NSX2NV

I was just wondering has anyone ever tested to see which mechanic makes the best horse numbers? I'm talking about the actual AMG techs who built the motor initially thats signs the charger when finished. I think this would be a really interesting thing to test and compare.

Jakpro1

I think I have pretty much figured out that the differing HP numbers come from different setup of the rings causing different piston compression numbers.

Mine was literally on the BOTTOM of the scale and thus a lower hp stock car. Higgins tested nearly at the top of the scale when he did his compression test and again, his car is a monster with just a K2 package.

Need to have a sticky. "Before buying a used 55, DO A COMPRESSION CHECK"

The numbers you get off the pistons will literally be an indicator where your car will fall on the hp scale AND the modding ET scale.

Perhaps the AMG guys are installing the rings a tiny bit differently and certain motors setup better etc, but otherwise I think it just comes down to how she sets up under initial breakin period. Fly in the ointment is Gid_e_up. He drove it like he stole it new off the lot and pulled the highest stock numbers we have seen. 517hp est crank at Kleemann while mine a week or 2 later pulled an embarrassing 470something.

Skeeter

Interesting! My E put up some strong numbers when I had it dyno'd stock (forget now, but I'll dig up the thread or dyno sheet when I go to work Thursday).

I now have TWO friends who want to buy E55's now. What type of compression numbers should they look for? What is 'good' and what isn't? I'm giving generic advice. Like don't EVER deal with the dealership-from-hell (S.F. Mercedes, or MB of Oakland), buy a low-mile 2005 with a CPO warranty, make sure it has keyless go and the premium package... Pano roof is a personal choice, etc... But to be able to advise/predict stock power based on compression, that'd be a good word to pass on.

Thanks,

Skeeter

jrcart

I hate to rain on your parade, but it would be near impossible to figure out what you guys are talking about. No matter how well calibrated, all dynos are going to show slightly different numbers. In addition to that, there are so many other factors that come into play when dyno testing a car such as elevation, temp, humidity etc.. Now throw in the different dyno manufactures and varying software and you have a whole mess of variables. Just because your car showed low numbers does not mean anything, but if it shows consistant lower numbers on different days and different shops dynos, it would be safe to assume you have a low HP engine. I've seen as much as a 5% variance on some of my cars from one dyno to another. You can take the same car, dyno test it today and then dyno it again in a few days on the same dyno and get slightly different numbers with a different curve. Most of us do not have access to climate and humidity controlled dyno rooms. I had my car dyno tested by Evosport in late February when the completed my mods, I believe they showed 500.3RWHP. A week later I dyno tested it at home, near Chicago and the car made 502.4RWHP, over two more WHP than Evosports dyno showed just a week previous. The thing that suprises me about those numbers are that I would have guessed the car would have made more HP on the Evosport dyno, they are in Huntington Beach, California which is at or very near sea level, Chicago is 600-700 feet above sea level if I'm not mistaken.

rflow306

The accepted values are 9 to 12 Bar, limit value is 8 bar and maximum allowed difference between cylinders is 1.5 Bar.1 bar = 14.503 psi

That's why the reading is sae corrected, if you were to compare uncorrected numbers and weather conditions you would see the difference from both locations.

Vadim @ FD

502.4 - 500.3 = 2.1, (2.1/500.3) = 0.4%. Well with 1-2% that I have seen Dynojets to be.

When Dynojet at Evosport was instaled in December of 1997, it was the third one in Southern California. Kenne Bell and HKS were the other two. We ran a Taurus SHO on all three dynoes on the same day, all of them were very close to 250RWHP, plus a minus a 0.5HP.

Murtaza

Interesting results but did you actually race your friend to see if he really had +47hp on you? Dynos vary but a race won't lie, he would pull on you significantly with that much difference in power.