T-build.SHE'S ALIVE!!!!!!!

Discussion pertaining to positive pressure E28s.
Rich Euro M5
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Post by Rich Euro M5 »

It appears to be working correctly. Since stoichiometric A/F ratio is 14.7:1, I think your A/F ratio at idle is just a touch lean. During closed loop operation, ideally you want to see the A/F ratio dither equally on both sides of 14.7:1 when at idle. Same thing holds true for steady cruise.
grey ghost
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Post by grey ghost »

Wideband acting a little off, maybe.
On 1st start the gooahj reads full rich,10.
After about 3 minutes of idling, it reads within the range.
Then it goes full lean until I've driven a few miles.
Its still a wee but lean. I turned the gear back three clicks and it went rich, in the mid 13s at idle.
so I turned it 2 click forward and it went right back to were it was.
So I went one one click back and it did nothing.

Also, every once and a while it goes full lean for a 1/2 second....
I went into a store today for about 4 minutes, and came out to a full lean condition. After about 2 miles it was back to it's old self.
Is this standard operating procedure?
grey ghost
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Post by grey ghost »

I'm having an issue now with the afr on partial throttle.
At idle its either a bit rich or a bit lean, and that's with just one click of the gear.
Under partial throttle no matter how the idle is set, its a little lean, 14.5 - 15.2 with spikes above and below but that's the primary range.
On full throttle it drops into the 11s and then sits on 10 til I let up.
What can I do about partial throttle?
turbodan
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Post by turbodan »

Definitely lean out the mix under full load. You want to be 12-13:1 at the richest. 10:1 isn't doing you any favors.

If you need more fuel under partial load you'll have to loosen the spring. You can counteract the effect this has on idle AFRs with the bypass screw adjustment.
grey ghost
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Post by grey ghost »

turbodan wrote:Definitely lean out the mix under full load. You want to be 12-13:1 at the richest. 10:1 isn't doing you any favors.

If you need more fuel under partial load you'll have to loosen the spring. You can counteract the effect this has on idle AFRs with the bypass screw adjustment.

OK, I'll loosen the spring a click or two.
The bypass screw is were??...... I just want to be sure I'm adjusting the right thing. I don't need anymore screwups.
I was looking at some of then afr's on the dyno sheet thread and figured those #s were ok under full throttle.
It doesn't go to 10 until about 5k RPM.
Rich Euro M5
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Post by Rich Euro M5 »

grey ghost wrote:
turbodan wrote:Definitely lean out the mix under full load. You want to be 12-13:1 at the richest. 10:1 isn't doing you any favors.

If you need more fuel under partial load you'll have to loosen the spring. You can counteract the effect this has on idle AFRs with the bypass screw adjustment.

OK, I'll loosen the spring a click or two.
The bypass screw is were??...... I just want to be sure I'm adjusting the right thing. I don't need anymore screwups.
I was looking at some of then afr's on the dyno sheet thread and figured those #s were ok under full throttle.
It doesn't go to 10 until about 5k RPM.
The bypass screw is located on the AFM body. It's recessed and requires a allen wrench to adjust.
mooseheadm5
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Post by mooseheadm5 »

Rich Euro M5 wrote:The bypass screw is located on the AFM body. It's recessed and requires a allen wrench to adjust.
On a big 6 you have to flip the AFM over to see the screw. It could be obscured by a plastic plug.
grey ghost
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Post by grey ghost »

mooseheadm5 wrote:
Rich Euro M5 wrote:The bypass screw is located on the AFM body. It's recessed and requires a allen wrench to adjust.
On a big 6 you have to flip the AFM over to see the screw. It could be obscured by a plastic plug.
Thanks for reading my mind..... I was going to ask that. That makes the adjustment a PITA. Having to take it off, adjust, reinstall, drive/check. damn........
Oh well, it needs to be done..
Rich Euro M5 wrote:
grey ghost wrote:
turbodan wrote:Definitely lean out the mix under full load. You want to be 12-13:1 at the richest. 10:1 isn't doing you any favors.

If you need more fuel under partial load you'll have to loosen the spring. You can counteract the effect this has on idle AFRs with the bypass screw adjustment.

