Ok fine, you got us. We have a thing for the LT series of motors, we just do. Sure, the trend is shying away from the LT1 right now for the more popular LS series of engines, but for a good number of you out there, the LT1 is in your ride right now. We are here to put some of the popular simple bolt-ons on the dyno and show once and for all what's worth what in terms of your dollar.
TPIS put together a test mule and operated the dyno while we made changes and recorded the results. First, let's go over what our test motor is and get that out of the way.
The motor is a. Coolant temps were a constant degrees throughout our testing and oil temp stayed right at degrees. For reliability reasons several aftermarket parts were added including Scat rods stock lengthSpeedpro hypereutectic flat top pistons with valve reliefsand the block was zero decked with a Fuel was your standard octane from the local Gas-n-Blow gas station. Our motor was broken in with the standard methods and then given 20 solid pulls to first make sure the motor was ready for our tests, and secondly to create a baseline.
Our baseline pulls netted us a healthy horsepower and lbs-ft of torque completely naked, no accessories or cats. The following tests were progressive, which means that each item was added in order and left on the motor to see the cumulative effect of each part. Each part was given three pulls on the dyno to ensure that it didn't get a bum pull and we could be as accurate as possible.
Most stock engines come with a pretty flimsy set of wires; sure they get the job done, but they don't allow for a greater spark. Upgrading the wires to a thicker, spiral bound core will improve spark plug discharge, thus creating a stronger ignition source and in theory, more power. Our plugs were gapped to 0. While we may have lost a bit of max torque, we did make slight gains in our average power numbers. Sure, the power per dollar cost here may not seem worth it, but if you plan on bigger upgrades in the future, these are a must.
The transitional style ignition system on the LT1 is perhaps the most maligned aspect of the engine, so a few basic upgrades in this area seemed appropriate.
We found an old MSD 6AL ignition box lying around and decided to throw it on the dyno to see what it could do in conjunction with a high-output coil. As with the plugs and wires, a stronger spark will create a more efficient burn of the fuel and air mixture. We decided to test the MSD 6AL and coil to see what effect, if any, a more efficient ignition source could gain us.
In theory, a stronger spark will create more power by fully igniting all of the fuel and air in the combustion chamber.Lt1 upgrades
In most cars, the stock ignition works just fine, however when cylinder pressure increases you'll need a greater source to ignite the mixture.Nothing is so inevitable as change -- that was reality that Chevy fans everywhere had to face when GM began phasing out the old small-block for the updated LT-Series engine. While minor revolutions brewed in the ranks at first, it didn't take long for enthusiasts to embrace the LT and its notable performance updates.
The LT1 was just cleaner, more modern and more efficient.
Right from the factory, the LT and its new heads proceded to set the standard for V-8 performance in the new millennium. The LT1 continues to be an immensely popular engine among hot-rodders, particularly since they're at least as cheap and easy to find as any old small-block. General Motors made no secret of the fact that it left a good bit of power on the table in factory LT1 cars.
Granted, it was a bit harder to find than on older engines, saddled as they were with compromise emissions parts and induction systems. But the potential for power is there without ever cracking the valve covers. On your average LT1, a new set of performance plug wires and plugs will net about 5 horsepower at the wheels, and a cold-air intake should be worth 3 to 5 horsepower. LT1 builders have kind of a standard bolt-on package that's worth a steady 20 horses and 25 foot-pounds on your average F-Body Camaro: A good cold-air intake, cat-back exhaust, electric water pump and underdrive pulleys should take a solid half-second or more off of your quarter-mile time.
A computer tune should net you a further 5 to 10 horsepower after these basic mods.
Dyno Testing 7 Popular LT1 Engine Modifications
If you want a bit more go-power, you'll need to start dealing with your engine's breathing apparatus. Along with your cold-air intake, install a larger MAF sensor housing like those offered by Granatelli. Next up comes a big 58 mm throttle body, which won't fit on the stock intake without enlarging the intake's throttle body bores to match. This is something you can do yourself if you've got a die grinder; simply remove the upper intake, scribe a pair of 58 mm circles on the intake using the aftermarket TB gasket, and start carefully grinding away the excess material to match the TB bores.
