Different power level tunes for supercharger?

Hello all, been lurking awhile and finally signed up a week or so ago. Have done some searching and can't find what I'm looking for. Have an '08 with frpp intake, cai, hot rod cams, gears, and barton short throw. Looking to put a forged shortblock in it and supercharge it, use my heads but have them ported/polished. Will sacrifice a little power due to overlap as I plan to keep the cams, I want it keep that lopey idle. Looking at whipple / edelbrock e-force, but am not ruling out anything right now as still in early stages. I like the old school straight cut gear whine though. Plan is to build a fairly stout runner for drag and drive type events. Car is not a DD, so 750+ at the crank is very manageable as it won't be on the road in the rain (unless it happened during a drag n drive or something similar.) 750 is an arbitrary number, just tossed it out there, but my question is with FI, can you have 2 or 3 tunes for different power levels, and how do you set the boost for those? (Obviously you can tune it however you want to, but I'm unsure how you do the boost side of it for that.) Would you need to have it tuned on three different pulleys and have a tune to load for whichever one you were going to run, or is there an easier way such as a bypass to limit the boost to the PSI the tune is set for? I'm thinking maybe you want just a mild street tune at 450/500 when you don't plan on giving it hell, and maybe a little hotter tune for another 150 or so and then a WFO tune? Just doing some pre-gaming here. Thanks for any feedback.

Lots of information here to read up. One of the better systems out there and should answer most of your questions: https://www.departmentofboost.com/

The tuner could pull timing out of the tune and probably drop you 150-200 HP from peak. You will be on E85 at 750. Boost wouldn't change, low and mid range could be kept strong with timing pulled out progressively.

With a positive displacement blower the only way to change boost levels is by swapping pulleys and tunes. You can control the power curve by manipulating timing so yes you can have different tunes with different power levels. If you have the tuning software (SCT ProRacer or HP tuners) you can use a base tune and adjust timing accordingly whenever you want.

I would not have different tunes/power levels. IMO, too much hassle to keep switching. Assuming you are getting a dyno tune, I would just pull timing back and add some fuel from the max power.
Or, since you are looking at the Eforce, just run their tune and leave it unmolested and be fully emission compliant.
But thats me. lol

When I had the twin screw SC on my car, I had a track tune and a street tune, but boost level was the same.

When I installed my E-force. Lito tuned it for the original 6 pounds of boost. Then I installed a smaller pulley and he tuned it for the 9 pounds. A year later, we tuned it for two different levels of E85. He also supplied a tune for 93 octane if the E85 is not available.. I have all these tunes at my disposal.

The short answer is yes, you can have different tunes for different fuels and levels of boost. I believe the SCT X4 will hold 10 tune files so you could swap tunes in 5 minutes or so.

I appreciate all the replies. I had briefly looked into the ProRacer, will need to do a little more reading. I need to give Lito a shout anyway, my previous tunes (NOT done by Lito) still give me a little rev hang here and there and I'm sure he could tune that out in the first try. Thanks again.

Ryan D said:

I appreciate all the replies. I had briefly looked into the ProRacer, will need to do a little more reading. I need to give Lito a shout anyway, my previous tunes (NOT done by Lito) still give me a little rev hang here and there and I'm sure he could tune that out in the first try. Thanks again.

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I have the ProRacer software. Very powerful tool and not easy to learn, especially if you never tuned an OEM EFI setup before.

The Hellcat has two power keys. One black and one red. Not sure who that works.

I think a good setup for a race week type car would be a paxton 2200. You could pulley it for whatever you want your max boost to be and then add an adjustable wastegate between the blower and intake. That way you could have your max boost race tune but adjust boost at the turn of a knob. Being a stick car, I feel the power delivery of the paxton would be good on the hit as well. Also your available boost would be higher so when wastegated down the boost would hit sooner than a normal centri blower.

Doug Huggard said:

I think a good setup for a race week type car would be a paxton 2200. You could pulley it for whatever you want your max boost to be and then add an adjustable wastegate between the blower and intake. That way you could have your max boost race tune but adjust boost at the turn of a knob. Being a stick car, I feel the power delivery of the paxton would be good on the hit as well. Also your available boost would be higher so when wastegated down the boost would hit sooner than a normal centri blower.

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Thanks for that input, Doug. Have been reading up on wastegate/blowoffs today. Haven’t found a lot of real recent info yet, whole lot of 10 year old stuff when boost controllers for Centris were just becoming a thing, will have to keep digging. Seems like you could set it up and then just adjust timing and maybe fuel table if you were really swinging the boost. I like that idea better than a positive with 3 pulleys to change and tied to exactly that power level for each pulley.

Your idea that you would actually use three or more different power levels might need to be reconsidered. The reason you aren't finding much info is because nobody actually does it. You control your power with your right foot, like everybody else.

You need a street tune and a race tune. If you really want to go crazy then get a 87 octane tune just in case for emergencies, but you will never use it.

With a PD blower you don’t always need to change pulleys to have different power levels. The tune controls timing and fuel and can be adjusted to whatever fuel you want to run.

skwerl said:

You control your power with your right foot, like everybody else.

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It is so amazing that this concept has seemed to have fallen off the map. Back in the day, it's how we learned to control the power levels of the car.

It's funny when someone says they lost traction with gears when they actully gained torque and don't know how to apply it.

I use Lito and have two separate tunes. One is a race tune the other is a 93 octane every day tune. But mine is fairly easy when I open the bottle I switch to the race tune lol. And I’d recommend Lito if you are going to use any kind of remote tuner. My car picked up a good bit after I had him tune my car. But as far as tuning for a supercharger you could have 3 different tunes on 3 different power levels just controlling timing and fuel

I've ran three different vehicles with turbo setups. I could dial in boost with an electric boost controller, and a fuel pressure regulator that used manifold vac/pressure to adjust fuel pressure which would ramp up fuel delivery per pressure. I just got the turbo install on the Shelby, I don't think that scenario will work here. But IDK. I would like to know. One of the said vehicles is a cummins diesel. I can electronically control boost, fueling, and timing. And all on the fly. I would LOVE to be able to do that on a gasoline powered vehicle. I don't think it's actually possible because of the obvious detonation issues.

Guess I'll just keep using the right foot to control power levels. I'm ok with that as long as the trees stay the hell out of the way.