Mine is totally stock and i can only get 17 with WG unplugged. That is it. Been through everything. Can't think of anything else to try.

 

On the Banks 99.5 7.3L test truck in a bone stock configuration the maximum boost on a load dyno was 17.5 psi. Below are the "Physics" that determine your maximum surge free boost pressure...

If you don't have a RAM air intake then the AFIAP=Air Filter Inlet Air Pressure, psi is the same as the AAP=Atmospheric Air Pressure, psi so AFIAP=AAP, and AAP can vary from 14.7 psi at sea level to 10.7 psi at 10K ft.

The TIAP=Turbo Inlet Air Pressure, psi is given by TIAP=AFIAP-AFPD where AFPD=Air Filter Pressure Drop, psi.

The MAP=Manifold Air Pressure, psi is given by MAP=(BP+AAP) where BP=Boost Pressure, psi.

The TOAP=Turbo Outlet Air Pressure, psi is given by TOAP=MAP+ICPD where ICPD=Intercooler Pressure Drop, psi.

The TPR=Turbo Pressure Ratio is given by TPR=TOAP/TIAP={BP+AAP+ICPD}/{AAP-AFPD} and if you solve this for BP you get BP={TPR}{AAP-AFPD}-AAP-ICPD= {AAP}{TPR-1}-{TPR}{AFPD}-ICPD so BP={(AAP)(TPR-1)}-{(TPR)(AFPD)}-(ICPD) and if you convert AFPD from psi to Inches H20 you get...

BP={(AAP)(TPR-1)}-{(TPR)(AFPD/27.68)}-(ICPD) psi

From this equation you see that ICPD trades one-for-one with BP... for example a 0.5 psi reduction in ICPD provides 0.5 psi of additional BP.

The effect of AFPD is magnified by the TPR... for example at a TPR=3 a AFPD=13.8" H20=0.5 psi causes a 1.5 psi reduction in BP.

The effect of AAP is magnified by (TPR-1)... for example at a TPR=3 a sea level AAP=14.7 psi gives a {(AAP)(TPR-1)}={(14.7)(3-1)}=29.4 psi contribution to BP, but at a 5.5K ft altitude a AAP=12.0 psi gives only a {(AAP)(TPR-1)}={(12.0)(3-1)}=24.0 psi contribution to BP which is a 5.4 psi reduction relative to sea level!

This is why towing at altitude is so hard on your turbo because it has to work at a higher TPR to make the same BP that it can more easily generate at sea level!

Your maximum surge free BP is determined by looking on the compressor map for your particular turbo and finding the maximum TPR that you can operate at while staying below the surge line. This operating point will always be at the maximum engine RPM=3,200. At sea level and RPM=3,200 a stock GTP38 turbo hits the surge line at a TPR=3.2. My best estimates are that at this operating point the AFPD=14" H20 and the ICPD=1.9 psi so the maximum surge free BP is BP={(AAP)(TPR-1)}-{(TPR)(AFPD/27.68)}-(ICPD)={(14.7)(3.2-1)}-{(3.2)(14/27.68)}-(1.9)=28.82 psi!

Based on this result if you see a BP=30 psi with a stock turbo you're definitely hitting the surge line and doing some unnecessary damage to your turbo bearing! Compressor maps are measured at a standard reference altitude of 315 ft and a 85 F turbo inlet temperature. At higher altitudes and higher temperatures the surge line on an "adjusted" compressor map moves down toward lower values of TPR and your maximum surge free BP is reduced accordingly.

 

SIGH.... Gene, you really have to give it up with the Banks quotes. Pretty much everything he says is to build up his stuff while putting down other stuff so people think the high prices he charges is worth it.

ZooDad -- The PCM sets the SES at about 22 or 23, and defuels at 25psi. My Overboost Annihilator is set to 21psi.

