LS1, LS6, LS2, LT1 & TPI Bolt On Parts Guide - The Best Budget Bolt-Ons For Under $800

Spend A Little-Pick Up A Lot Of E.T./MPH!

John Ryan Apr 1, 2008 0 Comment(s)
0804gmhtp_01_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Full_engine_view 1/36

There are few finer moments than the first time you wind out all the gears in your LS1-, LS6-, LS2-, LT1-, or TPI-powered ride. That glow can last a few weeks-even a couple of months-but fades once you wish you were a little quicker and faster. If you've been a rodder like me for 20 years, you can recall fondly and with some amusement how important it was to weld on some loud mufflers and immediately hit the local haunts. Now that I'm older and also more budget conscious (a few kids will do that to you), researching the best bolt-ons for the money is my number one priority when I start modifying a new car.

Now that the GM EFI scene is over 25 years old, the number of possible bolt-ons is in the hundreds. With the right combination of parts, the LS, LT, and even the TPI-powered cars have the potential to run 13s, 12s, 11s, and even 10s with internally stock engines. For our purposes, let's assume that LS1-, LS6-, and LS2-powered rides make between 290 and 350 rwhp stock, and run low- to mid-13s. Let's also assume that LT1-powered cars crank out around 245 rwhp stock and bust out high 13s at the track. And lastly, TPI cars make around 200 rwhp stock and run low- to mid-14s.

0804gmhtp_02_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Slp_air_box_lid_in_engine 2/36

Let's start discussing the best-bang-for-the-buck mods under $100, $500, and $800 for LS1-, LS6-, LS2-, LT1-, and L98-powered cars. We'll note the price, average power gain, performance, and level of install difficulty. And after you pick up some of these goodies, make sure your ride is in a good state of tune before you start wrenching on it. We advise throwing in a new set of spark plugs, a fuel filter, and checking all your fluids. And of course, take all precautions when jacking up and working under your vehicle-always use jackstands and be safe! J

The author would like to thank Speed Inc., Thunder Racing, Carey's Custom Auto (Kyle Hiznay), and Sikora Precision (Chris Sikora) for their assistance with this article.

Best LS1-LS6-LS2 Bolt-Ons
Under $100

0804gmhtp_03_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Slp_air_box_lid 3/36

Slp Air Box Lid
This bolt-on should take about five minutes, and that includes three minutes to get another cold one. Aftermarket lids don't have the restrictive baffles and resonators of the OEM stuff, and swapping the lid in most cases just requires removing the factory IAT grommet and popping it into the new part.

0804gmhtp_04_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Qtp_exhaust_cutout 4/36

QTP Exhaust Cutout
For about the cost of three pizzas, you can buy an exhaust cutout such as the QTP. By running an open 'dump' you can free up some horses without spending a lot of money on a catback. You will need to have this cutout welded into your stock exhaust, typically in front of the rear axle.

Price: $45
Gain: 12 rwhp
Performance: .1 e.t. reduction, and 1-2 mph gain
Install difficulty: Hard unless you know how to weld


Under $500

0804gmhtp_05_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Slp_off_road_y_pipe 5/36

Slp Off-Road Y-Pipe
Another good bang-for-the-buck would be this Y-pipe, which also eliminates factory catalytic converters. While not emissions legal in most states, this mod is worth some power and will turn heads at the strip.

Price: $299
Gain: 8 rwhp
Performance: .05 e.t. reduction and 1 mph gain
Install difficulty: Medium


0804gmhtp_06_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Asp_undercover_pulleys 6/36

ASP Underdrive Pulleys
Another tried-and-true bolt-on, the underdrive balancer pulleys free up horsepower while still charging up the factory system just fine. While not too hard to install, hitting the final torque spec will take some muscle unless you are using power tools.

Price: $269
Gain: 8 rwhp
Performance: .05 to .1 e.t. reduction and up to 1 mph gain
Install difficulty: Medium


0804gmhtp_07_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Slp_ram_air 7/36

SLP Ram Air
This is one of those mods that shines at the track, though the dyno gains are modest. This induction setup is a killer addition to LS1-powered 4th-gens, and is typically worth nearly a solid tenth and a 1 or more mph gain in the quarter.

