Feedback on dyno results - what's wrong here? - Page 7 - The Unofficial BMW M5 Messageboard (m5board.com)

cosioboy · 9th November 2006, 16:43

Quote:

Originally Posted by palantirion

I spoke with Reg Reimer (a well-known Canadian Dinan dealer and talented installer/hot rodder) at SEMA last week about dynoing. He said it was critical for many BMWs' to be brought up to operating temperature, set up on the dyno, THEN shutting off the engine and cooling the raditator. If there is not a sufficient differential between the radiator temp and engine temp (you want the engine to be much warmer), the ECU will use a different fuel map than the one for the road (there are 7 or 8 maps). In the case of Dinan they change only the map for the "road, normal conditions", leaving the other ones stock. So if a Dinan-software-equipped car doesn't think it's on the "road" it not only switches maps - it switches to a map for a car with stock hardware (safe, but bad for performance). Powerchip, he said, overwrites all the maps with a common one. Stock M5s may switch to a reduced performance mode without a sufficient temperature differential as a safety precaution against overheating.

Just to confirm my understanding, Palantirion, having Powerchip, in my case this wouldn't matter, correct? In other words, I don't need to worry about cooling off the radiator as the temperature differential with the engine is irrelevant?

palantirion · 9th November 2006, 23:19

Quote:

Originally Posted by cosioboy

Just to confirm my understanding, Palantirion, having Powerchip, in my case this wouldn't matter, correct? In other words, I don't need to worry about cooling off the radiator as the temperature differential with the engine is irrelevant?

-That is my understanding, yes. But it wouldn't hurt to try the described technique just in case.

cosioboy · 13th November 2006, 19:17

OK, so I was able to organize a mini Dyno meet with another Boardmember (verhagke) and we each had a dyno session at ICS Performance. It turned out that verhagke had already dynoed (and heavily modded) his E36 track car with these guys, so he knew them well. Great guys, thanks for the heads-up Carl, no offense, but when it comes to BMWs these guys are miles away from TT (the yellow Super Bee E36 M3 I am attaching a photo of has over 1000 rwhp and was in this year’s European Magazine cover story, impressive!). So here is how it went, very interesting results and some food for thought, so please chime in folks.

As a quick background, in July I went to a different outfit to get my Beast dynoed, and was left disappointed, not so much with the numbers per se, but with the conditions and manner in which it was run (results attached in my first post of this thread). The only meaningful differences between that dyno run and this are:

Ambient conditions: first dyno session was in July with about 91F outside temperature and 10% humidity, this in turn was in (a warm day in) November, 72F degrees and 33% humidity

Both are Dynojet chasis dynos, but obviously different machines, shops/setups, and operators.

In both sessions I had Powerchip 93, except that after the first session I shipped it back for a re-flash in light of what seemed to be a rich A/F ratio, particularly in top end of the RPM range (when arguably the air-flow from the two household fans the operator used in no way mimicked true road conditions, which in itself may have skewed the A/F ratio figures as engine goes into ‘safe’ mode)

Arguably gas quality may have been different (although I always gas at the same station with Shell V-Power 93 Octane)

What was really helpful is that member verhagke’s Beast is fully stock, same model year, similar production dates (although he has the redesigned rings), but less mileage than mine. Both were tested in same day, same dyno, 30 mins apart. Here is the compare:

Verhagke’s Beast:
2000 MY with 35K miles
Production date of June 00
Bone stock
Running on 91 Octane

My Beast:
2000 MY with 75K miles
Production date of Jan 00
Performance mods include CAI, Cat Back exhaust, Powerchip 93
Running on 93 Octane

I am attaching 4 screens, which are very telling, and I think I need to go back to Powerchip because now they have leaned the mappings so much, that I am not only robbed for power and torque in the mid range (about 25 hp/tq relative to stock), but the A/F ratio is way too lean and borderline dangerous IMO.

The first attachment is the comparo between the stock and ‘modded’ Beast at peak power (which for me occurred in 5^th gear, in 4^th in the case of Verhagke’s Beast). Sorry that I don’t have a color scanner, but basically my graph is the LOWER of the two!!! That’s right folks, the stock beast is displaying better numbers just about throughout the full RMP range, except at about 6200 RPM when I hit there 325 mark and the stock eclipses at 319. In no point prior to 6000 rpm is the ‘modded’ Beast better, and the torque and power curves are much more jaggedy than the stock, which is fairly smooth and linear. Notice too how my torque curve starts dipping rapidly after 4000 rpm. Also, my A/F ratio tiptoes in the 15s! If anything, given that the dyno conditions don’t represent the true air flow that would be seen on the road, I would expected it to richen, if not anything else, no?

The second attachment is the 5^th vs. 5^th gear pull for both (recall that the above test had verhagke’s Beast in 4^th). Similar results except perhaps a smaller variance between cars, but again, my car is consistently below the stock curve.

Third attachment is all my 3 runs superimposed together. The rightmost curve (looking at it at the 1500 rpm range) is the 4^th gear pull, the other two are in 5^th gear.

