my 50# injector tuning woes
Thread Starter
Joined: Nov 2001
Posts: 7,903
Likes: 1
From: Cleveland, OH
my 50# injector tuning woes I am trying to tune some msd/holley 50# injectors, Thing is I can't get them to idle for crap. my thinking is our high fuel pressure is really compounding the problem. I know they wont have a nice consistent spray like the stockers but if the turbo regal guys can tune them to idle like stock...we should be able to. My 1:1 regulator should be here SOON and I will hopefully get them tuned with around 44 psi of fuel pressure at idle. Anyone else used 50s before?
Re: my 50# injector tuning woes Sorry,
I haven't gotten around to pulling out my 38 lb/hr and tossing the 50s in.
I will be doing it in the next few weeks along with a fuel system.
Good Luck,
Scott
I haven't gotten around to pulling out my 38 lb/hr and tossing the 50s in.
I will be doing it in the next few weeks along with a fuel system.
Good Luck,
Scott
On The Tree
Joined: Apr 2002
Posts: 197
Likes: 0
From: Windham, NH
Re: my 50# injector tuning woes I run MSD/Delphi 50s in my TTA. They do idle and drive just like stock. I LOVE those injectors. I run 45psi fuel pressure with them on my TTA and run them at 69psi under boost with 24 pounds of boost.
Its all about the tuning. Good Luck... The LS1 stuff is still so new so not many people have played with them in an LS1 yet.
Its all about the tuning. Good Luck... The LS1 stuff is still so new so not many people have played with them in an LS1 yet.
Thread Starter
Joined: Nov 2001
Posts: 7,903
Likes: 1
From: Cleveland, OH
Re: my 50# injector tuning woes Yeah I'm thinking the ls1 60 psi fuel pressure is gonna make it tough to tune the idle. I'll drop it when my regulator gets here and see what happens. Do you happen to know the injector offset?
Trending Topics
TECH Resident
Joined: May 2002
Posts: 829
Likes: 0
From: Fremont, CA
Re: my 50# injector tuning woes </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Scott 98Z M6:
<strong>Sorry,
I haven't gotten around to pulling out my 38 lb/hr and tossing the 50s in.
I will be doing it in the next few weeks along with a fuel system.
Good Luck,
Scott</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">wanna sell those 38# injectors when you get around to it? email me
<strong>Sorry,
I haven't gotten around to pulling out my 38 lb/hr and tossing the 50s in.
I will be doing it in the next few weeks along with a fuel system.
Good Luck,
Scott</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">wanna sell those 38# injectors when you get around to it? email me
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
TECH Addict
Joined: Nov 2001
Posts: 2,659
Likes: 1
From: Bellevue, Wa
Re: my 50# injector tuning woes what do your ltrims look like?
I tried one of those spreadsheets and found for my car I had drop the values a good 20% to get ltrims dialed in and my eyes to stop tearing from the unburnt fuel.
may not be as simple as what I did but go out, log ltrims, I assume they will be -XX% the go drop the offset by XX% and go drive and log some more til you get your -1 to 3% most people seem to recommend dialing in and hopefully your in buisness???
seems to work for me.
I tried one of those spreadsheets and found for my car I had drop the values a good 20% to get ltrims dialed in and my eyes to stop tearing from the unburnt fuel.
may not be as simple as what I did but go out, log ltrims, I assume they will be -XX% the go drop the offset by XX% and go drive and log some more til you get your -1 to 3% most people seem to recommend dialing in and hopefully your in buisness???
seems to work for me.
Thread Starter
Joined: Nov 2001
Posts: 7,903
Likes: 1
From: Cleveland, OH
Re: my 50# injector tuning woes I'm using stock MAF. Forget ltrims...this thing is not driveable with the 50#ers. Cuts off...surges...etc. You gotta remember, the bigger injectors have poor fuel control at low pulse widths which is one reason to go to a low impedance injector. Compounding this is 58-60 psi of fp at idle (stock fp) Once I lower the fp I think I can get them under control.
Re: my 50# injector tuning woes just a thought.. mabey you should check the injectors, maybe one is sticking or something?
i know when i had my fuel pressure way up (85ish)on my 36's to not blow up using fastchip tuning it would kill my idle (cutting off etc.).. my injector pulsewidths went down to around 2ms.. and thats just not very long to get any precision.
i know when i had my fuel pressure way up (85ish)on my 36's to not blow up using fastchip tuning it would kill my idle (cutting off etc.).. my injector pulsewidths went down to around 2ms.. and thats just not very long to get any precision.
Thread Starter
Joined: Nov 2001
Posts: 7,903
Likes: 1
From: Cleveland, OH
Re: my 50# injector tuning woes I had no idle issues with 36-38-lucas 42-svo 42.
My pulse widths are in the 3.4ms range at idle. My maf is in the correct location...i have a turbo so no positive pressure at idle
My pulse widths are in the 3.4ms range at idle. My maf is in the correct location...i have a turbo so no positive pressure at idle
Thread Starter
Joined: Nov 2001
Posts: 7,903
Likes: 1
From: Cleveland, OH
Re: my 50# injector tuning woes I work when i want to .....and as you know...these sorry clients pay me the same way....when they want to. About to try injectors again...be back in a few with the results
Thread Starter
Joined: Nov 2001
Posts: 7,903
Likes: 1
From: Cleveland, OH
Re: my 50# injector tuning woes Ok now I'm getting somewhere. I pulled regulator in tank. Installed CAS billet regulator. Set static fp to 50....after hooking up vacuum/boost hose fp idles at 42psi. I used 5.12-5.61 for the injector constant. Yes this is a very rough tune but it idles and drives fine. Plenty time to tweak it.
Re: my 50# injector tuning woes Way to go!!!
I have found that it is easier to adjust LTRIMs with the regulator vs. LS1Edit.
Congrats. on getting it running better...now get that sucker tuned on a WB dyno and crank the boost <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I have found that it is easier to adjust LTRIMs with the regulator vs. LS1Edit.
Congrats. on getting it running better...now get that sucker tuned on a WB dyno and crank the boost <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Re: my 50# injector tuning woes Well it is good to see you are figuring that thing out. I cannot wait to see what my fuel pressure is like. I might need to get the old regulator from you.... We will see soon......
Re: my 50# injector tuning woes </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Blackbird:
<strong>
...I assume they will be -XX% the go drop the offset by XX% ...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Did you change the injector offset table or just refine the injector flow rate?
<strong>
...I assume they will be -XX% the go drop the offset by XX% ...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Did you change the injector offset table or just refine the injector flow rate?