Jackson Racing Supercharger Owners Thread

[86 South Africa]

Originally Posted by gtengr

When there are dramatic differences in weight, velocity becomes a relevant factor in the power to weight ratio because pure horsepower is more important when the wind resistance begins to exceed the rolling resistance. Assuming 14.4 lbs/hp in a 2800 lb car and a 3800 lb car, that gives 200 hp and 264 hp, respectively. If we assume both cars have roughly equal aero, and 100 mph is sapping 50 hp from each, then the 2800 lb car now has a power to weight ratio of 18.7 lbs/hp and the 3800 lb car is at 17.8 lbs/hp based on power available to accelerate the car. As velocity increases, so would the gap in the power to weight ratio.

I think you work for Lotus... :-)

[Irace86.2.0]

Originally Posted by CSG Mike

Jerk is the derivative of acceleration. It's not another term for force.

Force over time is acceleration. Change in force over time is Jerk. Force applied over time is impulse, aka the integral of the force over time.

I think you meant the change in velocity over time is acceleration--not force.

So using these physics terms I would say that the JRSC has more jerk or change in force such that the forces build over the rev range, and as such is the case, start off with relatively mild forces. Other kits or cars with flat torque curves yet with the same peak torque as the JRSC will not feel jerk over the rpms; they will feel a large constant impulse over the rev range that the JRSC will only feel at the end of its rev range.

Right?

[PR138]

Originally Posted by Irace86.2.0

Im sure this makes for an interesting and maybe unpredictable driving experience. Yes more rpms means more torque, but without a flat torque curve it may be hard predicting how much force the driver will be getting.

Having not driven a car with a centrifugal sc since my old 93 Mustang with a Paxton, I would have thought the gradual buildup of torque makes the car easier to handle. I'd think that a car with an immediate burst of torque is what would make you have to be judicious with throttle.

Has anyone here driven different FI setups on track or autocross? Can you comment on what's easier to handle?

[Irace86.2.0]

Originally Posted by PR138

Having not driven a car with a centrifugal sc since my old 93 Mustang with a Paxton, I would have thought the gradual buildup of torque makes the car easier to handle. I'd think that a car with an immediate burst of torque is what would make you have to be judicious with throttle.

Has anyone here driven different FI setups on track or autocross? Can you comment on what's easier to handle?

Im pretty sure that any torque curve can be learned with enough time. A driver can learn where torque builds or drops. The driver can learn to avoid torque dips with proper shifts or to modulate the throttle if there is a dynamic increase in torque. With all that said, a flat torque curve would be the most predictable; if the driver drops a gear or their foot then they know what to expect.

[CSG Mike]

Originally Posted by PR138

Having not driven a car with a centrifugal sc since my old 93 Mustang with a Paxton, I would have thought the gradual buildup of torque makes the car easier to handle. I'd think that a car with an immediate burst of torque is what would make you have to be judicious with throttle.

Has anyone here driven different FI setups on track or autocross? Can you comment on what's easier to handle?

It really comes down to how well the throttle is mapped. A powerful engine can be easily controlled with a linear throttle map.

[amcp1]

Anyone get the p0171 bank too lean code? System has been running great for the last 1000 miles when I received this code coming home tonight. Google comes back with all sorts of troubleshooting. I disconnected the maf, cleaned it and reinstalled as a first step.

[amcp1]

Following up, I cleared the cel today and went for a short drive. Looks like it shows up again in the Ecutek dtc tool. I sent an email to tech@jrsupport with the log from that drive. Will be checking engine bay out after work, see if I can find something amiss.

[mrg666]

Originally Posted by amcp1

Following up, I cleared the cel today and went for a short drive. Looks like it shows up again in the Ecutek dtc tool. I sent an email to tech@jrsupport with the log from that drive. Will be checking engine bay out after work, see if I can find something amiss.

What tune are you using? Is this a stock engine with JRSC? What other modifications do you have?

Lean code problem could be due to oxygen sensors or fuel injectors or fuel pump or your MAF although you had cleaned it. To me, it doesn't look like JRSC has a problem as the CEL is related to fuel supply not air. I would clean MAF and air filter again. Then, I would check the oxygen sensors. Maybe running an injector cleaner could help.

[amcp1]

Stock FRS with the C-30 JR Carb tune. No other motor mods.

[mrg666]

Originally Posted by amcp1

Stock FRS with the C-30 JR Carb tune. No other motor mods.

I have the same configuration and I was checking the possible causes. If you search the forum with keywords p0171, brz or frs, you will find the other possible causes. One P0171 CEL was fixed just by cleaning the MAF sensor. The other one was a vacuum leak under the intake manifold (a common problem with FI and there is a sticky in this forum). Search and go through the checks and clean ups, I am sure you will fix the problem. Good luck!

[amcp1]

Matter of fact I just cleaned the maf again and did the hoses under the manifold. Clamped those and went for another spin. Same code reappeared. Noticed at idle it stumbled. Rpms drop then surged up to keep motor alive. I cant hear any leaks from the engine bay. Short term fuel trims were -24 to +32 during the drive. Huge swing

To clarify, I clamped the 2 hoses that go to the evap sensor and 1 hose that goes from sensor to the intake manifold.

[keithr]

Has anyone replaced the air filter? It appears to be a custom part made for Jackson, but I would imagine any filter with the same approximate dimensions, sufficient surface area, and correct size outlet would work. I hate cleaning these K&N filters, so I usually keep at least two so I can just change it and then clean the other at my leisure. Has anyone found a fitting/compatible filter? I haven't taken mine off to measure it, hoping someone already has the info.

[CSG Mike]

Originally Posted by keithr

Has anyone replaced the air filter? It appears to be a custom part made for Jackson, but I would imagine any filter with the same approximate dimensions, sufficient surface area, and correct size outlet would work. I hate cleaning these K&N filters, so I usually keep at least two so I can just change it and then clean the other at my leisure. Has anyone found a fitting/compatible filter? I haven't taken mine off to measure it, hoping someone already has the info.

Extra filters can be ordered from @CounterSpace Garage or directly from @Jackson Racing.

There is a non-JR branded version of the filter availabe, and you'll also want to buy a K&N cleaning kit.

[new2subaru]

Is there a dry filter replacement?