CYCLEDOCTOR - Discussion

Fuel Injection tuning question answered

Response to inquiry regarding the Digital Fuel Optimizer:

DFO is inadequate in addressing the function of your Delphi fuel injection. Now that you have altered the breathing characteristics of your engine, it is vital that you teach the control module the new airflow to enable your system to mix the right amount of fuel accurately. Until you do that, you are running your engine "close enough" or perhaps not close at all in tune, and are likely not realizing the full potential of the performance investment you have made.

While there are many ways to change the injector pulsewidth (the DFO being one of them. Power Commander, etc.), none will do it with the capability of the TTS Mastertune.

Also, there is no other system that I am aware of that will operate as a speed density fuel injection (Zippers, Twin Tec, S&S etc.). They all resort to Alpha N. Speed Density offers many advantages and is much improved over the Alpha N. The early Magnetti Marelli EFI that the Harleys were originally equipped with were Alpha N. While neither system knows how much air is actually filling the cylinders (as in a Mass Air Flow EFI system), the Speed Density offers greater efficiency through the use of a Manifold Absolute Pressure (MAP) sensor.

With a speed-density EFI, the fuel delivery can change at any given RPM and throttle position from rich to lean depending on the load as interpreted by the MAP sensor. For example, a speed density system can be programmed to run 14.6:1 while cruising under light load circumstances, and 12.8:1 when you really need to be making some power, and everything in between.

Both Alpha N and Speed Density systems used on the Harley-Davidson motorcycles need to be taught the volumetric efficiency in order to have the ability to perform accurate calculations of the fuel necessary to achieve the desired air fuel ratio. That is the job of the person doing the tuning.

To work with the programming of the Delphi requires the necessary software and interface. The original Screamin' Eagle Race Tuner (a Mastertune with much trimmed down features) did it the best. It was fully copied by Techno Research whose product offered similar capabilities. Now Harley has dropped the SERT and replaced it with the Supertuner. The Supertuner works great with the Delphi EFI but lacks many of the features of the Mastertune.

Since the Race Tuner is obsolete from Harley-Davidson, the creator (Steve Cole, The Turbo Shop) has continued to develop and market that very same product under the name TTS Mastertune. It has all of the functionality that it had since being labeled the SERT and then some. It's development has far surpassed anything I have seen.

The biggest deterrent for tuners in using the Delphi and related tuning software has been the difficulty of use. Nearly everything else marketed has had ease of use as a feature. However, they are all at a cost of capability.

The equipment I use allows me to monitor AFR over the entire operating range and in each individual cylinder at all throttle positions. While doing this I can make changes to the mixture and verify the results. I can do it to carburetors, Delphi, Marelli, TMax, Twin Tec, etc. and on anything that will fit on my dyno: dirt bikes, Jap bikes, Big Dogs, Harleys etc. Engines operate and run best at a specific air/fuel ratio. It is just a matter of creating it.

The best product to create the most accurate and efficient conditions for your engine to operate in is the stock Delphi fuel injection. The best product to use to tune it with is the TTS Mastertune. Retail price is $425 and requires 4 hours of adjustment to calibrate the EFI to perform accurately. That is $400 (4 x $100/hr.) $825 total plus tax.

EFI Tuning and product selection

EFI Owner,

There is nothing that has the capabilities of the Mastertune. It is absolutely the best tool for the job.

The stock Delphi EFI is a speed-density system. There is not a better system available for your bike. Replacing it is a big mistake, unless you cannot find anyone capable of adjusting it.

The Thundermax is an Alpha N system and although available closed loop, depends on a base map for it's calculations. If you have to adjust the map (if it needs to correct itself outside the range of it's ability), then it defeats the purpose of buying one. Calibrations from Vance & Hines will do as good a job, if not better for much less.

If you have to do any adjusting, then do it with a Mastertune and the best EFI available - stock Delphi.

For true performance set-ups (cams, headwork) there is no substitute for a custom calibration, and the Mastertune does it the best.

