How to dyno '55

Hakaze · 06-05-2007

I am planning to dyno my car next week - and I never dynoed a car before. Do I just enable dyno mode, put in manual mode (1st gear) and let it rip? Just confirming.

**Zeiser50** · 06-05-2007

Yes .

... And try to avoid collision with walls, cars, ...

DansSlk · 06-05-2007

Yep thats it.

As Michel says just make sure it does not jump forward.

If your on a 4 wheel dyno where the rears drums are connected to the front then you don't need dyno mode because all the wheels will be rotating, you only need it if the back wheels are going to be the only ones doing anything.

leelk · 06-05-2007

just curous what is a Dyno?
what's the Pro/Con on turning to Dyno mode?

DansSlk · 06-05-2007

Dyno / Dynamometer is a device that uses the torque and rotational speeds of the driving wheels to measure a engines output in BHP.

Because its measured at the wheels a drive-train loss of about 15-20% is normally factored in.

Because the SLK's ESP system uses speed sensor information from all 4 wheels and a dyno drum normally only sits below the driving wheels leaving the front 2 doing nothing the cars computer gets confused and will either activate the ESP thinking the car is out of control or will engage the speed limiter system you don't want either of these happening on a dyno for obvious reasons.

Dyno mode disables all the traction control systems and the speed limit system (not the Vmax) so that the car can be run to its maximum without all the wheels turning this is great on a dyno or brake tester stand but not so good on the road because the traction control system will not step in at all to help you out if something goes wrong and you lose control of the car you also lose even simple things like ABS when in dyno mode.

**webslinger** · 06-05-2007

Along the lines of this thread- Does anyone know if there are any dyno's here in Northern California? (South bay would be best) I'd like to break in the car and then take it to the dyno to see what it has before I install things like the green filters, etc. (baseline)

leelk · 06-05-2007

Quote:

Originally Posted by DansSlk

Dyno / Dynamometer is a device that uses the torque and rotational speeds of the driving wheels to measure a engines output in BHP.

Because its measured at the wheels a drive-train loss of about 15-20% is normally factored in.

Because the SLK's ESP system uses speed sensor information from all 4 wheels and a dyno drum normally only sits below the driving wheels leaving the front 2 doing nothing the cars computer gets confused and will either activate the ESP thinking the car is out of control or will engage the speed limiter system you don't want either of these happening on a dyno for obvious reasons.

Dyno mode disables all the traction control systems and the speed limit system (not the Vmax) so that the car can be run to its maximum without all the wheels turning this is great on a dyno or brake tester stand but not so good on the road because the traction control system will not step in at all to help you out if something goes wrong and you lose control of the car you also lose even simple things like ABS when in dyno mode.

Thank you for your information, Dan you are the man...

I wonder are there anything Dan doesn't know?!?!??

VitaminT · 06-05-2007

Saturday 12:30CST I have an appointment to put mine on the dyno. Not sure what model but it is a Dynojet unit.

Anyone have an idea which gear to do the pull in. In most cars they do them in 4th but not sure if that would change with it being a 7spd. It doesn't really matter too much but usually on higher HP cars 4th puts more load on the car and it runs slightly different numbers than say 3rd. I guess I will look at the gear ratios on the 55 and pick 2 and try it in both.

To the guy that said 1st gear, it technically can be done in 1st I believe, but it is usually done in 3rd or 4th as it loads the engine more. You can actually sample multiple gears in one pull I believe.

DansSlk · 06-05-2007

If it where me i would run it up the range the car will not allow implausible shifts anyways so if you want to run it in any gear other than 1st you will need to shift while its on the rig.

Maybe S mode would be better because you could restrict the shift range to the highest gear you wanted to test and just nail the throttle, don't kick it down of course because that will bypass it.

VitaminT · 06-05-2007

I will probably just run in M mode in 4th. Just get it strapped to the dyno, run the car like driving down the road to 4th gear and then do a 2k-redline in 4th.

As you are probably aware they do the same thing with cars with sticks. Just drive like normal until you get in forth, lay out of the throttle in 4th, hit the "record" button on the dyno and punch it. When done, stop recording and let off.

I will post the pulls up Saturday or Sunday and let you all know how things went. I am hoping for 300whp but it is going to be like 95deg here so I don't know if I will make it. Won't be near as spectacular as my buddies 768whp turbo Honda Civic.

