[Rattfylleristen]

Couldn't find any fresh threads on this subject.. If I am wrong, I apologise!

I recently had my SXT 2018 a/t, great car in so many ways! MPG is acceptable and insurence cost is fairly low. I live in Sweden where the fuel tax is extreme, hence the choice of a smaller engine.

I have spent alot of time trying to learn about ways to improve engine power. I was about to spend on a custom tune and CAI, but realised that 15-20hp wont satisfy my needs and is therefore a waste of money.

Supercharging or turbocharging, on the other hand, seems to give more than enough power for a reasonable cost (though illegal) and would make my car one of a kind. So here's a couple of questions for you guys:

Is northern climate bad for converted engines? Swedish temperatures differs from 95 f to -5 f.

Are there any weak links in the engine that needs modification before charging?
Are breaks, transmission etc. up for the increase in power?

Life expectancy of modded vehicle? It's my daily driver, so I'm not taking it to the tracks.

 

[Rockster]

Couldn't find any fresh threads on this subject.. If I am wrong, I apologise!

I recently had my SXT 2018 a/t, great car in so many ways! MPG is acceptable and insurence cost is fairly low. I live in Sweden where the fuel tax is extreme, hence the choice of a smaller engine.

I have spent alot of time trying to learn about ways to improve engine power. I was about to spend on a custom tune and CAI, but realised that 15-20hp wont satisfy my needs and is therefore a waste of money.

Supercharging or turbocharging, on the other hand, seems to give more than enough power for a reasonable cost (though illegal) and would make my car one of a kind. So here's a couple of questions for you guys:

Is northern climate bad for converted engines? Swedish temperatures differs from 95 f to -5 f.

Are there any weak links in the engine that needs modification before charging?
Are breaks, transmission etc. up for the increase in power?

Life expectancy of modded vehicle? It's my daily driver, so I'm not taking it to the tracks.

Your climate is not much different from that of large areas of the USA. There has been no indication of any issues with the supercharged Hellcats from these areas.

If you buy a good supercharger kit, and ensure the tune is correct, as long as you keep the boost down in the 5 to 6psi area the engine should be fine. Should be. The engine is only as strong as its weakest link and by asking it to make more power means you might learn where the weakest link is sooner rather than later.

You will have to keep on top of the engine regarding oil/filter servicing, plugs, air filter, fuel filter. A supercharger changes things and the life of the engine oil and the plugs and filters goes down.

If you just mainly use the extra power to help over come driving at higher elevations -- my 2003 Porsche 996 Turbo and even my 2002 VW Golf TDi -- were fantastic at the higher elevations thanks to the turbocharging -- and I expect my Hellcat would do equally well at higher elevations -- and for faster passing the brakes and transmission and cooling system should be ok.

With a good supercharger kit installed and tuned correctly and by following appropriate servicing schedule the engine longevity may not be affected at least while you own the car. Unless you drive it to the point the wheels fall off you will probably at some point sell or trade in the car. It is possible that during the second owner's time with the car an engine problem could arise. But often the 2nd owner is part of the problem. He might use the car differently skimp on servicing, attempt to further mod the car.

 

[ChallyTatum]

Supercharging can give +100hp gains but it is not cheap...you are looking a +$6000 and possibly more if you are not going to install yourself. If you depend on the warranty then kiss it goodbye and if you do plan on selling the car don't be surprised that the resale value will tank. If you are ok with that then I'd say go for it...otherwise it is more cost effective to trade-in and upgrade. Don't forget that the SXT has a smaller axle, open diff which you probably want to upgrade otherwise it will be a one wheel tire smoker. If you are worried about high IATs then you could also go water/meth injection to keep things cool. Upgrading internal engine components to forged will easily put you in the cost range of trading in for a new Scat. Oh and once supercharged you must run premium.

 

[Rattfylleristen]

Thanks for the answers!

About the weak links; are there known flaws on the pentastar v6?

I expect the cost to be around 8k $ unless other mods are essential. To be in the high 4's would be awsome, but not planning to boost the engine to extreme levels over 500+ hp due to higher risk of damage.

The price between motor options differs alot in Sweden. The SXT costs around 35k, RT 50k and the 6.2 around 70k. With that in consider, I got plenty of room for a possible lower resale value

Would you say that the axle, diff needs to be changed?

And also, is there an MPG increase from supercharging?
Will the emission be affected?

 

[Dennis H]

Kenne Bell the way to go for 5.7. 2.8 litre, twin screw, liquid cooled! Under 10k installed by professional speed shop.

 

[MiHiHemi]

Check out a RIPP supercharger for the V6. I’ve read nothing but good reviews on those things.

 

[ChallyTatum]

Kenne Bell the way to go for 5.7. 2.8 litre, twin screw, liquid cooled! Under 10k installed by professional speed shop.

OP has a V6.

 

[Rockster]

Thanks for the answers!

About the weak links; are there known flaws on the pentastar v6?

