Fuel Pressure still dropping
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Fuel Pressure still dropping After the Walbro 340 Intank install. I have 62 psi @ idle and while running. At WOT, it will drop to 50 psi. Injector DC is still about 116%.
How much should FP drop with 5# of boost?
It is better than before, dropped to 35-40 and DC was 146%
How much should FP drop with 5# of boost?
It is better than before, dropped to 35-40 and DC was 146%
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Well I guess 50 psi isn't that bad. I just saw the 12 psi drop and thought damn, still not enough pump. 
After posting and reading, I got rid of the 38's for the 42's thinking that would be enough for 500 rwhp.
Would 50's be enough? Or should I just add an inline to get the pressure up?
When will this end!!!
After posting and reading, I got rid of the 38's for the 42's thinking that would be enough for 500 rwhp.
Would 50's be enough? Or should I just add an inline to get the pressure up?
When will this end!!!
I have seen over 500 with 42s @ ~50psi of pressure. You did change your filter right 
You can do a boost referenced regualtor also to keep the pressure up. Mine drops to ~52 at above 5lbs of boost and above. If you can control your a/f down to 10:1 or so you should be just fine..
Try to tune what you have, BTW there are several '42lb SVO' injectors out there, some on eBay are more like 39s (forget the part number) so be carefull..
You can do a boost referenced regualtor also to keep the pressure up. Mine drops to ~52 at above 5lbs of boost and above. If you can control your a/f down to 10:1 or so you should be just fine..
Try to tune what you have, BTW there are several '42lb SVO' injectors out there, some on eBay are more like 39s (forget the part number) so be carefull..
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Yep, the filter was the first thing I changed when I started having problems.
I'll get it on a dyno and see how it is. If I can get rid of that high rpm lean-out. I should be ok. Then I will pulley up and get my 500 rwhp.
I bought the 42's from SC-MECHAM-WS6. So I am sure they are 42's.
But it was weird that I didn't have to change the IFR.
I'll get it on a dyno and see how it is. If I can get rid of that high rpm lean-out. I should be ok. Then I will pulley up and get my 500 rwhp.
I bought the 42's from SC-MECHAM-WS6. So I am sure they are 42's.
But it was weird that I didn't have to change the IFR.
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Originally Posted by Ed Blown Vert
I bought the 42's from SC-MECHAM-WS6. So I am sure they are 42's.
But it was weird that I didn't have to change the IFR.
But it was weird that I didn't have to change the IFR.
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Verdad Gallardo I just cut the ford section out of the chart, there are dozens of bosch injectors that have green tops in the bosche number list. I figured they were all the same until someone brought a car in here with them and I couldnt figure out why the thing was running out of fue and the IFR table didnt make any sense.
I'm not saying anyone here misrepresented anything or what you have isnt 42lb ijectors, just be careful what you buy with these, just because they are green dont automaticaly mean they are 42lb.
I'm not saying anyone here misrepresented anything or what you have isnt 42lb ijectors, just be careful what you buy with these, just because they are green dont automaticaly mean they are 42lb.
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Which ones are the correct 42's?
This is the document I found.
http://www.powerpage.dk/produkter/pic/injectors.pdf
This is the document I found.
http://www.powerpage.dk/produkter/pic/injectors.pdf
Thats the same chart I have here..
someone can do the math to convert cc/min to lb/min but here are your injectors in the chart. Without knowing the correct test pressure they are rated at its more or less a guess anyhow.. I'm no injector expert, I just had troubles with a set of green top bosch injectors and when I swapped them out for a set that was pulled out of an SVO box (different p/n on the injector) the IFR fell right in line and the car ran way better even on stock offsets.
Whether or not the others could have been made to work fooling with the IFR and PE I dont know, wasnt my car and I didnt want to spend a lot of time on it..
someone can do the math to convert cc/min to lb/min but here are your injectors in the chart. Without knowing the correct test pressure they are rated at its more or less a guess anyhow.. I'm no injector expert, I just had troubles with a set of green top bosch injectors and when I swapped them out for a set that was pulled out of an SVO box (different p/n on the injector) the IFR fell right in line and the car ran way better even on stock offsets.
Whether or not the others could have been made to work fooling with the IFR and PE I dont know, wasnt my car and I didnt want to spend a lot of time on it..
Originally Posted by Ed Blown Vert
What was your Fuel Pressure @ 6K?
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Originally Posted by kp
Thats the same chart I have here..
someone can do the math to convert cc/min to lb/min but here are your injectors in the chart. Without knowing the correct test pressure they are rated at its more or less a guess anyhow.. I'm no injector expert, I just had troubles with a set of green top bosch injectors and when I swapped them out for a set that was pulled out of an SVO box (different p/n on the injector) the IFR fell right in line and the car ran way better even on stock offsets.
Whether or not the others could have been made to work fooling with the IFR and PE I dont know, wasnt my car and I didnt want to spend a lot of time on it..
someone can do the math to convert cc/min to lb/min but here are your injectors in the chart. Without knowing the correct test pressure they are rated at its more or less a guess anyhow.. I'm no injector expert, I just had troubles with a set of green top bosch injectors and when I swapped them out for a set that was pulled out of an SVO box (different p/n on the injector) the IFR fell right in line and the car ran way better even on stock offsets.
Whether or not the others could have been made to work fooling with the IFR and PE I dont know, wasnt my car and I didnt want to spend a lot of time on it..
next time I'm at the shop I'll dig up those injectors I pulled out and see what the part number was. Since you really dont know for a fact what pressure that 418CC is or at what pressure it can make 84hp per cylinder its all just a guess. I'm sure if you contacted racetronix or RC they would know what number you have there..
My main point was there are a ot of different bosch injectors out there, I dont know enough about the ones you have to say what they are
My main point was there are a ot of different bosch injectors out there, I dont know enough about the ones you have to say what they are
If you can get your a/f right and PE table changes seem linear on the dyno/wideband then dont worry about it. I bought my injectors used and I just went and looked and I have the same p/n as yours. I seen these injectors make 540rwhp with a blower so I'm not too worried about it..
