Jump to content

SDS Users - Fuel Map Spreadsheet?

Recommended Posts

  • 6 years later...

Anyone? I'm new to SDS and working on a car that has not run in 10 years. Initial thoughts are duty cycle is way to high for stock L28ET injectors but I'm at a loss for figuring out the fuel map on this thing. A guess would be a 77 at 500RPM 77 at 1000 RPM and then up from there but even with those settings I think there is too much fuel to start.


Any suggestions are greatly appreciated.



Link to post
Share on other sites

I don't have a map in that format, however when I was running SDS with 440cc's on a L28t I believe I used 62 as my constant value from idle to redline, maybe it was 65. Whichever it doesn't matter that much because you can use the MAP values to adjust the fueling. If you're at 77 I'd think that would be too rich, but it depends on your MAP values too.


In the idle range you want the MAP values to be the same. I think for 18,19,20 in vacuum I was around 30-32 then for every inch of vacuum I went up 3-4 until I hit boost and then I went up 5 for every psi in boost.


Do you have the fuel trim box? If so you could lean it out that way to get it started if what I told you doesn't work.


I think stock L28t injectors are what, 370cc? So I'd probably use 60 or less as my constant, and then manipulate the MAP values to adjust the fueling.

Link to post
Share on other sites

Well she runs! Doesn't idle yet because I think the throttle body is closed completely. Shouldn't be too hard to get that squared away.


Supra, I'm all the way down to 56 as a constant and still have the trim pulling another 17% to get a smooth idle with my foot holding the throttle open to keep 750rpm.


Dave, no wideband hooked up. Doing all of this by feel at the moment.


I would keep going but now I have to clean up the 5 quarts of oil on the ground from an oil filter that wasn't seated properly. :angry:


The car has no exhaust so I guess I'll be at it again tomorrow.


Still could use a speadsheet if anyone has one to check myself :)



Link to post
Share on other sites

At this point I'd probably pull more values from your MAP setting in the idle range until it idles fine without pulling using the knob. Good it's up and running.


Do you have a throttle screw you can use to open the throttle at idle? I never used a ZX throttle body, but I assume it's there.


I wouldn't run much boost without a wideband, but you should be able to make it run and drive fine without one. Even if it's pretty pig rich it's drivable, if it's too lean it will stumble and hesitate.


For the throttle pump I've only ever used 12-15 both high and low.

Link to post
Share on other sites

Lol, thanks. I've had the SDS in there (fuel only, long story) since 1997...Finally decided to run something newer so I just installed a Haltech e11v2 and got it up and running using LSx coils, but I'm taking it to someone else to tune.


One thing I always liked about SDS was the simplicity, even if it lacked features, but I'm excited to see what this system can do.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...