[dzenno]

Never ending quest in understanding the power my car makes under load. Given this latest chart and looking at all other charts I feel there's 3 things that I'd like to discuss and understand why:

1) Torque spike at 4400..I'm aware of the VANOS shift there but it seems most current dynos don't exhibit this spike anymore. It used to be there before on V2 AFAIK but think you've done something to smooth it out. Any idea?

2) Why would the curves be so jiggly after 4000rpm? Is this indicative of a boost leak? Most other curves I've seen, even comparing to other N54s on the same dyno (Irishace, gian335, luca335) don't show as much jiggle...what could this be? Think its present on valet mode map (stock tune) with my boltons...

3) whp and wtq curves intersect at ~5200rpm when they should do that at ~5600rpm.

Could all these problems above related to something common? Any thoughts/advice on what to check for?

The car's been running really good since I managed to replace all injectors, plugs, latest bmw software and fix a boost leak on the inlet side to the FMIC (pipe was slightly off). I'm still on the original HPFP (75,000 km), 1 relatively long crank in the last 2 months but other than that pretty solid...

FYI: Dyno was done on all stg 3 catless boltons + procede v4 5-15firmware, 50/50 meth and pump 94 gas, procede set for UT 85, 0 ign correction

[TakeOne]

don't know about 1) and 2), but all torque and horsepower numbers intersect at 5252 rpms.

[OpenFlash]

FYI: Dyno was done on all stg 3 catless boltons + procede v4 5-15firmware, 50/50 meth and pump 94 gas, procede set for UT 85, 0 ign correction

18.5psi really demands race gas. Or at least a stronger meth mixture. 50/50 meth/water mix stinks for max power because you don't get a lot of octane effect and water isn't combustable. Stick with the 75/25 mix if you want a good compromise between cooling and octane. For very high boost dyno glory numbers, you can even use close to 100% since you care more about octane and fuel enrichment.

Other thoughts I had were emailed to you.

Shiv

Ps... Didn't u run 121mph trap speeds after these dyno runs? I would put more weight in that than dyno numbers due to all the factors than can/could have come into play on the dyno.

[dzenno]

Originally Posted by shiv@vishnu

18.5psi really demands race gas. Or at least a stronger meth mixture. 50/50 meth/water mix stinks for max power because you don't get a lot of octane effect and water isn't combustable. Stick with the 75/25 mix if you want a good compromise between cooling and octane. For very high boost dyno glory numbers, you can even use close to 100% since you care more about octane and fuel enrichment.

Other thoughts I had were emailed to you.

Shiv

Ps... Didn't u run 121mph trap speeds after these dyno runs? I would put more weight in that than dyno numbers due to all the factors than can/could have come into play on the dyno.

1) I understand your meth comment but given timing was already going to 13.5-14deg for these runs are you saying more power would be availabe just by giving it more octane through 100% meth?

2) Why the 4400 torque spike? I can readily reproduce this any time on any Dynojet...

Car dynos 272whp/286wtq on the stock tune but with all boltons + catless with the same jiggles in the curves after about 5K rpm. So to start out (stock tune) the numbers are lower than avg for this "specific" dyno and these mods by about 20...If this is happening on the stock tune (proceed valet mode) I'm wondering what it could be mods related given boost leaks aren't evident through any codes/logs...

could it be maybe carbon build up on the valves on the exhaust side or ???

3) If you look at many recent dyno plots on this forum you'll see whp/wtq curves actually intersect at 5500rpm and power climbing steadily to about 5500 while on the chart I provided you can see the power start to go horizontal a few hundred RPM earlier..


If we take the hp equation of: whp = (wtq*rpm)/5252 and consider the torque curve posted above a better question would be why is torque falling off so quickly past the torque spike at 4400RPM (vanos shift)? Maybe addressing this would help? I had my vanos solenoids changed at the dealership about a year ago and its in this timespan that this mystery has manifested itself...however, i recall (and have charts) showing this spike at the VANOS shift from soon after I originally got the car so it seems its always been there..

[dzenno]

Originally Posted by shiv@vishnu

If a boost leak were to explain the ~20hp "loss" in valet/stock mode, then it would be hugely apparent when you double boost level. Which i don't think it is. With those trap speeds, which I believe are the fastest of any car in Canada to date, I really wouldn't be worried about dyno numbers. I know you want a dyno to back up your real-world performance numbers. But as a former dyno owner myself, they are just a tuning tool. And as such, they are sensitive to how they are used.

Shiv

comment above updated with questions on 4400 rpm torque spike..

[OpenFlash]

Originally Posted by dzenno

1) I understand your meth comment but given timing was already going to 13.5-14deg for these runs are you saying more power would be availabe just by giving it more octane through 100% meth?