Stock Delphi=Speed Density Everything else=Alpha N (S&S, T-Max, Twin-Tec, Power Commander)

Delphi tuners = Mastertune, Race Tuner (now obsolete), HD Super Tuner, Techno Research (copy of Race Tuner)

Nothing has near the features of the TTS Mastertune, and the TTS Mastertune is the only one that offers Vtune auto tuning for closed loop systems.

If a tuner knows how to build a base map (teach the EFI how much air is filling the cylinder), then they can tune a Delphi system. A Delphi system offers the maximum efficiency for any motorcycle operated on the street. Alpha N is fine if you are only concerned with wide open throttle, or don't care about fuel economy and cruising performance.

Cycledoctor Testimonials

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Thanks Geoff: I never really knew how a Harley was supposed to drive until NOW... I had no idea it wasn't suppose to "cough" at every intersection and backfire on deceleration... Thanks Again!

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Thanks Geoff - the bike really runs great. Smooth, great sound and man it pulls great. Very happy. Can't wait for my group ride today.

More Testimonials

After I picked my bike up this morning, I couldn’t stop smiling all the way home. My only regret is that I didn’t come into your shop sooner. Whatever magic you worked on the dyno really paid off. The torque improvement was obvious and the bike is running great!!! The crappy low end response I was experiencing is gone, gone, gone!! I feel like I’m riding a completely different motorcycle.

How to describe the ride home - Brilliant! Tons of traffic but what a great ride. Big change in the handling especially in the corners. Seams in the freeway surface were handled much better. I was braced for the bumps but they were much less. Hope to get time up in the mountains on the open road over the holiday and really see what it can do.

At a traffic light in major traffic, two other bikes pulled up alongside me at the front of the line: one was a Japanese cruiser, the other a sports bike. I beat them both off the mark then slowed down and let them go by; point made. :) Will let you know how it goes in the mountains…

Took a 100+ mile ride through the mountains Monday. Did not want to get off the bike. First full tank got 38mpg. This includes a portion of the commute home last Friday so it was very hot and lots of stop/go traffic. The bike just runs great.

The bike is all around more responsive, not lugging out of the hole, as far as I can tell. the ride back was on the freeway, but even there, it seemed to pull harder through all the gears, didn't really push it but it felt strong.

The bike is awesome. The difference is phenomenal. Response is immediate and I can transition through all gears smoothly. I no longer have to wonder whether or not I am going to bog down at a stop light or if I can corner smoothly. It was well worth every dime spent. You produced everything that you advertised to me and I will recommend you to everyone that I know.

The most obvious was the bark... when I hit the throttle it wakes up everyone around me. Torque - the bike really has no hesitation when i’m in first gear and then lean on the throttle (as you know this was the original problem). I can really feel the power in 2nd thru 4th gear. What I really noticed was how smooth and consistent the power was throughout all gears. To me it did not lack any performance...

Thanks again for all your help and great job on my bike. It has a full power band again with lots of pop on the top end.

I bought my first Harley from a friend in April of '06, after a life time of owning rice grinders. At the time I didn't really know or appreciate what I really had gotten into. I just knew that the bike ran really strong and I didn't lose many races with other V twins.

My bike already had the Stage II 95 ci. big bore, tuned with the Race Tuner, 203 cams, Thunderheader and had all been done at Cycledoctor. It ran strong and wasn't over built with a high maintenance grenade motor. The friend I bought the bike from always told me to bring it back to the Cycledoctor if I wanted any other work done. I wish I had listened.

Ego got the best of me and I wanted more. I was having my regular scheduled heavy maintenance, the things I couldn't myself, done by a local performance shop that recommended high volume heads, and bigger gear driven cams. It was a disaster - the bike didn't run half as good as it had before unless I was really on it. There was no torque in the lower RPM range, and it was pinging at cruising speeds! I learned that the mapping was off and there were few people in SoCal that could get it right again.

I finally brought it back to Geoff for a new clutch and dyno tuning. Using what he had to work with (my existing set up on the bike) Geoff tuned it up to perfection. I once again can enjoy plenty of pick up (torque) at around town speeds and it pulls the front wheel off the ground when I nail it.

