injectors if your running stock head(refreshed w/WFR gasket) with a mild turbo upgrade; without going lean, but that it also depended on aftermarket chips,,,

any idea how much the Huntley chips put in fuel and timing? I've heard they are not like the APE which add fuel and retard the timing a bit,,

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Old 11-12-2001, 03:18 PM
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David J. Harrington
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Bret, I think you may be right on the fuel pressure. IIRC, it is supposed to be 2.5bar at anythink but a vacuum. At idle, I believe it is supposed to be 29psi, I am not sure. I will read. The regulator is the OEM regulator(although, I guess it could be a 3.0bar regulator; my mechanic knows I am modding the car, so he might have ordered a 3bar regulator by default). Either way, I will be converting it to an adjustable regulator.

The DME is set to the stock position currently. Injectors are stock I believe. I can't imagine that the previous owner would have upgraded them, he didn't do anything else. I talked to Huntley when buying the chips, and the add gas and change timing a little. They only increase gas, never reduce it(I believe Autothority actually leans out at some point, and I KNOW Europroducts chip does; talked to the guy on the phone; said that is were you make your most power; sorry dude, that's also where you destroy your engine).

Pete, thanks for the reply; see above explanation of FPR.

Dave
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Old 11-12-2001, 07:27 PM
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Are you getting 17psi consistently across the board? I've got stock injectors on mine and find that I can't run more than 15psi without going lean in the higher-RPMs. But that may be due to my Autothority chips there were programmed for the stock turbo's dropping boost curve.

I think you're ok at 17psi, I've seen a couple of cars running 18psi with stock injectors and they only required higher fuel-pressure.

I'd dyno the thing to get an air-fuel mixture reading to be on the safe side though.
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Old 11-12-2001, 10:26 PM
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Perry 951
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David... I don't know if you have followed my threads... but I am having the same issues. However, my MAF and everything is in place, yet still too rich at 18psi.

I am back to the stock fuel pressures, and have it dialed in really well, but still rich when I am in it. If I lean it up, I go lean when crusing or at low speeds.

Strange beasts!! I have had many people tell me to get some custom chips.

Perhaps a MAF will help you get just a little more air up in there to help lean it. Your turbo is flowing a lot more air than mine, so you might benefit more than me.

FYI, if I hit it hard in 2nd gear at 4 grand, I can light up the tires. Sounds like we are about the same HP, but my dyno shows just over 250hp at wheels, and 300tq. A lot lower than I had thought. Who knows. I give up. I do know it is much much faster than it was.

I am going to try to lean it out with the DME 8 postion switch and see what happens.

I think it reduces the pulse of the injectors, and I like that better than lowering fuel pressure. This way I have instant fuel at the hit, rather than waiting for the fuel pump to catch up.

I'll let you know.
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Old 11-13-2001, 01:05 AM
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Perry...not to make you feel bad or anything but my 951S put down 260 to the rear wheels according to mr. Gtech...according to Farzaan's dyno day web page thats about right...at the lowest I would expect 245-250 with the stock K26/8 and autothority chip and 14-15psi boost.
Oh...but I can't light em up in 1st or 2nd...boost enhancer might fix that...running 245/45/16's out back...BFG G-force T/A KDW's...
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Old 11-13-2001, 01:54 AM
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David J. Harrington
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Perry, I have been following your threads, or should I say EPIC!

I don't remember off the top of my head what turbo you are running. I am only running 15psi of boost right now (trying to hold back until I have my MAF done and get to the dyno to tune it right). When I temporarily turned it up to 17psi, the car was really squirrly (traction wise) in 1st, 2nd, and 3rd.

I am also bleeding off boost at upper RPM, but not as badly as with the stock turbo. Tonight I did some testing. Here are the results:

I reach 15psi of boost at 3400RPM in first

fuel pressure is more like 32-33psi at idle, going up to 38psi with some throttle.

with the boost turned down to 9psi, the car feels the same as it did when I had 15psi of boost on the stock turbo.

It isn't running too rich, but I am sure it isn't optimized.

On the dark side, I have an oil leak that is very bad, mabye the main seal. I can't tell yet. Looks like I might get to take off the tranny thisweekend. Last time I did this clutch, the entire job took me around 8hours. I bet I can beat that by a long shot now that I have it dialed

Well, bed time,
Dave
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Old 11-13-2001, 04:25 AM
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hello
How fast are your cars from 60 to 100 in third gear? (Starting at 50 but stop the time from 60 to 100 mph)

Konstantin
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Old 11-13-2001, 06:18 AM
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Here's something for you guys. As most of you know, I have a Callaway Turbo on my '86 N/A with turbo pistons. I am running an ERL MF2 additional injector controller, and a Walbro high pressure 255lph fuel pump. Once, the ERL was disconnected and when I boosted up, it would hit 15psi without knocking or leaning out. This was done with just the stock injectors on a non-turbo. The fuel pressure is running at 70psi(!) and I haven't found a way to drop it other than changing the pump. So how did it manage to boost this high without knocking/leaning? And how can I drop the fuel pressure? AFPR won't do it, and I assume that the pump is too powerful for the stock fuel lines.
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Old 11-13-2001, 06:26 PM
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Tabor
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Originally posted by David J. Harrington:
<STRONG>...sorry dude, that's also where you destroy your engine)...</STRONG>
You should read this thread on Air/Fuel ratios.
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Old 11-13-2001, 08:53 PM
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David J. Harrington
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Tabor, I believe you are referring to Danno's post on A/F ratios. Correct me if this is wrong.

My point was this: sure, you will always make the most power as close to detonating as you can get. However, if you manufacture generic chips for cars, you run a huge risk in destroying your customers engines. Their chip might work great on the setup car to make the program, but what about the owners who have dirty fuel injectors or lower than normal fuel pressure, or just about a hundred of other things that vary with a cars condition. Guess what, if there is ANYTHING different about an individuals car that makes it slightly leaner than the setup car, and the manufacturer hasn't included a proper margin for variables, your likely to toast the engine. I would never buy a mass produced chip that leans out my mixture from stock, especially with intake improvements(such as a turbo).

Hope that explains my previous post.

Dave
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Old 11-13-2001, 10:03 PM
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Yes, that point makes sense. But I guess I just don't see much point in upgrading your turbo without the engine management to really use it. There is a lot of power to be made in tuning.
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Old 11-14-2001, 12:19 AM
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David J. Harrington
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Tabor, I agree on the tuning. I am only running like this for a couple of weeks. I will have my MAF soon, and will tune the car properly then. And in all reality, my car isn't running excessively rich right now, just a little. I was just wondering how it could even run a little rich.

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