DansSlk · 06-06-2007

Yeah that sounds cool.

Was just making sure you knew about getting it into the correct gear, we have had people come into the shop with the primary complaint being the car wont select gears and we have to explain that the car wont allow you to select a gear below a threshold speed or when the resulting RPM's would stall or over-rev the engine.

Clearly you know the score so i look forward to the results and good luck

**alroumi** · 06-06-2007

Expect to do 299-303hp to the wheels, I would try both 3rd and 4th gear runs due to the 7gearning of the SLK.

**webslinger** · 06-06-2007

I guess I answered my own question here- Apex Motorsports in Santa Clara off Central Expressway seems to have a Dyno. I'll contact them and maybe we can gather a few of us to go down and do a "dyno day" in August?

Hakaze · 06-06-2007

Hmm... does the tire effect the dyno results at all? I would assume so - I ask because I rear tires are in need of change.

VitaminT · 06-06-2007

Nope. The only difference, and it probably wouldn't show up at all, would be if the old tires weigh less than the new ones but really it doesn't matter.

VitaminT · 06-10-2007

Went to the dyno today. Did it just like we talked about here, put it in dyno mode, manual tranny mode and the operator just drove it up to 3-4th gear and did the pull.

Anyway in 3rd made 299.8. In 4th did 292.0. He said the resolution (? beats me) looked better on the 4th gear pull even though it was less. I didn't see the 3rd gear run for but a second but it didn't look smooth, it had lumps it it. Anyway did another pull jut like the last in 4th and did 290.7.

It was about 90-93 degrees, full tank of gas. Only mod is green filters and some BBS RA wheels. The runs were not too long after I had driven 10-15 miles on interstate so I am sure the airbox was very hot. At 3500rpm it is running about 12.5:1 AFR and by 5500 it is burried below 10:1 so I guess I need a Renntech tune or something because that is riiiich for a NA car.

DansSlk · 06-10-2007

Good results.

How did they get the AF ratio info OBD?

VitaminT · 06-10-2007

No it was just a tailpipe sniffer. Not really accurate but better than nothing. I wouldn't tune a car by it that's for sure but it is something worth having on the chart.

DansSlk · 06-10-2007

Yeah your right its better than nothing

VitaminT · 06-11-2007

One thing I wished I had him do is he seems to roll into the throttle and start recording about 3400. I wish on one of the two 4th gear runs he did I had him roll into it on one, and stomp it on the other. Just feels to me like the car responds differently sometimes.

I think it did it that way because he is used to most automatics downshifting it if jumps on it where mine was in Manual mode.

Hey there is always next time. Maybe I can get me a Renntech ecu and airbox and dyno again. They give those things away right? Nissan chipped ECU=$500, Renntech chipped ECU=$2000, hmm beats me why the difference other than they know they can get it.

06-05-2007	#1 (permalink)
Hakaze SLK World Member Join Date: Mar 2007 Location: Anchorage, Alaska Vehicle: 2006 SLK55 Posts: 39 Country: Thanks: 0 Thanked 0 Times in 0 Posts	How to dyno '55 I am planning to dyno my car next week - and I never dynoed a car before. Do I just enable dyno mode, put in manual mode (1st gear) and let it rip? Just confirming.

06-05-2007	#2 (permalink)
Zeiser50 Elite SLK World Member Join Date: Mar 2007 Location: Paris Vehicle: SLK 55 AMG Other Toys: Bike : '84 Z1300-6 Posts: 506 Country: Thanks: 6 Thanked 18 Times in 14 Posts	Yes . ... And try to avoid collision with walls, cars, ... __________________ To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. ------Michel------ -SLK 55 AMG 2005-

06-05-2007	#3 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,756 Country: Thanks: 96 Thanked 221 Times in 173 Posts	Yep thats it. As Michel says just make sure it does not jump forward. If your on a 4 wheel dyno where the rears drums are connected to the front then you don't need dyno mode because all the wheels will be rotating, you only need it if the back wheels are going to be the only ones doing anything. __________________ One thing you will learn with German cars - If it's simple it ain't happening.