I expect the cost to be around 8k $ unless other mods are essential. To be in the high 4's would be awsome, but not planning to boost the engine to extreme levels over 500+ hp due to higher risk of damage.

The price between motor options differs alot in Sweden. The SXT costs around 35k, RT 50k and the 6.2 around 70k. With that in consider, I got plenty of room for a possible lower resale value

Would you say that the axle, diff needs to be changed?

And also, is there an MPG increase from supercharging?
Will the emission be affected?

Initially I would not bother with the rear axle or diff. If you find you are smoking one rear tire all the time that's not necessarily the diff's fault but your fault. I can easily smoke both rear tires of my Hellcat but I don't. I just apply as much throttle as necessary given the situation and yet modulate the amount of throttle I apply to avoid tire spin. Part of driving the car.

(And not only my Hellcat, but the same goes for my MINI JCW. Its 228hp in MID mode can easily smoke the front tires and in SPORT mode definitely smoke them if I'm not cool with the gas pedal.)

There will be no improvement in gas mileage from the supercharger. Just the opposite. The supercharger represents a parasitic load to the engine which means the engine has to work to move the car down the road as desired by the driver and his application of throttle, but the engine also has to spin the supercharger even if the supercharger is not making boost.

Almost certainly the car will not be emissions compliant. However, there might be -- I doubt it but you'll have to research this -- a CARB/EPA (California Air Resources Board/Environmental Protection Agency) compliant supercharger kit that if chosen should have the car/engine still emission compliant but the real test would be a proper check of the car's emissions using a chassis dyno and an exhaust gas analyzer.

 

[ChallyTatum]

Yeah but I thought all SRTs have limited slip (anti-spin) as standard whereas the SXT comes with open diff standard?

 

[Rockster]

Yeah but I thought all SRTs have limited slip (anti-spin) as standard whereas the SXT comes with open diff standard?

Probably. Maybe. I'm not an expert on what models came with what features/options.

But my point is with proper application of the throttle the open diff should not manifest the 1 spinning wheel behavior. I suspect the factory stock SXT engine has sufficient power to spin the rear wheel(s) if the driver is too eager with the throttle.

Even with LSD one or both rear tires can spin if the driver is too eager with the throttle.

The OP indicated no tracking of the car so it is just street use. If I can manage to drive my Hellcat around without spinning one or both rear tires I'm pretty sure the OP can manage the same. If he can't then the diff is not the problem, the driver is the problem.

 

[ChallyTatum]

Probably. Maybe. I'm not an expert on what models came with what features/options.

But my point is with proper application of the throttle the open diff should not manifest the 1 spinning wheel behavior. I suspect the factory stock SXT engine has sufficient power to spin the rear wheel(s) if the driver is too eager with the throttle.

Even with LSD one or both rear tires can spin if the driver is too eager with the throttle.

The OP indicated no tracking of the car so it is just street use. If I can manage to drive my Hellcat around without spinning one or both rear tires I'm pretty sure the OP can manage the same. If he can't then the diff is not the problem, the driver is the problem.

Have you not seen posts of RT guys with auto trans and open diffs complaining of one wheel spin? Even on my limited slip diff I can get it to where only one wheel spins. Yes, you could roll in the throttle to prevent spin but 9/10 guys want both tires to roast when they launch hard...not just one. That is burnout quadratics 101.

 

[Rockster]

Have you not seen posts of RT guys with auto trans and open diffs complaining of one wheel spin? Even on my limited slip diff I can get it to where only one wheel spins. Yes, you could roll in the throttle to prevent spin but 9/10 guys want both tires to roast when they launch hard...not just one. That is burnout quadratics 101.

The OP did not express an interest in tandem roasting of the rear tires. If that ability is important to him then of course he needs to install a proper LSD diff which will hopefully deliver the tire roasting experience he seeks.

 

[trippytro]

Sometimes i wonder it its cheaper to buy an old corvette and mod the hell out of it rather then boost the v6 or rt crazy talk i know haha

 

[ChallyTatum]

Sometimes i wonder it its cheaper to buy an old corvette and mod the hell out of it rather then boost the v6 or rt crazy talk i know haha

Dude...you almost made me swallow my gum!

 

[McCloud]

Thanks for the answers!

About the weak links; are there known flaws on the pentastar v6?

I expect the cost to be around 8k $ unless other mods are essential. To be in the high 4's would be awsome, but not planning to boost the engine to extreme levels over 500+ hp due to higher risk of damage.

The price between motor options differs alot in Sweden. The SXT costs around 35k, RT 50k and the 6.2 around 70k. With that in consider, I got plenty of room for a possible lower resale value

Would you say that the axle, diff needs to be changed?

And also, is there an MPG increase from supercharging?
Will the emission be affected?

To answer your first question.. The Pentastar is aycually a really good engine. The only thing that I think is the weak link is the variable oil pump which has been known to give people problems. If you search the forum a couple of guys here have gone SC route. I do believe they are in the 400+HP and over 300TQ.