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New dyno numbers
Posted: Dec 30, 2006 2:17 AM
by Craig -535i- Seattle
For a couple reasons, I decided to just go with a piggyback system as opposed to a standalone ECU. Today I took the car into the shop for a Unichip install and tuning. Here are the numbers at just a tad under 12 psi.
Note how much faster this turbo spools than the old one, but it seems to drop off at high RPM. The boost stayed up, but I think it's just not able to flow any more air after a certain point- as you can see by the flat hp line. The old turbo had an .82 A/R and the new one is .58.
Here it is compared to my old '91 535i. That car had just an FMU and running 6 psi.
Here are the new AFRs
Notice how horribly rich my old '91 ran under boost. The FMU just didn't seem to be working right- it was either giving too little or too much fuel.
Posted: Dec 30, 2006 3:27 AM
by Jeremy
You're most likely dropping off due to cam, not turbo size. I'm really digging the shape of that torque curve, especially that big flat spot in the middle. Bet it's much more pleasant to drive now, right?
Jeremy
Posted: Dec 30, 2006 8:13 AM
by Duke
Looking good.
You have more HP available though. Your A/F is fat (between 11-12) for the complete run. If you pull some fuel out to lean it up into the mid 12's you will see more power.
I bet if you do that you will see the HP cross over the torque curve sooner than 5300 rpm.
Posted: Dec 30, 2006 8:25 AM
by DMNaskale
I bet if you do that you will see the HP cross over the torque curve sooner than 5300 rpm.
It would be a neat trick to see it get below(or above for that matter) 5252 RPM.
Posted: Dec 30, 2006 10:53 AM
by Craig -535i- Seattle
The car is very easy to drive- torque is generally available right now when you want it.
I will probably go back after driving for a couple weeks to have them fine tune things. Right now there is some odd behavior at very light throttle and high RPM, among other things. I am not sure if I want to lean it out any more, I might get some more power but this car will be on the track occasionally and I don't mind losing 5 hp in exchange for a safer tune.
The car picked up almost 20 hp ft-lbs or torque with the tune- the baseline dyno was just under 300rwhp and 330 rwtq. Even better, it picked up a lot more area under the curve too.
Posted: Dec 30, 2006 11:19 AM
by shifty
DMNaskale wrote:It would be a neat trick to see it get below(or above for that matter) 5252 RPM.
Posted: Dec 31, 2006 2:19 PM
by russc
Do you have any more info on the UniChip? Schems, specifications etc. I can't find any info on the net technical wise.
So how is mid throttle boost AFR's? That the real issue with what you have. Can the UniChip ECU run proper AFRs at 3-5psi at mid throttle? Does the UniChip clamp the O2 sensor ouput or do some other signal manipulation for mid throttle boost?
What is the second dyno chart? You .10 run is 315whp and 345lb-ft? Is that your best run? What where the AFRs there?
Overall, at 12psi, the #s are pretty close, maybe a little on the low side. Maybe some timing/AFR tuning can help a bit. But if your satisfied, thats fabulous. Nice looking numbers all around.
RussC
Posted: Dec 31, 2006 2:37 PM
by Craig -535i- Seattle
russc wrote:Do you have any more info on the UniChip? Schems, specifications etc. I can't find any info on the net technical wise.
I don't have too much of that, but
www.unichip.us is their US site. The biggest downside is that they work through tuners only, meaning you can't tune it yourself. For me, that was fine because I don't want to change anything on the car once it's tuned but some people like to have that ability.
So how is mid throttle boost AFR's? That the real issue with what you have. Can the UniChip ECU run proper AFRs at 3-5psi at mid throttle? Does the UniChip clamp the O2 sensor ouput or do some other signal manipulation for mid throttle boost?
I would assume the mid throttle AFRs are good- the shop did tune the car throughout the rpm range. But, I don't know what they are, I didn't ask other than to tell them to err on the safe side.
What is the second dyno chart? You .10 run is 315whp and 345lb-ft? Is that your best run? What where the AFRs there?
That was the best hp run, but there was *slight* pinging so they richened it up a bit. It was just over 12 at the leanest point. The red line is my '91 from 2 years ago, I just thought that it made for an interesting comparison of turbo sizing. The old car had a much larger exhaust A/R and you can see that reflected in how long it took to spool.
Overall, at 12psi, the #s are pretty close, maybe a little on the low side. Maybe some timing/AFR tuning can help a bit. But if your satisfied, thats fabulous. Nice looking numbers all around.
I'm pretty happy with the car. There are a couple minor driveability issues I'll be going back to have them fix but overall it's much improved over how it was driving before.