Stock truck will peak at around 17ish. Some get a little more, some get a little less. I was getting ~26psi with my stock turbo & WW. With my van turbo, stock wheel, and ATS housing, I'm getting about 30. When I get my injectors, I'll be at around 35. The 38r will support 40psi, if you have the sticks to drive it, and the engine parts to hold together while doing it.

 

I can hit 30-31 max WOT but I watch the EGT's mostly. I hope to get a bigger turbo 1 day and boost it a little more.

 

So Banks is wrong and you're correct???

 

Banks is a guy that distorts the truth to his own advantage. I'm sure he's right about some things, but do you stand by all his claims?

I'd say I'm right about this -- but does that make Banks wrong? No!! You've been coming in here recently quoting him like he's some kind of guru. He has built some cool stuff, no doubt. But have you read some the claims accommodating his products? Would you say he's right about all that?

 

Joe
I agree Banks has some good stuff but. As we can tell any one can come up with a formula that most people will not understand but will believe. Like it is wild how they are so fast and get so much HP and NO SMOKE. COOL!!!
Any thing I have ever seen in a strain like that will smoke a little.

 

The Banks truck is pretty cool....I've seen it run up close last year at TS. I was right by the tower as it came to the starting line and then did a burnout and launched.

 

Nitrious will do that for you...

 

Stock sticks, stock tuning most Superdutys max out at 17-19... OBS stock is about 14-17... Modded with stock sticks, about 30 is it...

Hybrids and a modded H2e... 47psi...

 

Sounds pretty much like what I said, Joe. I guess if our name isn't Gale Banks, we're wrong. LMAO!!!

 

This post is dedicated to those FTE members (I won't mention names) who think that Gale Banks doesn't know much about the 7.3L truck. As I'll show below one thing that Banks knows for sure and that most FTE members apparently don't is to not operate a stock turbo at dangerously high boost levels!

I can't count the number of posts I've read on this and other forums where members (and Izzy I won't mention your name here either) bragged about having pulled their red line and hitting 30 psi boost with their bone stock GT38 turbo!

In my post #17 on this thread I derived this equation... BP={(AAP)(TPR-1)}-{(TPR)(AFPD/27.68)}-(ICPD) psi and said... Your maximum surge free BP is determined by looking on the compressor map for your particular turbo and finding the maximum TPR that you can operate at while staying below the surge line ...and I went on to show that for a stock turbo... the maximum surge free BP at 3,200 RPM is BP={(AAP)(TPR-1)}-{(TPR)(AFPD/27.68)}-(ICPD)={(14.7)(3.2-1)}-{(3.2)(14/27.68)}-(1.9)=28.82 psi! ...and I then concluded that... Based on this result if you see a BP=30 psi with a stock turbo you're definitely hitting the surge line and doing some unnecessary damage to your turbo bearing!

Well operating with a BP=30 psi will not only damage your stock turbo, but as I'll show below using graphs and charts from a Banks marketing brochure for the 7.3L truck, bragging about your maximum BP is a rather meaningless endeavor to begin with!

Since most seem to have an aversion to equations I'll first give the conclusions and then fill in how I validated them with analysis, measurements, and my personal experience of how I prematurely wore out my stock turbo by switching from my Banks chip which came with my Stinger package to a plug-in Superchip which disabled the PCM waste gate control that normally limits the maximum BP.

On the Banks graph below I added 4 operating points using an equation which gives MAF as a function of BP, RPM, and other parameters. I also used a Garrett compressor map to verify that the stock and "Banks" surge lines are accurate.

First note that point #4 agrees with my above calculation that a BP=28.8 psi at RPM=3,200 is the maximum surge free BP possible with a stock turbo.

Now note point #2 which shows that a BP=17 psi at RPM=2,600 operating point is just below the stock surge line. The second Banks HP graph shows that for a stock truck the maximum HP occurs at RPM=2,600 so it seems that Ford was wise enough to design the PCM waste gate control to limit the BP to 17 psi at the operating condition for maximum HP to avoid surge! What purpose is served in pulling the red line on a stock truck just to watch the boost gauge hit a BP=30 psi at a 3,200 RPM when your maximum HP occurs at 2,600 RPM?





