968 Supercharger Kit Development
#183
Developer
Thread Starter
Back from the dyno.
The kit and the car performed flawlessly. No issues.
Note the excellent Air/Fuel ratio at 12.4:1 thoughout most of the boost up to 5700 RPM, where we start adding a little more until we reach 11.8:1 at redline and full boost. We do that to cool the charge air and add engine safety.
We also did a pull with the air filter/cold air system removed and gained only 4 HP. This is normal - all air filter media is necessarily somewhat restrictive in order to function, and a drop of about 4 HP is the lowest you can reasonably hope for. Higher drops with the air filter/cold air system removed would indicate that the air supply system is poorly designed and restrictive. We were very pleased with the 4 HP drop.
I did take a video too... in-car and out-of-car. I hope to find time to edit it and post it this weekend so you can hear what it sounds like.
CONGRATULATIONS. Your car now has more HP than a Nissan 350Z (6 cylinder) and a 1978-1984 Porsche 928 US (8 cylinder) and a Ferrari 308 and 328 (8 cylinder). I have supercharged each of these cars.
The next step for us is Manufacturing and writing the Installation Manual. The parts on the car are one-of prototypes. Now that we confirm they work and there is no belt slip or noises or interference, they come off the car so we can use them as patterns to make more.
This is when we will be able to quantify the cost of manufacturing the kit and get you guys a price.
Thank you for your interest! If you have any questions post them here and I will get back to them. Right now I need to jump back into the shop and catch up on some race prep for an event on Monday.
The kit and the car performed flawlessly. No issues.
Note the excellent Air/Fuel ratio at 12.4:1 thoughout most of the boost up to 5700 RPM, where we start adding a little more until we reach 11.8:1 at redline and full boost. We do that to cool the charge air and add engine safety.
We also did a pull with the air filter/cold air system removed and gained only 4 HP. This is normal - all air filter media is necessarily somewhat restrictive in order to function, and a drop of about 4 HP is the lowest you can reasonably hope for. Higher drops with the air filter/cold air system removed would indicate that the air supply system is poorly designed and restrictive. We were very pleased with the 4 HP drop.
I did take a video too... in-car and out-of-car. I hope to find time to edit it and post it this weekend so you can hear what it sounds like.
CONGRATULATIONS. Your car now has more HP than a Nissan 350Z (6 cylinder) and a 1978-1984 Porsche 928 US (8 cylinder) and a Ferrari 308 and 328 (8 cylinder). I have supercharged each of these cars.
The next step for us is Manufacturing and writing the Installation Manual. The parts on the car are one-of prototypes. Now that we confirm they work and there is no belt slip or noises or interference, they come off the car so we can use them as patterns to make more.
This is when we will be able to quantify the cost of manufacturing the kit and get you guys a price.
Thank you for your interest! If you have any questions post them here and I will get back to them. Right now I need to jump back into the shop and catch up on some race prep for an event on Monday.
#186
Instructor
Carl, do you have a before dyno to show what this car was putting down prior to the s/c install??
the only reason I ask, is that I thought we might see more power from ~6psi boost (about a 40% increase over stock based upon the engine size and compressor data, etc); in the neighborhood of ~100chp. your dyno plot show an approximate ~56chp delta. do you think this is low??? based upon your a/f's, I would think we could still safely pull more hp's from the kit. are you turning at max input speed on the charger with the pulley you've spec's? do you think up'ing the boost would cause more slip?
lots of questions I know. any info MUCH appreciated.
Thanks again for all of your hard work!
the only reason I ask, is that I thought we might see more power from ~6psi boost (about a 40% increase over stock based upon the engine size and compressor data, etc); in the neighborhood of ~100chp. your dyno plot show an approximate ~56chp delta. do you think this is low??? based upon your a/f's, I would think we could still safely pull more hp's from the kit. are you turning at max input speed on the charger with the pulley you've spec's? do you think up'ing the boost would cause more slip?
lots of questions I know. any info MUCH appreciated.
Thanks again for all of your hard work!
Last edited by lsinlv; 05-29-2009 at 06:39 PM.
#189
Instructor
but the variocam is funcitioning from 1,500 through 5,500 ....so I would think the airflow would be better not worse as boost rises.....unless there are some intake issues from changed volume???? am I missing something???
#191
Developer
Thread Starter
Yes, I am used to seeing a little more from 5 pounds of boost too (I've done this once or twice
On the other hand, 300 HP from a 4 cylinder motor is good all day every day.
We think the Variocam is doing its job - and widening the valve overlap as the RPM's increase. Although this is good for NA motors, it isnt so good for boosted motors.