Price: $169
Gain: 5 rwhp
Performance: .05 e.t. reduction and 1-2 mph gain
Install difficulty: Easy


0804gmhtp_08_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Hooker_headers 8/36

Hooker Headers
Headers should definitely be in the must-have category for bolt-ons. Gen III mills can pick up gains of 20 rwhp or more from the addition of a good set of long-tube headers. It's hard to beat the bang-for-buck of some uncoated Hooker long-tube headers. Headers can take awhile to install, but most DIY'ers can knock out a set in an afternoon.

0804gmhtp_09_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Nitto_drag_radials 9/36

Nitto Or Mickey Thompson Drag Radials
Traction is the name of the game with drag radials. Air down the tires according to the manufacturer's guidelines, do a good burnout, and enjoy some hookage. Nittos work well for cars that see a lot of daily driver miles, and will last longer. The Mickey Thompson drag radials will wear out a lot faster but will out hook all other drag radials.

0804gmhtp_10_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Random_technology_catback 10/36

Random Technology Catback
Most catbacks will free up some horsepower, and give you a kick-butt sound to boot. While the power gain is mostly from running a lower-restriction muffler, going from 2.75-inch exhaust to 3 or more helps out too. Most DIY'ers can swap out a catback in a couple of hours, or longer if you try to take it out in one piece. The Random Technology catback features the best of both worlds: great price and great gains.

0804gmhtp_11_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Hp_tuners_software_package 11/36

HP Tuners Software Package
Tuning options have come a long way over the last 10 years, and HP Tuners is a great option for the enthusiast who is prepared to do some research on how to best tune their vehicle. Being able to turn on your fans sooner, adjust air/fuel ratios, timing tables, and minimize torque management are just a few of the handy features of tuning software. In most Gen IIIs, horsepower gains are easily 10 rwhp to 20 rwhp depending on what other mods you have done to your car. Take precaution and do research before you start programming, since it's easy to get carried away. Saving a copy of your stock program is the first order of business.

Under $800

0804gmhtp_12_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Nitrous_express_wet_kit_in_engine 12/36

Nitrous Express Wet Kit
Expect 125 rwhp or more from this nitrous kit, which translates into e.t. drops of over a full second. Along with its high fun factor and great bang-for-the-buck comes great responsibility. Follow the manufacturer's instructions closely, as misused nitrous can damage engines and wallets. While there are some handy accessories for nitrous, like window switches and bottle heaters, you can get started fairly cheap.

0804gmhtp_13_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Yank_performance_torque_converter 13/36

Yank Performance Torque Converter
Gen IIIs respond extremely well to aftermarket torque converters, and Yank has a great line of converters that range from mild to wild. The Yank Pro Thruster 4000 is a great strip converter, and is usually good for five tenths or more drop in e.t. at the track. If you can put up with a loose converter, think 4,400, but if you have an extensive commute or want to maintain somewhat decent gas mileage, focus on a 3,500 stall, which will still yield a three-tenths drop in e.t. Converter installs are very time intensive for the first-timer, so budget a day or drop it off.

0804gmhtp_14_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Meziere_electric_water_pump 14/36

Meziere Electric Water Pump
As efficient as late-model GM engines are, electric water pumps are still worth over a tenth at the track and some measurable ponies on the dyno. Veteran DIY'ers will typically wire the pump to keyed ignition since most of us would probably forget to turn the pump on until after the car has overheated. Some diehard rodders prefer to have the pump triggered manually so that they can cool the engine down after making a pass without running the engine. While not a hard install, the wiring takes some skill.

Best LT1 Bolt-Ons
Under $100

0804gmhtp_16_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Qtp_exhaust_cut_out 15/36

QTP Exhaust Cutout
For less than 50 bones, you can buy an exhaust cutout such as the QTP. By running an open 'dump' you can free up some horses without spending a lot of money on a catback. You will need to have this cutout welded into your stock exhaust, typically in front of the rear axle. Don't wear your Sunday best when opening it up, since you have to undo a few wing nuts underneath the car.

