Downey Off-Road Exhaust Headers

We figured the best way to be in the Header business was to learn everything we could about Headers on Toyota engines. Downey spent large amounts of time and money testing Header theories on Toyota engines during 1985. Before 1985 we had sold many 1

tubing Headers with a 2

stinger pipe that reduced down to 1

. Our Dyno testing verified that the restriction was necessary to prevent a drop in H.P. as the RPM. increased. In 1985, we believed that a Tri-Y Header might give good performance at higher RPM’s, so we purchased a 1

Tri-Y Header for testing purposes. We also believed that a smaller diameter tubing would create drastically improved low RPM performance, so we manufactured a 1

tubing 4 into 1 and Tri Y Header for testing purposes.

This test was conducted on a 1985 EFI 4 Runner. It confirmed our theories and proved the following:

The 1 Tri-Y does very little at lower RPM’s but gives very good performance at higher RPM’s with a 7 H.P. gain at 4500 RPM (rear tire).
The smaller tube Headers are extremely punchy in the lower RPM range, as we expected, giving a 7 H.P. gain at 2500 RPM (rear tire).
Smaller diameter tubing will produce lower RPM performance where you want it (2500 RPM as opposed to 4500 RPM).
A Tri-Y design does NOT out-perform a 4 into 1 design on a Toyota engine. (both gave a 7H.P. gain)

This test was conducted to determine if a small tube Tri-Y might be the best design. We manufactured a 1 Tri-Y for testing purposes. The small tube Tri-Y results were identical to the small tube 4 into 1.

This test proved the following:

Tube diameter is important, tube routing or matching is not (at least on Toyotas)
There is no reason to offer a Tri-Y Header. Larger diameter tubing (1) is of little use on your Toyota, and even with 1 tubing a Tri-Y will not out perform a 4 into 1 Header.

Each Header was fitted with a strategically located O2 sensor. The sensor was mounted into two opposite firing tubes for a constant sampling of gases. Painstaking pyrometer tests were conducted daily to determine where the O2 sensor should be mounted in the Headers to equal the same environment the sensor was designed to operate in. The strategically located O2 sensor allowed the Toyota’s onboard computer to correct and supply the engine with the proper air/fuel mixture.

There is NO other 4 Cyl. Header on the market that can pass this test!

WARNING – Do not lift up on exhaust system when mounting to hangers. Length of exhaust system will act as a long pry bar to lift engine weight off motor mounts, then exhaust header will crack at it’s welds.
No Warranty !!!

WARNING – Do not wrap Header with insulation wrapping or heat shields. Wrappings hold-in heat which quickly melts or cracks Header (we’re not sure who invented wrapping for what purpose??)
No Warranty!!!

17410-79	79-80 50 State Header, Chrome	$427.47
17410-79C	79-80 50 State Header, Ceramic	$474.15
17410-81	81-87 49 State Header, Chrome 4WD Header	$350.00
17410-81C	81-87 49 State Header, Ceramic 4WD Header	$395.00
17410-88	88-95 49 State Header, Chrome 4WD Header	$350.00
17410-88C	88-95 49 State Header, Ceramic 4WD Header	$395.00

17412-81	81-87 49 State Header, Chrome 2WD Header	$350.00
17412-81C	81-87 49 State Header, Ceramic 2WD Header	$395.00
17412-88	88-95 49 State Header, Chrome 2 WD Header	$350.00
17412-88C	88-95 49 State headers, Ceramic 2WD Header	$395.00

17410-81S	81-84 California Only, Chrome, 4WD Header	$427.47
17410-81SC	81-84 California Only, Ceramic, 4WD Header	$474.15
17412-81S	81-84 California Only, Chrome, 2WD Header	$427.47
17412-81SC	81-84 California Only, Ceramic, 2WD Header	$474.15

