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Tune for bracket racing consistency

Unread postPosted: Wed Feb 21, 2018 8:07 pm
by Patricktjms
I am wondering about using the U4P2 for bracket racing. I want the car to be as consistent as possible and predictable to weather change. I am used to carb fueled cars. What is suggested for consistency and predictability? Locked timing and open loop would be my first two guesses. Any suggestions?

Re: Tune for bracket racing consistency

Unread postPosted: Thu Feb 22, 2018 5:24 am
by decipha
when you tune your ecu properly it will run the engine as efficiently as possible for all given conditions.

Re: Tune for bracket racing consistency

Unread postPosted: Sun Mar 04, 2018 7:04 pm
by Patricktjms
In reading your transmission write up, you specify to divide old tire size by new tire size and multiply it by old gear divided by new gear. But in the example you show, you divided the tire sizes opposite of what you stated. Can you clarify please?

I am going from 273 to 410 gear and from 25.7 to 28 inch. It makes quite a difference if you divide the other way.

Re: Tune for bracket racing consistency

Unread postPosted: Mon Mar 05, 2018 9:34 am
by Patricktjms
Got it figured out.

Re: Tune for bracket racing consistency

Unread postPosted: Mon Mar 05, 2018 1:28 pm
by decipha
i see what your saying, i'll flip it around in the write up, but yea the example is correct

Re: Tune for bracket racing consistency

Unread postPosted: Tue Mar 06, 2018 7:55 am
by Patricktjms
Just double checking, the u4p2 tune shouldn't need anything extra changed for cat-less exhaust? Other than obviously tuning for fuel needs as normal?

Re: Tune for bracket racing consistency

Unread postPosted: Wed Mar 07, 2018 7:20 am
by decipha
no, cats do not affect the tune

Re: Tune for bracket racing consistency

Unread postPosted: Mon Mar 12, 2018 4:22 pm
by Patricktjms
Aode equipped so I need to set mechanical idle IN GEAR at or <50 rpm above NUBASE? not in neutral or park correct?

Re: Tune for bracket racing consistency

Unread postPosted: Mon Mar 12, 2018 5:57 pm
by decipha
you should

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 17, 2018 11:47 am
by Patricktjms
So when setting the idle mechanically in gear, I have found that everything is great when in open loop, but when it switches to closed-loop, the car will not idle in park. It's like it stops adding idle air when it goes to closed loop. I know I shouldn't be setting idle in open loop, it's just something that I noticed when it switched back to open loop after dying and restarting.

If you open the throttle stop to where it will idle in park in closed loop, it will run away with you when you drop it into gear.

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 17, 2018 6:07 pm
by decipha
closed loop and open loop are fueling only, if its making the idle change that means your fueling is off and the hegos are compensating making the engine more efficient and raising the rpms

if its idling fine in park and u toss it in gear and it takes off u need to reduce fn1862d the drive isc multiplier table so its not opening the iac as much

also another good thing, it makes for a much nicer transition for the dashpot min clip if u set dasmph to 0.5 mph and set dasmphhys to 12 mph, that way when u let off the brake and idle in gear dasmin doesnt take over and drag u forward til u get over 12.5 mph which u shudnt at closed throttle, then dasmin will kik n and let it coast down to 0.5 mph before decaying dasmin out making for a very nice and smooth transition

set minmph and mphctl to 25 mph, as well as setting dasctl to 0.35 and make sure you dont dasmin clip above .35

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 17, 2018 7:15 pm
by Patricktjms
Thank you for the suggestions.

The idle is actually opposite of that. It idles great when in gear during closed loop but when you go into park it absolutely won't idle unless tps is open to .04. Ispbm r remains at 0.0

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 17, 2018 9:20 pm
by decipha
if ipsibr isnt kicking up to maintain dsdrpm then your not setting the idle flag

Re: Tune for bracket racing consistency

Unread postPosted: Sun Mar 18, 2018 1:40 pm
by Patricktjms
Thank you for all the recommendations. It seems to be fairly happy right now.......

Went to change cooling fan on/off speed and now the fan stays on regardless of temps I enter. Any clues where to start with that?

Re: Tune for bracket racing consistency

Unread postPosted: Tue Mar 20, 2018 8:33 am
by Patricktjms
I don't suppose this could be a relay issue instead of a tuning typo could it?

Re: Tune for bracket racing consistency

Unread postPosted: Tue Mar 20, 2018 8:39 am
by decipha
unless u put the turn on fan temp extremely low then no

most likely you have aftermarket fan wiring and who ever ran it didnt run a double relay so it fused it shorted open

Re: Tune for bracket racing consistency

Unread postPosted: Tue Mar 20, 2018 1:46 pm
by Patricktjms
It's the oem fan and wiring. I will look at the ccrm and start there. Thank you!

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 24, 2018 6:06 pm
by Patricktjms
What is Des-slip on the dashboard and why is it at a constant 1020? Is that correct?

