No matter what I do I cannot get my pressure above 80psi. I have the brass needle turned in all the way, now. I started at the 2 turns out and went from there. I tryed 2 different guages at my work both of them are Kent Moore gauges and when I was on the dyno last week, even on there too !! I don't know if I'm having issues with the BEGI FMU or not. I called Hahn Tech but no one answers yet.
Does anyone else have this problem ? Maybe I need to try the Blazer fuel pump swap.
It's the fuel pump. It's only so strong, stock.
I've taken my blazer to 110 psi but I wouldn't recommend it... heck I wouldn't recommend taking an injector over 75 psi personally...
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
What are you doing?!?! Injectors can collapse at anything above 80psi.
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I have the same issue, it runs awesome but a little lower on fuel pressure than what hahn wants. Think I am going to put the walbro in to help get the fuel to the external at a higher psi, you might want to do the same thing. From what I have heard we don't need the 255 so just go with the 195. Anyone else have any GOOD opinions or options?
you guys have the stage II, it should have came with an inline pump? and yes anythign above 80-90 psi is pushing the injector a lil far. id recomend swapping to a lager injector.
for what its worth.. when i still had my stock motor w/16g and fmu i pegged the end of the 100psi fuel pres guage. lol not something i would recomend doing.
hahn made 400+fwhp and mid to low 11s on stock pump with just an inline
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12.5@116 2.0 60ft 19psi
yeah our stock pump has a pretty impressive volume in which it can pump but as said its not overly strong as far as PSI. The inlines certainly help to increase your pressures beyond stock and the stock is plenty of volume to supply the inline. Your inline will start to get grumpy though when your fuel levels decrease below 1/4 tank as the fuel is becoming much hotter with less ability to dissipate heat in the tank. As far as your injectors every brand handles pressures a little differently the accels that hahn supplies seem to take to HIGH pressures better than others before jamming. I cant say I have known anyone to run pressures high enough to jam the accels to be honest. The GM ones take a lot as well. The RCs however do not like pressures over 75psi. Ive ran two sets of them and they jam between 75 and 80 psi. This is not a bad thing just their peak. The higher the pressures the less effective the atomization can be too (psi beyond their intended max I mean). A stronger in tank or an inline will work they require pretty close to the same skill and time to install along with the prices are pretty comparable so its your preference really. Good Luck
ASE Master Certified Automotive Technician
John H [CavalierKid wrote:
for what its worth.. when i still had my stock motor w/16g and fmu i pegged the end of the 100psi fuel pres guage. lol not something i would recomend doing.
If this is the case, maybe I have a problem with the FMU, or upgrade to 2.0supercharged injectors or larger ? Any sugestions ?
My car only has 28,000 miles on it. The stock pump should be fine. I have the inline pump hooked up as per Hahn's "bible" manual.lol I'm not the only person with this kit, so whats the deal?
I did the '03 reflash. I'm lost and Hahn Tech is not picking up the damn phone!!!
You're not having a problem. The stated pressure range is for max safety (conservative) hoping to keep a decent AFR. You need to buy a wideband and tune by that. I have talked to Hahn about this before. Tech is only open 2pm - 6pm CT. What boost level are you at. If you're at 7 psi, 80 psi fuel is plenty. You really need to buy a wideband.
"If you aren't shifting, then you certainly aren't driving!"
I finally did get through to Hahn Tech and
silvercav02 you are right. I'm at 7.5 psi and he said that 85-90 psi fuel pressure is for 9 psi. He also told me that for each 1 psi of boost is about 6 psi fuel pressure. I should of bought a wideband instead of the pyrometer. Atleast with the pyrometer I know my egt's are about 200'F colder than it was n/a.
Thank you to everyone who gives me honest advise!!!
John H [CavalierKid wrote:]you guys have the stage II, it should have came with an inline pump? and yes anythign above 80-90 psi is pushing the injector a lil far. id recomend swapping to a lager injector.
for what its worth.. when i still had my stock motor w/16g and fmu i pegged the end of the 100psi fuel pres guage. lol not something i would recomend doing.
hahn made 400+fwhp and mid to low 11s on stock pump with just an inline
I pegged 100 also when i was using the same setup...
What raito disk is in the FMU?
2004 Turbo cavalier 11PSI and blown!
EcoEnvy, I have a bone stock Hahn Stage II kit. It is what ever they gave me. How could I even check ?
That fuel pump supplied in the kit will pump way more than what you are reading. I bet it you have you signal hose routed incorrectly. Route your hose between the intake manifold and BOV.
I have the same setup, Hahn Stage II. Except I am running vac to my FMU directly off the manifold no T. However, my fuel PSI is way high on the gauge. When I hit boost is goes past 90psi. I have tried to adjust the brass valve, but I can get the numbers to change. Also, the brass adjusting valve is open. There is no vac line connected to it, is that the correct way?
