Fuel System Tuning Q's

Hi guys,
I'm new to the blower / mechanical injection deal and have a few questions.
I guess my biggest question is how is the best way to know what jet I need to run for varying atmospheric conditions. I have heard of some computer software to do this and would like to hear more about exactly how each works...what I will have to input, pro's & con's of each, etc. I also expect that there are a lot of guys who are doing it without "software"....I'm told by using corrected altitude and a "chart"....if this makes sense to anyone, where do I get one of these "charts"?
I'm sure I will be adding questions to this thread as it goes along, but just wanted to get it started.
Thanks for all your help, I love this site!

 

It all boils down to how much oxygen is getting into the cylinders.
More Atmospheric pressure puts more oxygen in.
More humidity in the air puts less oxygen in.
The higher the air temperature the less dense the air so the less oxygen gets in.
It used to be real common to take all these readings then look at a chart and finally it combined all the data. From that you could determine pill size changes. Of course with electronics its now easier and faster.
Perform Aire is an easy to use portable weather station that will spit out a pill size.
I personally use Density Altitude and every 500 ft change in altitude (for my setup)constitutes a pill change.

 

We use the Davenport software. It takes a little time to get used to, but is a real help. I would buy the software, then take my whole system to be flowed. Enter this data as your starting point.

 

blower newbe...check your pm's..Dave
www.myspace.com/daveloweswr

 

web site

does davenport have a web site

 

Phone 403 938 6200

 

tech manuals for what you are doing

We have two books all about what you are doing.
Fuel Injection Racing Secrets has math to determine jetting.
5000 Horsepower on Methanol has math to determine jetting changes for weather.
Both books have a lot more info including jetting setups from several engines.
Same math in the calculators.
www.racecarbook.com
Bob Szabo

 

Bob,
Was looking at your website to see about ordering your books. Would be interested in both but you want $16.00 to ship both? What's with that? Don't mind paying a reasonable shipping and handling but geez.

 

For what the books have in them for knowledge, they're worth double what he charges. If you can afford blown alky, the books and shipping are a pitance.

 

WJ,
I can afford it and have no problem if the price is in the book itself but when the shipping gets inflated, I have a problem with that. If you ship this at book rate (probably $5 or less) and then add a few bucks for the trouble, that's fine. When you say the book is $99 but is on sale for $69 and you recoup the "savings" by jacking up the shipping, I don't think that is right.
This is no different than the thread for the Lenco front seal. Why pay $10 S&H for something you could mail in a .43 cent envelope? Just like everyone else, I'd try to find a local source.
I'm sure the books have good info in them just like Jim's at hre.com or Ken Lowe's. Not knocking the books, just the shipping.

 

I highly recommend both of Bob Szabo's books as well as Jim Harvey's HRE manual.

EDB

 

Bob's Books

What's the fundamental difference between them? I've got Ken Lowe's book, so I don't want to double up

 

another source of fuel injection info

I have heard and read a lot of good comments about Ken's book. I have not ever seen one, so our fuel injection manual is from other sources. Believe me, there is more to write about fuel injection than what could be in one book.
In addition, we have a second book on methanol fuel that is quite extensive and, I have been told, beyond any other written source.
For what this racing stuff costs, a book or manual cost is trivial for the knowledge that is in it. If I knew when I started racing what we have now in our manuals, I would have a whole new engine from the money I would have avoided spending with broken stuff to learn, and our fare share of some added wins.
Thanks Eric and WJ for the favorable comments.
REGARDING SHIPPING COSTS: We ship USPS Priority air. Most are shrink wrapped and well packaged. Priority mail orders have to be "hand delivered” to the post office and “hand received with a postal worker inquiry about whether there is any hazardous contents. Then answered in person, no by our worker.” Our charge for handling is less than our costs.
BOOK RATE NOT: The low cost "book rate" referenced by Tom is not viable. A cheaper book rate box can sit at the post office where it was dropped off for weeks before it is shipped.
SEPARATE ORDER ENTRIES: Regarding orders for each books at one time, they are processed separately. Some locations require separate packages. So orders have to be entered separately as of this time. The combined S&H costs that we charge are less than our costs whether the books go in one larger package or two separate packages.
We loose money on every one of our S&H charges especially now with the 4th increase in postage fees since we started. And we still have not increased S&H charges or our manual prices like most every other racing supplier in the world.
Bob Szabo
www.racecarbook.com
author of
Fuel Injection Racing Secrets
5000 Horsepower on Methanol