06-05-2007	#5 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,756 Country: Thanks: 96 Thanked 221 Times in 173 Posts	Dyno / Dynamometer is a device that uses the torque and rotational speeds of the driving wheels to measure a engines output in BHP. Because its measured at the wheels a drive-train loss of about 15-20% is normally factored in. Because the SLK's ESP system uses speed sensor information from all 4 wheels and a dyno drum normally only sits below the driving wheels leaving the front 2 doing nothing the cars computer gets confused and will either activate the ESP thinking the car is out of control or will engage the speed limiter system you don't want either of these happening on a dyno for obvious reasons. Dyno mode disables all the traction control systems and the speed limit system (not the Vmax) so that the car can be run to its maximum without all the wheels turning this is great on a dyno or brake tester stand but not so good on the road because the traction control system will not step in at all to help you out if something goes wrong and you lose control of the car you also lose even simple things like ABS when in dyno mode. __________________ One thing you will learn with German cars - If it's simple it ain't happening.

06-05-2007	#9 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,756 Country: Thanks: 96 Thanked 221 Times in 173 Posts	If it where me i would run it up the range the car will not allow implausible shifts anyways so if you want to run it in any gear other than 1st you will need to shift while its on the rig. Maybe S mode would be better because you could restrict the shift range to the highest gear you wanted to test and just nail the throttle, don't kick it down of course because that will bypass it. __________________ One thing you will learn with German cars - If it's simple it ain't happening.

06-05-2007	#4 (permalink)
leelk Senior SLK World Member Join Date: May 2007 Location: San Ramon, CA Vehicle: 06 SLK55 AMG Posts: 135 Country: Thanks: 0 Thanked 0 Times in 0 Posts	just curous what is a Dyno? what's the Pro/Con on turning to Dyno mode?

06-05-2007	#6 (permalink)
webslinger Elite SLK World Member Join Date: Apr 2007 Location: Bay Area, CA Vehicle: '07 SLK55 AMG Other Toys: Honda motorcycle Posts: 549 Country: Thanks: 22 Thanked 22 Times in 14 Posts	Along the lines of this thread- Does anyone know if there are any dyno's here in Northern California? (South bay would be best) I'd like to break in the car and then take it to the dyno to see what it has before I install things like the green filters, etc. (baseline)

06-05-2007	#8 (permalink)
VitaminT Elite SLK World Member Join Date: Apr 2007 Location: Alabama Vehicle: 2005 SLK55 Posts: 361 Country: Thanks: 0 Thanked 0 Times in 0 Posts	Saturday 12:30CST I have an appointment to put mine on the dyno. Not sure what model but it is a Dynojet unit. Anyone have an idea which gear to do the pull in. In most cars they do them in 4th but not sure if that would change with it being a 7spd. It doesn't really matter too much but usually on higher HP cars 4th puts more load on the car and it runs slightly different numbers than say 3rd. I guess I will look at the gear ratios on the 55 and pick 2 and try it in both. To the guy that said 1st gear, it technically can be done in 1st I believe, but it is usually done in 3rd or 4th as it loads the engine more. You can actually sample multiple gears in one pull I believe.

06-05-2007	#10 (permalink)
VitaminT Elite SLK World Member Join Date: Apr 2007 Location: Alabama Vehicle: 2005 SLK55 Posts: 361 Country: Thanks: 0 Thanked 0 Times in 0 Posts	I will probably just run in M mode in 4th. Just get it strapped to the dyno, run the car like driving down the road to 4th gear and then do a 2k-redline in 4th. As you are probably aware they do the same thing with cars with sticks. Just drive like normal until you get in forth, lay out of the throttle in 4th, hit the "record" button on the dyno and punch it. When done, stop recording and let off. I will post the pulls up Saturday or Sunday and let you all know how things went. I am hoping for 300whp but it is going to be like 95deg here so I don't know if I will make it. Won't be near as spectacular as my buddies 768whp turbo Honda Civic.

06-06-2007	#11 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,756 Country: Thanks: 96 Thanked 221 Times in 173 Posts	Yeah that sounds cool. Was just making sure you knew about getting it into the correct gear, we have had people come into the shop with the primary complaint being the car wont select gears and we have to explain that the car wont allow you to select a gear below a threshold speed or when the resulting RPM's would stall or over-rev the engine. Clearly you know the score so i look forward to the results and good luck __________________ One thing you will learn with German cars - If it's simple it ain't happening.

