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Base run statistics:
- 14.5 lbs Boost
- 6# lower pulley and 68 inch belt notched tensioner
- Stock Supercharger
- Cold Air Intake, 9 inch filter, C&L elbow
- Air filter drilled for IAT sensor
- High Flow Cat Back Exhaust
- Stock tune (except for transmission shift points)
- Transmission quick shift into 3rd gear, no down shift allowed.
- Spark plugs NGK TR6 gapped .038.
- Temperature and humidity were Very High during all these tests, around 95 degrees F.
1500-3500 -IAT1-94-IAT2-126-Timing-13-Coolant Temp-176
4000 - IAT1-94-IAT2-128-Timing-14-coolant temp-177
4500 - IAT1-94-IAT2-131-Timing-15-coolant temp-178
5000 - IAT1-94-IAT2-136-Timing-16-coolant temp-179
5200 - IAT1-94-IAT2-141-Timing-16-coolant temp-180- Volts-4.73
Below is the resulting dyno graph after the update: Click on graphs for lager images.
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First Ported Blower Run:
The only alteration made for this run was the use of a ported blower, stage 4.009. The graph shows the result against the base run.
The ported blower run moved more air, ran cooler and improved the boost over the base run. This resulted in a gain of 1 degree of timing in the engine. As you can see by the dyno graph below the improved efficiency of the ported blower had a positive effect on many points which added up to a nice gain. I would like to point out the the ported blower in this test has a stripped rotor. The base run used a stock blower with normal, painted rotors. Our process of stripping the rotors helps gain additional boost and lower inlet air temps while eliminated any possible blower damage due to flaking and tip scouring. |
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Second Ported Blower Run:
This run used the stage 4.011 ported blower, AKA .the "recalled stage". Here is the result graphed against 4.009. Note that it actually outperforms the standard stage 4 design, thus proving the recall was a bit hasty.
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Third Ported Blower Run:
This run used the stage 3.013 ported blower. Here is the result graphed against 4.009:
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Final comments about the ported blower testing:
The Final graph shows Stiegemeier Ported Blowers in different stages compared to a non Ported blower. There are differences in designs but overall it is clear to see there are No Bad Stiegemeier ported blowers. Also note the A/F stayed basically the same thru all the tests. The IATs (down stream of the blower) dropped on average 23 degrees across the board.
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Testing for improved low-end torque:
Many porting tests were attempted trying to increase air velocity and boost low-end TQ. All were conducted with a 6 # lower pulley and none of them showed any significant difference. There is a sweet spot that has an effect on boost charge and rise meaning quick to 10 then rise to 16. A stock blower will go quick to 10 but only go to 14.5. If you over extend you will drop the charge but not the rise.
Note: when port matching the manifold to heads the most important element is keeping the floor angle the same. Keep the port match equal or a little smaller on the intake. Your air flow will not be disrupted by a 1/16 showing but a 1/8 is bad. Porting the intake roof on a Lightning is not necessary due to the rotor exposure.
A simple and common sense way to improve torque and lessen belt slippage is to grind the pulley stop.
First move your water tank to the side and then remove center bolt. Grind the notch 3/4 back, replace bolt-then tank.
This next graph used the Stage II port with both a 2# and 4# lower. While we no longer offer this stage of porting it has good power but has a lower boost charge and rise. As you can see the 2 # lower pulley made a huge difference on this Stage Test. If you look close you can see a bit of boost charge flutter with the 4# lower. These tests mimic earlier review which prompted our Stage III.
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Test summary and associated notes/comments:
After running a multitude of porting designs it has become apparent that the timing of the rotors affects the balance of HP to TQ. If the duration is increased we do make more HP at the sacrifice of low RPM TQ up to a point of 3000 rpm at which the TQ increases 10 ft lbs and HP climbs on an average of 30-35 from 3000-5000.
The TQ loss at low RPM is more noticeable on an automatic vehicle than a stick shift-the manual transmission can easily be shifted at higher intervals to take full advantage of a ported blower. On the other hand, the automatic transmission is just that- it is automated thru the pcm.
To spread out your shift points to take better advantage of your ported blower you must alter the tranny tune start with a 300 rpm increase get a feel for your combination and go from there. Another rotor timing affect is the boost charge before the climb the first stage 4 had a boost charge of 8#s and then a quick climb to 16#s, the “re-clocked” stage 4 had a boost charge of 10#s and a quick climb to 16#s. The first stage 4 makes a few more HP but sacrifices a few ft #s of TQ up to 3500 rpms. The 2 lbs of increased boost charge of the update is noticeable thru the lower rpm the automatic vehicle lives in. All designs tested had a boost increase of 1 ½ #s over a non ported blower.
The best thing to come out of this was a better understanding about the Eaton Supercharger that will allow for more fine tuning of Eaton blowers for automatic Eaton vehicles. These tests were done with a stock (2.93) upper and a 6# lower pulley. If we ran these combos on a Cobra we would over spin the rotors due to the higher rpm redline of the 4 valve engine. For a 6# lower with stock upper run a 68 inch belt. For a 4# lower with stock upper run a 67 inch belt You will need to notch the tensioner. Boost charge and rise was solid on all tests, although total boost numbers varied with design. Current design charges 10 runs to 16. |
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