How much boost is the walbro good for?

[supraman502]

How much boost can the high flow walbro hold? (a real one, not the knock off)

quick specs:
Gt4088
Maf pro + speed density
680cc injectors
ffi
fmic
fpr, tuned at about 25psi
etc

 

[GrimJack]

This is really easy to figure. A certain amount of fuel can only turn into a certain amount of power.

Check this page: http://www.slowgt.com/Calc1.htm#FPHP

BSFC = ~0.6 for a turbocharged engine
Try plugging in 693 hp.

That said, you need headroom on your pump, AND the numbers produced by the calc are crank power, not wheel power.

 

[suprarich]

How many more threads are there going to be where the OP realizes that PSI does not = HP. I could care less how much boost something will hold. How much HP will it hold is the real question.

 

[tlo86]

How many more threads are there going to be where the OP realizes that PSI does not = HP. I could care less how much boost something will hold. How much HP will it hold is the real question.

but how much torque will my walbro hold :sarcasm:

 

[Rennat]

if ONE walbro can do almost 700HP... i dont ever see a reason to get dual walbro on a street car...

what does the stock fuel pump flow though?

 

[gaboonviper85]

make sure to pick up a good set of adjustable metric wrenches when installing the walbro....

 

[GrimJack]

if ONE walbro can do almost 700HP... i dont ever see a reason to get dual walbro on a street car...

what does the stock fuel pump flow though?

Well, considering that you want at least 25% headroom... that's down to 519... and considering these are CRANK numbers, that's probably 415 wheel.

So, ya, duals isn't out of the question at all.

 

[Rennat]

shit... when ya put it that way i see your point.

wouldnt it be easier and quieter to run dual MK4 TT pumps? or just an inline fuel pump like an A1000 (i think)?

 

[GrimJack]

Yes, especially when you take into consideration the problems that have been talked about re: magnetic interference between 2 pumps. Most of the folks I've seen just go for a bigger single pump.

 

[Rennat]

but for a "street" car... shootin for the 400-500HP range, a single walbro 255 is enough?

 

[supraman502]

How many more threads are there going to be where the OP realizes that PSI does not = HP. I could care less how much boost something will hold. How much HP will it hold is the real question.

seriously?
How does psi not = HP, you do realize the more boost the more hp right?
When you show me how to set HP on the ebc and fpr, I'll ask that question instead.

 

[jdub]

LOL...that is really funny. Rich has more knowledge about working on and building these motors in his little finger than you will likely ever have.

Typical - you are confusing boost psi with turbo flow. A 4088 turbo is going to flow a LOT more air at 10 psi vs an upgraded CT26 at 10 psi. Flow on a CT26 max's out at 16 psi or so...the 4088 is hitting it's sweet spot at 16 psi. So, what matters is how much HP you get for a given amount of flow...boost psi doesn't mean squat.

You need to get a clue before you take a jab at someone...especially a guy like Rich

 

[supraman502]

LOL...that is really funny. Rich has more knowledge about working on and building these motors in his little finger than you will likely ever have.

Typical - you are confusing boost psi with turbo flow. A 4088 turbo is going to flow a LOT more air at 10 psi vs an upgraded CT26 at 10 psi. Flow on a CT26 max's out at 16 psi or so...the 4088 is hitting it's sweet spot at 16 psi. So, what matters is how much HP you get for a given amount of flow...boost psi doesn't mean squat.

You need to get a clue before you take a jab at someone...especially a guy like Rich

1st I find that HIGHLY unlikely, maybe you should practice what you preach. I've been a member for 3yrs and had 130 posts for a reason.

So fuel pumps are rated on turbo flow and not psi output? I dont care how much HP. And How is replying to a answer that doesnt answer my question taking a jab? I'm asking what the fuel system is capable of in THIS situation.

Obviously putting a A1000 on would correct any fuel pump issues and move the question to the injectors. But spending 500 on a fuel pump setup on a car that will be sold, isnt something I'm going to invest in. I would just like to run as much boost as possible (safely) on the current setup. The motor will hold as much boost as I can give it.

I understand how turbo flow works and that wasnt my question. 16psi is NOT the sweet spot on a gt4088.

So I want to be proven wrong that more boost doesnt = more hp......

