Tuning the Chrysler 5.7 Hemi

"Comprehensive guide to tuning the Chrysler 5.7 Hemi engine!"

We often are seeing threads about the best 5.7 Hemi upgrades. So let us look into Chrysler 5.7 Hemi modifications and outline the best modifications on this great engine and point out some common pitfalls along the way.

The Chrysler 5.7 Hemi are popular engines and with the optimum motorsport parts like remaps, turbo improvements and camshafts you will certainly maximize your driving fun.

This pages aim is examine the options for your 5.7 Hemi tuning and highlight the greatest modifications for your car.

The best 5.7 Hemi upgrades on an engine are sensibly the ones that give the best power gain for you spend.

We won't be swayed by popular 5.7 Hemi upgrades, they need to be cost effective.

The cam profile plays a big part in the engines power output so cam upgrades make quite a large difference. The intake & exhaust durations will alter depending on the chosen cam profile, so large power band gains are on offer for cam upgrades.

NB: Fast road cams commonly raise the bhp and torque over the rpm range, you may lose a little low end power but your higher rpm power will be higher.

Race cams, raise the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a car driven daily you need to optimize your power band to your driving style.

I'd never have ever thought a 5.7 Hemi Motorsport camshaft is a pleasure to live with when driving in heavy traffic.

Some 5.7 Hemi engines respond better to less aggressive cam durations check your engine on a rolling road.

The map and fuelling also have an effect on the bhp gains you'll get.

Extending exhaust or intake durations can alter the bhp band and on most engines the exhaust and intake durations do not need to match, although most cams and tuners use matched pairs there are some advantages to extending the intake or exhaust durations.

5.7 Hemi Tuning Stages

Stage 1 5.7 Hemi modifications: Sports exhaust manifold, Panel air filters, Drilled & smoothed airbox, Remaps/piggy back ECU, Intake headers, Fast road camshaft.

Stage 2 5.7 Hemi modifications: Ported and polished head, Fast road cam, induction kit, high flow fuel injectors, Sports catalyst & performance exhaust, fuel pump upgrades.

Stage 3 5.7 Hemi modifications: Competition cam, Crank and Piston upgrades to alter compression, Engine balancing & blueprinting, Adding or Upgrading forced induction (turbo/supercharger), Internal engine upgrades (head flowing porting/bigger valves), Twin charging conversions.

Remaps allows a tuner to fully realize the full potential of all the parts you've done to your 5.7 Hemi.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results usually vary depending on the parts you've fitted and the condition of your engine.

It is vital to any car tuning task to pull more air into the 5.7 Hemi engine

Intake take the air from the filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

Structure and flow rate of the Intake manifold can make a large effect on to fuel atomisation on the 5.7 Hemi.

We often see intake are in dire need of an upgrade, although some makers provide well optimised intake.

Big valve conversions on the 5.7 Hemi, doing a bit of port matching and head flowing will also lift torque, and importantly will allow you to get an improved torque increase on other upgrades.

Turbo upgrades for the 5.7 Hemi

NASP engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your 5.7 Hemi

The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes impressive power gains.

When an engine has a turbocharger upgrades are giving better power gains and most turbo charged engines will have uprated components.

However most engines have weakspots

Discover these limitations and upgrade to more solid crank and pistons to utilize the power.

We've seen drivers spending a a stack of money on turbo upgrades on the 5.7 Hemi only to have the whole thing explode on it's first outing after it's finished.

Larger turbochargers often experience low end lag, and little turbochargers spool up really quickly but don't have the top end power band gains.

Over the last 20 years the range of turbo chargers is always developing and we now see variable vane turbo chargers, where the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo chargers divert the exhaust flow into two channels and flow these at differently angled vanes in the turbo. They also help the scavenging effect of the engine.

It is not unusual that there is a limitation in the air flow sensor MAP/MAF/AFM on the 5.7 Hemi when considerably more air is being drawn into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting bhp at a much lower level.

Adding a supercharger or additional turbo will make large torque gains, although harder to setup. We have this guide to twinchargers if you want to read more.

Uprating 5.7 Hemi fuel injectors

Don't omit to improve the fuelling when you are increasing the performance - it makes the car more thirsty. It makes sense to over specify your injectors flow rate.

The accepted safe increase is to add another 20% when buying an injector, this allows for injector deterioration and gives a bit of spare capacity should the engine require more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

Best 5.7 Hemi performance exhausts

You may need to replace your exhaust if the existing exhaust is actually creating a flow problem.

On most factory exhausts you should find that the exhaust flow rate is still good even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Please dont run with the largest exhaust you can get this will slow up the exhaust flow rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Common exhaust restrictions can be located the filters installed, so adding a faster flowing sports alternative will help avoid this restriction.

Problems and issues to look out for on the 5.7 Hemi

The 5.7 Hemi engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the 5.7 Hemi, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your 5.7 Hemi engine please join us in our friendly forum where you can discuss tuning options in more detail with our 5.7 Hemi owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which mods were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our 5.7 Hemi guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Chrysler. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.