Nissan USA
Upgrade Photos:
Stillen SR20DE Header

rd_dot.gif (326 bytes) Introduction
rd_dot.gif (326 bytes) The Stillen Header
rd_dot.gif (326 bytes) The Installation Saga



When I purchased my shiny Stillen 2nd-generation header in mid 1998, I planned for a moderately difficult installation requiring about four hours, followed by loads of high-revving excitement. What actually happened was more traumatic, expensive, and time consuming than anticipated. Despite a serious turn of bad luck, the header was successfully installed with satisfying results. A good installation procedure already exists on, so I have not published my own.

In the months following the header installation experience, my priorities and attitude changed as I determined a faster and more mature machine with an extra pair of doors would better fit my lifestyle. In September 1998, my SE-R passed into the hands of another owner, and I acquired a 1996 Acura Integra GS-R sedan. What could have been the beginning of an expensive long-term upgrade project simply ended as another chapter in my automotive adventures.

The Stillen Header

What did I get for a few hundred bucks?

The Kit
Header kit Header assembled front view Header assembled rear view
All parts Front view Rear view

The Stillen second-generation ceramic coated header has a number of improvements, including longer primaries and a double-walled flexpipe. The dark composite gasket for the secondaries is supplied by Stillen, and the others were bought from Nissan.

The Primaries
Primaries top view Primaries bottom view Primaries top flange Primaries bottom flange
Top view Bottom view Top flange Bottom flange

The primary ports are are finished smoothly, if not exactly port-matched. Any turbulence is probably negligible. The fitting for the O2 sensor is much lower than on the stock header, requiring the wiring harness to be lengthened about 6" before installation. Just above is the fitting for the AIV tube, applicable to 1991-93 model years. This fitting must be closed with a supplied plug for 1994+ model years.

The Secondaries
Secondaries top view Secondaries bottom view Flexpipe Secondaries front flange Secondaries rear flange
Top view Bottom view Flexpipe Front flange Rear flange

Welds on the secondaries are smooth, and the flexpipe is double-walled. The quality of the flexpipe seems good, but I question the Slinky-type noise it emits when accelerating. I later acquire a replacement secondary assembly from Stillen, but the new unit exhibits the same behavior.

The Gaskets
Gasket comparision Gasket comparision Stillen gasket Nissan gasket
Gasket comparison Stillen Nissan

I had previously purchased a metal gasket designed for the 300ZX, but the composite gasket for the secondaries looked beefy enough for my use. To fit in this application, the 300ZX gasket must have its bolt holes enlarged with a grinder.

The Difference
Comparison of primaries Comparison of secondaries
Primaries Secondaries

The stock header is actually a good 4-2-1 design, but with shorter unequal-length primaries and an ugly appearance. Hey - looks do matter on occasion.

The Installation Saga

Here we begin...

One Last Look
Engine before the header Stock secondaries Stock secondaries Stock location for O2 sensor
Engine front Stock
O2 sensor

Take one last look. My car and my wallet will look a little different by the end of this job.

Stock Header Removal
Stock primaries Exhaust ports Front buffer and bracket
Front buffer
and bracket

The bracket mounted behind the front buffer 'dogbone' connects to a flange on the stock secondaries, removing some stress from the manifold studs. The Stillen header does not have a matching flange, and might contact the bracket when the engine rocks, so the bracket can be easily removed by unbolting and reinstalling the front buffer. Some installers beat the @#$! out of the bracket, expending more effort than simply removing it.

Big Trouble
EGR tube Broken stud
EGR tube Broken stud

The EGR fitting on the Stillen header is about 1/8" too far forward, so the EGR tube had to be lengthened by this amount using whatever crude means of bending I had available. If this wasn't enough trouble, look at the broken stud on the #4 port. It broke inside the head under a nominal 30 ft-lb of torque, which was obviously too much for this previously-stressed part. To complicate matters, the extractor I used also broke, requiring a trip to the shop for a few hours of drilling, grinding, and torching, after which the tech inserted a HeliCoil. My advice? Install new studs during a header upgrade, regardless of mileage.

Stillen Header Installation
New dipstick location EGR fitting New location for O2 sensor
New dipstick
O2 sensor
& AIV fitting

The dipstick must be bent toward the front and passenger side to clear the #1 header tube, fitting it closely between the header and the alternator. Notice the much lower installation position of the O2 sensor as previously described.

Before & After
Engine before the header Engine after the header Complete engine
Before After Complete

Isn't it clean? From these photos, you'd never know about the trauma that climaxed with this successful installation. Elated with the increased performance, I enhance the upgrade by installing my old POPCharger that's been laying in a box for many months. Unfortunately, high underhood temperatures are driven even higher by the worst heat wave to hit Texas in decades, causing a loss in performance as the POPCharger sucks in volumes of hot air. The POPCharger is later removed, then sold. The entire car is also sold within several months (as perviously explained).

Rick's SE-Rious Procedures

Original material is the creation of Rick Zotz, 1999, 1998, 1997, and has been contributed to