I spent thousands of dollars at a few of the other so called V-twin performance shops. The work Geoff and his crew have done on my bike speaks for itself. I am very grateful to Cycledoctor for spending the time to write a custom map for my individual situation.

Thanks for the great tune (or as you say, calibration)!!! Night and day difference between your work and the other (shall go unnamed) well known tuner. There’s no stumble off idle, and a smooth roll-on with plenty of power. I checked inside of my pipes when I got home – toasty brown, as they should be. After I left the other guy, they were soot black.

Not only does a well-tuned bike just flat out run better, but it adds to my riding confidence. BIG smile on my face, Geoffrey. Thank you very much!

Follow up: I took the scoot for a ‘therapy ride’ after work today. MAN what a difference. It’s back to being fun to ride!!! Great work.

Just wanted to let you know that the bike is running great. Had a chance to get it up to freeway speeds this morning and there is a definite difference in performance as a result of your tuning.

A few of my riding buddies are taking off work early today for a run up through Malibu canyon so I should be able to experience the performance

I will be using you for all of my future maintenance... I have to tell you that I was the most impressed with your shop vs. ANY other HD service shop I’ve been to here in SoCal. I appreciate your attention to detail and how immaculate my bike was when you finished the work... I also recommend you to all my Harley friends...

Thanks to Geoff @ Cycledoctor for taking the time to work with and tune my 131” EFI motor. I was having some detonation, starting, and idle problems that were very frustrating. Geoff took the time to listen to the problems that persisted after a tune that was done previously somewhere else. He spent 5-6 tedious hours working to get the AFR spot-on and making the correct timing adjustments based on fuel quality here in California.

I recommend Geoff to everyone I know who is looking to have a tune or work done on their bike. He has tuned 2 bikes for me and they are the best tunes I’ve ever had. Geoff prides himself in being and doing the best job the first time. You will get the very best while dealing with Geoff@ Cycledoctor. FWIW- You get what you pay for when it comes to tuning…

Hi Geoff, Just wanted to stay in touch and let you know that I'm approaching 10,000 miles on the 95 inch build you did for me. The engine runs exactly the same way today as it did when I left your shop after the post-build dyno tuning. It pulls hard EVERYWHERE, never runs hot, starts readily cold or warm, and idles correctly regardless of how aggressively I ride it. All of this is just as you said it would be -- a great breathing, high performing engine that is completely reliable. After riding the bike for nearly 10K miles, I've come to the conclusion that this is a perfect street engine, because of the combination of performance and reliability. The real kick for me is how much fun I have on the bike because I love snapping the throttle and feeling the same response every time from this rock solid engine.

Thanks again for your great work, and the integrity and customer focus you bring to the Southern California motorcycle community.

Geoff- I wanted to take a moment to say thank you to you and your CYCLEDOCTOR team. The conversations about performance upgrades have been fun and educating. It is very refreshing to see someone operating a business where integrity and ethics are the first priority… especially in the world of motorcycle mechanics. I have taken every opportunity to pass your name along while hearing guys complaining about not finding a good tuner in Southern California. I wish you many years of success and hope your business continues to grow.

Wanted to let you know how bitchin' my bike is running. You dialed it in just like I asked. Handles great, has more power, and best of all I look cool riding it. Thanks again brother for the great work.

Just had to email you and say what an incredible difference you made to the performance on my Hellion Chopper.... I never realized how underpowered the acceleration was until you 'Tuned" it correctly. The throttle response is instantaneous, no hesitation, all power right now...and right thru the power band in all gears.

Thanks for everything, I wouldn't hesitate to bring my bike to you for anything I need and would absolutely recommend you to anyone who is looking for and appreciates quality work.

A follow up report on my 2005 FLHTI that you did the extensive remapping on: The bike has never run as good as it does now. There is virtually no popping on deceleration, no spark knock or pinging even in 100 degree ambient desert temperatures and mileage of 42 MPG.