 

Bob;

Just as a suggestion to you.

I use a shipping service called Endicia for my business. www.Endicia.com

I bought a used 4x6 label printer (ex-UPS machine) from Ebay. Between the printer and Endicia, I print my own shipping labels at my computer, on my own time schedule, at all hours of the day or night. I do this for my own business.

I am then able to use the USPS Carrier pick up feature on the postal service web site. It takes about 1 minute to schedule a pick up for the next day.

These two services alone have saved me over an hour every day from standing in line with many stupid people at the post office. Packages are picked up from here in the St. Louis metro and have arrived in as far as Hawaii in 2-3 days.

Additionally, because it's a commercial account, I get discounts on shipping. A 1 pound box typically costs me about 4.80 to 6.00 to ship.

 

Thanks WJ, that is what I was trying to articulate. I was not trying to bash Bob but there are better ways to ship things without adding extra charges to the buyer. The Post Office has done a good job recently at sending stuff for a fair price. They only lack a good tracking system. I can ship most anything Priority Mail flat rate up to 70LBS for $9.80 to all 50 states and all US possessions such as Puerto Rico, Guam, Samoa, etc. It has to fit into their FREE flat rate boxes, most of the time that is no problem. You are 100% correct that you can set up free pickup so that you don’t have to stand in line. I guess the biggest thing that stuck in my craw was the statement that there would be no combined shipping. I feel that if there is a delay in shipping because one book is not in stock, I should have the choice of paying the higher fees because I want the one book or have the choice to wait until both books are in stock to get both books at a combined lower rate.
With all that said, I own both Jim Harvey’s book and Ken Lowe’s book. I paid an extra $25.00 shipping to get Ken’s book to me so I’m not afraid of spending the money for shipping but this came from Australia. Ken’s book has a lot of good info in it and it is very helpful. His book is geared to his products but it is still very useful. Jim’s book is just as useful but it is more geared to the science instead of selling product. Kinsler’s manual is a good read too.

 

back to original inquiry

USPS provides us with the best customer service which is what we concentrate on even if we have to pay our dues in a postal line.
Regarding Sodacs response to the original inquiry about changes for the weather and altitude, when we researched SAE combustion tech projects, the fact that air is about 21% oxygen kept on coming up thoughout the various studies. THe potential temperature of a methanol fire is over 5000 deg. F. Then I realized that what we are doing with race engines is harnessing a monster chemical reaction in a cold engine with air full of basically inert contents, N2. In fact, it is all the other gas in the air that keeps our engines from blowing the cylinder heads off. So we buy a bunch of parts to move more air and do a tune-up based on plug readings, engine temperature, experience, etc. As the air changes pressure, temperature, and humidity, that amount of oxygen left in it is changed. Regardless of how you track it or adjust for it, your engine settings and power output are different for diffent air.
When we run nitrous, we are supplimenting in only about 35% oxygen when full nitrous dissociation occurs which I am not sure is happening to many setups. Even with that small increase 21% to 35% for only part of the air in the engine (with more fuel) the power is dramatically increased. With that awareness for the power of oxygen, I now look at a race engine differently than I did before. I really respect the power of oxygen and the appropriate amount of fuel. And I have a great respect for any racer / tuner who does a good job of harnessing the O2 and fuel for what ever the power output from 5 to 5000 horsepower.
With commitments temporarily keeping me from running & testing our racecar, I am still getting off from the study of these machines, reading this forum about what all of you are doing, and hope to continue writing about it.
Bob Szabo, author of Fuel Injection Racing Secrets and 5000 Horsepower on Methanol
www.racecarbook.com

