Weak Dyno results - 2011 SS Auto with Edelbrock Supercharger

[lahatte]

We are disappointed in the dyno results. The car has the following specs:

• 2011 SS Automatic Trans with all factory upgrades including aftermarket GM performance mufflers
• Edelbrock Supercharger
• Hedman ss shorty headers
• JBA Mid pipes with high flow cats

I've attached the 2 dyno runs. The car ran lean at peak torque.

Any input on this? Are these normal figures for this setup? I was hoping for around 450-500rwhp...

[LS7 427]

Thats about 50-60 rwhp over stock. Seems a little light to me. My A6 dyno'd 357 rwhp when it had only headers, exhaust, CAI and a tune.

Are you running an aftermarket air intake? How much boost?

[lahatte]

Originally Posted by CAMROSS

Thats about 50-60 rwhp over stock. Seems a little light to me. My A6 dyno'd 357 rwhp when it had only headers, exhaust, CAI and a tune.

Are you running an aftermarket air intake? How much boost?

Stock air intake and i have no clue on the boost. We don't have a boost gage. We used the programer that came with the Edelbrock supercharger and the pulley it came with (auto tranny), so whatever it's programed to do boost wise is what it will be.

[10aSSee D]

You need to do the Jannetty fuel rail upgrade and your numbers will go up and fix your lean condition.

[Unreal]

What type of dyno? If it is a loading bearing dyno like a mustang/dynapack then 380rwhp could be fine. That would be 410-420rwhp on a dynojet which is what I would expect out of a edelbrock L99/auto.

[Camaroshark]

Originally Posted by lahatte

We are disappointed in the dyno results. The car has the following specs:

• 2011 SS Automatic Trans with all factory upgrades including aftermarket GM performance mufflers
• Edelbrock Supercharger
• Hedman ss shorty headers
• JBA Mid pipes with high flow cats

I've attached the 2 dyno runs. The car ran lean at peak torque.

Any input on this? Are these normal figures for this setup? I was hoping for around 450-500rwhp...

Had another friend where this happened. Does the computer know there's a supercharger installed? I've heard that you get the most bang from long tube headers in this car and that'll be the route I go...

Have you adjusted all other aspects of timing and tune?

[IPS Brandon]

Originally Posted by 10aSSee D

You need to do the Jannetty fuel rail upgrade and your numbers will go up and fix your lean condition.

Honestly that is the least of his problems (but not un-important)

You should see about 6 psi with that system in its "stock" form, with the other modifications you have I would expect about 100 rwhp increase. Granted you are dynoing on a dyno dynamics, which read low, lets say 5% low, correcting for this would put you at 400 rwhp...Still unusably low in my opinion.

Edlebrock advertises (on a manual trans car http://www.edelbrock.com/automotive_...o/street.shtml) 599 engine horsepower, so lets say being overly aggressive a 22% drivetrain loss of 467 rwhp, then another 5 lost for the auto, 440 rwhp, less the dyno dynamics lower readings around 420 rwhp would be at least in the ball park.

One of the issues we have seen with these blowers is they run fairly high intake air temperatures, so verify those, second verify how much air is moving into the engine (your MAF hz or Map Kpa) so we can calculate boost pressure, maybe you have a slight leak...You can also monitor with a boost gauge or sensor on the dyno. Finally are you using their "canned" tune, and what octane?

There is a nice little laundry list of checks you can make to solidify the full function of this system!

[lahatte]

Originally Posted by 10aSSee D

You need to do the Jannetty fuel rail upgrade and your numbers will go up and fix your lean condition.

I'm not familiar with this...

Originally Posted by Unreal

What type of dyno? If it is a loading bearing dyno like a mustang/dynapack then 380rwhp could be fine. That would be 410-420rwhp on a dynojet which is what I would expect out of a edelbrock L99/auto.

I'm not sure what type of dyno it is. On the dyno sheet it was called a "Dyno Dynamics".

Originally Posted by Camaroshark

Had another friend where this happened. Does the computer know there's a supercharger installed? I've heard that you get the most bang from long tube headers in this car and that'll be the route I go...

Have you adjusted all other aspects of timing and tune?

We just used the programer that came with the Edelbrock supercharger.

Originally Posted by IPS Brandon

Honestly that is the least of his problems (but not un-important)

You should see about 6 psi with that system in its "stock" form, with the other modifications you have I would expect about 100 rwhp increase. Granted you are dynoing on a dyno dynamics, which read low, lets say 5% low, correcting for this would put you at 400 rwhp...Still unusably low in my opinion.

Edlebrock advertises (on a manual trans car http://www.edelbrock.com/automotive_...o/street.shtml) 599 engine horsepower, so lets say being overly aggressive a 22% drivetrain loss of 467 rwhp, then another 5 lost for the auto, 440 rwhp, less the dyno dynamics lower readings around 420 rwhp would be at least in the ball park.

One of the issues we have seen with these blowers is they run fairly high intake air temperatures, so verify those, second verify how much air is moving into the engine (your MAF hz or Map Kpa) so we can calculate boost pressure, maybe you have a slight leak...You can also monitor with a boost gauge or sensor on the dyno. Finally are you using their "canned" tune, and what octane?

There is a nice little laundry list of checks you can make to solidify the full function of this system!

How do we verify the temperatures and amount of airflow moving into the engine to determine if there is a leak or high temperatures?

We are using the tune that came with the Edelbrock supercharger. We updated the programer with the latest version off of Edelbrock's website and followed the instructions. We had no errors and it completed the update.

93 octane pump fuel was used.

Where can I find the check list to solidify the full function of this system?



Thanks

[sscamaro]

You definitely need a dyno tune. You better get the lean F/A ratio fixed or you will hurt the engine. Shorty headers don't do anything for you either. 1 7/8" long tube headers will work a lot better. Before I installed the S/C I had LT headers, ported intake and dyno tune. It made 414/rwhp. After installing the S/C it was dyno tuned. The F/A ratio was also very lean. It took a few runs to get it where it should be. I know mine is a manual, but you should have more HP than what you are getting.

[NickJRE]

Can you hook this car up to a Wideband on the Dyno? Even datalog the fuel trims with Edelbrock Programmer so you can see how they are.

[Caliman93230]

should have gotten a whipple

[SGOS252382]

Whenever someone posts crazy dyno numbers it seems to always be from a Dyno Dynamics dyno.

If you get your car re-dynoed, try to find a dyno jet. Dyno jets seem to be fairly consistant (SAE - corrected numbers).

[GEN-IV]

Do you have baseline dynamometer data before the supercharger install?

[Sack Rat 2SS]

Just one other thing could be a tank of bad fuel. I have seen several cars dyno low plus much knock retard due to bad fuel. Drain and refill with known fuel from a quality station, not Sams or Kroger. Eliminates one varable.