I've got a long way to go to max out the current combination.
Today I was working on getting the new firmware functioning, and finally got the car to start. (I missed to enter some critical parameter data) After that, I moved to setting up the launch control....which I wasn't able to do with the previous firmware due to an issue with how switch inputs were being transmitted over CAN.
With 40% throttle, -20 Degrees timing, and 10% more fuel, I was getting the turbo to spool to 12 PSI @ 3200 RPM. I honestly think that will be too much power for my current combination, because I was launching at 3500 RPM with ZERO boost and sometimes blew off the Hoosiers....
Weather is looking good for Tuesday night...so I've got 2 days to get the software sorted out....
Can you fit a 275/40/17 Hoosier under there ? Those work exceptionally well. They will dead hook anything you throw at them l, till at least 750tq that is. Maybe more.
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
Yes, but I don't have a 17 X 9.5 wheel.
Currently not minding the slip, as it's easier on the rest of the drivetrain. Also, the strategy for tuning the launch and power ramp in are the same for both....would be better to start with a tire that's more sensitive to learn with...
Most of us run them on a 8.5 wheel.
Last edited by Butters Stoch; 06-25-2017 at 08:00 PM.
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
When I wear out the 245...I'll have a look at it.
On another note, I'm getting a pretty strong knock signal in the 6 kHz band with 15 PSI of boost. I was previously focused on 6.7 khz and above. Interestingly, something is causing manifold pressure to drop once this happens....and I'm not sure what it is. There are so many layers of safety measures, it's hard sometimes to understand what is triggering what. (The knock warning is being triggered, but I'm not getting any ignition retard or fuel cut) Differential fuel pressure is constant at 3 BAR, so it's not fuel related, and the AFRs are good.
Do you have the ability to record if any of the engine protection levels are active? If so can you see which specific issue is detected that is causing the reaction? I assume so given the complexity of the M1 software.
Oh yeah, I've got that. I'm currently logging 628 channels at everything from 1 hz to 200 hz.
Wheel spin is an option....but I don't have wheel speed back yet. I just got some help on that, so I should have more data today to sort it out.
Also....I probably should pull the spark plugs to have a look.....
My thoughts after spending 3hrs testing, reading data, and "tooning":
There is definitely some cylinder knock, mostly on cylinder #6. I've tried running a tight band of knock frequencies to see which is more significant...but so far the 6 kHz center point seems to work best. I pulled 4 degrees of ignition timing and added 5 % fuel to #6, but there still were some events at 15 PSI boost target.
With Water/Meth injection setup again, I went out for a series of tests to see of running W/M would help with knock. On back to back to back testing.....turning the W/M system on resulted in no significant knock events. There was still a lot of noise up to 50% or so, but the spikes over 100% under load were gone. So it seems I've hit a fuel limit with 91 octane, that W/M will help me overcome.
There is significant exhaust back pressure occurring above 10 PSI of boost. At 15 PSI of manifold pressure, I'm seeing upwards of 30 PSI of manifold pressure. Interestingly, when you look closely at the pressure trace from the front and rear exhaust manifold sensors.....they oscillate across each other. (One is high, and the other is low) I still have to play with the exhaust VANOS to see what changes can be do....
There is a very mysterious drop in manifold pressure that is completely linear from 15 PSI. It starts before I release the throttle to shift according to the data, but I can't find the cause. Timing, fuel, WG Duty cycle, and throttle are not the cause. Running on just the WG spring at 11 PSI of manifold pressure, it doesn't occur. It seems to correspond to using EBC, but I haven't done back to back testing with the EBC off yet to confirm.
After working on the fuelling a bunch, the VE table now has a peak at 5200 RPM going well out over 6000 RPM. I raised the rev limit to 7600 RPM, but if feels a little soft over 7000 RPM so for now I'm just going to use a 6800 Shift point in 2nd and 3rd, and use the extra RPM for launch and going through the traps in the 1/4.
Launch control set at 3250 RPM might be too much. I think I'm going to dial it down to 2750, with the 2nd Map position being 3000 RPM if I can get some grip. I know this sounds soft, but I can easily build 10 PSI of boost with this, and then I blow off the tires pretty badly.
The street alignment of the tires is not good for what I'm doing. I've got -2 deg on the back, and the tire wear is noticeable on one side. I'm going to have it changed to -1 deg, with a little bit of toe, and a bit less in the front as well. I also think that the springs have settled a bit, and the toe in the front looks to be either dead ahead, or slightly toed out. The car darts a bit when braking hard on uneven roads....so I'm looking to improve that.
This manifold pressure drop has me really confused.....
My inlet manifold pressure issue was user induced.