The above HP graphs for the various Banks performance packages show that as more air is added he adds more fuel and that the combined effect is to increase the HP over the entire RPM range and to increase the RPM at which the maximum HP occurs from RPM=2,600 to RPM=2,800.

Now look at point #3 on the first graph and note that for RPM=2,800 a BP=26 psi is the maximum BP possible without encountering the damaging effects of surge. So a knowledgeable and responsible provider of performance equipment would ensure that his products limited the stock turbo to a maximum BP=26 psi or less at RPM=2,800!

Now look at the chart below and you'll see that this is precisely what Banks did! At the RPM=2,800 for maximum HP all of his products limit the BP to a BP=25 psi or less! Maybe there's some truth to the Banks claim that his equipment is designed for both performance and reliability!



Ok now look at point #1 where RPM=2,000 and BP=16 psi because this is where you encounter the worst surge condition when trying to tow up too steep a grade in 4th gear with an auto tranny. As the grade steepens you apply more throttle to stay at your RPM=2,000 cruising speed until the BP hits the surge line at BP=16 psi then if you keep pressing on the throttle you'll hear various and sundry "strange" noises!

Well some noted experts might say you're just hearing normal turbo noises that were always there but are more audible now that you've installed an "open element" air filter. That's what the Doug Lewis speed shop in Atlanta GA told me after they installed an "open element" air filter on my truck! In addition to pushing too hard at 2,000 RPM in 4th I was routinely pulling long grades in third at RPM=2,800 and a BP=28 psi and of course I was hearing strange noises that I was assured were normal! Well as I learned the hard way the noises were in fact "normal" but by no means were they desirable!

So after I blew my turbo I wised up and decided I was probably smart enough to become my own "expert" advisor and that's when I did some experiments and discovered that my Superchip disabled the PCM waste gate control that normally limits the maximum BP.

The picture below shows how I fixed that issue by installing a "helper spring" that helps to override the spring in the waste gate canister. As can be seen I used a stack of thick washers to adjust the tension of the "helper spring" so that the wastegate would "blow open" at exactly a BP=22 psi when towing a grade at RPM=2,800.



In the first Banks graph the MAF is given by MAF={(VE)(CID)(RPM)(AAP+BP)}/{(MAT+459.67)(1,278.46)} lb/min where VE=Volumetric Efficiency a ratio 0 to 1, CID={(Nc)(Pi/4)(Bore)^2(Stroke)} in^3, Nc=Number of Cylinders, RPM=Crankshaft revs/min, AAP=Atmospheric Air Pressure psi, BP=Boost Pressure psi, and MAT=Manifold Air Temperature F.

For a 7.3L PSD use CID={(Nc)(Pi/4)(Bore)^2(Stroke)}={(8)(Pi/4)(4.11)^2(4.18)}=443.65 in^3, and then the MAF equation for a PSD becomes... MAF={(VE)(RPM)(AAP+BP)}/{(MAT+459.67)(2.8817)} lb/min. You can get real time values of your MAT using AE or you can pull to the side of the road after doing my road test procedure and use an "IR gun" to shoot temps of the intake plumbing to get an estimate of MAT.

To illustrate how this equation was used to calculate point #3 I used an AFIAT=Air Filter Inlet Air Temperature F of 80 F and a AFIAP=Air Filter Inlet Air Pressure psi of AAP=14.53 psi which corresponds to an altitude of 315 ft because these values work out to give a TIAT=Turbo Inlet Air Temperature F of 85 F and a TIAP=Turbo Inlet Air Pressure psi of 13.95 psi and these are the "standard conditions" at the turbo inlet when turbo compressor maps are measured.

