This is the logic (I think):

1. Sent the wastegate past the bumper by fabbing up a pipe. This is so the spent exhaust gasses do not deflect up and go back into the intake (K&N filters). Rick told me they showed a 60 hp difference from this alone!

2. Remove the rear tail lights. This is not to get MORE air, but to get FRESH air. There is plenty of emtpy space behind the tail lights, but with the car moving, it is more apt to be fresh (non-wastegate air...)

3. Heat up the system... Ah, screw it, I just found the email!! Read Below:




When testing the twin turbo C5 on the dyno, here are some guidelines that will help you to get the best results:

FULL BOOST PULLS: Turbochargers produce boost based on load. Many dynos will not load the vehicle as much as driving on the road and consequently, will have a hard time producing full boost quickly on the dyno. Here are a few steps to help ensure that your vehicle produces good boost on the dyno:

1. Make sure that the exhaust system, including the turbos, is up to full temperature. Regardless of whether the engine is up to temp, the exhaust system may not be up to temperature. With the turbos located near the rear, the entire exhaust system must be hot to ensure quick spool times. This is best accomplished by running the car on the dyno in 4th gear at about 3000 to 3500 rpm for a few minutes. When the system is warmed up, you will be able to stab the throttle and the boost should come on quickly. If the boost isn't coming on, the exhaust system is most likely not warm enough yet. Don't do full pulls to get the exhaust up to temp as you will heat-soak the intake tubing and intercooler more than necessary. The object is to heat up the exhaust system without heating up the intake tubing.

2. Once the exhaust system is up to temp and the turbo is ready to come on boost quickly, get the vehicle in the gear which you will make the pull in (typically 4th on manual trans and 3rd on automatics). Run the rpm to about 500 rpm more than the test starting rpm. Apply the brake on the dyno and press the accelerator down as far as possible to compensate for the brake load on the dyno. This should produce significant load on the dyno to bring the boost on. Let the dyno brake pull the rpm down to the test start rpm. The vehicle should now have sufficient load to be seeing at least 1-2 psi boost (full boost would be best but is sometimes not achievable) and be at the test start rpm. Quickly release the dyno brake and start the test pull while accelerating to WOT as quickly as possible (but still avoiding a downshift on automatics). The vehicle should see full boost very quickly and maintain that boost throughout the entire pull. (Note: These operational steps may not apply to all dynos.)

(IMPORTANT: Constantly monitor the AIR FUEL RATIO and the BOOST LEVEL as well as KNOCK RETARD. AFR should stay in the 11.5:1 range during the pull. BOOST should be approximately 5 psi on most base kits. KR should be ZERO. If AFR goes lean, BOOST goes higher than normal, or KR shows more than 1-2 degrees you should abort the dyno pull and make necessary corrections to ensure proper operation and tuning or SEVERE ENGINE DAMAGE could result!)

OPTIMAL RESULTS: There are many factors that will be different between driving your vehicle on the road and operating it on the dyno. The main differences are the loading capability as previously discussed and the lack of airflow across and specifically through the intercooler and under the vehicle. Here are a few steps to help ensure that your vehicle produces optimal results on the dyno:

1. Set up fans to blow through the intercooler (if applicable) and across the intake tubing under the vehicle to help dissipate heat from the air charge piping and keep Intake Air Temperatures (IAT's) as low as possible.

2. Set up fans to blow through the radiator to ensure that the engine coolant temperature stays at the lowest possible temperature within the appropriate operating range.

3. Set the electric fans to constantly be on to help pull cool air through the radiator and intercooler.

4. Remove the protective air filter cover (Precharger or Drycharger) and make sure that the air filter is clean to allow maximum airflow with the least restriction.

5. On vehicles with air filter snorkels, place the snorkel in an area where it can pull in the cleanest, coolest air. This may mean pulling the snorkel out and placing it away from the underside of the vehicle. On the C5 Corvette system, remove the 4 rear tail lights to allow air to be pulled in from the top rather than from below the vehicle.

6. On vehicles with externally dumping wastegates, it is VERY IMPORTANT to place an exhaust dump extension on the wastegate to run the dumped exhaust out behind the vehicle. This is especially a problem with dyno testing as most externally dumping wastegates will dump the exhaust straight down onto the dyno platform. This exhaust will then be deflected off the dyno platform and recirculated back into the air filter. This will dilute the intake charge with exhaust and severely raise the IAT's and reduce the power output. We have seen as much as 60+ rwhp reductions in rwhp from exhaust recirculation problems. Since the air is drawn into the vehicle from the rear, also make sure that the exhaust exiting the tailpipe (as well as wastegate) is directed out of the shop and that it can't be drawn back into the air filters.

7. Allow enough time between pulls to keep the IAT's at a consistently low level (should be within 10-20 degrees of ambient).

8. Remember to bring the exhaust back up to temperature before the next pull.

9. Use caution when using boost controllers. Using a boost controller to increase the boost level needs to be done carefully as there may be other factors that are limiting the boost. If the turning up the controller isn't raising the boost properly, that is a WARNING SIGN that there may be another factor effecting boost (ie, system not up to temperature yet). By continuing to increase the settings on the boost controller, a VERY DANGEROUS condition can occur: If the base problem (ie, system not up to temp) is resolved, the boost level could be dramatically increased and SEVERE ENGINE DAMAGE could result!

(WARNING: Always reset the boost controller based on actual street driving conditions. NEVER SET A BOOST CONTROLLER ON THE DYNO without rechecking the boost level under actual driving conditions!)

 

Wow, I'm beginning to think these guys are the kings of deception! First the 6 hour install time. Then the "over 600 rwhp" on 7 psi comment. And now every way possible to cheat the dyno! Brake boosting on the dyno, taking out the tail lights, taking the socks off the air filters (which need to be used on the street I assume), installing wastegate extension pipes (sorry, I should say pipe since they decide to only install one wastegate), preheating the exhaust system w/o adding any heat to the intake pipes...

Whatever it takes I guess.

 

I don't really think they are trying to cheat the dyno. They are just trying to replicate street conditions, where there is a bigger load, lots of airflow, etc....

I don't think anyone with a C5 would use the socks on the filters. There is no need since the filters are located so high up.

Tommy