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Forum nameTurbo/Nitrous Tech
Topic subjectOff the chart fuel pressure at ilde, please help?
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=99335
99335, Off the chart fuel pressure at ilde, please help?
Posted by TEAM OVER REV, Mar-07-07 03:27 PM
I have a Hahn Race Craft stage 2 kit, and my idle fuel pressure is over 100psi. I have checked it with other guages. I think my regulator is stuck open, or my vaccum lines are hooked up wrong. I would like to know how other people have set up their vaccum lines for the Hahn fuelpressure regulator. I have very little vaccum at idle. Wich causes compressor surge at low boost, and opens up the b.o.v at high boostieve. Some people belive that is because of the crower stage III's. I would like to know how much vaccume I am suppose pull at idle? Thanks.
99340, RE: Off the chart fuel pressure at ilde, please help?
Posted by ChloRure, Mar-08-07 01:48 AM

Mine at idle is around 16-17 of vacuum. Im using the vortech fmu.
99341, RE: Off the chart fuel pressure at ilde, please help?
Posted by cs82685, Mar-08-07 04:41 AM
Originally posted by TEAM OVER REV
I have a Hahn Race Craft stage 2 kit, and my idle fuel pressure is over 100psi.


Did you just install it or is it suddenly just really high?

If you just installed it I would say that make sure you removed the schrader valve from the test port on the fuel rail.
99346, RE: Off the chart fuel pressure at ilde, please help?
Posted by TEAM OVER REV, Mar-08-07 02:57 PM
It just recently got high. I took it apart, one of those begi from hahn, it was one of those aluminum plates that was cut, at the bottom of the regulator. They are pretty weak. Thanks
99352, RE: Off the chart fuel pressure at ilde, please help?
Posted by thedawg, Mar-09-07 10:34 AM
Originally posted by TEAM OVER REV
begi from hahn, it was one of those aluminum plates at the bottom of the regulator. They are pretty weak.

LOL CRAPTECH!

Your regulator sucks dude, it's an embarrassment to the rest of the HRC kit. Get a Vortech SFMU and sell the BEGI/Craptech on ebay to a domestic owner that can use it for its intended purpose.

But yeah, use a coke can or spare aluminum stock, and cut yourself a new plate. You may want to replace the diaphragm while you're in there.
99353, RE: Off the chart fuel pressure at ilde, please help?
Posted by TEAM OVER REV, Mar-09-07 10:48 AM
Yea, ha ha. Thats true. You do that too? I took mine apart and did the same thing. What kind of drink should I use?
99354, RE: Off the chart fuel pressure at ilde, please help?
Posted by thedawg, Mar-09-07 11:18 AM
I heard using a Guinness can will give you 3 extra hp. Although you could go with Diet Sprite if you wanted to get some weight savings...

Oh and don't bother calling HRC and complaining or trying to get tech support, Bill Hahn is friends with Corky Bell (who designed the BEGI and knows more about turbos than anyone on this site, especially me) and wants to give him business. HRC will just tell you you're doing it wrong and to find a qualified mechanic. The regulator actually works really well for lower fuel pressures and non-turbo applications like domestic v8's, so it sells really well on eBay. Almost well enough to cover most of the cost of the Vortech SFMU that we love because it's rock solid for our application. :shrug Who knows maybe we're all just doing it wrong. ;)

Note the fuel regulator they use in their new portfueler kits (upper left of photo):
http://www.hahnracecraft.com/hahn/parts/eclipseportfueler2.JP G

"If you've ever tried to make an FMU (variable rate of gain) regulator run with big injectors at high boost, you can forget about all those frustrating issues
...insane 100+ PSI you might see with an FMU in such a high boost application.
...high-pressure related failures of injectors, lines, pumps, and even the stock ECM due to excessively high fuel pressure combined with big injectors and an FMU.
...the "best" FMUS can only be calibrated at 4 different points, with the remainder of the fuel curve left to vague "slopes" caused by the overlapping methods of adjustment.
...Why limit yourself to a device that is about as adjustable as a carburetor when you can go PortFueler instead?"

- Direct quote from HRC website.