0804gmhtp_17_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide March_underdrive_pulley 16/36

March Underdrive Pulley
Another tried-and-true bolt-on, underdrive balancer pulleys free up horsepower while still charging the electrical system. While not too hard to install, hitting the final torque spec will take some muscle.

Under $500

0804gmhtp_18_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide K_n_cold_air_induction 17/36

K&N Cold-Air Induction
While there are several notable air-induction manufacturers for the LT1, K&N is among the most popular and was frequently the best priced in our research. Expect between a one and two tenths drop in e.t., and a 47-percent increase in airflow. Installation is straightforward and should take about 10 minutes.

0804gmhtp_19_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Hooker_catback 18/36

Hooker Catback
Most catbacks will help you net about 15 rwhp, and give you a kick-butt sound to boot. While the power gain is mostly from running a lower-restriction muffler, going from 2.75-inch exhaust to 3 or more helps out too. Most DIY'ers can swap out a catback in a couple of hours, or longer if you try to take it out in one piece. The Hooker catback is the best of both worlds-great price and great gains.

0804gmhtp_20_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Crane_1_6_roller_rockers_7_rwhp 19/36

Crane 1.6 Roller Rockers
Swapping out the stock, stamped, 1.5 OEM rockers for a set of Crane self-aligning rocker arms is done for several reasons, however, the gain of 5-7 rwhp is why LT1 enthusiasts routinely suggest this swap as one of the must-dos. The other top reason is for increased valvetrain stability when turning the engines at higher rpm.

0804gmhtp_21_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Meziere_electric_water_pump 20/36

Meziere Electric Water Pump
Even though stock water pumps are efficient, electric water pumps are still worth over a tenth at the track and some measurable ponies on the dyno. Veteran DIY'ers will typically wire the pump to keyed ignition since most of us would probably forget to turn the pump on until after the car has overheated. Or, if you prefer, wire it to have the pump triggered manually to cool the engine down after making a pass without running the engine. While not a hard install, the wiring takes some skill.

0804gmhtp_22_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Mickey_thompson_drag_radials_400 21/36

Nitto Or Mickey Thompson Drag Radials
Traction is the name of the game with drag radials. Air down the tires according to the manufacturer's guidelines, do a good burnout, and have your head snapped back. Nittos work well for cars that see a lot of daily driver miles, and will last longer. The Mickey Thompson drag radials will wear out a lot faster but will out hook all other drag radials.

Under $800

0804gmhtp_24_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Precision_industries_torque_converter 22/36

Precision Industries Torque Converter
Look no further than Precision Industries' Vigilante line of torque converters for the LT1 engine. Their single-disc lock-up converters have helped propel many a bolt-on LT1 car into the 12s. Many LT1 enthusiasts recommend running a 3,200 stall with internally stock engines. While it's on the more difficult end of the scale for the DIY'er, this is a mod that can be done in an afternoon-or in about two hours by a professional.

0804gmhtp_23_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Nitrous_express_wet_kit 23/36

Nitrous Express Wet Kit
Expect 125 rwhp or more from this nitrous kit, which translates into e.t. drops of close to a full second. Along with its high fun factor and great bang-for-the-buck comes great responsibility. Follow the manufacturer's instructions closely, as a poorly installed nitrous system can damage engines, your wallet, and your eardrums when the old lady hears about it. While there are some handy accessories for nitrous, like window switches and bottle heaters, you can get started fairly cheap.

Best TPI Bolt-Ons
Under $100

0804gmhtp_26_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Adjustable_fuel_pressure_regulator 24/36

Adjustable Fuel Pressure Regulator
Crane's adjustable fuel pressure regulator provides rodders with the ability to tweak the fuel curve, which can not only help increase horsepower, but even improve fuel economy. It's not unusual for most DIY'ers to bump up their base fuel pressure 5 psi once they have added most of the bolt-ons mentioned in this article.

0804gmhtp_27_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide March_underdrive_pulleys 25/36

March Underdrive Pulleys
March's underdrive balancer pulleys free up horsepower while still charging up the electronics. An easy install, save for the final torquing.