NOTE - 85-95 California vehicles use 49 State Header

7410-95	95-99 4WD with 2.7 engine, Chrome	$350.00
17410-95C	95-99 4WD with 2.7 engine, Ceramic	$395.00
17412-95	95-99 2WD Tacoma with 2.7 engine, Chrome	$350.00
17412-95C	95-99 2WD Tacoma with 2.7 engines, Ceramic	$395.00
17412	99-02 2WD Tacoma with 2.4 engine (no tail pipe), Chrome	$280.00
17412-C	99-02 2WD Tacoma with 2.4 engine (no tail pipe), Ceramic	$325.00
17412-4R	99-02 2WD 4 Runner with down pipe and 2½” Cat	$455.00
17412-4RC	99-02 2WD 4 Runner with down pipe and 2½” Cat	$500.00

WARNING – You may need to have your Tacoma’s exhaust system modified (cut & weld) to custom fit Downey’s exhaust pipe. We have found different Cat. Converter locations on “identical models”. All 4 Runners must cut & weld, you converter has no bolt-on flange. These headers do not fit models with a column shift!

17410-30	88-95 3.0 V-6 Headers, Chrome	$425.00
17410-30C	88-95 3.0 V-6 Headers, Ceramic	$575.00

NOTE - Won’t fit T-100 with column shift, RH Header hits T-100 firewall, must ball peen firewall back approximately 3/8”. See crossover exhaust #17430, see #32910.

17410-34	95-98 V6 Header with EGR, Chrome	$395.00
17410-34C	95-98 V6 Header with EGR, Ceramic	$485.00
17410-98	98-04 V6 Header without EGR, Chrome	$395.00
17410-98C	8-04 V6 Header without EGR, Ceramic	$485.00

NOTE - 3.4 V6 engines installed into 3.0 V6 vehicles always use 1998 + Headers without EGR retrofitting.

NOTE - These Headers do not fit vehicles with a body lift kit unless steering drive shaft is modified – inquire.

NOTE - California engines have EGR tube connected to exhaust manifold up to 10/99 production date. THERE ARE MANY EXCEPTIONS! Check your engine before ordering Header. See Crossover Exhaust kit # 17434

NOTE — Downey does not manufacture bolt-on exhaust systems for 1999-newer V6 and V8 OBDII vehicles. Your home town muffler shop will have to make the connector pipes between Downey Headers and your stock catalytic converter. In some cases this will require slight repositioning of the catalytic converter, generally rearward a few inches. You must determine if your local muffler shop is able to do this work prior to purchasing Downey Headers!

17410-00	Tundra V-8 Headers, Chrome	$425.00
17410-00C	Tundra & Sequoia V-8 Headers, Ceramic	$575.00

17410-FC	‘69-87 Landcruiser Header, Chrome	$335.00
17410-FCC	‘69-87 Landcruiser Header, Ceramic	$380.00
17410-F6	‘73-83 Street Legal, Chrome, FJ40 only	$450.00
17410-F6C	‘73-83 Street Legal, Ceramic, FJ40 only	$495.00

We invented 1FZFE engine Headers back when non-enthusiast bought new $50-60,000 FJ80’s, and they had no interest in aftermarket accessories. Today older FJ80”s are being purchased for $6-10,000 and turned into Baja war wagons. There is so much demand for FJ80 Headers now, we absolutely had to bring them back. Not enough call, however, to get them exempted ( $ ) from emissions (although they are fully emission retro fitted). These Headers are sold as Headers & Gaskets only, no down pipes from Header to catalytic converter. Your hometown muffler shop will have to make the converter connection for you.

17410-93

93-97 FJ80 Header, Chrome

$395.00

Check Downey catalog for :
Buick 231 V-6 Conversion Headers, Pickup & 4 Runner
Chevy 4.3 V-6 Conversion Headers, Pickup & 4 Runner
Chevy V-8 to Landcruiser Headers
Chevy V-8 Ultra Block Huggers, Landcruiser, Pickup & 4 Runner

Not Legal for sale or use in California on emission controlled vehicles.