Geoff: I just want to thank you for all the great work you did on my Road King Classic. You delivered everything you promised. As you remember I wanted increased horsepower and torque. I did not want a radical hot rod but I wanted high performance. I wanted a bike that would work well around town and on long trips. I wanted power when I needed it and that is what I have.

My brother had his Road King Classic upgraded from 88 to 95 by a Harley dealer. They did a screaming eagle upgrade. They put a bigger cam in than you did for me and installed Thunder Headers with Harley's download for the fuel injection. It took "5 WEEKS". You coordinated things with me and your great staff and pre-ordered my parts. I dropped my bike off on a Tuesday and picked it up on Thursday. "3 Days" what a difference. I had other items handled at other times at your place, such as adding after market parts and I received same day turnaround. As far as performance, my bike has Vance & Hines Pipes versus my brother's Thunder Headers which are higher performance. He has a significantly upgraded cam versus what you gave me.

With all these advantages my brother's Harley dealer's upgrade had, my bike out performs his. The torque I have is greater and the horsepower is equal. My air fuel ratio print out on the dyno is almost a straight line. His has significant dips in it. If I put his pipes (Thunder Headers) on my bike, my horsepower would be even greater. He cannot pull away from me. When he gets on his bike, it takes little effort with my bike to stay with him or pass him.

As far as gas mileage, right after the rebuild the mileage wasn't that great, but after the break in period and your dyno tuning my mileage is even better than "stock". My bike is performing so well, my brother is going to bring his Road King in to have you put in a Power Commander III and dyno tune his bike.

It is obvious that your solution using the Johnson heads is far superior to Harley's Screaming Eagle solution. You truly are The Doctor in fact you are more than that you are a master surgeon. Taking an inefficient bike and converting it into a well breathing performance machine.

My 2008 Road king Classic is three months old. I had 1.50" Flyin' Ape Hangers installed by the Cycledoctor this week in Costa Mesa. Geoff had recommended Carlini bars as a choice to consider. Geoff and his staff did an outstanding job completing the work. I know this was uncharted waters for an 08 with the fly by wire technology, but in the end, a great result. Geoff thought these might be the first Carlini Bars installed on an 08 Road King Classic, in So Cal, anyway. Love the bars, Geoff and his staff did a great job and most importantly the customer is happy.

Thanks for the great bars Carlini and thanks Geoff and your staff at Cycledoctor.

Geoff has been servicing my 1997 Electra Glide Standard since I bought it. When I first bought it I was happy to have been referred to Geoff from some reliable sources. They proved to be right-on in their assessment of Geoff’s skills in the shop and great customer service.

Though I was quite the rookie, lacked the simplest of mechanical skills and likely asked crazy and ill informed questions he helped me and treated me with great respect. Several years after I met Geoff he rebuilt my engine and added design features as I wanted a little more punch and a different look to my bike.

Again, a great job and to this day my bike runs like a top. I have never had any problems and though I don’t ride as much as I use to I am reminded every time I get on it how fortunate I am to have a top notch mechanic! Geoff is a knowledgeable technician and a great guy! Trust the servicing on your bike to no other!

As a proud owner of a 2002 Indian Spirit I can't relay the dismay I felt when I began to experience mechanical problems both great and small with new bike. Soon I became a frequent visitor back to the dealership where I purchased my bike. Being aware of the condition of my bike I was always greatly concerned of break downs when I was out on the road.

When Indian MC announced their quitting that's when the panic set in. With dealerships closing and more mechanics reluctant to work on Indians I was ready to throw in the towel.

A buddy of mine told me about the Cycledoctor. When I took my bike there not only did I find a guy more willing to help me, but here's a guy who's very knowledgeable. I could fill pages with the good experience I have had doing business with the Cycledoctor. I must note on more of a personal level. I can't tell you how much Geoffrey and his crew has helped me during times when my bike needed repair and my cash flow wasn't flowing too good.

To sum it up, my bike runs better than new and stops on a dime. The American Motorcycle Community needs more of the type of business the Cycledoctor is and more of the type of people that run it. Amen.

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