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How to TBI
https://slantsix.org/forum/viewtopic.php?t=25968		 Page 2 of 4
Author:  Sam Powell [ Sun Nov 25, 2007 6:02 pm ]
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Thanks for posting your maps. I have a couple of questions for you: How does the ECU set the timing during cranking? Do you have idle control? How did you decide on your fuel map? What was guiding your choices there?

Looking at your timing map, if the ECU looks up cranking/start timing from the timing map, then you might get faster starting if you reduced timing from the 500 RPM column down to 6 degrees, all the up and down the column. I just did this on mine, and it starts more reliably now. It is interesting that you took out fuel at 3500 and 4300 RPM above 70 KPA. What led you to that?

See if you can take out fuel at 15 KPA. This should give you better mileage. It can also help to increase timing at the lowest KPA value.

Good job!

Sam
Author:  runvs_826 [ Sun Nov 25, 2007 7:21 pm ]
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Sam did you ever use the megasquirt program or did you just go with accel? I'm not quite sure what you meant on timing during cranking, I believe it's a constant 10-15deg according to the HEI setting. Than it jump to the table after it reads 300rpm which isn't no longer cranking. The maps are mostly based on the Megatune program which I assume uses an algorithim to change the VE from current to match 14.7 stoich. This is mostly built for fuel economy. Also it seems to focus on the areas I dove into so some were untouched.
Also, no I need to set up an idle control for warm-up maybe during winter break. Thanks for the heads up about the lowering timing, I was trying to keep it constant but I'm going to give that a try to see what it does? How's your tuning going? I gotta say so far it's been easy once I got a good map roughed out, is it much more difficult with the turbo?
Last, "It is interesting that you took out fuel at 3500 and 4300 RPM above 70 KPA. What led you to that?" it was pretty much the anaysis program in megatune, it was running really rich from the original table generated (first map). The area cut down in the middle seems to be where I hit mostly while I was driving so it changed it. I need to run autotune and ride with someone else driving to see if it hurt or help.
Author:  Joshie225 [ Sun Nov 25, 2007 9:34 pm ]
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Very cool! I see the latest VE map tapers off above 3000 RPM so the torque peak can't be that much higher than a stocker. I want to do something similar, but use two single throttle bodies on an Offy dual carb intake. I have to read up on MegaSquirt and see if it is capable of handling fuel enrichment for nitrous injection. :twisted:
Author:  Sam Powell [ Mon Nov 26, 2007 4:51 am ]
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I did have the first version of mega Squirt. I switched to ACcel just about the time they were bringing out MSII. The Accel program has too many tunable variables for an amatuer, which I am absolutely. So there are many things I am not doing at all. I think it is difficult to get an engine tuned for NA, and boost at the same time. They require such different things. I think you have to maybe have several different maps you can choose from depending on how you are going to use the car, and what kind of fuel you have.

So far I am just working on tuning the NA side of things. It is getting cold around here now, so I am driving the car less.

Again, congratulations. Your inovativeness, and creative solutiions are an inspiration.

Sam
Author:  Matt Cramer [ Mon Nov 26, 2007 6:45 am ]
Post subject: 
Quote:
Very cool! I see the latest VE map tapers off above 3000 RPM so the torque peak can't be that much higher than a stocker. I want to do something similar, but use two single throttle bodies on an Offy dual carb intake. I have to read up on MegaSquirt and see if it is capable of handling fuel enrichment for nitrous injection. :twisted:
The newer code versions can do this with the right mods:

http://www.msextra.com/manuals/MS_Extra ... al.htm#nos
http://www.msextra.com/ms2extra/MS2-Ext ... tm#nitrous
Author:  Joshie225 [ Mon Nov 26, 2007 7:41 am ]
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runvs_826, whatever your given name may be, sorry to hijack your thread! But maybe you want to run N2O too.

MS2 will do 2 stages of N2O huh? Very nice. I doubt the K-car throttle bodies would have big enough injectors to handle much nitrous so at least one stage would have to be wet.

A related problem is do I go with a big clutch or swap in the automatic? I like my stick, but the auto is cheaper and probably safer.
Author:  runvs_826 [ Mon Nov 26, 2007 4:33 pm ]
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Megasquirt from the looks of it is very n20 friendly, it has a couple easy functions that set it up including: a code base section which talks to the relays I believe, a seperate timing table that kicks in when nitrous is activated, and last a simple set-up table. Also TBI unit I used has multiple injector set-up which should handle as much nos as I can give it, unfortunatley the car can't handle more the 100lbs/hr and a lower end I'm feeding it closer to 110.
Image
I spent a lot of time to find a 4-speed duster, I personally like shifting. But let's face it auto's are faster, easier to drive, and when built right don't need clutch replacements. So look at what you built the car for, and personally like. So all in all.... keep the clutch.
Thanks for the complement Powell, gotta give credit where it's due. Pop's has been a huge help and did a lot of the frustrating work when I was stuck. I'll update when we get the accel wizard worked out.
Author:  Dart74 [ Sun Dec 02, 2007 12:18 pm ]
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Hi all,