They did a baseline before the tuning and installation and the curve is up about 20hp and ft-lbs across the whole rpm range. I imagine that it would be possible to get a little more power, but this car will be on the track a few times so I wanted a nice conservative tune on it.
Posted: Dec 31, 2006 6:38 PM
by T_C_D
Craig,
Glad to see you dynoed it already. The numbers would improve with a leaner mixture. I tune m30s for 12.0-12.5. Anything below that causes a loss in power. Your peak tq s/b at 4000-4500 not 3000rpm. I would like to see 330/360 with a perfect tune. That said the curve looks pretty good. Spool up is immediate. I am sure it feels plenty fast on the road. 315/348 is nothing to sneeze at for less than 12psi.
Is the uni chip controlling timing as well? You have any idea what the timing is? Remember the CR of this motor is ~8.0 since it has the thick HG. At 12psi you can probably run 25 degrees of advance at 6000rpm.
Todd
Re: New dyno numbers
Posted: Dec 31, 2006 6:41 PM
by T_C_D
Craig -535i- Seattle wrote:The boost stayed up, but I think it's just not able to flow any more air after a certain point- as you can see by the flat hp line. The old turbo had an .82 A/R and the new one is .58.
Rich AFR and possibly too little timing is the culprit not the turbo housing. I made 388/441 with the exact same turbo and the peak HP was close to 6000rpm.
Todd
Posted: Dec 31, 2006 8:22 PM
by Craig -535i- Seattle
T_C_D wrote:Craig,
Glad to see you dynoed it already. The numbers would improve with a leaner mixture. I tune m30s for 12.0-12.5. Anything below that causes a loss in power. Your peak tq s/b at 4000-4500 not 3000rpm. I would like to see 330/360 with a perfect tune. That said the curve looks pretty good. Spool up is immediate. I am sure it feels plenty fast on the road. 315/348 is nothing to sneeze at for less than 12psi.
Is the uni chip controlling timing as well? You have any idea what the timing is? Remember the CR of this motor is ~8.0 since it has the thick HG. At 12psi you can probably run 25 degrees of advance at 6000rpm.
Whoa, 8:1? I didn't know that, so neither did the tuner. I can go back and have adjustments made, with this information it certainly will affect how he tuned it (he was going off the assumption it was 9:1).
Thanks for the info.
The Unichip controls both timing and fuel so I can have it set to just about anything.
Posted: Dec 31, 2006 9:04 PM
by russc
Craig -535i- Seattle wrote:T_C_D wrote:Craig,
Glad to see you dynoed it already. The numbers would improve with a leaner mixture. I tune m30s for 12.0-12.5. Anything below that causes a loss in power. Your peak tq s/b at 4000-4500 not 3000rpm. I would like to see 330/360 with a perfect tune. That said the curve looks pretty good. Spool up is immediate. I am sure it feels plenty fast on the road. 315/348 is nothing to sneeze at for less than 12psi.
Is the uni chip controlling timing as well? You have any idea what the timing is? Remember the CR of this motor is ~8.0 since it has the thick HG. At 12psi you can probably run 25 degrees of advance at 6000rpm.
Whoa, 8:1? I didn't know that, so neither did the tuner. I can go back and have adjustments made, with this information it certainly will affect how he tuned it (he was going off the assumption it was 9:1).
Thanks for the info.
The Unichip controls both timing and fuel so I can have it set to just about anything.
Woa,
The 0.140 MLS will lower the compression a point? Gees. Now wonder the #s seemed a little low for 12psi.
Any yes, I believe I won't be looking at UniChip. I don't want to buy something I can't tune myself. I wonder if the Exede ECU is the same way? I bet it is.
RussC
Posted: Jan 01, 2007 10:38 PM
by Craig -535i- Seattle
russc wrote:
Any yes, I believe I won't be looking at UniChip. I don't want to buy something I can't tune myself. I wonder if the Exede ECU is the same way? I bet it is.
That's my guess too- I think most piggyback systems probably are proprietary.
Posted: Jan 02, 2007 3:09 PM
by Craig -535i- Seattle
I'm going to try to get back to the dyno later this month, and have them lean out the AFRs a bit and add more timing. They were operating with the assumption it was a 9:1 so were being conservative but it looks like we can push things somewhat more than we did.
Posted: Jan 04, 2007 8:21 PM
by bimmerboy
It would be a neat trick to see it get below(or above for that matter) 5252 RPM.
audi did it once! haha i dont know how they did, but it sure made me question audi's claims from there on out.
Posted: Jan 04, 2007 8:47 PM
by Jeremy
Easy. The Y scale for Torque is different than the Y scale for HP. The torque number still matches the hp number at 5252 rpm.
Jeremy
Posted: Jan 04, 2007 9:02 PM
by bimmerboy
silly me i didnt even think to look that close.