I took the absolute pressure from the sensor on the manifold, and used a maths channel in i2 change it to Gauge pressure. No issue with that...but then I decided to use a smoothing feature on that channel to be able to compare it to Turbo outlet pressure. (Which is a lot smoother because there's no inlet pulses) The maths channel doing the smoothing did a fantastic job.....creating a linear slope from full boost to Zero boost! When I looked at the inlet manifold sensor trace, it followed the throttle position perfectly. I suspect this won't be the first time I chase my own tail with data....
Perry,
I've been learning how to setup the boost control, which created some strange artifacts with regard to exhaust manifold back pressure. I just went out and did another test drive with a much smoother manifold pressure trace, and the exhaust manifold pressure trace was a lot more reasonable. At 15 psi boost pressure, I was seeing 20-21 psi exhaust manifold pressure on both banks.
In other news, I received 2 new EGT sensors from Motec....but I can't remember where I put my spare mounting bungs. UGG!!! So no new EGT data. I also got the same IAT sensor that Tony Palo uses on his 2500+ Hp GTR...will be figuring out how to mount that into the manifold shortly. It's supposed to be super fast...
I'll post some data later, but the "drive pressure" is consistently about 28-29 PSI with a 15 PSI boost target. I think I'm at the limit of this turbine/housing on pump fuel, and don't want to use race fuel to go any further.
EGTs are in the 1400-1500 area under load.
I've been dumping in WAY too much Water/Meth into the intake by using a generic PWM table. Last night I finally got the firmware I wrote to work for W/M injection, with calculates a water/meth flow target, and adjusts PWM to achieve it. (Inj. DC X Target Percentage = Total flow target, Injector size table X (Pump pressure - manifold pressure) = Solenoid DC to achieve total flow target) Today I'm hoping to get this dialed in on both the pre-turbo circuit, and the manifold circuit......
Bah....I'm out of fuel.
At 3 Bar of static fuel pressure, I'm at 85% DC with 18 PSI of manifold pressure (Spike)
Bumping the fuel pressure up to 4 Bar....
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
you're wasting too much fuel in the exhaust from not adjusting vanos.
Went to the drag strip, and it didn't go well.
Something is damaged inside of the Diff...was able to limp the car back to the city, but I had to get a flat-deck to take it home when a severe oscillation started after a traffic intersection turn.
I was also running 4+ PSI more boost than last time, but my MPH was down. (The car felt really soft up top in 3rd and 4th gear) Best of 114 MPH....but my launches and shifting were horrible. Looking at the data logs, I had a LOT of timing being pulled for what I think are knock events that I never picked up on the last trip to the strip. So I might be slower, but the engine is running a lot safer.
The car also was having a hard time idling...after many test sessions earlier today making changes due to knock events. I'm pretty sure individual cylinder timing and fuelling changes I made are the cause; they were not based on RPM. For example, 4 degrees of timing that I pulled from cylinder #6 was applied at all RPM ranges; I've since added an RPM table so that the timing is pulled from that cylinder progressively as RPM increases. I can also base individual cylinder trims on manifold pressure...
I have a "stock" 3.46 open diff on the shelf that I can throw into the car, but I'm not sure I want to. I'll need to pull the other one first to see what the damage is....no point in killing another diff doing the same thing. The 8 clutch race diff was also very noisy....so this might be a chance to move to something less "race".
Last edited by PEI330Ci; 06-27-2017 at 09:52 PM.
Any chance for a 210? Maybe from a e46 m3?
328i Sedan Twin s366's, 6.0LS, TH400, MS3 Ultimate
9.20 at 150 on 22psi
The nicest passive diff for street manners is a helical IMO. It will provide more biasing than a weaksauce stock BMW clutch diff, and is entirely silent. Just setup your suspension to never lift an inside rear wheel and you're good to go there (should be setup that way anyway, but with a helical you really pay the price when the inside rear lifts).
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
I replaced the diff with the stock 3.46. It's much quieter, but doesn't have the grip of the LSD. I also put Poly trans mounts in while I had the car up, and I'm pretty happy with the reduction in in-cabin vibration.
The 8 clutch race diff "failed"; but I didn't break it. It's got approximately 1200km of driving on it, and what I found inside I wouldn't call a wear or abuse problem. More details once I have a chance to talk to the vendor I bought it from.
No plans for a 210 diff yet....the 188 I have doesn't show any sign of NOT taking the power I'm putting down.
The problem will be the output shafts. Once you really nail it out the hole, they will snap. I even had custom DSS bullet ones made, snapped them too. 3 times.
1996 332IS
Built 3.2
CES/Steed TS Precision 6466, spraying a "$π!℅" load of meth.
Technique Tuning 80# tune.
1/4 mile 10.84 @ 136.72
Your 1 and only stop for all your BMW performance needs
WWW.CESMOTORSPORT.COM
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