Assume you apply 100% WOT in 3rd gear with a 4R100 and the TC locked, and that you're on a load dyno like Banks uses to measure his HP graphs or you're pulling a long grade for a few miles so that the MAT reaches an equilibrium at MAT=158 F, BP=26 psi, RPM=2,800, and assume the VE=0.6975. These numbers give... MAF={(VE)(RPM)(AAP+BP)}/{(MAT+459.67)(2.8817)}={(0.6975)(2,800)(14.53+26)}/{(158+459.67)(2.8817)}=44.5 lb/min, and this is how I got point #3 for RPM=2,800, BP=26 psi, and MAF=44.5 lb/min.

So my conclusion is that Banks knows a lot more about these trucks than people give him credit for and even if you're not interested in buying any of his products you should learn from the technical information on his site. I've discovered some technical errors with a few things on his site, but this is true of almost every technical site that I've visited. Everyone should rest assured that when I quote Banks I've checked his results and found them to be correct!

 

I hit 28 psi once with my stock early 99 turbo towing my 28' TT from Florence, OR back across the hill- only mods were 6637 intake, 4" turbo back duals, and maybe wastegate unhooked (can't remember now). After putting the DP tuner in I maxed out my 30lb boost gauge coming home one night in 80 eco, just to see if I could pull it off. My poor little turbo was begging for mercy! EGT's were climbing like an SOB when I let off too... the stock turbo just wasn't designed to go that hard. Maybe I should plug the wastegate back in until I can afford a different turbo...

 

Before cutting straight to your conclusion, I'm going to correct a few things... I have NEVER "Bragged" about hitting 30psi on my stock turbo! I know because I never have!! I have hit 28 with the stock wheel surging away, which is why I changed to the WW. That dropped me to about 26psi, maybe close to 27 tops.

About your conclusion, I never said Banks was wrong, or didn't know anything!! I said he distorts the truth and over-charges for his stuff. In fact, I said I'm sure he is right about some things. A person can be correct about things and still be an A-hole! All I was saying was that coming in here quoting Banks won't buy you much, Gene. Most folks here don't like him or his ways.

I know that for what I do, my truck is getting right where I want it to be. Once some things settle down here, I'll be putting in some injectors which should put me just under 400 RWHP, ~750ish Tq, and 35psi on my van turbo. Some testing with AE while on a dyno will tell me what I need to know about how it's doing health-wise. And if I prematurely wear my turbo out (which is my own damn business, BTW), I can rebuild it with $100 kit. I'm not worried about it at all. If it flies apart, or my engine windows, that's also my business, and the risk I (and everyone else) knowingly take when I take the 7.3L to nearly double its stock HP range.

I'm done here. Hasta la vista!!

 

Post #29 current thread...
Post #21 current thread...
I didn't actually use your name in this statement but for the sake of argument lets assume that I had and see where I might've gotten that notion by looking at the 3 points covered in the statement... #1 pulled their red line, #2 bragged, and #3 hitting 30 psi boost.

Post #10 here... https://www.ford-trucks.com/forums/6...99-wheels.html
Your reply in Post #12...
Post #35 here... https://www.ford-trucks.com/forums/8...ml#post7165192
Due to its controlled boost leak I don't think an ATS housing produces a higher maximum boost than a stock housing does and my measurements indicate that with the red line disconnected the wastegate doesn't blow open until 30+ psi and this has been confirmed by others as well...

Post #4 here... https://www.ford-trucks.com/forums/6...-red-line.html
So if you have your red line disconnected and you add enough fuel with a chip you'll hit a 30 psi boost!

Post #18 current thread...
Post #21 current thread...
Post #29 current thread...
I'd like to see at least one example where your above statements are true for the 7.3L truck!

In Post #90 here... https://www.ford-trucks.com/forums/8...n-turbo-6.html
...when I accused the vendor who promotes your favorite "open element" air filter of giving misleading and distorted information on his web site I quoted from the Dale Isley Tymar Performance web site exactly what the distortions were and then I proceeded to refute them!