2) Why the 4400 torque spike? I can readily reproduce this any time on any Dynojet...

Car dynos 272whp/286wtq on the stock tune but with all boltons + catless with the same jiggles in the curves after about 5K rpm. So to start out (stock tune) the numbers are lower than avg for this "specific" dyno and these mods by about 20...If this is happening on the stock tune (proceed valet mode) I'm wondering what it could be mods related given boost leaks aren't evident through any codes/logs...

could it be maybe carbon build up on the valves on the exhaust side or ???

3) If you look at many recent dyno plots on this forum you'll see whp/wtq curves actually intersect at 5500rpm and power climbing steadily to about 5500 while on the chart I provided you can see the power start to go horizontal a few hundred RPM earlier..

If a boost leak were to explain the ~20hp "loss" in valet/stock mode, then it would be hugely apparent when you double boost level. Which i don't think it is. With those trap speeds, which I believe are the fastest of any car in Canada to date, I really wouldn't be worried about dyno numbers. I know you want a dyno to back up your real-world performance numbers. But as a former dyno owner myself, they are just a tuning tool. And as such, they are sensitive to how they are used.

If you want to rule things out, do this:

1) Pressure test your induction system. To 20psi at least. That will rule out a boost leak.

2) Dyno test with race gas with a 75/25 mix. That will rule out knock retard CAN logs only show cyl 1 ignition advance. For all we know, cylinder 2-6 aren't running full boost. Very very unlikely but it's possible.

3) Inflate rear tires to 50psi. This will rule out tire-induced frictional losses.

4) Make sure the dyno straps are on tight. This will rule out the car rocking back and forth during the run.

Without doing all these, we could be guessing forever.

Shiv

[dzenno]

Originally Posted by shiv@vishnu

If a boost leak were to explain the ~20hp "loss" in valet/stock mode, then it would be hugely apparent when you double boost level. Which i don't think it is. With those trap speeds, which I believe are the fastest of any car in Canada to date, I really wouldn't be worried about dyno numbers. I know you want a dyno to back up your real-world performance numbers. But as a former dyno owner myself, they are just a tuning tool. And as such, they are sensitive to how they are used.

If you want to rule things out, do this:

1) Pressure test your induction system. To 20psi at least. That will rule out a boost leak.

2) Dyno test with race gas with a 75/25 mix. That will rule out knock retard CAN logs only show cyl 1 ignition advance. For all we know, cylinder 2-6 aren't running full boost. Very very unlikely but it's possible.

3) Inflate rear tires to 50psi. This will rule out tire-induced frictional losses.

4) Make sure the dyno straps are on tight. This will rule out the car rocking back and forth during the run.

Without doing all these, we could be guessing forever.

Shiv

Ok, good points, will try all of these and re-dyno, no problem.

As to your point about cyl 1 ignition advance, is it safe to say that bank 1 is fine then because if there was a timing drop in any of the cylinders in that bank it'd manifest itself in some sort of a drop on cyl 1 as well a few rpms later, although not as much, as DME would try to keep balance there...but if this timing dropout happend in a bank 2 cylinder we would be less likely to see this in that cyl 1 timing datalog?

[OpenFlash]

Originally Posted by dzenno

Ok, good points, will try all of these and re-dyno, no problem.

As to your point about cyl 1 ignition advance, is it safe to say that bank 1 is fine then because if there was a timing drop in any of the cylinders in that bank it'd manifest itself in some sort of a drop on cyl 1 as well a few rpms later, although not as much, as DME would try to keep balance there...but if this timing dropout happend in a bank 2 cylinder we would be less likely to see this in that cyl 1 timing datalog?

As with all modern engine control computers, the DME is capable of individual cylinder ignition retard. So, theoretically, it can have 1 cylinder run full advance while another one (more more) runs several degrees retarded. That's only theory because I have yet to see cylinder-to-cylinder ignition advance deviate to any significant degree. Then again, I never run 18-19psi of boost on pump gas as a weak meth mix

Shiv

[dzenno]

Originally Posted by shiv@vishnu

As with all modern engine control computers, the DME is capable of individual cylinder ignition retard. So, theoretically, it can have 1 cylinder run full advance while another one (more more) runs several degrees retarded. That's only theory because I have yet to see cylinder-to-cylinder ignition advance deviate to any significant degree. Then again, I never run 18-19psi of boost on pump gas as a weak meth mix

Shiv

Ok, point taken. What about the VANOS torque spike? When I tried the JB3 2.0 they richen up AFRs a bit there and reduce boost on purpose to eliminate it. Does proceed do anything similar, any advantage doing this?

In any case, I'll do a prep on the points you raised above and re-dyno soon..

