Cramer Posted December 18, 2009 Report Share Posted December 18, 2009 Hey guys I am gathering parts for my top end upgrade and was looking for some injector help. I will be installing a Comp XR265HR cam with either yellow springs or 918's Comp 7.4" hardened pr's, Timing chain, OBX long tubes with cat delete, A wideband. I will prob have to upgrade the injectors if so will LS2 injectors work and be plug and play or will I have to go with some 42#ers? Are there any drop in injectors for the truck intake and rails? I don't want to put some huge injectors or money in the top end cause I will be gathering a block and parts for a 408 stroker to put in the truck next year. The reason I want to go with a low lift cam is cause it's a DD and I drive about 60 miles a day in it. I will be getting a beater work car in the spring so that is when i'm going to go about the other motor. Quote Link to comment Share on other sites More sharing options...
SSplaytoy Posted December 18, 2009 Report Share Posted December 18, 2009 The 8.1 injectors are plug and play. If you get bigger injectors for your upcoming 408, then there are a few people that make them so you don't have to splice and solder wires. Quote Link to comment Share on other sites More sharing options...
chpspecial Posted December 18, 2009 Report Share Posted December 18, 2009 Don't forget about the tunning for which ever injectors you go with Quote Link to comment Share on other sites More sharing options...
Cramer Posted December 18, 2009 Author Report Share Posted December 18, 2009 Don't forget about the tunning for which ever injectors you go with I have EFI Live so if I had some injectors that already had the files as a stock injector I wouldn't have to do all the settings. That is what I was hoping for atleast. I don't think I will have to put injectors in with the small cam But my last log had my duty cycle at 72% I believe. I think it is running rich to though. I will look into the marine injectors and see what I can find. Thanks. Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted December 18, 2009 Report Share Posted December 18, 2009 I have EFI Live so if I had some injectors that already had the files as a stock injector I wouldn't have to do all the settings. That is what I was hoping for atleast. I don't think I will have to put injectors in with the small cam But my last log had my duty cycle at 72% I believe. I think it is running rich to though. I will look into the marine injectors and see what I can find. Thanks. http://www.racetronix.biz/itemdesc.asp?ic=...&eq=&Tp= Quote Link to comment Share on other sites More sharing options...
misterp Posted December 18, 2009 Report Share Posted December 18, 2009 I have EFI Live so if I had some injectors that already had the files as a stock injector I wouldn't have to do all the settings. ... VERY GOOD THINKING, I've had hell with my aftermarket injectors in this area and have been basically fudging things in the injector settings tables. I would go with the 44# Delphi's because then you are dealing with a "known quantity". Another option is to send your existing injectors off to a company that rebuilds yours with different (larger) orifices, the price is cheaper but then unless they test/flow them to death and get all the EFILive parameters to accurately describe dynamic flow characteristics you'll be a long time tuning. Mr. P. Quote Link to comment Share on other sites More sharing options...
Cramer Posted December 24, 2009 Author Report Share Posted December 24, 2009 Ok so with the 8.1l injectors I will still have to get the flow settings figured out in EFI Live then still? Will I have to use 8.1l wiring harness or adaptors? I found a 8.1l stock wiring harness for pretty cheap and don't know if it will plug into my main injector harness. Can I use the injector settings from a 2500hd with the 8.1l to get my tune settings on them? Thanks everyone. Merry Christmas. Quote Link to comment Share on other sites More sharing options...
detjoe Posted December 24, 2009 Report Share Posted December 24, 2009 the tables are out for the marine injector. great injector for 90% of modded SSS's. only the nuts need to go bigger...or if you want to go e85 then you might go bigger. Quote Link to comment Share on other sites More sharing options...