If you really want to gain some power, you can send your stock manifold out to be extrude honed to enlarge the passages -- or you can skip all of this and buy an aftermarket manifold.
Combine these intake enhancements with a set of ceramic headers, 1. Some will tell you that if you're serious about performance, you have to start with either LT4 or aftermarket heads -- and that might be true if you have unlimited money and horsepower goals. But the reality is that, while LT4 heads do have larger valves and better port designs, there's plenty of potential in the stock LT1 heads after a bit of porting.
More to the point, LT4 heads require LT4 manifolds, and aftermarket heads are wasted without a new manifold. You can save quite a bit in terms of parts buy-in and ancillary costs by porting your own heads; a gasket-matching job, basic bowl blending, blending the area behind the valve support and smoothing out the short-side turn on the bottom of the port can give you horsepower potential when used with the previous bolt-ons and a somewhat more aggressive cam with intake and exhaust degrees of duration at 0.Question: I just got a '96 Camaro Z28 with a six-speed.
It has 86, miles on it. The guy I bought it from blew the clutch in three different places.
Aside from that, my mechanic says the car is in decent mechanical shape. I want to push the horsepower and torque up a bit to around the range.
It's just a toy to beat up on Mustangs on the weekends. This is my first hot rod. Please help get me started in the right direction. Derek CobbStillwater, OK. Answer: The '96 Camaro 5. The most cost-effective way to get from there to hp is to add 85 hp or so with some bolt-ons and a cam swap, then get another hp with a mild nitrous-oxide kit.
With the stock 1. With the increased airflow through the engine, moving up from the stock 48mm throttle body to the TPIS 52mm throttle body is now a worthwhile upgrade. TPIS tests indicate the factory after-cat exhaust system is sufficiently efficient that it is not cost-effective to upgrade it for this combination.
Finally, the ZEX jettable hp dry nitrous system should bring the engine up to or hp. Custom computer reprogramming is required with so many mods, but TPIS can handle that as well. But you don't have to do everything in one gulp. These mods can be performed in stages as your finances permit. Share on Facebook Share on Twitter.C4 Corvettes are -- by nature -- performance machines precision engineered to offer their drivers the power and handling that real auto enthusiasts demand.
This type of driver may well be interested in customizing their car, and the modifications they are most likely to undertake are those that help the vehicle perform better.
Getting more oomph out of a Corvette can be as simple as changing out one critical part, or it can involve a complete replacement of entire systems, depending on the abilities and desires of the car's owner. C4 Corvette Smooth Intake Coupler. Status: Available. C4 Corvette Cooling Fan Switch. C4 Corvette Air Intake Housing. C4 Corvette Accelerator Cable. C4 C5 Corvette Shock Simulators.
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JLT Oil Separator 3. Performance parts for a car like the Vette is a fairly inclusive category. It covers everything from the air intake to the exhaust system, including things like heat shield and cooling ducts as well as control chips, MAFs and other sensors and even regulators. Upgrade and relocation kits and heavy duty parts to help the Corvette apply its substantial muscle are all easily available performance modifications.
Replacement of the throttle and parts associated with it also fall into this category. Finding the right part for a specific modification can be involved. The component must be manufactured for the specific make and model of car for which it is intended, and in some cases it must be appropriate for a particular option package. To find the parts you need to give your to era Corvette a performance boost, consult with experts like the staff at Corvette Mods, who know the best ways to improve any aspect of the car's functionality.
Try your questions on them via telephone, email or snail mail, and take the first steps toward unleashing your Corvette's true power.See all 20 photos. Way back in our Dec. For its time, it was very advanced, utilizing reverse flow cooling, improved cylinder head design, and sequential fuel injection '93 and later. The LT4 variant improved on the recipe even further with an aggressive cam profile, even better heads, and a lightened valvetrain.