Chuck, 03Sport wrote:I have the same setup, Hahn Stage II. Except I am running vac to my FMU directly off the manifold no T. However, my fuel PSI is way high on the gauge. When I hit boost is goes past 90psi. I have tried to adjust the brass valve, but I can get the numbers to change. Also, the brass adjusting valve is open. There is no vac line connected to it, is that the correct way?
yes. that is the correct way. there is two hose barbs. one without the adjuster and another with the adjuster. the one without the adjuster is the boost in signal and that connects to your intake manifold boost source. the other hose barb with the adjuster just regulates the fmu's fuel pressure ratio by how much boost it vents. the brass valve adjusts how much boost leakes past it. if you close it all the way then there is no boost leak which will max out the fmu's boost pressure/fuel pressure ratio. if you open it all the way then there is a larger boost leak which will lower the fmu's boost pressure/fuel pressure ratio.
example:
if brass adjuster valve is closed all the way you will have max fmu ratio. 14:1(every one psi boost will raise fuel pressure 14psi)
if the brass adjuster valve is open all the way you will have minimal ratio. 2:1(every one psi boost will raise the fuel pressure 2 psi)
if the brass adjuster is anywhere in between then you will have a ratio in between the numbers above.
JOE L wrote:Chuck, 03Sport wrote:I have the same setup, Hahn Stage II. Except I am running vac to my FMU directly off the manifold no T. However, my fuel PSI is way high on the gauge. When I hit boost is goes past 90psi. I have tried to adjust the brass valve, but I can get the numbers to change. Also, the brass adjusting valve is open. There is no vac line connected to it, is that the correct way?
yes. that is the correct way. there is two hose barbs. one without the adjuster and another with the adjuster. the one without the adjuster is the boost in signal and that connects to your intake manifold boost source. the other hose barb with the adjuster just regulates the fmu's fuel pressure ratio by how much boost it vents. the brass valve adjusts how much boost leakes past it. if you close it all the way then there is no boost leak which will max out the fmu's boost pressure/fuel pressure ratio. if you open it all the way then there is a larger boost leak which will lower the fmu's boost pressure/fuel pressure ratio.
example:
if brass adjuster valve is closed all the way you will have max fmu ratio. 14:1(every one psi boost will raise fuel pressure 14psi)
if the brass adjuster valve is open all the way you will have minimal ratio. 2:1(every one psi boost will raise the fuel pressure 2 psi)
if the brass adjuster is anywhere in between then you will have a ratio in between the numbers above.
While the rate of gain, and the total pressure achieved under boost is adjustable to some degree via the flow control valve as you describe, the range from min to max is not so large as you describe. Further, our FMU's are recalibrated internally (varies with application) to achieve different actual mechanical rates of gain than the standard BEGI unit, so the general information associated with the standard BEGI does not apply to our product.
To the OP: We can help, IF you have purchased a complete new Hahn RaceCraft turbosystem. Is it new or used? If new, did you purchase it from us directly, or from one of our dealers?
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
Bill Hahn Jr. wrote:JOE L wrote:Chuck, 03Sport wrote:I have the same setup, Hahn Stage II. Except I am running vac to my FMU directly off the manifold no T. However, my fuel PSI is way high on the gauge. When I hit boost is goes past 90psi. I have tried to adjust the brass valve, but I can get the numbers to change. Also, the brass adjusting valve is open. There is no vac line connected to it, is that the correct way?
yes. that is the correct way. there is two hose barbs. one without the adjuster and another with the adjuster. the one without the adjuster is the boost in signal and that connects to your intake manifold boost source. the other hose barb with the adjuster just regulates the fmu's fuel pressure ratio by how much boost it vents. the brass valve adjusts how much boost leakes past it. if you close it all the way then there is no boost leak which will max out the fmu's boost pressure/fuel pressure ratio. if you open it all the way then there is a larger boost leak which will lower the fmu's boost pressure/fuel pressure ratio.
example:
if brass adjuster valve is closed all the way you will have max fmu ratio. 14:1(every one psi boost will raise fuel pressure 14psi)
if the brass adjuster valve is open all the way you will have minimal ratio. 2:1(every one psi boost will raise the fuel pressure 2 psi)
if the brass adjuster is anywhere in between then you will have a ratio in between the numbers above.
While the rate of gain, and the total pressure achieved under boost is adjustable to some degree via the flow control valve as you describe, the range from min to max is not so large as you describe. Further, our FMU's are recalibrated internally (varies with application) to achieve different actual mechanical rates of gain than the standard BEGI unit, so the general information associated with the standard BEGI does not apply to our product.
To the OP: We can help, IF you have purchased a complete new Hahn RaceCraft turbosystem. Is it new or used? If new, did you purchase it from us directly, or from one of our dealers?
i know. ratio's are not exact, i was just giving a general example of the ratio change. each fmu is different.
Bill he got it from you directly, brand spankin ass new lol
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
WHITECAVY wrote:Bill he got it from you directly, brand spankin ass new lol
Yes, I bought it directly from you Bill, brand new. Thanks for everyones input. I have it hooked up directly how it is in the manual and I now have adjustment of fuel during boost. I believe I had a signal hose routed wrong.
Awesome! Thank you everyone for lending a hand.
Chuck, please enjoy, and feel free to PM me if you ever have a question. If I don't reply quickly enough (sometimes I don't come here often), we are just an email away: tech@turbosystem.com. Thank you for going with Hahn!
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
sounds like it's time for a portfueler