 

Thanks for the backup Bob.
FYI, I have your first book and it's well worth it. My folks gave it too me for x-mas last year and dad thoroughly enjoyed simply ordering it because of your "fuel conversation".
I plan on getting the "5000 HP" book for winter reading and would love to talk to you about it since in the tractor pulling world their are many inline 6 cylinders making 5000 HP with alky and 3 turbo's. I would like to build one someday.
Blower Newbie, I recommend buying, reading and studying Bob's book.
Than the first thing you need to do is keep track of the weather and your tuneup. Once your baseline is established (aka, xx pill = xxxx weather) it's real easy.

 

Hi BlownAlky,
Have both books of Mr.Szabo. My advise, paid the extra money in shipping cost to have thoses book rapidly. This will be the best 16,00$ investment you will ever made.
Take care,
Charlie

 

wow, this got a bit off topic. From a fuel question to shipping charges.

I am also a newbi at this and have a question that hopefully has a simple answer.

I race Top Dragster which is a bracket class. Since I have to put a dial on the run, wouldnt I want to leave the same tune up in it and calculate the DA and other factors like normal to put a dial in on the run? As long as the tune up is safe for the motor of course and not going to lean it out. I plan to run a bit fat anyway for safety to the motor while I am learning.

A pill change would affect the motor to compensate for the DA change and then I wouldnt know how to dial it. This is more for heads up racing to get the best performance from the motor isnt it?

Thanks in advance. And I'll be looking at the books as well.

 

consistency with fuel injection

Thanks Sodac and Charley for the good words. It is appreciated. In response to TD4141's question, bracket racing with fuel injection, I met an interesting competitor in IHRA who ran an injected normally aspirated combo. I believe it was set up by Kinsler. He said he never has to change a pill. I know from our experience that the tuning window in methanol is wide and I believe this racer is in the middle of his window. As a result, when he goes to different air densities, the engine in OK.
In our case, we would always adjust jetting to maintain the same air to fuel ratio for what ever air density we were in. There you have two extremes. When I analyzed these two ways, I concluded the following;
If a car is running flat out such as NHRA comp eliminator, pro mod, top alcohol, etc., the combination may be at the edge of the tuning window. in that case, adjustment of the fuel system for different air densities is probably a necessity. I consider the knowledge of what the air to fuel ratio as an enormous aid to find the jetting needed in different air densities. In our case, we would adjust the jetting according to simple calculations to maintain the same air to fuel ratio and life became simple.
In bracket racing to a fixed ET, life gets real complicated for some. In our case instead, we simply changed the blower overdrive to compensate for the different air densities, and the car seemed to run the same. In our case, we do not change the jetting, but the blower overdrive. Again knowledge of the blower air and air density effect makes that simple.
In bracket racing to a consistent ET such as a dial in, we would again find the air density, leave the blower alone, and adjust the fuel system to maintain the same air to fuel ratio. As air density would change, we would change our shift point according to a Quarter Jr. program algrythm to repeat the same performance. A consistent racecar setup was more difficult to accomplish than the previous few words indicated. In our case we evolved towards a linear setup. That is one in which the shift point determined the ET. And our life became simple. That is not always the case in some combinations. Some setups are not linear. Your supposition is right. Changing only the pill causes a whole lot of changes to the setup, different air to fuel ratio, different system pressure, different high speed opening point, different ET, etc. And that is where tuning this stuff gets interesting and custom to the individual tuner and racecar. Hats off to all of you who have mastered a combination the best at an event and well whether it was the first, second, or the third case from above.
Bob Szabo author of Fuel Injection Racing Secrets and 5000 Horsepower on Methanol
www.racecarbook.com