Member Credit: ViperVadim

The purpose of this thread is to compare the available headers for the 95-03 VQ3x Maximas. I’ve managed to get together the following different headers in the same room and do this comparison.

I was able to pull it off thanks to:

• speed racer for SSAuto/XS Power
• secondtonone317 for OBX
• M&R MAX for Hotshots
• Maximariceboi for Cattmans
• tavarish for the Stock Fed Spec header (thanks to qnzmax too)

Let the comparison begin:

Stock for Stock (Federal Emissions vs California Emissions)

There are the two types of Stock VQ front headers:

• 95-00 Federal Emissions Header
• 99-00 California and ALL 2001+ Header

The California front header is a system that incorporates a Huge pre-cat (cat converter) doing it’s job for the environment.

The pre-cat up close is big, and the stock headers are restrictive to the exhaust gasses flowing through.

The front headers kinda look similar, until you look inside them.

The fed spec has a round exit hole and has superior internal flow to the Cali-spec, the shape of the openning on the cali spec is irregular, and more restrictive.

The bends and rough edges inside the manifold all hinder exhaust flow, creating backpressure.

Furthermore the outlet after the pre-cat on the cali spec is much smaller than the fed, with an oxygen sensor placed directly in the exhaust path restricting even more flow.

Tthe rear VQ header is unchanged from 95-01.(EGR is closed off with a Large Bolt on all 01’s) But in 02+ ALL rear headers also received a pre-cat similar to the california front header in 99.

Here is a pic of 02+ rear header pre-cat, used from BLAKKILLA.GTR, thanks Man

Now everybody knows what all maximas come with from the factory. As you can see from the pictures the Stock headers are designed very cost effectively, they comply with auto standards and compromise heavily between good Fuel Economy and power output. (Very Bad for HorsePower)

Before we discuss Aftermarket Headers we need to discuss:

EGR: Which cars have EGR?

• All 95-00 Maximas Have external EGR.
• All 01-03 Maximas have NO (external) EGR.

This is the EGR guide tube used on all 95-00.

This is how the EGR bolts into the REAR header – and why you need the EGR bung on the rear header.

GASKETS

Aftermarket Headers will come with Aftermarket Gaskets (read as: POS Gaskets).

The difference between POS and OEM

DO NOT USE the supplied POS Gaskets! They cannot stand up to the heat of the headers. The gaskets are prone to cracking. OEM gaskets are multi-layered Steel and provide the best seal.

OEM Multilayer FTW!

XS Power/SSAutochrome/Stone Mountain Racing Headers

These are the very first headers designed and mass produced for the maxima, it has went trough many names, but not so many changes, the latest distributor is XS Power.
This is the only system that can be used with a Budget/Cattman/Warpspeed y-pipe, meaning if you already have a (Fed Spec) aftermarket y-pipe, the headers will bolt right up to it. I still prefer to use the Supplied XS Power Y-pipe (for ideal fitment)

Cost $325 

They are derived from the stock header design except they have a nice flow improvement. every runner is separate, and merges into a 3-1 collector. They have much better flow over stock.

This is the flow improvement, you can see the 3-1 collector.

The rear header has longer runners than the front with EGR bung as well

Fresh from vipervadim’s paint shop

However when comparing them to the header system from OBX you can clearly see the difference between long and short runners.

With short runners, peak power is delivered earlier in the powerband. low-end and midrange is emphasized. (at top-end the headers are choking the motor)

with longer runners, peak power is delivered later in the rpm range. Midrange and Top-end power are affected better since the engine has less backpressure and less restriction for exhaust gasses.

