ANOTHER boosted 5.3 build with summit bottom end
04-20-2020, 03:20 PM
#541
If you have a card style MAF, there is definitely an advantage. Re-read my last post. There's no advantage to a STOCK MAF. The way the stock tune works is its blended an idle/transition/low rpm. There is a cell "rpm threshold for airflow calc" that you set an RPM above which it only looks at the MAF and not the MAP. If I were you and I already had the 340's, I'd run both with good wiring/fuses, add the meth and re-evaluate.
So if I use the Maf, the ecm ignores the map above a certain rpm and goes off the maf? what about the boost fuel table what is map referenced?
04-22-2020, 09:05 AM
#543
So...I have a couple questions. First off, I just got the car back running yesterday, cranked it up for the first time with 80lb dekas. Something odd, it seems to drive better, idle better and the fuel consumption dropped by .15 gal per hour at idle, and at cruise instead of saying 22.1mpg at 60mph, it now says 24-25mpg. cool. but why? The only two reasons I can come up with is 1) my injector data was wrong? 2) the 60's had four spray holes, you couls see where it was spraying at hte top of the port but some of it was hitting the flat surface of the port instead of spraying directly into the port.....and puddling the fuel if i had to guess. 80's I have, they have a single nozzle hole and in my opinion, are probably spraying into the port better. Just my thoughts.
I did have to retune it and pulled about 10% fuel from idle and cruise. So my theory about wasting fuel from puddling, may not be so far off. So I guess the question is....what do you guys think the difference is?
Next, more important question. Scaling. So Greg shows that when you scale a Hp tuners file, the fuel table numbers get bigger instead of smaller....opposite of what you want. So he says copy the table...then go change the cylinder volume size to your percentage lower (in his case, 24%) and the go back to your fueling table and paste the original values back in....question is, I dont recall him saying to scale those numbers after the copy and paste....also, do the fuel injector flow values get scaled too?
04-22-2020, 09:11 AM
#544
On the idling/mpg stuff, I'd lean more towards #1 or your injectors were dirty or something like that. I've never heard anyone talk about mpg increase going from 60's to 80's.
On the scaling, I can't answer the "fuel table number" question because I use EFI Live almost exclusively. In there you scale the size of the engine and any/all parameters that are based on g/cyl, grams, etc. Then scale the VE or MAF. Typically I would be retuning something anyways so I wasn't bothered if the VE or MAF was off on first crank after a scaling exercise. As far as fuel injector flow values, yes you scale the flow rate of those as well and make sure its sloped vs. linear depending on whether or not you have a boosted reference FPR.
On the scaling, I can't answer the "fuel table number" question because I use EFI Live almost exclusively. In there you scale the size of the engine and any/all parameters that are based on g/cyl, grams, etc. Then scale the VE or MAF. Typically I would be retuning something anyways so I wasn't bothered if the VE or MAF was off on first crank after a scaling exercise. As far as fuel injector flow values, yes you scale the flow rate of those as well and make sure its sloped vs. linear depending on whether or not you have a boosted reference FPR.
08-02-2023, 04:58 PM
#545
I just wanted to give you guys a long term update. Got the car running 2/16/2020 and the only issue I've had was a tuliped valve. Thats entirely my fault too, I bought cheap *** valves. Should have bought ferrea from the get go. Well I'm happy to say its holding up. I've had to daily it a few times for a month or more over the past couple years because my sons truck kept breaking (trans, rear end, transfer case) and he'd borrow my truck while his is down. I've been on a few road trips, car shows out of town....etc. Oddly the 4l60 is holding up too. I daily it on drag radials (NT05R or 555R2). I did upgrade the turbo and put a 3.5" exhaust, but of course those were by choice. On a cold morning the forged pistons make a little noise at 2500ish rpm until it get a little heat in them. The dipstick will pop up out the tube every so often under 22+psi of boost so it may have a little blow by but I think I gapped the rings a little wide. Maybe its my crankcase venting. Maybe it could be the oring on the dip stick have pretty much zero resistance in the tube. Well I look at it as a blow off valve for the rear main seal to not get blown out lolz.
The following 2 users liked this post by Kfxguy:
G Atsma (08-02-2023), Ls7colorado (08-03-2023)
The following users liked this post:
Kfxguy (08-02-2023)
08-02-2023, 09:20 PM
#547
both valve covers are drilled and tapped for 1/4” pipe. I have a 90 elbow on each valve cover that I drilled out for flow, then 1/2” hose on each valve cover, 3/8 pie on the valley cover. They all go to a catch can that did have a filter on the top but then I made a fitting and put a 3/4” hose in place of the filter and ran it to a fitting in the turbo air intake elbow. It pops the dipstick up less with it run to the air intake vs having just a filter in the top of the catch can. Next I might need to run a 1/2” hose to the valley cover and maybe go to a larger hose to the turbo intake. I’m scared to put new orings on the dipstick for fear it’ll blow a seal on the engine. But the dipstick has really no resistance holding it in the tune. I dunno.
08-03-2023, 08:31 AM
#550
TECH Resident
A low pressure gauge and hose slipped over the dipstik tube and routed up to the wiper blade?