Tuning the GM LS7

"Building the best modified GM LS7 engine!"

Carref prides itself on providing the latest tips and guides to your modification project.

The GM LS7 have loads of potential and with the optimum modified enhancements like remaps, turbo kits and camshafts you will definitely enhance your driving enjoyment.

This pages aim is provide a guide to LS7 tuning and show the optimum modifications.

We rely on our visitors to pass on tips and tell us about their projects and what worked on their car, and this article is the culmination of the feedback we have received. First let us look at the history and specs of this engine and then consider which tuning modifications work best on it.

History of the Engine

• 505 bhp  at 6300 rpm  470 lbft at 4800 rpm

Tuning the GM LS7 and best LS7 performance parts.

What are the most effective LS7 upgrades

Just because particular modifications are appear in lots of LS7 projects it doesn't mean you should fit it, we will concentrate) on the top modifications that will give your LS7 the best power gain for you money.

Altering your LS7 camshaft will make a dramatic difference to the engine power band. Choosing a higher performance camshaft profile raises the power band accordingly.

Fast road camshafts usually raise the torque throughout the rev band, you may sacrifice a little low down power but the top end will improve.

Motorsport and race camshafts, raise the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Competition cam is not great in heavy traffic.

You should ideally match your bhp range to your preferences so for a car used daily stick with a mild fast road LS7 cam

Each engine responds better to more or less aggressive camshaft durations so set your engine up on a rolling road.

The map and fuelling also have a large bearing on the bhp gains you'll get.

A longer valve duration 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.

Modifying to STAGE 1:

Remaps/piggy back ECU, Intake headers, Fast road camshaft, Panel air filters, Drilled & smoothed airbox, Sports exhaust manifold.

Modifying to Stage 2:

high flow fuel injectors, fuel pump upgrades, Sports catalyst & performance exhaust, Ported and polished head, induction kit, Fast road cam.

Modifying to Stage 3:

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

Remaps helps unlock the full potential of all the parts you've done to your LS7.

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

It is the main goal to any performance tuning task to feed more air into your LS7

Intake manifold take the air during the suck phase from the air cleaner and allow it to be drawn into the engine and mixed with fuel.

Design and flow rate of the Intake manifold can make a substantial change to fuel delivery on the LS7.

Commonly we find the intake headers are needing aftermarket tuning parts, although some manufacturers provide fairly well optimized intake headers.

Larger LS7 valves, getting 3 or 5 angle valve jobs and porting and head flowing will also lift bhp and torque, & importantly will afford you an improved bhp and torque increase on other tuning mods.

Which turbo upgrades are best?

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 LS7

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

If the engine is fitted with a turbo modifications are going to net you a larger power gain and turbocharged engines already contain strengthened components.

However you will find an engines will need better parts at higher power limits

It is important to find these limitations and fit better quality crank and pistons to handle the power.

We've seen mechanics spending a loads on turbo upgrades on the LS7 only to suffer the humiliation of seeing the motor catastrophically fail soon after it's been enthusiastically driven.

Large upgraded turbo chargers tend to suffer no power at low rpm, and smaller turbo chargers spool up more quickly but don't have the high rpm engines power gains.

Thanks to progress the range of turbo chargers is always increasing and we are seeing variable vane turbo chargers, where the vane profile is altered according to speed to lower lag and increase top end bhp.

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

It is common that there is a restriction in the air flow sensor (AFM/MAF/MAP) on the LS7 when a lot more air is being drawn into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to configure. We have this in depth look at twinchargers if you want to read more.

Fuelling

Don't dismiss the need pay attention to the fuel system when you are increasing the performance - it makes the car more thirsty. We would recommend you to be generous with your injectors flow rate.

The accepted safe increase is to add another 20% when specifying an injector, this takes into account injector deterioration and gives a little 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.

Choosing the right performance exhaust

One of the most common mistakes and problems we see in tuning projects is usually down to the exhaust, or rather a poorly chosen exhaust for your engine.

Only look to improve your exhaust if your exhaust is creating a restriction in flow.

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

Sports exhausts can help balance the flow of air through the engine.

But if your exhaust is too big, ie: it's over 2.5 inches bore, you will lose a lot of your flow rate and end up sapping power and torque.

Usual exhaust restrictions are traced to the catalyst and filters installed, so adding a freer flowing sports alternative will help avoid this restriction.

Weak spots, Issues & problem areas on the LS7

The LS7 engines are generally reliable and solid as long as they are regularly serviced and maintained.

Regular oil changes are vital on the LS7, especially when tuned and will help extend the life and reliability of the engine.

For more information on Tuning your LS7 engine please join us in our friendly forum where you can discuss tuning options in more detail with our LS7 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We love to hear what our visitors have got up to and which parts work best for them on each model of car. Comments are used to improve the accuracy of these LS7 articles which are continually updated.

This article was written by Waynne Smith on TorqueCars, and I appreciate your feedback and suggestions. This entry was filed under GM. You can leave a response below or join TorqueCars forum to discuss this article and car modification in detail with our members.

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