How much boost is the walbro good for?

[jdub]

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?

No, you asked "How much boost is the walbro good for?"
sounds a lot like "how much boost can a walbro hold" to me

I didn't say boost doesn't increase HP...I said psi doesn't mean squat. It's turbo flow in CFM that produces HP.
There's a difference...one a lot of guys do not understand.

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.

You need to understand that a boost level in psi tells you nothing...it's turbo dependant. And that is my whole point...a guy could respond to your post saying "I'm running 14 psi and the walbro is working great". The problem is he's running a CT26 and that tells you absolutely nothing when it comes to fuel required at the same psi on your 4088.

 

[87mgte]

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?

Boost increases hp technically I guess... what really increases hp is flow. If you throw down 20 psi on a stock CT26 and then pull 20 psi on a BorgWarner S595, you're gonna see a huge difference in whp because the BW would be flowing at least 1,000 jiggawatts more than the CT.

 

[supraman502]

No, you asked "How much boost is the walbro good for?"
sounds a lot like "how much boost can a walbro hold" to me

I didn't say boost doesn't increase HP...I said psi doesn't mean squat. It's turbo flow in CFM that produces HP.
There's a difference...one a lot of guys do not understand.

I see that now, but I put some specs of the veh in to point in more specific directions

 

[supraman502]

how would I make my gt4088 flow more?

 

[jdub]

I see that now, but I put some specs of the veh in to point in more specific directions

I added to post #21.

I understand...but, that assumes someone is going to take the time to fiqure it out. I'm just trying to help you get an accurate answer

 

[87mgte]

how would I make my gt4088 flow more?

It flows what it flows... more than a CT, less than a GT55 from Boost Logic's car.

 

[s turbo 87]

lets get all technical here and talk about what our cars and turbos and pumps are theoretically and mathematically built for...
chris, you got my input...but if you take the square root of the cosine tangent of pie squared and divide it into the price of beans in china with a fancy fluid dynamics equation, you may find that my approximate answer was slightly off....

does anyone disagree that 20psi would be a good place for him to stop crankin the boost up on his given setup? if so, then what should he stop at based on wtf ever kind of reasoning you wanna throw out.

he asked a simple question, gave his setup in which based off that people could have given an approximate answer. it DOES come down to how much boost measured in psi, bar, w/e that his walbro will handle, given his setup. at some point his 65mm turbo will flow more than the pump can keep up with...and this magical change WILL occur at X amount of pressure...no?

 

[jdub]

how would I make my gt4088 flow more?

The turbo is limited by the housing and compressor wheel. However, a couple things you can do to deliver max efficiency:

- Exhaust manifold - port the stock one out or go with a header type.
- IC piping - 2.5" should be sufficient
- IC rated CFM flow - 2.5" inlet/outlet...core flows what the turbo is capable of with min pressure drop.
- TB - This is the restriction (2.36" on stock)...the TB plate adds more restriction.

 

[jdub]

lets get all technical here and talk about what our cars and turbos and pumps are theoretically and mathematically built for...
chris, you got my input...but if you take the square root of the cosine tangent of pie squared and divide it into the price of beans in china with a fancy fluid dynamics equation, you may find that my approximate answer was slightly off....

does anyone disagree that 20psi would be a good place for him to stop crankin the boost up on his given setup? if so, then what should he stop at based on wtf ever kind of reasoning you wanna throw out.

he asked a simple question, gave his setup in which based off that people could have given an approximate answer. it DOES come down to how much boost measured in psi, bar, w/e that his walbro will handle, given his setup. at some point his 65mm turbo will flow more than the pump can keep up with...and this magical change WILL occur at X amount of pressure...no?

That's just it...guys don't think about HOW THIS REALLY WORKS and crank up the boost. The result is a blown motor. You can ignore the math if you like (and even make smart remarks about it), but it is the way it REALLY WORKS and boost measured in psi MEANS SQUAT. For it to be valid, the response would have to have the same turbo or one that flow very close to the same CFM at a given boost level.
Your comments simply display ignorance.

It is true that theory only goes so far, but it's a heck of a better starting point than the usual "guess" or "gut feel" (what you are doing) you see posted here.

 

[s turbo 87]

Okay, so perhaps a better question....since we are being ignorant: He wants to maximize power output on his current setup, obviously the single walbro fuel pump is his restriction. So what is the maximum amount of power that he can achieve?
Obviously he is thinking about HOW IT REALLY WORKS or he would already be on the dyno cranking the boost up and blowing his motor up.

btw-the amount of flow is increased by an increase in pressure...it certainly does mean a lot more than SQUAT when youre in his situation

based on my knowledge of his setup, and others, 20psi seems like the maximum amount of boost pressurzz he could run, achieving the maximum amount of power while still having a pillow of safety with a walbro. please correct me if im wrong.

now instead of arguing, lets hear your opinion

 

[Doward]

Something nobody's mentioned.

Flow goes down with increased pressure. Keep that in mind with the Walbro.

 

[s turbo 87]

Something nobody's mentioned.

Flow goes down with increased pressure. Keep that in mind with the Walbro.

For turbochargers or the fuel pump? I'm assuming you mean past a certain point..?

either way, im leaving this thread...i dont have time to argue or give my ignorant outlooks all day long on an online forum.

 

[jdub]

either way, im leaving this thread...i dont have time to argue or give my ignorant outlooks all day long on an online forum.

You know what...me too. I give up. Good luck with whatever you and your friend decide to do.

 

[GrimJack]

Holy crap, there are a lot of grumpy people out today.

The problem that the OP is going to run into is that there won't be another guy out there running a system that's similar enough to his. Something as simple as 1mm oversized valves in the head, or a ported head, will change the boost readings enough that they won't transfer from car to car nicely.

That said, he's heading for a dyno, and he's relatively sure that the limiting factor will be the pump. A dyno can tell him how much power he's running, so the link I posted earlier will work fine for what he wants to know.

Take whatever number you get on the dyno, subtract ~20% from it, and keep turning it up until you get close to the magical 693 bhp number posted, or you start to run lean, or you detect knock with a set of electric ears.

 

[Doward]

Pressure is resistance to flow. Period.

 

[jdub]

Give up John...Boyle's Law, Bernoulli's Principle and Fluid Dynamics in general don't apply in this thread.
That would be way too technical.
Pressure (psi) = HP...it's just that simple. There you go thinking like an engineer again

 

[Nick M]

For turbochargers or the fuel pump? I'm assuming you mean past a certain point..?

either way, im leaving this thread...i dont have time to argue or give my ignorant outlooks all day long on an online forum.

The more restriction there is, the less flow there is. When you run a garden hose without a sprayer, how do you get it to spray further? Restrict the opening with your thumb. That increases resistance which is pressure. Less comes out, but with more force.

Grim, why do you think you need so much headroom on a pump? In first hand experience a 190 lph pump holds 400 rwhp no problem. A 255 is beyond most street cars. Then again, I don't think 400+ hp is a street car. That is well beyond what I would want in traffic.

 

[GrimJack]

Grim, why do you think you need so much headroom on a pump? In first hand experience a 190 lph pump holds 400 rwhp no problem. A 255 is beyond most street cars. Then again, I don't think 400+ hp is a street car. That is well beyond what I would want in traffic.

Actually, to be 100% honest, I pulled that percentage out of thin air. I wouldn't personally replace a pump if it gets within 80% of max flow, however, I figured that posting here I'm better off to err on the side of caution.