scaled back my VE tables alot and played around with the base timing. Got it to idle pretty good so far but need to keep my foot on the gas still since the throttle body screw cant go to 900 rpm or so like i need. I need to take it out and flip it to the other side to get it to work but i cant seem to get the screw out, think i stripped the starpoint.
TPS sensor is high as well. It reads .59 volts with it closed but that is near stock position. I need to slot the holes to and open up the throttle to read .54 or so at desired idle position I believe
You shouldn’t really have to mess with the screw to get your idle. That’s what the IAC motor is for. You keep the throttle plates closed & adjust your air bleed thru the IAC solenoid. At least that’s how most of them work.
I’ve always let the IAC work as little as possible at idle. During crank it opens lots but from everything I’ve read and done, the most stable idle is when IAC step count is low. Thirdgen IAC reset is done by adjusting idle screw to about 100 or so rpm below desired rpm while IAC is disconnected. Once you get that done, replug in the IAC and it will control the rest of the airflow for desired idle.
Right now I"m at something in the 60’s which aint bad, but could be better. At crank it wont start unless i give it some throttle. It may be abit rich on startup right now but with my desired idle speed of 900 rpm, i have to give it gas to maintain that else it drops to 500-600 and it simply cant stabilize. I’m sure its fine tuning but right now with these large injectors I’m happy where its at, it just needs the TPS adjusted and the IAC steps should come down
Air fuel is on the rich side, something like 13.2-13.5 to 1 but idle was pretty stable. Gonna try subtract abit of VE to get it more like 14 to 1 and see how it goes
I just want it to start up on its own without throttle input and idle by itself without me in it.
Only thing I"m worried about right now is how hot the pipes are getting. They get pretty hot so far and its heating my brake booster a good bit so far. Its only gonna get worse on a long run or WOT. I dont know what to do about it. I have heat shields and wrap on the pipes/etc but still hot in that area.
Also is it common for wrap to keep smoking?
the wrap will prob smoke for a while
need to get a few heat cycles. thirty mins on first startup should get rid of most of the smoke. you also have grease on the pipes from your hands plus the wrap itself. if it were to persist after hour or two of run time then there may be a leak.
instead of advancing the throttle screw. Enlarge the TB blade hole one drill bit size. makes a huge difference and keeps IAC counts in check. also when you advance the throttle screw which alot of ppl do it actually changes the parameters in the tune to a higher point then it needs to be at idle. My TB is closed 100% and idles on the IAC and tb hole.
also your can enlongate the holes only to a certain point the LS1 tb isnt as friendly as others.
Well maybe I’ll drill it open since i cant get the screw out at this moment. I just dont want to go too large on the hole.
TPS is fine where its at right now, it just wants to idle higher meaning more air flow at its current tune. Last night after cool down i started it for a buddy of mine and it was tryin to idle at 500 rpm and holding it, although very choppy, so its almost there
not doing so well. Starting driving it and tuning and it was going well til third run down the street the motor just shut off on me and would not restart. Something in the wiring or ecm or something else i dont know of failed on me and i havent figured it out.
I’m in Houston texas right now for work. Been here the 13th and wont be home till late the 25th. I got a new ECM to try and i’ll recheck my wiring/distributor and see whats up. HOpefuly its just a bum ecm and it will run good again
On side note, will start doing exhaust and either heads/cam package or just cam only and bolt ons for the LS1 TA i have now. Gotta have one powerful car with me when i move to texas in january…i dont think the maro will come down with me
I did the new ecm as mentioned above, not the problem… turned out it was alternator wire to alternator for the feed current was loose and not supplying battery voltage. This also made my injectors act retarded so i had to secure that wire to the alternator better, recharge battery and then tweak my battery voltage vs injector pulsewidth tables to compensate better for the voltage drop if happens again.
Got that all taken care off. Had a noise on passenger side that I thought was a rocker arm loose, so i played around that area listening and found exhaust leak so I attmped to fix that and it has quieted down but still there. Oh well.
I just went back to tuning last weekend. Started to get into heavier throttle and saw 2.7 psi of boost before i was hitting lean spots in the rpm range so it was acting like a limiter.
Redid my VE Map to look better…it just looked like shit and not what I’d expect VE table to look like for a motor. Compared to others and just scaled things up to ensure i had enough fuel everywhere. Turned out to be good.
Got over that 3800 rpm lean spot and took it to 6K with heavy throttle. 60-70% and saw 5-6 psi made. Still lean so i tweaked it abit more and took it out again.
6-7 lb springs in the wastegates but I saw 9.7 psi tonight running high 13’s to 1 air fuel so its stilll way lean. Not happy that i got some boost creep here but i did expect some based on where my gates are.
Car felt like a monster at 9psi. I was only there for a bit as the driver side turbo went RED ORANGE and i saw some flame so i got out of it in a hurry. But from a 50 roll in high gear, it blew the rubber off the tires. 295/30/19’s and it tore them apart. The nitrous car only did that when it was cold out and if i was in the lower gears. So the car is coming along nicely but still lots of fine tuning to do. I have hope to see the track this year and its gonna perform well I believe
Been working on the tune and got it pretty good i think. STill need to tweak some lower gear pulls as it was breaking up in some spots. Have abit toomuch timing in some spots and a few lean spots which caused the hesitation. I think my acceleration enrichment needs tweaked abit.
Anyway, i took the car out on a local stretch where i could get a good WOT pull and not spin tire. From my logs if my speedo input is correct, i started at about 47mph and hit 76mph in 2 seconds at what i THOUGHT was 3rd gear. 3000-5300 rpm pull just about, which from my gearing and tire size would mean i was in 2nd gear. No big deal tho, car feels pretty fast.
This was on 10psi. I got the tune to about 11 to 1 air fuel with 26-27 degrees of timing and the log was showing 4 degrees being pulled so i’m gonna back timing down abit more. Next i gotta take it over 6000 rpm to see how fuel looks in those cells and then after i get my acceleration enrichment tuned up, I should be good to do some track runs or dyno runs.
Gonna rain this weekend they say so looks like 24th it may make a debut run at 10 psi. By then i hope to add boost controller and race gas to try 15 like i wanted. SHould run 9’s on that. Feels about as fast as the nitrous car maybe abit quicker on 10psi and I went 10.6 last year. Dont expect this car to hole shot like that car tho.
kinda offcenter but the driver turbo does sit inward to the cowl abit more than other side. Not sure what i’m gonna do about the turbos out the hood. May leave it alone to help get rid of heat but i did want to build covers. My idea i had i mocked up and i didnt like it…so i dont know what to do nw