I did not want to introduce any "funny stuff" on this dyno pull. I left the Variocam plugged in and the stock chipset.
We could consider pulling out the Variocam by shipping a custom chipset with each kit, if that would help. It would, of course, raise the cost of the kit.
The stock pulls would be 200 HP at the tire, 236 at the crank. 191 Lb Ft of Torque at the tire, 225 at the crank.
On the other hand, 300 HP from a 4 cylinder motor is good all day every day.
We think the Variocam is doing its job - and widening the valve overlap as the RPM's increase. Although this is good for NA motors, it isnt so good for boosted motors.
I did not want to introduce any "funny stuff" on this dyno pull. I left the Variocam plugged in and the stock chipset.
We could consider pulling out the Variocam by shipping a custom chipset with each kit, if that would help. It would, of course, raise the cost of the kit.
The stock pulls would be 200 HP at the tire, 236 at the crank. 191 Lb Ft of Torque at the tire, 225 at the crank.
Last edited by Carl Fausett; 05-29-2009 at 09:57 PM.
#192
Instructor
I have...and thus my confusion....at ~5,500 rpm's the intake advance is stopped, and then reversed to increase HP but lower TQ......but based upon the above dyno plot we see a loss of BOTH HP and TQ.....yet the charger is pushing a much larger volume of air.....thus, I would assume you'd see the TQ stay with the HP plot, yet both drop off.
not to hijack this thread technically, but I am not sure as to why we are seeing this (or more accurately, why I don't understand what is happening).
not to hijack this thread technically, but I am not sure as to why we are seeing this (or more accurately, why I don't understand what is happening).
#194
the dyno figures look good ,for the time being on 91 octane.Remember that the 968 ROW is specified with 98 octane , and presumably if this fuel is available the figures should be definetedly higher.
if the 968 was fitted with individual throttle bodies ,45 mm to each cylinder, the 300 FLYWHEEL H.P n/a
would be quite feasible without any mods , as the cylider head , valves and cams ,with an 11 to 1
c.r. could very well support it.
also true performance sometimes is not measured by figures alone as it depends on the correction factors and accuracy of dyno pulls.Having said that ,in my opinion, the figures are on the conservative side and given the potential of the supercharger and intercooler, i would have expected to see, the wheel BHP/TORQUE hovering around the 300 figure at max rpm .Perhaps massaging the fuelling
and ignition could give that figure.
we have here few 350z ,fitted with similar superchargers and are around the 350-375 flywheel h.p.
they are ultra quick.I dont see why the 968 engine be different.
a food for thought-- a 944 std turbo s, gives with a modest chipping from 2.5 litres at 10 psi boost,
the same flywheel HP and torque, AT 200RPM less.
if the 968 was fitted with individual throttle bodies ,45 mm to each cylinder, the 300 FLYWHEEL H.P n/a
would be quite feasible without any mods , as the cylider head , valves and cams ,with an 11 to 1
c.r. could very well support it.
also true performance sometimes is not measured by figures alone as it depends on the correction factors and accuracy of dyno pulls.Having said that ,in my opinion, the figures are on the conservative side and given the potential of the supercharger and intercooler, i would have expected to see, the wheel BHP/TORQUE hovering around the 300 figure at max rpm .Perhaps massaging the fuelling
and ignition could give that figure.
we have here few 350z ,fitted with similar superchargers and are around the 350-375 flywheel h.p.
they are ultra quick.I dont see why the 968 engine be different.
a food for thought-- a 944 std turbo s, gives with a modest chipping from 2.5 litres at 10 psi boost,
the same flywheel HP and torque, AT 200RPM less.
#195
Rennlist Member
Having said that ,in my opinion, the figures are on the conservative side and given the potential of the supercharger and intercooler, i would have expected to see, the wheel BHP/TORQUE hovering around the 300 figure at max rpm .Perhaps massaging the fuelling
and ignition could give that figure.
we have here few 350z ,fitted with similar superchargers and are around the 350-375 flywheel h.p.
they are ultra quick.I dont see why the 968 engine be different.
a food for thought-- a 944 std turbo s, gives with a modest chipping from 2.5 litres at 10 psi boost,
the same flywheel HP and torque, AT 200RPM less.
and ignition could give that figure.
we have here few 350z ,fitted with similar superchargers and are around the 350-375 flywheel h.p.
they are ultra quick.I dont see why the 968 engine be different.
a food for thought-- a 944 std turbo s, gives with a modest chipping from 2.5 litres at 10 psi boost,
the same flywheel HP and torque, AT 200RPM less.
This setup does not use an intercooler.
Also, when a 951 S is chipped the boost is increased. It does not remain at 10-10.5psi. That is how they make their power.
Regards.
Raj