FishtailnZ

264hp and 280 torque on a DynoDynamics dyno. These are similar to a Mustang Dyno in that they typically read 10-15% lower than a Dynojet version. Friends who have used both have noted the same difference. The numbers may seem low but the car still runs 110 traps and 12.7 in the 1/4 mile so I know it's not down on power - again just characteristic of DynoDynamics machines.

IIIMBPIII

Wow def not what i was expecting but still cant deny that the car is a beast no matter the numbers!!!

FishtailnZ

Like I said, DynoDynamics brand dyno's characteristically give lower numbers than the more commonly used Dynojet machines. I knew that going in, but I just wanted to get another set of baseline figures to go with those obtained at the track - which is where the real proof of the pudding is anyway, so to speak *L*. So when I start changing things down the road, I have some starting points to refer back to .

One other thing of importance though I did find out on the dyno today is that the car runs much richer in higher rpms than down low/mid range. A/F starts of at 12.5 around 2000rpm, dropping to 11.2 as it passes 6000. Some gains to be had there for sure with a custom tune. Again, down the road I also now suspect taking the car right to redline in each gear may not actually be the quickest way down the track, as power starts to drop off a lot again past that 6000rpm mark. So next time I get it back to the track, I'm going to try dropping the shift rpm points manually and see what that does for ET. Maybe that alone will net me 12.6's.

dsb

I'll be curious to see the results. Although, I'm somewhat skeptical it will speed up your time. I don't claim to be a real gearhead nor do I think I'm an expert at the dragstrip. Just thinking aloud here...

1) I believe it will be quite difficult to time the shift change better than the gearbox. Not only will it be difficult, but it will be hard to upshift consistently through each gear. Now, maybe you can leave it in S mode with a max of 3rd gear. That will allow it to automatically upshift the first few gears as they come rapidly then allow you to upshift into 4th, etc.

2) Here's my other hunch. I see your point about HP dropping greatly past 6k. Now, if you shift around 5700, then your next gear will engage around what 4000? At that point, you'll be around 205hp. Whereas letting the car shift at redline, will allow the next gear to engage at a higher rpm speed netting a higher hp. Wouldn't that be better overall giving you the best outcome?

Again, none of this is based on facts. It's just my mind thinking logically. Ultimately, it will take a track experience to see the true results. I hope you can get into 12.6. That will be a great performance for a stock 55. Good luck.

FishtailnZ

All good points dsb, but worth a try in playing around with next time out - which won't be til next spring now, track is closed up here for the season. Hardest part will be dealing with the shift delay using manual mode. Right now I find if I want to shift at 6000 WOT, I have to hit the paddle at 5000. It'll be hard to fine tune the timing to alter shift points by 100 rpm or so for sure.

Addicted2Speed

When my car was stock, it did 285whp and 280wtq on a hot day, so these numbers are definitely not that low. Were you in the dyno mode and 3rd gear? I think this makes a slight difference in power. And also you need to have a huge fan blowing air in front of your car, if you don't, you'll lose 30whp easy.

FishtailnZ

Unfortunately no fan, but it was a cool day anyway - mid 60's ambient at the shop. The guy running the dyno wanted to know which gear is 1:1, which is 5th gear for the SLK55. I was always told that whatever the model of car being tested, it has to be run in the gear that is 1:1, or closest to it, for accuracy?

P.S the car was in dyno mode.

Addicted2Speed

I ran mine in several gears and 3rd and 4th produced the highest whp. 5th is usually too high when you're dynoing the car IMO.

E55 PWR

Dyno Dynamics is by far the most accurate & reliable dyno out there, I like it even more than mustang dynos and their results are actual on road results (not inflated, drum spinning pseudo power). Don't let the low numbers fool you thats what you are ACTUALLY making. typically to get accurate engine numbers on loading dyno (like DD) you do roughly 28% correction factor and if you do the math that puts you right at 366 HP which seems dead on the money. Seems good to me.

FishtailnZ

Thanks E55 PWR, that's basically the same thing others who've used DynoDynamics have told me. I did some research on the brand, and asked a lot of questions of those who've used it, before putting my own car on there, so I'm more than comfortable with the "numbers". Especially since I have the track results to go along with it. Using some hp calculators based on my ET/trap speed also put the car's hp in the 360 range - sounds right to me!

FishtailnZ

P.S. I forgot to add in my origional posting that I also tested a set of Green Filters in back to back runs that day and they gave a gain of 9hp and 11ft/lb torque. Not bad for just a filter.

I'll be taking these out though next spring before hitting the track once more to attempt that 12.6x still stock! But I thought people might like to know these filters are a decent gain for very few bucks.