Post inexpensive mods here

[dolson]

beers2u, yes, I go about things a bit off from the thundering herd. For instance I tuned a 1957 Ford T'Bird with a stock 4bbl Y block engine that ran 16.5's at 92 mph in the 1/4. It runnered up at the national Oldies but Goodies race. It ran 16 races that day and didn't vary more than .03 all day long. The reason we got first loser is because it broke out. (Ran too fast in the finals) but we still made it into 3 national publications.

I like to work with what I have and try and make the best of it. Optimize that and then go from there.

To the others that are interested in the fuel pressure thing I need a little time to get the tank off, get some pics and take some measurements which I'll post in our tech album.

Don

[preachp]

On 2004-08-11 00:24, dolson wrote:

I like to work with what I have and try and make the best of it. Optimize that and then go from there.

Don

Hi Don,
A man after my own heart. I just couldn't see spending the dollars that they want for a new can, so I found a way to improve what was already there. The noise level is such that I doubt anybody will ever check to see if the baffles are still there.
As for the Sprint there is a lot there to work with. :-D Maybe I'll give that regulator thing a try.

Preachp

[preachp]

On 2004-08-11 00:24, dolson wrote:

I like to work with what I have and try and make the best of it. Optimize that and then go from there.

Don

Hi Don,
A man after my own heart. I just couldn't see spending the dollars that they want for a new can, so I found a way to improve what was already there. The noise level is such that I doubt anybody will ever check to see if the baffles are still there.
As for the Sprint there is a lot there to work with. :-D Maybe I'll give that regulator thing a try.

Preachp

[dolson]

Have you ever heard these things shriek without the can on? It wakes the dead....On the other side of the earth

Preachp, Have you ever felt a slight throttle snatch just off idle like going around a corner and attributed it to the cables or the phase of the moon? Fuel pressure changes all that. Instant on like a light switch.

The best is to do this and then get the TuneBoy/TuneEdit. (I have no affiliation with Wayne other than believing that the ability to develop your own maps is the way to go.)

Don

[dolson]

Have you ever heard these things shriek without the can on? It wakes the dead....On the other side of the earth

Preachp, Have you ever felt a slight throttle snatch just off idle like going around a corner and attributed it to the cables or the phase of the moon? Fuel pressure changes all that. Instant on like a light switch.

The best is to do this and then get the TuneBoy/TuneEdit. (I have no affiliation with Wayne other than believing that the ability to develop your own maps is the way to go.)

Don

[ctballos]

Well I drilled out the baffles. It went pretty smooth. I used an 18" extension with a 1" high speed steel drill bit. The first hole went easy but because of the slight angle in the tail piece of the can I had to ream out the first hole (enlarging it) so I could get the bit and extension near the center of the front baffle. So the first hole ended up being about an inch an a quarter in diameter. Drilling the second hole also went pretty smooth.

The sound is awesome, deeper and more throaty. It also seems more responsive throughout the entire RPM range. It feels quicker but it may just be the way it sounds I don't really have any way of telling until this weekend and I ride against some other bikes.

I do have a question. Should I have the Dealer load the off road fuel map the next time I am in?

Another question. Can I modify the fuel pump pressure myself and if so how?

Thanks for the info,
ctballos - Tom

[preachp]

I do have a question. Should I have the Dealer load the off road fuel map the next time I am in?

Thanks for the info,
ctballos - Tom

Hi Ctballos,
If you are getting a lot of loud backfires on decelleration yes, if not it is optional. I am not talking about the burble and small pops. Those are normal. I'm talking about the m-80 bangs that leave cheek creases in the seat! Thosae loud bangs are a result of an overlean mixture and do require a richer map.
BTW I am going up to New England Motosports on Saturday to a dyno shootout. Don't care just want to see what's at the back wheel. I DO know that it is not your imagination about to the extra oomph.

Preachp

[dolson]

You can modify the pressure regulator. Take a look at the fuel panel pics. in our tech album. It's the thingy on the right.

Remove that and you can see that it has a flange and an indent in the top of what I call the hat. That's were the spring is. Get a large socket to support the unit on the outer flange and a smaller one to match the indent on the top of the hat.

This is where the rocket science and engineering come into play so pay attention :razz:

You put the regulator with sockets into a vise and squeeze a bit so the socket that's in the indent makes a deeper indent. How much? Using the the engineering term, TAR. (That's About Right)

This will make Dan'l freak and geek :razz:

This is why I am going to make some pics and using a depth mic. take some measurements of a stock one comparing to a modified one.

What you are doing is adding pre load to the spring underneath the hat changing the psi from the stock 40 to about 50 or 60 psi.

What this does is to enrichen the F/A ratio per injector shot across the board of the current map. In addition to a superior driveability and much crisper throttle response I have seen my MPG get more stable and even a bit better that before. It looks like the added pressure aids in the spray pattern from the injector. (Last little 200 mile trip loafing along I got 56.7 mpg.

I'd still advise getting another regulator to modify. They are easy to come by.

I see this as no different than changing the jetting on the carbed. twins to get a better running engine.

Don

"Take a look at the fuel panel pics. in our tech album."

Dolson, where do I find the tech album? had a look and search and cannot find it.

Thanks

Martin

[dolson]

Hi Martin and all. Just take a peep at the upper right of our panel here. You'll see Album. Just click on the clicky and it will take you to the Sprint Tech album.

Don