Good job on the EFI-conversion! I was wondering if you could send me the MS-tables you are using? It would give me a place to start and save me the hassle you´ve been trough :wink:

Anyway, I strongly recommend using a wideband o2-sensor whle tuning, it makes tuning alot easier and you don´t have to guess what AFR the engine is running. I´m running Innovative LS-1 witch I got new for ~180$, worth every penny.
Author:  Dart270 [ Mon Dec 03, 2007 7:43 am ]
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Very nice work there. This takes a while to get things right.

I have one TBI'ed Slant and one MPFI'd, both MSI so far. I've logged about 30k miles and plenty of racing on these setups.

TBI is on the fast car (14s) and I use 2X85lbs/hr injectors and have run them to 85% duty cycle before upping the fuel pressure to about 19psi from 15psi. They work fine at low RPM. Mind you this motor makes power to around 6000. External pumps on both cars. Built some shield around the MPFI pump and quieted it down. I'd love to do an in tank pump, though, and yours will be a model.

Cheers,

Lou
Author:  sandy in BC [ Sun Feb 03, 2008 11:29 am ]
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Imageclick to view full-version

Heres my version.
Author:  runvs_826 [ Sun Feb 03, 2008 1:44 pm ]
Post subject: 
Looks great, got an offy that I was planning on doing that with, but thought I might chop up the one barrel first. Duster has been running great, but the motor mounts are shot so no more tuning untill that is fixed. Got to say, this slant has got some kuHAH now that I built it, defintly as satisfing as a 318 would've been.
Author:  Sam Powell [ Wed Feb 06, 2008 4:34 am ]
Post subject: 
Runs, I was studying your fuel map, and noticed that you have the VE designated as 82 at 600 RPM and 100KPA. This is the cell that the pointer would move to during crank to start. Does your engine start right up? Does it seem like it starts rich? That is a lot of fuel. If it starts well, then that is a good guideline for us all to follow. Your ECU is providing about 3 times the fuel at crank to start as it is at idle, and that is without any coolent temp enrichment modifiers. Please share your thoughts and experience here. Would you do me a personal favor here: Start your car up while watching the injector open time in MS's during crank. Then watch and record the same time in MS,s of the injector cycle at idle, both cold, and warm. The size of the injectors would be nice to know, but the comparison of the three conditions would be a bigger help. Thanks!

Sam
Author:  Matt Cramer [ Wed Feb 06, 2008 7:41 am ]
Post subject: 
Megasquirts don't use the VE table until the RPM goes over cranking RPM - they have a separate cranking pulse width table used below the cranking RPM value.
Author:  440_Magnum [ Wed Feb 06, 2008 1:49 pm ]
Post subject: 
Quote:
I'm curious: Why use a pump unit that required cutting the trunk, rather than an external in-line pump?
If you remember when a mutual friend of ours ran TBI (albeit the crappy ProJection) in his Diplomat, fuel slosh was a big problem. Basically, whenever he had less than half a tank and maneuvered the car, it would slug some air in the pickup and fuel pressure would drop to nothing for a second or two. Not good.

In-tank pumps have the advantage of being inside a baffled can that keeps the pickup submerged at all times. You can also put a baffle cylinder in the tank around the pickup and then run an external pump, but if you're hacking up the tank that much already, then an in-tank pump makes a lot of sense.

Another option is put an external low pressure fuel loop from the tank to a vertical vapor/liquid separation cylinder, run the pickup for the high-pressure pump out the bottom of that cylinder, and a return line to the tank from the top of the cylinder. The downside is that it takes 2 pumps to do that, but a simple low-pressure pump can be had for less than $30.
Author:  440_Magnum [ Wed Feb 06, 2008 1:55 pm ]
Post subject: 
Quote:
It is incovenient to pull the tank to change the puel pump. I have always hated that part of modern auto construction.
Not all modern cars are like that. The first-gen Chrysler LH vehicles (Intrepid, Vision, Concorde) all have an access panel in the forward part of the trunk floor. You can remove the fuel pump assembly from inside the trunk, and it doesn't even matter how much fuel is in the tank. Full works just as well as empty. Chrysler did a LOT of things right in those cars, too bad that so many of the "right" things have been undone in the second-generation LH, the Cloud Cars, Neons, and (especially) the Calibers, Nitros, etc. they sell now.

Of course I've only made use of that access panel *once* in 247,000 miles on my wife's 93 Vision TSi. Electric fuel pumps can be really, really reliable nowdays.
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