OK, I'll loosen the spring a click or two.
The bypass screw is were??...... I just want to be sure I'm adjusting the right thing. I don't need anymore screwups.
I was looking at some of then afr's on the dyno sheet thread and figured those #s were ok under full throttle.
It doesn't go to 10 until about 5k RPM.
The bypass screw is located on the AFM body. It's recessed and requires a allen wrench to adjust.
Thanks, thats major.
1 - loosen the spring to richen in up for partial throttle.
2 - use the bypass screw to get the idle right.

What affect if any will those two adjustments have on my wot afr #s.
mooseheadm5
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Post by mooseheadm5 »

grey ghost wrote:
mooseheadm5 wrote: On a big 6 you have to flip the AFM over to see the screw. It could be obscured by a plastic plug.
Thanks for reading my mind..... I was going to ask that. That makes the adjustment a PITA. Having to take it off, adjust, reinstall, drive/check. damn........
Oh well, it needs to be done..
Install it upside down temporarily while you are tuning.
grey ghost
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Post by grey ghost »

mooseheadm5 wrote:
grey ghost wrote:
mooseheadm5 wrote: On a big 6 you have to flip the AFM over to see the screw. It could be obscured by a plastic plug.
Thanks for reading my mind..... I was going to ask that. That makes the adjustment a PITA. Having to take it off, adjust, reinstall, drive/check. damn........
Oh well, it needs to be done..
Install it upside down temporarily while you are tuning.
Its currently installed upside down so its easy to adjust the spring. So this allen screw is on the same surface as the spring?
Xenocide
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Post by Xenocide »

Do you have plans to go to a standalone EMS?

Megasquirt would give you infinitely more control over what's going on. It's not particularly cheap or easy, but it'd get you where you want to be. If it were me I'd fiddle fart with motronic while piecing together megasquirt (and in fact that's sort of what I'm doing with my car right now).
grey ghost
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Post by grey ghost »

Got the boost gauge mounted today. I thought the car had a little more to give and that became evident as I am only making 7psi.
It held that for a little while then dropped to 6psi.
My hopes are that its the wg, weak spring.....
I even have the three holes on top on the wg plugged.
I'm going to compress the top tonight and see what happens.
I can only imagine what it will be like it if I can squeeze 12-15psi out of it.
cvillebimmer
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Post by cvillebimmer »

grey ghost wrote:Got the boost gauge mounted today. I thought the car had a little more to give and that became evident as I am only making 7psi.
It held that for a little while then dropped to 6psi.
My hopes are that its the wg, weak spring.....
I even have the three holes on top on the wg plugged.
I'm going to compress the top tonight and see what happens.
I can only imagine what it will be like it if I can squeeze 12-15psi out of it.
WAIT! Seriously, I strongly suggest not upping the boost until you are 100% positive your car and its tune are in tip-top shape. Then drive it for a couple months to make sure. If all is still well and you are willing to do another head gasket or engine build, then compress your wastegate. If you like tempting fate, proceed.
grey ghost
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Post by grey ghost »

got the vac/boost lines right..........
3rd gear holds 10psi to 6k RPM.......
4th holds 9.5 to 6k RPM.......

afr still drops to 10 on wot, gotta work on that......
grey ghost
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Post by grey ghost »

OK, so I went ahead and compressed my wg. I know, I know.
The car is crazy fast now.
The 1st time I went into boost it went to 20psi in lightspeed.
So I'll be staying away from full boost until I get my tial 38mm.

I noticed I could hear my transmission working under the pressure on full boost. Whats the chance that I blow the tranny.
I know the gear oil is ok, but, I'm going to check the level tomorrow, just to be sure.

It was changed about three years ago..

Victor Reinz HG
ARP Head Studs
M. Holtmeier
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Post by M. Holtmeier »

Hehe...

What weight are you using in the trans?
grey ghost
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Post by grey ghost »

M. Holtmeier wrote:Hehe...

What weight are you using in the trans?
I can't remember, but its the nonhypoid stuff you can't find in the local autoparts store anymore.
I remember having the bentley with when I went to get it years ago, so I know its the right spec.
Should I go with something else?
turbodan
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Post by turbodan »

Run what it calls for. Probably ATF.