Stats:

Header:
A. Runner Inlet (oval) 1 3/4W x 1 1/4H
B. Runner Diameter (outer) – 1 5/8in
C. Runner Length – Front (5, 5 1/2, 10 1/2) Rear (7, 8, 8 1/2) in
D. 3-1 Collector Diameter (inner) – 2 1/8 in

Y-Pipe
E. Y-Pipe Diameter (outer) – 2 1/8 -> 2 3/8in.
F. Collector Diameter (inner) – 2 1/4
G. Not Equal Length W/ EGR

OBX

OBX is not new to Maxima headers, they used to have this (below) header system for the 95-99 Maxima, 3-piece design, however they had a big fitment problem: the front header was right in the way of the front motor mount bracket (needed to be cut), and the rear header joined the y-pipe in a 90 degree bend (bad exhaust flow).

 I WOULD NOT Advise buying it because of Bad Fitment.

OBX has however smartened up from ^^those times^^ and completely redesigned their New Maxima Header System (fits 95-03, same VQ block) and this is what they offer:

Cost – $325 

They have improved from the original header design, redesigning the whole system. the new design is now 2-piece. It incorporates long runners in the front header, with the mount issue solved (similar to hotshots design), and a distinctly improved 2-1 collector, eliminating the previous 90-degree bend. the rear header (with EGR bung) is integrated into the y-pipe as one piece

This is how the system looks put together.

Notice there are 4 o2 bungs for the front and rear oxygen sensors (ideal for 99+ cali spec), there is also 2 small flex sections instead of a single.

I am very impressed with the OBX, they officially put themselves back on the map with their new redesigned Maxima headers. for the price and the end-result, this is the ideal header system for a ‘budget minded’ maxima enthusiast. I think the SSAuto/XS Power have met their downfall, because the OBX are in a similar price range offering a better designed system similar to (cattman and hotshot). I still have yet to find out how well they fit or how well they perform.

However the new OBX has it’s one drawback. unlike the Cattman and Hotshot and even the SSauto/XS Power Y-pipes, the inside diameter of the y-pipe outlet is only 2 1/16in, (outside diameter 2 1/8) smaller than stock.

If you can replace the flex section and the outlet piece with 2.5in piping more gains will be had in the midrange and top-end.

Stats:

Header:
A. Runner Inlet (oval) 1 3/4W x 1 1/4H
B. Runner Diameter (outer) – 1 5/8in
C. Runner Length – Front (9 1/2, 11, 14 1/2) Rear (9 1/2, 10 3/4, 12) in
D. 3-1 Collector Diameter (inner) – 2 1/16 in

Y-Pipe
E. Y-Pipe Diameter (outer) – 2 1/8 -> 2 1/8in.
F. Collector Diameter (inner) – 2 1/16
G. Not Equal Length, W/ EGR

Hotshot

Hotshot is Out Of Business, so the Headers are no longer produced. There are some resellers who still have the last remaining stock, and of course the people who bought/installed them.

Cost $639 

Hotshot headers are on par with Cattman. they look very similar and the construction is very good. According to my measurements the Hotshots have the longest header runners and longer equal length runners on the y-pipe. They also have well machined inlet and oulets.

The only problem with Hotshots: In the Front header, the O2 bung needs to be welded in another location. The original location puts it too close to the A/C compressor. Also depending on what year maxima you have, you will need to weld in an EGR bung to the rear header, since the Hotshots do not have EGR.

Headers put together

Fresh from vipervadim’s paint shop

Stats:

Header:
A. Runner Inlet (oval) 1 7/8W x 1 5/16H
B. Runner Diameter (outer) – 1 5/8in
C. Runner Length – Front (15, 15 1/2, 20) Rear (12 1/2, 14, 15 1/4) in
D. 3-1 Collector Diameter (inner) – 2in

Y-Pipe
E. Y-Pipe Diameter (outer) – 2 1/8 -> 2 1/2in.
F. Collector Diameter (inner) – 2 7/16
G. Equal Length (23 1/2in each) W/ NO EGR

The Hotshots like the Cattman headers have equal length runners (notice the round bend at the rear header), unlike the SSAuto and OBX.

Equal length pipes help the sound and they provide less backpressure.

Cattman

Put together
Fresh from vipervadim’s paint shop