0804gmhtp_28_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Thunder_racing_air_foil 26/36

Thunder Racing Air Foil
Aftermarket air foils smooth out the air path by eliminating the dead space between the throttle blades. While hard to measure, this is one of those supporting modifications that's hard to pass up and only helps as your car makes more power.

Under $500

0804gmhtp_29_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Slp_cold_air_industion_components 27/36

SLP Cold-Air Induction
Look no further than SLP for a great cold-air system. SLP designed this system for maximum performance by creating a more direct air path, and including a better-breathing, cotton-gauze air filter.

0804gmhtp_30_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Hooker_super_comp_long_tube_headers 28/36

Hooker Super Comp Long-Tube Headers
While there are many options for the tuned port injection crowd, the Hooker long-tube headers provide the best overall horsepower gains as well as a substantial increase in torque. These headers are available coated and uncoated-the uncoated ones will cost less than $200.

0804gmhtp_31_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Hooker_cat_back_components 29/36

Hooker Catback
Hooker exhaust systems are 100% mandrel bent and built to their high standards. This system utilizes their Aero Chamber mufflers, which provide major horsepower gains and a deep, powerful sound. This system gets the nod based on the gains and best average price.

0804gmhtp_32_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Msd_ignition 30/36

MSD Ignition
While more of a supporting cast member in this ensemble, the venerable MSD ignition system increases spark, improves combustion, and improves throttle response for most TPI combinations. While spending upwards of $300 on an ignition box and a coil does not seem like a direct value, these mods are typically needed to support the TPI rodder's quest for e.t.'s in the 11s and 12s.

0804gmhtp_33_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Crane_1_6_roller_rockers_5_rwhp 31/36

Crane 1.6 Roller Rockers
Swapping out the stock, stamped, 1.5 OEM rockers for a set of Crane self-aligning rocker arms is done for several reasons, though the gain of 5-7 rwhp is why TPI enthusiasts routinely suggest this swap as one of the must-dos. Stock rockers are now 20 years old and were never designed for higher performance levels.

0804gmhtp_34_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Nitto_mickey_thompson_drag_radials 32/36

Nitto Or Mickey Thompson Drag Radials
Traction is the name of the game with drag radials. Air down the tires according to the manufacturer's guidelines, do a good burnout, and enjoy serious hookage. Nittos work well for cars that see a lot of daily driver miles, and will last longer. The Mickey Thompson drag radials will wear out a lot faster but will win a Pepsi challenge on which drag radial hooks hardest.

Under $800

0804gmhtp_35_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Holly_stealth_ram_intake_mnifold 33/36

Holley Stealth Ram Intake Manifold
While the stock TPI intake manifold is out of breath around 4,500, the Holley Stealth Ram intake manifold can help an internally stock engine pull clean to 6,000 rpm. Gains of 20 rwhp or more make this a must-do mod. You'll need a set of Holley's fuel rails to complete this mod, and a set of new valvesprings are also recommended.

0804gmhtp_36_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Nitrous_oxide_systems_wet_kit 34/36

Nitrous Oxide Systems Wet Kit
A long time favorite of the TPI crowd, this nitrous setup features a spray bar plate that mounts between the throttle body and the plenum. Gains are around 100 rwhp, with e.t. reductions of close to a second. As said before, nitrous is a demanding mistress and must always get a lot of attention. Make sure to run colder spark plugs and have a dependable fuel system.

0804gmhtp_37_z Ls1_ls6_ls2_lt1_tpi_bolt_on_parts_guide Precision_industries_torque_converter_components 35/36

Precision Industries Torque Converter
Precision Industries' Vigilante line of torque converters has your TPI engine covered. Their single-disc lock-up converters have helped propel many a bolt-on TPI car into the 13s and 12s. Most TPI experts suggest a 2,800 stall speed for an internally stock TPI. While on the more difficult end of the scale for the DIY'er, this is a mod that can be done in an afternoon-or in about two hours by a professional.

MORE PHOTOS

VIEW FULL GALLERY

COMMENTS

TO TOP