I'm sure you won't hurt the tranny. The synchros will die if anything, as they all do sooner or later.
M. Holtmeier
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Post by M. Holtmeier »

grey ghost wrote:
M. Holtmeier wrote:Hehe...

What weight are you using in the trans?
I can't remember, but its the nonhypoid stuff you can't find in the local autoparts store anymore.
I remember having the bentley with when I went to get it years ago, so I know its the right spec.
Should I go with something else?
Just curious. I've tried Redline MTL and MT90(among others) but have been running straight 30 weight motor oil for the last couple of years. It's always been a somewhat noisy box, but the 30 weight makes it shift the best, IMO.
grey ghost
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Post by grey ghost »

Bentley says SAE 80, API-GL4, MIL-L-2105 (non-hypoid).
But in text it says ATF will not effect the service life.
Can I top it off with ATF or does it need to be drained, if it indeed needs to be topped off.
grey ghost
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Post by grey ghost »

Got a quick clutch question:
whats the difference in wear over popping the clutch at 4500rpms versus, rolling into it hard on full boost?

I know popping the clutch it worse, but by what degree, if one can be assigned to it.......
The clutch in my car is at least 10 years old. It was in my car when I bought it in 2002.
Its does not slip at all.
I'm not one to dump the clutch at high revs to spin the tires or launch off the line, but I do like to power thru 2nd and 3rd.

I'm just a little worried about my clutch......
turbodan
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Post by turbodan »

The clutch only wears when its slipping. It shouldn't be wearing at all once your foot is off the pedal. If its slipping under boost thats obviously a big problem.
grey ghost
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Post by grey ghost »

turbodan wrote:The clutch only wears when its slipping. It shouldn't be wearing at all once your foot is off the pedal. If its slipping under boost thats obviously a big problem.
No slippage here.
Just trying to broaden my knowledge...
Thanks....
grey ghost
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Post by grey ghost »

Spoke too soon about the clutch.
I was doing a high speed 4th gear pull and the RPM just took off.
I repeated it to make sure and there is slippage under boost.
turbodan
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Post by turbodan »

Either turn the boost down or start looking at a new clutch/flywheel.

I would recommend a new flywheel considering the cost of some of these high end clutches. Its half of your clamping surface after all.
grey ghost
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Post by grey ghost »

turbodan wrote:Either turn the boost down or start looking at a new clutch/flywheel.

I would recommend a new flywheel considering the cost of some of these high end clutches. Its half of your clamping surface after all.
I'll leave things as they are and just stay off boost until the clutch and flywheel are replaced.

I have two flywheels in storage and was thinking on milling one down a few lbs when the time came. Should I stay away from that and just go with a new setup all together.
grey ghost
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Post by grey ghost »

I have another afr question..
I know that under wot, the ratio should drop to 12-13.1 or so pretty fast.
I can increase the boost slowly right up to 15psi, were should my afr be under slow increase of boost?
I noticed it doesn't go rich like it does when I punch it all at one time.
As I slowly increase boost, the afr stays in the partial throttle range.
Although under partial throttle and partial boost, I just want to be sure the afrs are right......

Thanks guys....
turbodan
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Post by turbodan »

13-13.5 would be fine for spoolup. Its not too important though. As long as its not leaning out. IIRC you're still running motronic so you're not likely to get it dialed in perfectly under all conditions. #1 priority is AFR under boost.
grey ghost
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Post by grey ghost »

turbodan wrote:13-13.5 would be fine for spoolup. Its not too important though. As long as its not leaning out. IIRC you're still running motronic so you're not likely to get it dialed in perfectly under all conditions. #1 priority is AFR under boost.
I'm running Todd's chip in my 059 ecu.
Since the clutch started to slip, I've not been able to do any tuning under wot..... but idle and partial throttle are fine. I could go .5 richer, maybe .3

I made a camera mount for the passenger side headrest and will post a video in the next few days.
turbodan
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Post by turbodan »

Motronic is inherently limited when it comes to tuning for boost. If you burned a full blown custom chip and never changed anything that could fix it, but short of that you may have portions of the map that run richer than necessary.

If you're slightly rich as boost builds, no big deal. Slightly lean is okay too, as long as it doesn't detonate. Lean tends to feel flat and may make it feel like its taking longer to spool.
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