Jackson Racing SC Kit - C30-94 Rotrex Supercharger High Boost Pulley Release

[CSG Mike]

Originally Posted by B L U E S L A T E

#factoryboostlifeftw



/troll

Took you long enough to get boosted...

[ck-GT86]

Originally Posted by CSG Mike

That depends completely on how sensitive your butt dyno is.



Come to 86CUP on the 12th and you can feel what a JRSC + Ace header + HBP feels like.

Yep, already signed up to run that day given the weather is good to us.

Thanks!


Sent from my iPhone using Tapatalk

[sprintamx]

Just a quick note that I'll be installing the HBP with new tune either today or tomorrow, and will get back with impressions. I've been running the stock equipment for more than a year with a few track days so I should have a good personal comparison of the difference. I'll also be paying attention to the clutch (still on the stock disc) and guess I'll check off each day until I need to upgrade . . .

[sprintamx]

Ok folks, post HB pulley install report . . . $%^_)%$#%_&@##$!!!!!


How's that for a disciplined, scientific, data-driven report!


Install was straightforward as expected; with the right tools and practice the pulley swap really can be done in 5-10 minutes. New tune by Mike at Moto-East. Upgrade fuel pump and injectors from original install with flex-fuel. Currently running on e85 but will likely run 93 oct most of the time.


Power band and progressive power development through the band is essentially the same, there's just much more power everywhere. The power is now neck-snapping! Excellent response throughout the rev range, great roll-on power and an absolute blast (on public roads mind you) from 3500 rpm and beyond. There is just no question that the HB pulley produces much more power with the JRSC set up.


Ambient temps were around 43 F, and I did not experience any clutch slip in my 10 miles of testing. This is likely to become an issue, but I won't take any steps until slippage starts occurring.


With the amount of power now on tap and how much quicker the car is as a result, I think supporting systems such as brakes and suspension are going to become interesting limiting factors. We'll have to see how that plays out.


One immediate practical benefit is gaining clearance between the intake tube and the rotrex pulley because of the smaller diameter. I noticed contact between the standard pulley and the tube, and that the pulley was starting to cut into the clamp and tube. This suggests a need to pay attention to the installation and check on the location regularly. I admit I never looked that closely before. Shame on me.


Ultimately, the pros, cons and potential dangers have been well-discussed. But this is a terrific and very entertaining upgrade if you already have the supporting components or are ready to take the plunge with pump, injectors and an appropriate tune.


Thank you JR and Moto-East!

[Deep Six]

^^^^^^ Made my day!!

[sprintamx]

Originally Posted by Deep Six

^^^^^^ Made my day!!

Mine too!!

[sprintamx]

Here's a daily living update from Capt'n Obvious: power is noticeably down on 93 vs. e85. E85 for the win with this setup.


Daily drivability in all situations is excellent; throttle operation is nice and smooth everywhere. So far I've not experienced any clutch slippage.


Depending on your particular situation of course, I'd say there's no reason not to move into the HB pulley. Even on 93 oct the power increase is quite evident. It doesn't change the character of this Rotrex application, but it does move it up a notch or two. Very nice.

[Alltezza]

Originally Posted by sprintamx

Here's a daily living update from Capt'n Obvious: power is noticeably down on 93 vs. e85. E85 for the win with this setup.


Daily drivability in all situations is excellent; throttle operation is nice and smooth everywhere. So far I've not experienced any clutch slippage.


Depending on your particular situation of course, I'd say there's no reason not to move into the HB pulley. Even on 93 oct the power increase is quite evident. It doesn't change the character of this Rotrex application, but it does move it up a notch or two. Very nice.

You have any plans to get on the dyno?

[sprintamx]

No immediate dyno plans, but I can set up a session pretty easily as I have access to a dyno setup. I just need to get on the ball.

[dj2020]

Originally Posted by Jackson Racing

This is all dependent on how your tuning is setup with your tuner. A lot of guys are doing 91/E85 flexfuel. So yes, in that case you can run the high boost pulley on 91... If your tuner has setup the tuning for it.



I would not blanket trust all tuners to put in the necessary safety that allows a 93+ octane tune to be ran on 91. I also don't trust myself to not go WOT.



In the end, the way your custom tuning setup is between you and your tuner. The safety of the high boost pulley on your car is in your tuner's hands.

I'm thinking of doing this soon and Shawn Church says it's no problem for him doing a 91/e85 flex fuel tune. I'll probably run e85 full time but he says he can make it safe when on 91 for road trips.

He also said something interesting that I never thought of, which is to add a wastegate to the intake tube to limit your boost to 9psi on the HBP. That would be another way of making the HBP safer for 91 octane. I did some research and it looks like a lot of domestic muscle cars on centrifugal SCs will run a higher boost pulley but limit the actual boost at the top end with a wastegate. That way you'll have higher boost levels at a lower rpm. Just thought I'd share and have a discussion.

[Deep Six]

Originally Posted by dj2020

I'm thinking of doing this soon and Shawn Church says it's no problem for him doing a 91/e85 flex fuel tune. I'll probably run e85 full time but he says he can make it safe when on 91 for road trips.

He also said something interesting that I never thought of, which is to add a wastegate to the intake tube to limit your boost to 9psi on the HBP. That would be another way of making the HBP safer for 91 octane. I did some research and it looks like a lot of domestic muscle cars on centrifugal SCs will run a higher boost pulley but limit the actual boost at the top end with a wastegate. That way you'll have higher boost levels at a lower rpm. Just thought I'd share and have a discussion.

I think lowering the rev limiter is much simpler and more effective considering the relationship between RPM's, boost and power with this type of supercharger.

[dj2020]

Originally Posted by Deep Six

I think lowering the rev limiter is much simpler and more effective considering the relationship between RPM's, boost and power with this type of supercharger.

So automatically lower the rev limit based on ethanol content via the tune or can this done with only two maps? On the HBP, happen to know at what rpm do you hit 9psi?

[CSG Mike]

Originally Posted by dj2020

I'm thinking of doing this soon and Shawn Church says it's no problem for him doing a 91/e85 flex fuel tune. I'll probably run e85 full time but he says he can make it safe when on 91 for road trips.

He also said something interesting that I never thought of, which is to add a wastegate to the intake tube to limit your boost to 9psi on the HBP. That would be another way of making the HBP safer for 91 octane. I did some research and it looks like a lot of domestic muscle cars on centrifugal SCs will run a higher boost pulley but limit the actual boost at the top end with a wastegate. That way you'll have higher boost levels at a lower rpm. Just thought I'd share and have a discussion.

This is something CSG and Shawn have experience with; it's been around for years, even on this platform

[CSG Mike]

Originally Posted by Deep Six

I think lowering the rev limiter is much simpler and more effective considering the relationship between RPM's, boost and power with this type of supercharger.

Yes and no. The purpose of the EBC/MBC would be to restrict peak torque, while allowing you to build it sooner.

Theoretically, you could have a turbocharger powerband with supercharger response, with the appropriate setup.