misterp Posted December 24, 2009 Report Share Posted December 24, 2009 (edited) Ok so with the 8.1l injectors I will still have to get the flow settings figured out in EFI Live then still? Will I have to use 8.1l wiring harness or adaptors? I found a 8.1l stock wiring harness for pretty cheap and don't know if it will plug into my main injector harness. Can I use the injector settings from a 2500hd with the 8.1l to get my tune settings on them? Thanks everyone. Merry Christmas. Those injectors plug & play into your existing harness and fuel rail; and in EFI Live yes you lookup these tables from a stock truck with those injectors (8.1 3/4-ton for example) and copy the values from these tables to your new tune - * B3701 Injector Pulse Width Voltage Adjustment * B3702 Injector Timing * B3703 Injector Timing Trim * B4001 Injector Flow Rate * B4002 Injector Voltage Correction * B4003 Injector Minimum Pulse Width (you may have to lower these values to get a better idle) * B4004 Default Minimum Pulse Width * B4005 Small Pulse Adjust That way the computer has an accurate definition of the "hardware" you've installed in your motor, you will find it a lot easier to achieve a quality idle. The 8.1L injectors are 42# and are good up to about 500hp; these are not the same as the Marine 44# but may be enough for what you require and certainly are cheaper & easier to find. Mr. P. Edited December 24, 2009 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
chpspecial Posted December 24, 2009 Report Share Posted December 24, 2009 Those injectors plug & play into your existing harness and fuel rail; and in EFI Live yes you lookup these tables from a stock truck with those injectors (8.1 3/4-ton for example) and copy the values from these tables to your new tune - * B3701 Injector Pulse Width Voltage Adjustment * B3702 Injector Timing * B3703 Injector Timing Trim * B4001 Injector Flow Rate * B4002 Injector Voltage Correction * B4003 Injector Minimum Pulse Width (you may have to lower these values to get a better idle) * B4004 Default Minimum Pulse Width * B4005 Small Pulse Adjust That way the computer has an accurate definition of the "hardware" you've installed in your motor, you will find it a lot easier to achieve a quality idle. The 8.1L injectors are 42# and are good up to about 500hp; these are not the same as the Marine 44# but may be enough for what you require and certainly are cheaper & easier to find. Mr. P. Negative on that, the truck 8.1l injectors are 32# and the Marine 8.1L injectors are 42-44# depending on who is doing the rattaings. And I have a gmc 2500HD with the 8.1l and the stock IFR is 29.9483 lbs/hour Sinr98 make sure they are the marine injectors, all of the settings are the same or close to the truck settings with just a higher IFR and are plug and play, you don't need any harnesses' or mods to them. Teh truck injectors are OK but many people out grow them fast Quote Link to comment Share on other sites More sharing options...
SRT10KLLR Posted December 24, 2009 Report Share Posted December 24, 2009 Just get 60lb Plug n' Play Multech II truck injectors and call it a day. No need to sell your current or 42's later and upgrade. I put in 60lb injectors almost two years ago in anticipation of a turbo but have yet to install it and the injectors have been working flawlessly even though my highest IDC is 33-35%. After the new year I will be going back to the track one more time N/A then the turbo will finally go in. Also, the 60lb injectors are rated at 43.5 PSI(3 bar) but flow 72'b at our 58 PSI(4 bar) fuel pressure. Quote Link to comment Share on other sites More sharing options...
misterp Posted December 24, 2009 Report Share Posted December 24, 2009 Negative on that, the truck 8.1l injectors are 32# and the Marine 8.1L injectors are 42-44# depending on who is doing the rattaings. And I have a gmc 2500HD with the 8.1l and the stock IFR is 29.9483 lbs/hour Sinr98 make sure they are the marine injectors, all of the settings are the same or close to the truck settings with just a higher IFR and are plug and play, you don't need any harnesses' or mods to them. Teh truck injectors are OK but many people out grow them fast Thanks for the correction Mr. P. Quote Link to comment Share on other sites More sharing options...
chpspecial Posted December 24, 2009 Report Share Posted December 24, 2009 Thanks for the correction Mr. P. No worries, not to many people know that marine and truck injectors have different flow rates. and didn't want sinr98 to go with the wrong ones and have them tunned different from what they are Quote Link to comment Share on other sites More sharing options...
Cramer Posted December 24, 2009 Author Report Share Posted December 24, 2009 Thanks for the heads up. With the Marine injectors will I still be able to get the tuning values and all that from somewhere? I know I won't need 60# or more in this motor. When I build my next one YEAH I WILL. I just want to have some spare larger injectors on hand when I do my cam swap in case I am maxing out my stockers. I don't want to spend a tom of $ on this motor so I can put the rest of the $ the wife don't know about into another motor and a show car build. She don't know how much money goes into a vehicle. I will tell her it's a third of what I paid for things and she believes me. GULLA WHAT? Thanks again and Have a great X-MAS Quote Link to comment Share on other sites More sharing options...
chpspecial Posted December 24, 2009 Report Share Posted December 24, 2009 the setting from a truck will get you very close to ideal where the only change will be in the IFR table. all three types of injectos have the same characteristis so you shouldn't have to much problems tunning them. an SSS with full bolt ons will max out the stock injectors, if you are going to go with a cam, injectors are needed. Quote Link to comment Share on other sites More sharing options...
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