Some of these innovations became standard equipment on the forthcoming LS1. But the LT production run was limited to just six years between andmeaning the number of these engines and the parts available are much fewer than the Gen I small-block and the LS engines as well.
So, based on the limited appeal of this engine, who, if anyone, should care about this article? Plus, some restomod guys are swapping LT1s into older GM muscle cars because they drop right in place of a standard small-block without all the fiddling you have to do to get an LS engine in.
So, here's the deal: We scored an LT1 out of a '94 Caprice police car with the intention of rebuilding it and bolting parts onto it to find out the potential of these engines. Here's how it went down. If our engine looks a little crusty, that's because it is. This is a high-mileage unit out of a 9C1 Caprice that saw hard time first as a police car and then as a taxi cab.
The car had more thanmiles on the clock when we pulled the engine. B-body trivia experts will note that our engine has aluminum heads instead of the factory iron heads.
Before we bought the car, someone installed Edelbrock heads but never ran the car with them. More on that later. We wanted to rebuild this engine as cheaply as possible, reusing as many of the stock components as we could.
During the teardown, we encountered the normal stuck fasteners. One of our flexplate bolts was seized, and the head of the bolt rounded when we tried to unscrew it. Though we tried special sockets, we eventually had to chisel it off. LT1s have a unique, press-on balancer hub that requires a special puller. In a pinch, you can remove it with an air hammer. We were encouraged by the cleanliness of the bores and hoped to get away with just replacing the rings and bearings.
Our hopes were dashed when we checked the thrust flange on our crankshaft. It was worn so badly that the crank was unusable. JMS' Jeff Johnson said this is a common problem. The torque converter loads up the crankshaft in such a way that it causes excessive wear on the thrust bearing and flange. We replaced the crank with a new one from Scat.
Here's a look at the new timing set, which includes the water pump drive gear partially hidden behind the cam gear. JMS handled the assembly, but we had to get it ready to run on the dyno.
To speed up the process, we ordered a wiring harness from Painless Performance rather than try to decipher the factory harness. We were impressed with the Painless harness--all the connections were labeled and the kit included this nice, braided loom. We had the engine wired up in just a couple of hours.
450 Hp For '96 Camaro
Here's the engine wired up and ready to be rolled into the dyno cell. To get an accurate baseline, we decided to run the engine totally stock with the original cam, iron heads, iron exhaust manifolds, and stock catalytic converters.
Unfortunately, our engine wouldn't start. We double-checked all our wiring and even replaced the mass airflow sensor and ECM before finally getting out our factory service manual and tracing the problem to a bad OptiSpark. There was no high-resolution signal from the optical trigger to the ECM, so the plugs wouldn't fire.
Though aftermarket OptiSpark units are available, we wanted one from GM--and good luck finding one in stock at your local Chevrolet dealer.
They're not cheap, either.Aftermarket parts are scarce, the work itself is often maddeningly difficult, and even the most intrepid Corvette tuners may be inclined to treat you like an end-stage Ebola victim. Given these hurdles, we were pleasantly surprised to learn of Trick Flow Specialties' new Fast as Cast GenX LT1 top-end kit, which should be available by the time you read this.
Carrying PN TFS-K, the package generates a claimed horses and lb-ft of torque when installed on a healthy, stock-displacement LT1 engine. If accurate, those figures would put a ''96 Vette's output on par with Bowling Green's latest, and restore much sorely needed performance credibility to the aging Gen II small-block. We'll be installing the full kit on our '96 C4 coupe in the weeks ahead, but for now, let's take a closer look at the package's specifics.
Heads TFS has offered GenX LT1 cylinder heads for a few years now, but the company's first effort employed largish cc intake ports and was intended for stroked or forced-induction engines. The new Fast as Cast version relies on a downsized, cc port that makes it ideally suited to naturally aspirated, stock-cube combinations. As the name implies, these heads are designed to offer superb flow right off the shelf, eliminating the need for costly and time-consuming port work.