Lastly, the 4^th attachment is meant to measure tire running losses. After the pull, we simple let the drum roll from the inertia generated from the pull and measured the time until complete stop. We achieved a top speed of around 175 mph, and this was with an extra gear available! (I have the speed limiter repoved). I know Nascar (and others) have a way of measuring (and compensating) for tire running losses, but frankly I am not sure how to apply a ‘correction’ factor based on this. Any ideas?

What I plan to do next is:

Get the actual Dynojet run files from the dyno operator and send those (along with the comparos above) to Powerchip

Change oil, get lab analysis, and perform leak down test

Conduct compression test

Re-flash the ECU to stock via $tealer since there is a re-call anyhow

Send the ECU to Powerchip for new revised mappings

Go back to dyno to make sure PC “got it right” this time around.

Basically, what I want to make sure is that all else on the Beast is in line, and that Powerchip is not re-programming the chip around an existing compression or other issue (which I am pretty sure is not the case).

Appreciate everyone’s feedback on this.

TQ2K · 13th November 2006, 20:28

Cosio, my recommendation is to have it Dynoed with the stock DME software so you can get a better indication of how you're beast is running...

jimmyz2 · 13th November 2006, 20:43

Cosio,ICS is a great shop for modded enthusiates.I realy like the fact that you are checking out the power claims from Powechips(or any company for that matter).I never accept what any company advertises untill proven again and again.Good luck and I am sure you will get everthing sorted out.

coolcarlski · 4th December 2006, 05:35

Quote:

Originally Posted by cosioboy

Great guys, thanks for the heads-up Carl, no offense, but when it comes to BMWs these guys are miles away from TT

No offense taken.Glad I could help. Is there some special way to dyno E39 M5 BMW's?

cosioboy · 4th December 2006, 19:42

Here is a great 'white paper' on dynoing the E39 M5 (and dynos in general), and all the multiple factors that may affect the results. A bit long, but if one has the patience to read it, one will come out knowing a heck of a lot about both the car and the subjectivity of dyno testing... Worthy bedtime reading material

coolcarlski · 5th December 2006, 13:51

Quote:

Originally Posted by cosioboy

Here is a great 'white paper' on dynoing the E39 M5 (and dynos in general), and all the multiple factors that may affect the results. A bit long, but if one has the patience to read it, one will come out knowing a heck of a lot about both the car and the subjectivity of dyno testing... Worthy bedtime reading material

I agree with all of Dinans points and it's nothing new to me. Honestly! I also agree that the dyno and fan they use can give one more optimal results. There are not many if any shops that use the huge "hurricane" fan that Dinan uses . This is also why it's better to tune your car on the road vs tuning it on the dyno which alot of guys I know do. "Real world conditions".

Still,other than the fact that the M5 should be dynoed in 5th gear, what did George do that was different than Jeff and Mark?

That's what I wanna know beccause I've had dyno's done on two diferent cars at their shops.

George uses a much smaller fan than Jeff does hence my low dyno #'s at ICS. Used a larger fan and picked up almost 25 more hp. Common sense I feel.

P.S. I've been to TONS of dyno sessions at many different shops with cars that put out twice and a little more than twice the hp as a stck E39 M5 or AMG 5.5L car.

Difference I see between Dinan and others is that they are more meticulous with the cable to car tension,they don't use the more common drum roller dyno and that they use that huge "Hurricane fan" which I think is excellent. But a majority of shops won't have that kinda fan or use that kind of dyno.

I think you should get your car dynoed at Dinan

!

PS there's a fantastic article on dynoing a car in this months "Modified magazine".

George 322hp 323ftlbs TQ in NOVEMBER in 5th gear
Jeff/Mark 311hp 297ftlbs TQ in JULY 4th gear

I see a lot of factors affecting the differences in hp #'s right there and they are obvious. I can almost conclude that if Jeff had dynoed your car in 5th gear,in NOVEMBER(temp and humidity),with his BIGGER FAN,your #'s would have been higher or the same as Georges. This is not to take away from George as George is a good friend of mines. More so than Jeff. Just knew Jeff a couple of yrs longer.

Take it back to TT with what you learned and have them dyno the car again is my opinion. Tell them exactly what you want since you are the one paying your $$$$.

THRILOS5 · 5th December 2006, 20:04

cosioboy wait until march we go to Englishtown raceway park,we do a couple of 1/4 mile runs & weight your car on the scale then we calculate your trap speeds & figure out your exact HP numbers,very accurate & always on par with your buttdyno!It works for me for years with many modified cars,no dyno can duplicate a car during a run...your trap speeds say a lot about your HP even though your ETs are not always what you are expecting

ELEVENS · 5th December 2006, 20:08

Quote:

Originally Posted by THRILOS5

cosioboy wait until march we go to Englishtown raceway park,we do a couple of 1/4 mile runs & weight your car on the scale then we calculate your trap speeds & figure out your exact HP numbers,very accurate & always on par with your buttdyno!It works for me for years with many modified cars,no dyno can duplicate a car during a run...your trap speeds say a lot about your HP even though your ETs are not always what you are expecting

Amen!