[scottp999]

Nice torque numbers. Interesting that I saw 390whp with 93 octane (no meth), but much less torque with the 10-09-2009 maps at only 14.8 PSI.

With Meth (72/25) and 17PSI, with 93 octane, I am hoping for 420whp.

Thanks for sharing.

[dzenno]

basically how do I get a dyno curve this smooth with no spikes?

http://www.e90post.com/forums/showth...t=procede+dyno

EDIT: He did run 101 octane and 75/25 meth..but no 4400rpm torque spike...

[OpenFlash]

Originally Posted by dzenno

Ok, point taken. What about the VANOS torque spike? When I tried the JB3 2.0 they richen up AFRs a bit there and reduce boost on purpose to eliminate it. Does proceed do anything similar, any advantage doing this?

In any case, I'll do a prep on the points you raised above and re-dyno soon..

Because it can, the Procede retards a bit of timing during the vanos shift. That's really the only proper way to handle it.

shiv

[OpenFlash]

Originally Posted by dzenno

basically how do I get a dyno curve this smooth with no spikes?

http://www.e90post.com/forums/showth...t=procede+dyno

EDIT: He did run 101 octane and 75/25 meth..but no 4400rpm torque spike...

So let's follow his lead and redyno with proper fuel. And check the car for leaks as mentioned before. You're really putting the carriage before the horse here.

Shiv

[dzenno]

Originally Posted by shiv@vishnu

Because it can, the Procede retards a bit of timing during the vanos shift. That's really the only proper way to handle it.

shiv

Ok, but the spike is still there with ign retard...Am I missing something you're saying?

P.S. By the way, just looked at my JB3 2.0 dyno and the spike is there even with the JB3 running 15.8psi boost peak on 94 octane, no meth.

EDIT: This was a different DynoJet, just illustrating the spike presence on a different dyno as well..

[OpenFlash]

Look at the difference between the spike with the two tunes. With the procede, it's not a spike. Look at the hp curve and it will be more clear. Seriously man, re-dyno after following my suggestions. And then let's discuss.

Shiv

[dzenno]

Actually if you look at run #16 in the first chart above which was proceed + no meth + pump 94 at the same boost level as JB3 you'll see there's a spike in whp as well with the procede...

I didn't dyno jb3 2.0 with meth and higher boost so don't know what would it would've looked like...

[Irishace]

I have the exact same vanos blip at 4400 rpms on my dynos. The only difference on my dynos is that my torque curve does seem to be a touch smoother, but only marginally and it drops off about 500 rpms later than yours.

[Irishace]

I also would agree with Shiv, your real world performance under load is pretty staggering, trapping 121mph is no joke. You accomplished this without the combo of race gas and 100% meth. You can easily push another 2-3mph when doing this. Your car is a horse

[dzenno]

Originally Posted by Irishace

I also would agree with Shiv, your real world performance under load is pretty staggering, trapping 121mph is no joke. You accomplished this without the combo of race gas and 100% meth. You can easily push another 2-3mph when doing this. Your car is a horse

I actually had MS103 and 100% meth at the 1/4 mile for the 121mph run. The dyno, you're right, pump 94 and 50/50 meth...

i'll follow the direction given above, prep the car with MS109 and 75/25 meth, pressure test the system at 20psi and once I get all those in check I'll go for a redyno

[Irishace]

Originally Posted by dzenno

I actually had MS103 and 100% meth at the 1/4 mile for the 121mph run. The dyno, you're right, pump 94 and 50/50 meth...

i'll follow the direction given above, prep the car with MS109 and 75/25 meth, pressure test the system at 20psi and once I get all those in check I'll go for a redyno

Hmm, I thought you only started 100%% meth last time we ran. I thought you were running a water mix previous when you went alone and ran that 121.

[dzenno]

Originally Posted by Irishace

Hmm, I thought you only started 100%% meth last time we ran. I thought you were running a water mix previous when you went alone and ran that 121.

Last time (July 1st) it was pump 94 + 100% meth...when I went alone and did the 121mph I had MS103 and 100% meth as far as I remember...last time (july 1st) my shifting sucked as I was concentrating too much on my launch with those damn DRs

Really what I'm after here is why on the stock tune/boost (map0 for jb3, valet mode on procede) i put down only 272whp/286wtq with full boltons catless DPs/exhaust...This would mean that without them I'd be at 245-250whp stock which is approx 25-30whp lower than avg...

what did you dyno stock with your boltons at Champion Motors (map0)? have that chart to share?

EDIT: I actually ran 80/20 meth mix with MS103 when I ran that 121mph...just checked my old post for details...

[enrita]

I dynoed exactly the same as you on stock boost fully bolt on (stock turbos) and 251 completely stock.
You cant compaire to what other people dynoed. Important you keep doing them at the same place to see the delta and differences.