TFS' Al Noe explains the concept:. With current manufacturing processes, we can make a cylinder head with tight-tolerance cast ports. Another characteristic that separates these heads from everything else on the market is the orientation of the valves.
Rather than using the standard SBC valve angle of 23 degrees, the Fast as Cast heads employ valves that are rotated to 21 degrees. The second problem is the small, tight chamber with a degree valve angle is not a great design. Rolling the valve angle two degrees allows us to have a small, torquey intake port with an excellent-performing chamber design attached to it. Other notable features include 67cc exhaust runners, 2. In addition to being the prime mover in the Fast as Cast LT1 top-end package, the heads are available separately, as well as in a bare version.
Camshaft Realizing that few Corvette enthusiasts are willing to trade driveability for a few extra high-rpm horsepower, TFS engineers designed the package's camshaft to embody an acceptable compromise between enhanced output and everyday civility.
The specs Like any internal engine modification, the cam does require post-install ECM tuning, preferably performed on a chassis dyno. Given the power increases involved, that seems like a small price to pay. Supporting Hardware To minimize last-minute parts-store shuttling, the kit comes with a complete set of gaskets and all required fasteners. You will need to supply your own timing chain, 1. TFS, meanwhile, sent us a full set of its own 1. Best of all, they come in a natty black-anodized finish that's guaranteed to wow onlookers any time you pull the valve covers.
The final elements of our particular package included pushrods and a TFS pushrod-length checker. Noe recommends verifying this critical measurement prior to installation, as TFS engineers have observed considerable differences in length requirements among various years and versions of LT engines.
To minimize downtime during our install, the company shipped us pushrods in two different lengths.
Modifying an LT1 Corvette - To Top It All Off
After determining which one is right for our combo, we'll simply ship the unused set back to the company. The Bottom Line Offering top-quality engine upgrades is one thing, but doing it affordably is critical when dealing with an older vehicle such as the LT1 C4. While that's not exactly couch-cushion money, it's a bargain compared with the cost of a full-on engine swap or trading up to a newer-model Vette. And besides, with horses corralled under the hood, who needs a C6?
We left off last month's torque converter-installation story with a promise of follow-up testing, so when a cold front blew in recently and dropped temperatures into the low 50s, we headed north, deep into Gator Country, for a day of quarter-miling at Gainesville Raceway. Considering that our '96 coupe had already logged a best pass of This March Performance accessory drive pulley kit fits the LS1, LS2, and LS7 engines, demonstrating the interchangability of the LS engine universe, which has played a significant role in the ever-growing popularity of using LS engines for new car builds and engine swap projects.
While the LS6 emerged from the factory with more power than the LS1, both engines can make the same power with common upgrades. The throttle body diameters are identical. Short-runner intakes are better from rpm and up. Long-runner intakes make more power through the entire range.
These are generally better for cars with stock gearing and a mild converter. F-body cars and the GTO were cable-operated. The Corvettes came with electronic throttle control drive-by-wire. Aftermarket manifolds usually have a four-bolt flange. Custom tuning will be required to properly adjust the fuel and ignition systems. Both respond well to custom machine work:. Just match the other parts you choose to support it. It includes intake, heads, exhaust, torque converter, rear-end gears, etc.
As horsepower increases, so does heat. The excess heat can cause the top piston ring to expand. Under enough heat, it will close the ring gap and the ends will butt together. When they do, a broken ring land can result. This will limit piston-to-valve clearance. Stroker cranks also add extra displacement.
If rods and pistons are replaced, it makes sense to upgrade the crank at the same time. Honing them 0. It has solid main webbing and better rear oil galley passage than the earlier blocks. These blocks have windows cast into the bulkheads for improved breathing. When machining for larger liners, there is less material to support the cylinder which results in a weaker engine block.
With boost, sleeved blocks have been pushed to over 2, hp. These blocks have added bracing, oiling upgrades, and provisions for six head studs per cylinder. Information for this article originally appeared in this Upgrading the Gen.
You should definitely read this. Good Article though, good baseline info.