 

[s turbo 87]

Chris, it seems like most 4088 setups are achieving ~500rwhp at 20psi or so. I've heard walbros are good for 6-700 crank hp. That being said, I wouldn't run more than 20psi with a single walbro.

btw-if you think 16psi is the sweet spot for a gt4088, see what 22 feels like.
My upgraded ct felt like it was at its sweet spot at 16-18psi...

 

[antman]

Your guestion has been answered. More than once. Please stop argueing.

 

[supraman502]

Your guestion has been answered. More than once. Please stop argueing.

where?

 

[87mgte]

:ban:

Are you seriously arguing with Rich and jdub? Wow... if you've been here for 3 years and have 130 posts for a reason, you should know that jdub's an expert "for a reason."

 

[jdub]

1st I find that HIGHLY unlikely, maybe you should practice what you preach. I've been a member for 3yrs and had 130 posts for a reason.

So fuel pumps are rated on turbo flow and not psi output? I dont care how much HP. And How is replying to a answer that doesnt answer my question taking a jab? I'm asking what the fuel system is capable of in THIS situation.

Obviously putting a A1000 on would correct any fuel pump issues and move the question to the injectors. But spending 500 on a fuel pump setup on a car that will be sold, isnt something I'm going to invest in. I would just like to run as much boost as possible (safely) on the current setup. The motor will hold as much boost as I can give it.

I understand how turbo flow works and that wasnt my question. 16psi is NOT the sweet spot on a gt4088.

So I want to be proven wrong that more boost doesnt = more hp......

Ok...so, you are saying a fuel pump should flow the same for 10 psi on a CT26 as 10 psi on a 4088?
Think about that

The question should be "What is the Max HP the flow a Walbro can support?" -or- "I want to make 450 HP on a 4088 turbo, will a Walbro flow enough fuel to support this goal?" This is what Rich was getting at.

Fuel is used to support HP produced, regardless if it is from boost or any other mod on any motor. The link Grim posted above provides that...this assumes the injectors can deliver that fuel to the motor.

I was using the comparison as an example...maybe I should have said "just hitting the center edge of the compressor map". I just did the calculations...16 psi at 4000 RPM on a 3.0L motor produces a pressure ratio of 2.08 and 26.4 CFM flow. Plotted on a 4088 map, it's doing very close to what I said.

You are trying to compare an apple to an orange...fuel flow to the injectors and injector capacity support HP...boost (to the limit of compressor housing flow) produces HP based on the CFM a turbo can flow. The common phrase is "HP"...that should be the question. If you understand turbo flow, you should understand that concept.

 

[supraman502]

:ban:

Are you seriously arguing with Rich and jdub? Wow... if you've been here for 3 years and have 130 posts for a reason, you should know that jdub's an expert "for a reason."

I didnt ask a general question like "how much boost can a walbro hold"
I gave specs, looking for someone with a similar setup, so I dont have to spend 2hrs on a dyno creeping up the boost until the fuel falls off.

Hes expert in oil & lubrication..... and I've delt with rich before and have 0 respect for him.

I have a 130 posts for the reason that anytime something is asked, by the 4th post its off topic

and "experts" believe that boost doesnt increase hp?

 

[supraman502]

Ok...so, you are saying a fuel pump should flow the same for 10 psi on a CT26 as 10 psi on a 4088?
Think about that

The question should be "What is the Max HP the flow a Walbro can support?" -or- "I want to make 450 HP on a 4088 turbo, will a Walbro flow enough fuel to support this goal?" This is what Rich was getting at.

Fuel is used to support HP produced, regardless if it is from boost or any other mod on any motor. The link Grim posted above provides that...this assumes the injectors can deliver that fuel to the motor.

I was using the comparison as an example...maybe I should have said "just hitting the center edge of the compressor map". I just did the calculations...16 psi at 4000 RPM on a 3.0L motor produces a pressure ratio of 2.08 and 26.4 CFM flow. Plotted on a 4088 map, it's doing very close to what I said.

You are trying to compare an apple to an orange...fuel flow to the injectors and injector capacity support HP...boost (to the limit of compressor housing flow) produces HP based on the CFM a turbo can flow. The common phrase is "HP"...that should be the question. If you understand turbo flow, you should understand that concept.

I understand that, thats NOT what I asked
I'm not looking for a safe HP number to run, the car has not been dyno'd at any psi, I'm looking for somebody with a similar setup that knows what a safe max boost level is.
I dont care if that psi # makes 300rwhp or 1000rwhp
I maybe asked the question in a way that wasnt understood, the way I wanted it to and I appologize for that.