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 24, 2018 6:28 pm
by decipha
thats the amount of tq converter slip the ecu is commanding of the tq converter, 1020 being full slip, if it stays there then you don't have it commanding lock up

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 24, 2018 6:31 pm
by Patricktjms
Perfect. Thank you sir. So is there a way to put fuel strategy on the dashboard? I see it in the edit gauge window but I can't seem to get it to display.

Re: Tune for bracket racing consistency

Unread postPosted: Sat Mar 24, 2018 11:25 pm
by decipha
Can u elaborate more? the lambse and kamrf are on the dashboard

Re: Tune for bracket racing consistency

Unread postPosted: Sun Mar 25, 2018 9:23 am
by Patricktjms
When you are in the edit gauges window, there's a bitmap labeled FLAGS3. I was wanting that on the dashboard so I could review logs and see what the fuel source was doing
Under different conditions but it won't let me choose it for display.

Re: Tune for bracket racing consistency

Unread postPosted: Sat Apr 14, 2018 9:50 am
by Patricktjms
When testing the car at the track last night, I have WOT shift points at 4k and it shifts into 2nd at 5500, and into 3rd at 5000. Any way to lessen the delay?

Also the 1-2 shift is very lazy and long. 2-3 is quick and firm. How can I make the 1-2 feel the same?

Re: Tune for bracket racing consistency

Unread postPosted: Sun Apr 15, 2018 7:26 pm
by decipha
lower the vehicle speed in the shift functions not just the wot scalars

reduce the shift slope scalar to give it more line pressure on shift, or/and increase the torque values in that range in the engine tq table

Re: Tune for bracket racing consistency

Unread postPosted: Sat May 19, 2018 2:22 pm
by Patricktjms
Adjusting speed in the shift functions had no effect on my WOT shift rpms. Still occurring 1k-1500 rpm late.

I did notice on the dashboard that RVSS and VSS are off from each other by a progressive amount as speed increases. Could this be part of the issue? And how do I correct this?

Re: Tune for bracket racing consistency

Unread postPosted: Sat May 19, 2018 5:20 pm
by decipha
you have to dial in nvbase, its in the trans write up on the homepage

Re: Tune for bracket racing consistency

Unread postPosted: Tue Jul 10, 2018 6:25 pm
by Patricktjms
Ok...so i have a lot of track time with this car now and i have tweaked about all i know to tweak. It runs consistant but slow. which is fine. but i just realized i didnt compensate for the fuel pressure change to 55 lbs by raising the hi slope. I changed it by the % of fuel pressure change and i will test tomorrow but i noticed something. I run the car in open loop and demand 1.05 all the way up to 90 load. it works for me right or wrong. but when i play back a recording, it shows commanding lambse anywhere from 1.00 down to .922 what is causing it to demand a value that isnt in any cell whatsoever? ill try and attach the recording of the run and the tune. any advise appriciated.

Re: Tune for bracket racing consistency

Unread postPosted: Tue Jul 10, 2018 8:39 pm
by decipha
more than just the high slope

load has no affect on fuel perload does, are you interpolating?

Re: Tune for bracket racing consistency

Unread postPosted: Wed Jul 11, 2018 5:51 am
by Patricktjms
No I dont believe I am. I'm just wondering why it is commanding fuel that isn't in any block on the table. How is that possible?

Re: Tune for bracket racing consistency

Unread postPosted: Wed Jul 11, 2018 7:13 am
by decipha
it sounds like its doing exactly what its supposed to

you have to interpolate the value

Re: Tune for bracket racing consistency

Unread postPosted: Wed Jul 11, 2018 10:07 am
by Patricktjms
I don't have anything horribly messed up in the tune that I posted above do I?

Re: Tune for bracket racing consistency

Unread postPosted: Wed Jul 11, 2018 12:57 pm
by decipha
sounds like all is working correctly so I didnt bother to look

Re: Tune for bracket racing consistency

Unread postPosted: Fri Jul 20, 2018 2:23 pm
by Patricktjms
I got that all sorted out. Much better now. Car repeats very consistently.

I am putting in my good C4 and converter this weekend. Do I need to change to the T4M2 tune or will the U4P2 tune work ok still?

If I need to change, is there an easy way to transfer all of my little changes over to the T4M2?

Re: Tune for bracket racing consistency

Unread postPosted: Fri Jul 20, 2018 7:27 pm
by decipha
no the c4 isnt controlled by the ecu so its still a manual trans basically

if u have stalling issues going in and out of gear you can wire up the nds and set trload to differentiate neutral and drive still with t4m2 tune tho

Re: Tune for bracket racing consistency

Unread postPosted: Sat Jul 21, 2018 2:42 pm
by Patricktjms
I realize how the c4 transmission works, I am taking out my AODE transmission. Can I still run the tune that I have? Or do I need to change over to the T4M2 tune?

Re: Tune for bracket racing consistency

Unread postPosted: Sat Jul 21, 2018 7:55 pm
by decipha
you can swap between an auto and manual pretty easily just set trload and tstrat to 0, theres a few little tidbits in the background that needs to be adjusted to disable any codes that pop up but its no biggie