Turbo Install Finished!

[justin146]

I run 12.5-1 under boost with 94 octane and Im running on the edge of ping on a warm day and add 2 deg overall on a cooler day, depends how close to the edge you want to go, it is pushing it though

I wouldnt want it to be that lean on the top, but your centri-blower has a lower threshold for knock in the midrange than a turbo will. This is because a turbo will make full boost here where your blower wont make full boost until near redline.

The thing about knock is that when you hear it- it's too late. You could be knocking and not hear it..

 

[rocket 5979]

Running a 12.5:1 AFR on a vehicle this heavy with forced induction is asking for trouble. I would stick around 11.4-11.6 AFR. 12.5:1 is just way too lean. Keep in mind that going more lean with AFR's does not always equal more power either. There is a threshold you will cross with every vehicle where it stops making more power when going more lean. This threshold is not set and will be different for every vehicle and combo. If you go past that point you are just adding more potential for catastrophic failure without any benefit.

 

[V8RangerBoy]

Yeah I hit a wall with the fuel pump, like I figured. The 12.5:1 will be coming down after the fuel pump gets swapped! I went and stuck a fuel pressure gauge on it this morning, and above about 1/2-2/3 throttle I'm dropping from ~40-42psi clear over to 26-28, so I backed the hell out of it to say the least. Is basically any of the Walbro GSS342's going to fit? I can't find one at all for like a '94 Ranger, but would one for like a '93-97 Probe accomplish the same thing given that it's a 255LPH? Does high pressure matter or not since I have a factory fuel pressure reg?

 

[rocket 5979]

Yeah I hit a wall with the fuel pump, like I figured. The 12.5:1 will be coming down after the fuel pump gets swapped! I went and stuck a fuel pressure gauge on it this morning, and above about 1/2-2/3 throttle I'm dropping from ~40-42psi clear over to 26-28, so I backed the hell out of it to say the least. Is basically any of the Walbro GSS342's going to fit? I can't find one at all for like a '94 Ranger, but would one for like a '93-97 Probe accomplish the same thing given that it's a 255LPH? Does high pressure matter or not since I have a factory fuel pressure reg?

The high pressure is for fuel injected and the low pressure pumps are for carbed setups.

 

[reserved50]

I wouldnt want it to be that lean on the top, but your centri-blower has a lower threshold for knock in the midrange than a turbo will. This is because a turbo will make full boost here where your blower wont make full boost until near redline.

The thing about knock is that when you hear it- it's too late. You could be knocking and not hear it..

true, especially since his intake air charge is probably hotter also, I went by mph and got that number on my combo. I dont have a waste gate that can jam and creep boost also, 12.5 is on the lean side when setting it up I agree.

Some classify their pumps as "high pressure" for use with boost etc, due to some pumps losing output after say 50-60 psi, depends.

 

[reserved50]

http://www.autoperformanceengineering.com/html/fpspecs.html

some manufacturers only sell the high pressure version, I forget which , should say in their specifications, I just called BBK I think? and asked before purchasing. I doubt I even hit close past to what the non HP pumps put out with decent flow.

 

[rocket 5979]

Some classify their pumps as "high pressure" for use with boost etc, due to some pumps losing output after say 50-60 psi, depends.

You are correct. I know Holley likes to call their Forced Induction pumps "high pressure" pumps in the manner in which you speak. All they are is a Walbro GSS340 fuel pump. By those companies calling their pumps that it really can screw people up. I can just see a person new to this stuff asking, "So let me get this straight? There is a low pressure pump, a high pressure pump and then a high high pressure pump?" Just simpler to say that all high pressure are for EFI and all low pressure are for carb setups.

 

[reserved50]

you can use a non high pressure pump for NA applications since they barely hit 40PSI. I would be more worried about the FMUs and nitrous pressure on the regulators for non NA.

I know I had a heck of a time figuring out who sold what just by looking at the box, they should all include a spec sheet, or just tell everyone to refer to the Walbro site

 

[justin146]

you can use a non high pressure pump for NA applications since they barely hit 40PSI. I would be more worried about the FMUs and nitrous pressure on the regulators for non NA.

I know I had a heck of a time figuring out who sold what just by looking at the box, they should all include a spec sheet, or just tell everyone to refer to the Walbro site

The pressure is much higher in returnless Explorers.

 

[V8RangerBoy]

The high pressure is for fuel injected and the low pressure pumps are for carbed setups.

Yeah I called and talked to them about it. I ended up going with the universal HP 255lph pump.

 

[rocket 5979]

Yeah I called and talked to them about it. I ended up going with the universal HP 255lph pump.

You will be just fine with that. Worst case scenario you have to make a little wiring harness in the tank and run a longer fuel line. Nothing crazy.

 

[rocket 5979]

you can use a non high pressure pump for NA applications since they barely hit 40PSI.

While it may just barely suffice, it would be best to get the correct pump that flows the proper amount in the first place. Those low pressure pumps meant for carbs can hit 40 psi but they will do so at a flow MUCH MUCH less than the high pressure pumps will.

This is why it is always best when shopping for fuel pumps for really high power applications you will want to compare what the rated flow is at a given pressure level. That will tell you which pump is truly more powerful. Some manufacturers rate their pump flows at 40 psi, others at 45 and still others at a gph rating.

 

[reserved50]

While it may just barely suffice, it would be best to get the correct pump that flows the proper amount in the first place. Those low pressure pumps meant for carbs can hit 40 psi but they will do so at a flow MUCH MUCH less than the high pressure pumps will.

