Jackson Racing C38 vs C30 with stock pulleys
 

I’m ready to go with JRSC, question now is C30 or C38. I’m fully aware what the differences are between the two. For $100 more I’d be dumb not to pick the C38 with higher power potentials down the road. However, I do plan on keeping stock pulleys and running on 91 gas for the foreseeable future.

My main concern with getting C38 now is Jackson Racing does not have CARB tune for 2017+ model yet, therefore I’d have to stick with my Tomei EL header and go with Delicious Tuning Flash and Go tune. Has anyone here with C38 , stock pulleys and a non-factory tune? How do you like it?

Also I’ve heard C30 does provide more power down low whereas C38 has more room for power in upper RPMs, is the difference quite big and obvious down low?

Unless you plan on a built motor and the RS pulley upgrade, the potential of the larger supercharger is largely meaningless.

It's like getting a giant turbocharger "for the potential", knowing you realistically would probably never use it.

Do you see yourself building an engine in the next 2 years or so?

No I do not planning on rebuild motor. However, I do planning on getting ACE header, HBP and flex fuel kit down the road. Can stock motor handle C38’s potential with those supporting mods?

Can it? Yes. How long? Luck of the draw.

Again, unless you're getting the RS pulley, you are not exploiting the potential of the C38.

What’s RS pulley?

The "super high boost" pulley a C30 cannot use.

Now what are the cons of getting C38 over C30 if I do not planning on exploring the full potentials of C38? Other than the $100 premium of course.

I’m gonna rock the boat and say no. I was on c30 with standard pulley, ace type a350, and flexfuel, and a rod broke at probably 2500rpm. It was massive catastrophic damage. Only one head blank could be salvaged. I didn’t routinely redline the engine. The rods and apparently rod bearings are the weak links in this engine. My rod bearings were not damaged at all.

What's the whp potential of a C30? I'm currently building a motor with stronger rods for insurance if I decide to go boosted later down the road (maybe next year). I'd only be looking for up to 300whp. C30 handle that with ease?

If you can do flex fuel, you’ll exceed that. It’ll be less by some margin if you do 93 octane and a good header. I was a spec over 280 with that setup on 93 octane and ace header

What or who was the tuner?

Maybe weight. Maybe less efficiency.

Delicious on ecutek

Dang, seems to be pretty hit or miss for some people. I have a friend who has the high boost pulley on a C38 and flexfuel who's been dailying it for months with no problems!! I can't trust off the shelf tunes haha but Delicious makes good stuff.

If he pushes it at all, he will be hit.

I asked just to ask but I wasn’t implying that the tune was the fault in asking.

Most engine failures I have seen (if not all) are with flexfuel and/or HBP. I am sticking with C30 and CARB tune for the stock engine.

what is the efficiencies that the c30 and c38 run in? i dont have the maps

Here
http://www.rotrex.com/Home/Technolog...Technical_Data

now i just have to reremember how to do these graphs

I didn’t read that into it at all. Just saying that the rods are the weak link. I don’t blame the tune quality at all. Everything within my engine was sound- except for the carnage caused by a rod that broke at the wrist pin that then turned into a weed eater inside an aluminum block. Savage!

This is the kind of thing that makes me think twice before going FI - any pics of the end results?

Honestly I'm torn. I own this car outright, love it, but part of me still wants more. So I've been doing the "should I go buy that Cayman S" or "lets go bananas on the ole berz" back and fourth.

My latest swing is ack to keep this thing and make it really fun for less than the cost of a new Porsche. That said I don't PLAN on building the motor.

If i do go FI I'll keep the smaller blower, and if I do decide to get the big guy I'll just build the engine.

Any stats on this forum for FI builds gone boom and at what boost/use?

Need to do some searching.

The risk is reasonable with reasonable power gains.

Remember, Edelbrock is so confident that they are willing to put a powertrain warranty on a drivetrain they did not design, when using their supercharger kit and tune, provided you meet their other requirements.

Unfortunately, in your case, your car has too many miles.

Whether you got JRSC, or another supercharger, CARB tunes will generally add minimal risk.

I've yet to ever see a ***SINGLE*** Edelbrock powertrain warranty claim.

I’m making 385whp on c30

Here's what I approximated when I looked at them a few months ago. I forget which pulley I was looking at, but it might have been the high boost pulley with a redline lowered to 7000 rpm. Starting point I think was 4000 rpm. 93 octane.

didn't expect it being that close with that much room on the c30

Keep in mind that I can't say for sure if that is the standard pulley or the high boost pulley. I investigated both, but I'm not sure which one I was looking at when the file was saved. I also used a lowered redline of 7000 rpm as my own subjective safety factor, and that is less taxing on the blower.

To me those graphs area bit misleading. With different scales on a axis a visual comparison is not possible. I'm not sure how to make use of the graphs though so maybe it doesn't matter but for someone just glancing at them to compare they look fairly identical when there are significant differences between them.

Just a thought. I may be completely out of my league and need to go back to my corner and shut up lol.

The difference in scales isn't relevant imo. Essentially, the way to use those graphs is to estimate your horsepower at X psi, and see how the pressure ratio lines up with the efficiency of the blower. In my examples, I assumed a flywheel horsepower of ~320 hp (I used an Ace header in my analysis), and then making some more estimates I assumed the FA20 is flowing between 28-30 lb/hr of air at 7000 rpm to make ~320 boosted hp on the X-axis. Using boost logs, I then estimated the pressure ratio on the Y-axis, and plotted them to see where they fall on the efficiency curves of each blower. It's not an exact science by any means, but that's the process.

C30 with high boost pulley, injectors/feul pump, full exhaust sound like a good setup?
I have the c30 with a catback. Everything else oem.
I'm thinking about adding the hbp/injectors/pump and heads/overpipe/frontpipe. I'm wondering if I can leave it at that or if other supporting mods have to be done

Have you seen the post #8 in this thread? I wouldn't use HBP without at least upgrading the connecting rods and bearings.

That what u did when u went hbp?

I still have the stock pulley with CARB tune.