Modding uprating the GM LS7 engine!

Car tuning tips:LS7 Modifications"

LS7 Modifications Guide

How to modify and upgrade the GM LS7

"Comprehensive guide to performance parts and tuning the GM LS7 engine!"

TorqueCars are frequently seeing threads requesting information on how to improve the LS7 from people wanting to know what are the things tuners are recommending when it comes to LS7 upgrades. So let us look into GM LS7 tuning mods and outline the best modifications on this great engine and point out some potential pitfalls along the way.

In this article we detail the best approach to LS7 tuning and summarise the greatest modifications. GM LS7 make awesome project engines and with carefully picked motorsport mods like remaps, turbo upgrades and camshafts you will noticeably enhance your driving enjoyment.

The optimum LS7 modifications on an engine are typically the ones that give the best gains for your money.

We won't be swayed by popular LS7 modifications, they need to be cost effective.

LS7 induction kits

Improving air intake on the LS7

You need air matched to fuel for an engine to work. If there is too little fuel then it will run lean, if there is little flow of air it runs rich sapping power which risks damage to the LS7. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pushing fuel and air into each cylinder is the primary aim to any engine modification project.

It is common that there is a limit in the air flow sensor AFM/MAF on the LS7 when considerably more air is being drawn into the engine.

When tuning you may well find you need to get an air sensor or flow meter capable of upto 4 bars to cope with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Engine intake manifolds flow the on the suck phase from the air filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

Structure and rate of flow of the Air Intake manifolds can make a large change to fuel atomisation on the LS7.

On popular production engines plenum chambers are crying out for motorsport parts, although a few manufacturers provide decently flowing plenum chambers.

Big valve conversions on the LS7, carrying out port work and head flowing will also increase torque, the fantastic side effect is it will permit a better torque increase on other upgrades.

LS7 performance cam tips.

Each engine responds better to mild cam durations so view each engine as unique.

The map and fuelling also will make differences on the torque gains you'll get.

Longer valve durations can alter the torque 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.

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

NB: Fast road camshafts tend to push up the bhp over the rev range, you might lose a little bottom end bhp but the higher rpm power will be better.

Motorsport and race camshafts, push up the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport camshaft makes it harder when driving around busy urban areas.

You should ideally match your torque band to your driving style so for a road car stick with a shorter duration LS7 camshaft

Stage 1, 2 and 3 mods for the LS7

Stage 1 LS7 parts:

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

Stage 2 LS7 parts:

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

Stage 3 LS7 parts:

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

The LS7 engine blocks are great to work on and we're finding that there is an increase of upgrades and tuning parts around.

A remap helps fully realize the full potential of all the parts you've done to your LS7.

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

You will typically expect to see gains of approximately 20-30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results usually differs on the parts you've applied and the condition of your engine.

Turbo modifications on the LS7

To get a turbo working on a NASP engine there is a lot involved, from lowering compression ratio to improved fuel supply and mapping, so we have found a great guide to helpavoid the common pitfalls or end up with an unfinished project because you were not told what you were getting into by doing this on the 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 excellent power gains.

When a car is turbo charged tuning mods are relatively easy and you will discover turbocharged engines are built with better components.

There are common areas of failure for every engine, with some being extremely strong and some only just able to handle stock power

We recommend you find these limitations and upgrade to higher quality crank and pistons to utilize the power.

There are many tuners spending a loads of money on turbo upgrades on the LS7 only to suffer the humiliation of seeing the LS7 literally blow up when it's been enthusiastically driven.

Larger upgraded turbochargers commonly experience low end lag, and smaller turbochargers spool up much more quickly but do not have the peak rpm torque gains.

Thanks to new tech the market of turbo units is always developing and we are seeing variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo units divert the exhaust gases into 2 channels and direct these at differently profiled vanes in the turbo charger. They also boost the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp and torque gains, although harder to configure. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the LS7

You will need to ensure that the engine is not starved of fuel so must increase the fuelling when you start extending past 20% of a torque hike. It is important to over specify your injector capacity.

As a rule of thumb add 15% to the flow rate when fitting an injector, this takes into account injector deterioration and affords some spare capacity should the engine need more fuel.

Don't forget that different fuel grades will usually require different settings, a high octane fuel will burn more efficiently than lower octane fuel for example. A car will trim fuel supply to keep within the ideal air fuel mix but at the extreme ends you may need to adjust your injector capacity, or the mapping or you'll get flat spots and potential lean or rich fuel issues..

Recommended LS7 performance exhaust upgrades

The only time you should look to boost your exhaust system with an upgraded one is if your exhaust is creating a flow problem.

On most factory exhausts you'll see the flow rate is fine even on modest power gains, but on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Sports exhausts balance the flow of air through the engine.

But if the exhaust pipe is too big, ie: it's over two and a half inches diameter, you will lose a great deal of the flow rate and end up sapping power and torque.

The usual suspects causing problems in your exhaust flow rate come around the filters installed, so adding a better flowing sports alternative will help avoid this restriction.

Decat pipes (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the LS7

Like most engines an LS7, should have few issues if it gets properly serviced and looked after.

We cannot stress enough the need for oil changes with the correct grade of oil on the LS7, failure to do this will exacerbate engine wear, on a tuned LS7 this is more important than ever and close attention should be paid to your maintenance schedule.

If you are interested in learning more or getting impartial tuning advice for your LS7 why not pop over to the forums at TorqueCars where you can chat about LS7 tuning options and read about others projects who may be planning to do similar modifications on their LS7.

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