This is why it is always best when shopping for fuel pumps for really high power applications you will want to compare what the rated flow is at a given pressure level. That will tell you which pump is truly more powerful. Some manufacturers rate their pump flows at 40 psi, others at 45 and still others at a gph rating.

if you call 1 gal per hour at 40 PSI MUCH MUCH less sure, if you arent worried about that for a NA setup it wouldnt matter. They call them FORCED INDUCTION and BOOST pumps, not carb and EFI pumps.

The pressure is much higher in returnless Explorers.

yes, if I remember right if you use a non returnless pump in a returnless system it will burn out.

in his signature it does say 97 Exploder EFI

 

[manaen]

yes, if I remember right if you use a non returnless pump in a returnless system it will burn out.

that would be an interesting setup since there would be two FPR's in the system. one on the return rail and one on the fuel pump. The Fuel pump FPR would never get used since it is set at 62psi, it would act as more of a high pressure relief.

I don't understand why it would burn the pump out running at a lower pressure

It would seem to me that the 62psi pump should perform quite nicely with a 40 or 50 psi FPR setting. After all it's not like the pump ever shuts off in either setup once the engine is started.

 

[justin146]

that would be an interesting setup since there would be two FPR's in the system. one on the return rail and one on the fuel pump. The Fuel pump FPR would never get used since it is set at 62psi, it would act as more of a high pressure relief.

I don't understand why it would burn the pump out running at a lower pressure

It would seem to me that the 62psi pump should perform quite nicely with a 40 or 50 psi FPR setting. After all it's not like the pump ever shuts off in either setup once the engine is started.

the returnless and return Explorers use the same pump- this is because we have a mechanical returnless system (and use a return style pump). The returnless cars (like the Focus and Aviator) uses a PWM (pulse width modulation) returnless and don't have a regulator at all. These PWM pumps do not work in return cars because there is no check valve in them, and a return style pump cant handle the PWM without burning up.

 

[rocket 5979]

if you call 1 gal per hour at 40 PSI MUCH MUCH less sure, if you arent worried about that for a NA setup it wouldnt matter. They call them FORCED INDUCTION and BOOST pumps, not carb and EFI pumps.

You are apparently not looking at the actual low pressure pumps if you are only seeing a 1gph difference between pumps. There is a much larger difference in flow between a 255 lph rated carb pump and a 255lph rated EFI pump. There are electric fuel pumps for carbed setups, EFI and EFI with higher pressure (usually for boosted setups). While you may have seen someone call their pumps FI and boost pumps that is not the proper nomenclature for them. If you take a look at the pump psi and flow ratings you will see huge differences between the EFI and the carb pumps. The EFI pumps will have a 190, 220, or 255lph rating at 40 psi while the pumps intended for carb use will have their flow ratings rated while anywhere between 4 to 9 psi.

 

[rocket 5979]

yes, if I remember right if you use a non returnless pump in a returnless system it will burn out.

in his signature it does say 97 Exploder EFI

The Gen2 Explorers do not use a true returnless system with a PWM turbine pump. You can swap pumps between them. You should check it out sometime.

 

[rocket 5979]

the returnless and return Explorers use the same pump- this is because we have a mechanical returnless system (and use a return style pump). The returnless cars (like the Focus and Aviator) uses a PWM (pulse width modulation) returnless and don't have a regulator at all. These PWM pumps do not work in return cars because there is no check valve in them, and a return style pump cant handle the PWM without burning up.

The returnless pumps can work in a return application even without the check valve, but it is not optimal for long pump life. The system does not hold pressure so it will have to reprime every time you start the engine but the reprime only takes about 2 seconds. There are only a few examples of situations where I would recommend using a pump setup like this. Most people in here would be best to get the right type of pump for the job from the beginning.

Using return in true PWM returnless application will burn the pump out really quick like you said.

 

[jah81592]

James, your lettering is green, pretty! I have spent some time on the Corral forum lately. Whew they would make you cringe at how they tune pre-OBDII cars.

I'd suggest having the engine tuned properly. You have invested a lot of quality time into the truck, now make the PCM happy and make it drive even better. Good luck,

I currently tune the Fox Mustangs and OBD-I cars, my datalogging is prehistoric. But the software looks the same just a whole lot less to adjust. But still the concept is the same. OBD-I or II, still has a cerain a/f it likes for n/a and boosted.

I wouldnt want it to be that lean on the top, but your centri-blower has a lower threshold for knock in the midrange than a turbo will. This is because a turbo will make full boost here where your blower wont make full boost until near redline.

The thing about knock is that when you hear it- it's too late. You could be knocking and not hear it..

Exactly!

the returnless and return Explorers use the same pump- this is because we have a mechanical returnless system (and use a return style pump). The returnless cars (like the Focus and Aviator) uses a PWM (pulse width modulation) returnless and don't have a regulator at all. These PWM pumps do not work in return cars because there is no check valve in them, and a return style pump cant handle the PWM without burning up.

I have preached this so many times, actually I mentioned this information in Justin's turbo build up thread. Stay away from returnless pumps in return style/mechanical returnless fuel systems. It will keep the problems to a minimum.-j

 

[manaen]

Very good, I like all of it except the frame cutting. I avoid altering the frame for anything, I hope that it continues to work for you. I'm on the fence about a turbo also, the under hood space is very limited.

I would have James tune it if possible, you would need a laptop. Regards,

You know I've got to agree with you, after doing structural welding for a few years that shot of the frame really scares me. I will accept the welds on the pipes, but those welds on the frame look really poor for structural welds, that is a lot of metal missing there, and it is at the most stressed part of the frame, right between the wheels. It could just be the images, maybe I cannot see the full details of how you reinforced the area, but I would really question its integrity. But then again I've always overbuilt/over engineered structural items so maybe it is just me.