Accel MAPdot and TPS dot explanation of the terms

[HPjunkie]

I have been running MSII 2.88 code for a while an a dune buggy. It starts great idles great but accel is lacking. I have played with the mapdot and tps dot for hours. what I dont understand in laymans terms is % of throttle opening mixed with time and how that relates to mixture enhancements. I dont know what to look for.
I would like a longer pump shot from the tps side.
But I know I should be able to patch, blend or augment that with MAP enrichment. It will go flat and stumble with moderate throttle if I dont return to idle. I just dont under stand what to put in the % 5 boxes Like increasing or decreasing values (or what values) and where to start with the additional fuel. on either side. summer is flying by and just want to do some driving!

[Bernard Fife]

hpj,

Did you see this: http://www.megamanual.com/ms2/tune.htm#accel ?

Lance.

[HPjunkie]

Hi Lance, I have read that over and over. I cant seem to get the just of it in my head. I have the threshold part down I believe, 'as low as possible above noise" to get max enrichment as early as possible? Correct?

I have had the slider all the way over to tps only thinking like a carb guy.

The settings for the rates in kPa/s and % /s are the most confusing. In each respective column /s there are 4 boxes starting from the bottom going up what is the rule of thumb? Low to high going up? I am assuming I can then lean the values (ms) a little at a time per the link you sent to get it crisper. I was running richer at idle and low range to help cover the holes during acceleration. Im tired of that tho.

Then the slider option. What is the reason to add map enrichment? Is it just like a blanket of fuel to cover holes in the tuning? Or similar to the power valve in a carb? Any tips on that?

I feel that I may have some problems with a big throttle bodie and plenum area and its been hard to get a good crack out of it and strong pull at various rpms. wide open is great but i cant go everwhere like that. It also mentions going to the defaults and starting over. How is that done?

[HPjunkie]

I will post the last log and the MS file soon. I still need help understanding.

[HPjunkie]

Here is the MSQ. this one I was fooling with the MAP vs Throttle position.

[HPjunkie]

it wont let me add anymore. I am logging out and starting over

[HPjunkie]

heres a couple Msqs. I am going to have to edit some data logs to get them to fit

[HPjunkie]

I just want it snappy. off idle. and while driving of course. the throttle body is about 24 inches from the injectors and the valves.

[HPjunkie]

here is one datalog.

[Matt Cramer]

It looks as if there are quite a few points where the fuel map could use more tuning (it's running at 10.2:1 in some places and dangerously lean at high boost at others, in situations where AE is not a factor). It also appears to be a bit short on injector as the dangerously lean points are also at over 80% duty cycle. My advice is to do the following, in this order.

1. Swap to injectors that are about 50% larger.
2. Dial in the VE table with the new injectors.
3. Then get the AE tuned.

[HPjunkie]

thanks for the reply Matt, I would just like to talk about the injector for a second. they are low impedance injectors rated 55 pounds per. the fuel pressure is 43 pounds. the motor is 142 cubic inches. I did go thruthe mass and thought I had size them correctly. any additional thoughts on sizing and or fuel pressure

[Matt Cramer]

Hmmm... maybe the fuel pump isn't up to snuff. Check to be sure you're not losing pressure at full boost.

[HPjunkie]

Well I got the car tuned in! I Enlisted the services of someone that had Megasquirt experience. Scott Clark. Found the Dwell was too short, 1ms vs 3ms. that cleaned up alot of running issues. Then he dyno tuned it. Runs like a champ. Runs so well the clutch couldnt hold on the 2400# dyno wheel! Now I need a better clutch setup.