Here's a cut and paste just posted today on the COG about the Shoodaben Vs Guhl flash. Don't know the man, other than as a customer. This repost is with his permission. thanks Harvey - Steve
"Comparing Stock Flash Vs Don's Flash Vs Steve's Flash
Today at 07:49:59 am »
Hi Everyone,
I've been through some of the threads and I thought I'd help others who were in my position. What I felt lacked was a detailed review of all 3 ECU flashes. So I thought to share some of my findings with everyone. I won't write paragraphs upon paragraphs of feedback, but rather copy part of my own personal notes below for everyone to see. However, please keep in mind the following:
1. I do not know Don or Steve and have only spoken to each of them twice on the phone. Both times were strictly about he flash, what I currently have, what my expectations are and current bike configuration.
2. I do not receive any royalties from either of them for saying anything positive (or negative).
3. I do not belong to any organization/forum, nor do I have any association to any group that may or may nor benefit from my evaluation.
4. My evaluation was based on what was important to me and what I could perceive (everyone detects and perceives different things).
5. The following is my opinion and my opinion only. I welcome all questions/comments and will respond only to the ones that are respectful. I will not respond to accusations or derogatory comments.
Conditions:
1. Multiple rides (easy touring, hard accel/decel, mountain type riding, hard cornering, MSF testing) were performed with all 3 flashes (stock, Don, Steve) and evaluated.
2. Riding conditions, bike conditions, road and climate conditions were similar.
3. Bike used was 2013 Kawasaki Concours 14, stock form, no mods other than Muzzy Slip on exhaust.
4. Octane 91 was used on all rides.
Overall Assessment of Don vs Steve (please see table for details of rides and evaluation):
1. From 0-6000 rpms, Steve's flash superior from Don's by roughly 10-15% (again, this is my perception) based on throttle response.
2. From 6000-9000 rpm, Steve's flash is vastly superior over Don's. It is as improved over Don's as Don's is over the stock flash.
3. Fuel Efficiency: Steve's flash is far superior over Don's. Don did not work on the ECO mapping, Steve did. His flash is the equivalent of the ECO mapping in terms of fuel efficiency.
4. Engine braking (chopping or rolling off throttle): Steve's flash is almost identical to Don's but there are subtle differences (see table)
So if have the stock flash and are looking to upgrade, my assessment is to go with Steve's flash. It is superior and less expensive.
If you have Don's flash:
1. Conservative riding: You will gain 10-15% better quality rides with the added benefit of using a lower octane (89), equivalent fuel efficiency as the ECO map and a smoother more responsive throttle. Does the cost of another $300 justify 10-15% gain? That's for you to decide.
2. Hard riding (6000 rpms or above): You will gain 100% in performance. Steve's flash is definitely the way to go.
From a professional and personal stand point, both Don and Steve were A+, all the way. What I was most impressed about was the packaging of the ECU from Steve. The ECU was bubble wrapped, placed in a box. Then the box was bubble wrapped and placed into another box. If Steve's conservatism and attention to packaging is that detailed, there should no doubt about his quality of work with his ECU.
His ECU flash is an excellent product and if you are looking for a major difference in performance/fuel efficiency without anything to do other than "plug n play", his flash is the way to go.
TABLE OF RESULTS: Please see attachment
Hope I have helped someone out there.
Take care,
- Harvey"