Stillen Fuel Pressure Riser

Comments by Brian

I just read the article so I thought I'd pass on some info from it. They tested it on 2 cars, one being a 200sx w/ ECU, cams, header, exhaust, and intake.   And the other a Sentra that they described as "lacking the cams, exhaust and ecu of the 200sx."  I assume the sentra had an intake and maybe a header by the looks of the dyno results.  The 200sx produced best results w/ the pressure set to 36psi while the sentra gained the most at 34psi.  Here are some of the Dyno results.

3000 RPMS- no gain on either car 
3500 RPMS- 200sx  +.5HP, Sentra  +.7HP
4000 RPMS- 200sx  +.3HP, Sentra  +.3HP 
4500 RPMS- 200sx +1.1HP, Sentra  -.4HP 
5000 RPMS- 200sx +1.2HP, Sentra +1.3HP 
5500 RPMS- 200sx +2.8HP, Sentra +2.2HP 
6000 RPMS- 200sx +3.6HP, Sentra +3.5HP 
6700 RPMS- 200sx +2.4HP, Sentra +4.0HP 

Seems like a descent mod if the price is reasonable, but they don't say the price in the new Stillen ad so I expect it to be expensive.

Comments by Shell Black

Earlier this week I called Jim Wolf and got a hold of Clark Steppler (Mr. ECU). I had recently been to the dyno and the guy who ran the car had said that I was running lean (posted a while back). I asked Clark if I could fax over the dyno charts and wanted to know if he could confirm this. Clark said don't bother unless the guy had a sniffer or some sort of airflow meter hooked up, the charts won't point to running lean. OK, I had a some of responses (2-3) that said wolf runs the ECU on the lean side at WOT, so I continued the conversation about their ECU being on the "lean" side. Clark confirmed this. He mentioned that JWT had a chuckle at the Sport Car write up b/c they thought the test car was WAY lean to begin with (sorry I didn't have the article), so they were not surprised at the 3-4 hp gain. Also he thought that there was really not enough information given about the before and after set / up or back to back to really know for sure if the fuel pressure did much of anything. Clark says the ECU does the mix, and the Fuel Pressure Riser should not make a difference (or I should say substantial difference) besides making the car run RICH.

Comments by Mike Kojima

The article was in turbo magazine. Clark is totally correct. The car does run on the rich side and the way the riser was hooked up AFTER the stock regulator, it could only raise the fuel pressure to richen it up more.

Sometimes if you get the car too hot or too cool on the dynojet you will register that kind of power gain or loss while doing nothing! thats why all of my testing is based on the second back to back run once the cars temperature is stabilized.

Comments by Shell Black

Stillen Fuel Pressure Riser: The magazines reviewed it with a 2-3 hp gain on a SE-R with dramatic gains on heavily modified hondas (different set-up to measure air flow etc. - our computer seems to control fuel delivery more) I found very little if any on the dyno, 3 hp I think is optimistic. Very simple upgrade to install though you absolutely need a dyno to set correctly as it is VERY easy to HURT your power by running too rich or too lean. I found a screw hole on the firewall that was perfect to mount the FPR. I used a dremel to trim away a lip running along the top of the fire wall - cut a little semi-circle out so the FPR would fit nicely. The brass fitting in the body is were the gauge goes to tweak while on the dyno. You have to remove this and plug with the brass fitting once you have set before driving the car. The metal fitting on top is where you adjust the FPR pressure. Set at 33 I made best hp. You have to splice into a vacuum line but there is no splicing on the fuel line. Simply disconnect the fuel line from the stock regulator and hook the fuel to one side of the FPR and the other side to the stock regulator. I found the construction and materials to be top notch. I did have some leakage on the gauge port. Make sure you use lock-tite when setting this plug as per the instructions. This product is still up to debate as Jim Wolf will say our motor makes best hp running a slightly lean at wide open throttle and does not recommend this upgrade.