06-06-2007	#12 (permalink)
alroumi Moderator Join Date: Jun 2006 Location: Kuwait City, Kuwait Vehicle: 2006 Kleemann Designo Mocha Black SLK55 AMG Other Toys: 2007 Ebony Jaguar XKR Coupe' and 06 Black Cayenne S Posts: 6,271 Country: Thanks: 288 Thanked 231 Times in 145 Posts	Expect to do 299-303hp to the wheels, I would try both 3rd and 4th gear runs due to the 7gearning of the SLK. __________________ 06 Kleemann Designo Mocha Black SLK55 AMG 06 Porsche Cayenne S 07 Jaguar XKR Coupe' I use the Torque and keep the HP for my Steak Sauce!

06-06-2007	#13 (permalink)
webslinger Elite SLK World Member Join Date: Apr 2007 Location: Bay Area, CA Vehicle: '07 SLK55 AMG Other Toys: Honda motorcycle Posts: 549 Country: Thanks: 22 Thanked 22 Times in 14 Posts	I guess I answered my own question here- Apex Motorsports in Santa Clara off Central Expressway seems to have a Dyno. I'll contact them and maybe we can gather a few of us to go down and do a "dyno day" in August?

06-06-2007	#14 (permalink)
Hakaze SLK World Member Join Date: Mar 2007 Location: Anchorage, Alaska Vehicle: 2006 SLK55 Posts: 39 Country: Thanks: 0 Thanked 0 Times in 0 Posts	Hmm... does the tire effect the dyno results at all? I would assume so - I ask because I rear tires are in need of change.

06-06-2007	#15 (permalink)
VitaminT Elite SLK World Member Join Date: Apr 2007 Location: Alabama Vehicle: 2005 SLK55 Posts: 361 Country: Thanks: 0 Thanked 0 Times in 0 Posts	Nope. The only difference, and it probably wouldn't show up at all, would be if the old tires weigh less than the new ones but really it doesn't matter.

06-10-2007	#16 (permalink)
VitaminT Elite SLK World Member Join Date: Apr 2007 Location: Alabama Vehicle: 2005 SLK55 Posts: 361 Country: Thanks: 0 Thanked 0 Times in 0 Posts	Went to the dyno today. Did it just like we talked about here, put it in dyno mode, manual tranny mode and the operator just drove it up to 3-4th gear and did the pull. Anyway in 3rd made 299.8. In 4th did 292.0. He said the resolution (? beats me) looked better on the 4th gear pull even though it was less. I didn't see the 3rd gear run for but a second but it didn't look smooth, it had lumps it it. Anyway did another pull jut like the last in 4th and did 290.7. It was about 90-93 degrees, full tank of gas. Only mod is green filters and some BBS RA wheels. The runs were not too long after I had driven 10-15 miles on interstate so I am sure the airbox was very hot. At 3500rpm it is running about 12.5:1 AFR and by 5500 it is burried below 10:1 so I guess I need a Renntech tune or something because that is riiiich for a NA car.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

06-10-2007	#17 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,756 Country: Thanks: 96 Thanked 221 Times in 173 Posts	Good results. How did they get the AF ratio info OBD? __________________ One thing you will learn with German cars - If it's simple it ain't happening.

06-10-2007	#18 (permalink)
VitaminT Elite SLK World Member Join Date: Apr 2007 Location: Alabama Vehicle: 2005 SLK55 Posts: 361 Country: Thanks: 0 Thanked 0 Times in 0 Posts	No it was just a tailpipe sniffer. Not really accurate but better than nothing. I wouldn't tune a car by it that's for sure but it is something worth having on the chart.

06-10-2007	#19 (permalink)
DansSlk Dude Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,756 Country: Thanks: 96 Thanked 221 Times in 173 Posts	Yeah your right its better than nothing __________________ One thing you will learn with German cars - If it's simple it ain't happening.

06-11-2007	#20 (permalink)
VitaminT Elite SLK World Member Join Date: Apr 2007 Location: Alabama Vehicle: 2005 SLK55 Posts: 361 Country: Thanks: 0 Thanked 0 Times in 0 Posts	One thing I wished I had him do is he seems to roll into the throttle and start recording about 3400. I wish on one of the two 4th gear runs he did I had him roll into it on one, and stomp it on the other. Just feels to me like the car responds differently sometimes. I think it did it that way because he is used to most automatics downshifting it if jumps on it where mine was in Manual mode. Hey there is always next time. Maybe I can get me a Renntech ecu and airbox and dyno again. They give those things away right? Nissan chipped ECU=$500, Renntech chipped ECU=$2000, hmm beats me why the difference other than they know they can get it.