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Discussion Starter · #1 ·
currently have stock eaton with 8pound pulley wondering if I got the 55 pound injectors with the proper tune on my chip would I see an improvement . would like to optimize what I have before going to another style blower . Rdy2rac you might be able to answer this question since we basically have the same set up except your pulley is larger.:blob
 

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Unless your maxing out the 42#'ers...............I don't see how bigger injectors would help you.
Another words.........if the stock injectors (with or without a BAP) are supplying enough fuel already then there is no need to increase injector size. However if your tune requires running the stock injectors at like 90-100% duty cycle you risk burning them up.

--Joe
 

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i had a chart of whats recommended for proper efficiency (sp?) of the injectors but, cant seem to find it. like joe is saying the 42's are good upto a certain duty cycle but we are near that overall efficiency and starting to demand way more than the 42's are really designed to take. actually i would be way more concerned about the fuel rails, many have found that the no.4 cylinder has been the one that runs the leanest. its the last injector to see the fuel supply. be it new 255 fuel pumps, a boost a pump or a new fuel system all together. i would worry more about total volume in the fuel system than trying to get more fuel through larger injectors. at least upgrade fuel system 1st then if thats not enough then do injectors.


i was on the dyne getting tuned a few weeks ago and we kinda forgot to put the chip back in. long story short we had an 10.7 a/f on the stock pcm. horsepower and torque greatly suffered but atleast i know my combo will run with no chip if need be. no i'm not saying go out and run a large pulley you'll be fine. here's my combo and the reason why i think we got away with it, 2000 L stage 2 ported heads stock cams, stepped long tubes 3 inch exhaust(no cats), accufab, 90 mm, jlp ram air, 50 lb. delphi injectors, 10 lb lower 1.5 upper, e-fan cobra pump, and a jlp super cooler full of ice. i'll see if i can find the dyno graphs to post sometime tommorrow.
 

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rdy2rac said:
2000 L stage 2 ported heads stock cams, stepped long tubes 3 inch exhaust(no cats), accufab, 90 mm, jlp ram air, 50 lb. delphi injectors, 10 lb lower 1.5 upper, e-fan cobra pump, and a jlp super cooler full of ice. i'll see if i can find the dyno graphs to post sometime tommorrow.
Can't wait to see that dyno graph! Any chance you can post your numbers tonight>??? I have always been curious what your truck makes HP and TQ wise. Has does the eaton do up top spinning that fast>??? Does it fall off>??? Any reason why you haven't stepped up to an aftermarket blower>??? -Mat-
 

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Discussion Starter · #5 ·
speakinf of running with out a chip I accidently made a time trial without the chip when I was running at martin if Iremember correctly it ran a 12.92 unsure of mph . When I run my truch the first half it hauls but the second half it falls on its face.
 

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conleymotorsports said:
When I run my truch the first half it hauls but the second half it falls on its face.
Is that only without the chip or also with the chip in>??? If that happens with the chip in it sounds like you are running out of fuel. Have you ever had it on a dyno to check the A/F>??? Might be a good idea. I know when my truck got tuned for the KB it lost fuel up top and pegged the MAF so we went with 55LBers and the ProM 92MM MAF. All is well now. :D -Mat-
 

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Discussion Starter · #7 ·
I just took my plugs out after I answered the thread the are white in color looks like it could use some more fuel to me .
 

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well i flat out cant get more than 15 psi. it comes up and flattens out. i'm at work right now but as soon as i can get home and find the last dyne session i'll try and scan it and post. last dynojet i was on it made 427hp 498tq then i went to a mustang dyne and we tuned it. get 10 more hp than what we got from the base line went out and it was running 12.40's at route 66 went to atco and sal tweaked it and ran 12.20 12.23 12.22. anyways i'll post the graph tommorrow.
 

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Your torque seems very very low>??? Is there a reason for that>??? With 15PSI you should be closer to 550RWTQ. Are those numbers SAE or Actual>??? -Mat-
 

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agreed that torque should be higher and it is just cant find the post i made with the last dyno numbers. also i'm running a PI 2800 stall convertor. and they are sae corrected numbers on a mustang dyne so add about 25 or so hp and tq and thats what a dynojet would be. also a/f is set for 11.4 across almost the whole rpm band under boost. running 22 degrees of timing now where on the dyno it slowly climbed to 22 degrees (sal tweaked the program at atco) and its a whole different truck. i was getting 1.86-1.87 60's before and now its seeing 1.63-1.64's. with the head work before and after i lost a little over 2 psi in boost and i have very little back pressure using 6the stepeed 1 5/8 to 1 3/4 primaries into 3 inch collectors and 3 inch dynomax ultraflows with a dr gas x-pipe dumped in front of the axle.
 

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rdy2rac said:
many have found that the no.4 cylinder has been the one that runs the leanest.

Wow thank you so much, I have searched for the longest time to find which cylinder was leanest. Now I just need to weld the hole in number 1 and move the EGT probe.
 

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rdy2rac said:
agreed that torque should be higher and it is just cant find the post i made with the last dyno numbers. also i'm running a PI 2800 stall convertor. and they are sae corrected numbers on a mustang dyne so add about 25 or so hp and tq and thats what a dynojet would be. also a/f is set for 11.4 across almost the whole rpm band under boost. running 22 degrees of timing now where on the dyno it slowly climbed to 22 degrees (sal tweaked the program at atco) and its a whole different truck. i was getting 1.86-1.87 60's before and now its seeing 1.63-1.64's. with the head work before and after i lost a little over 2 psi in boost and i have very little back pressure using 6the stepeed 1 5/8 to 1 3/4 primaries into 3 inch collectors and 3 inch dynomax ultraflows with a dr gas x-pipe dumped in front of the axle.
Ahhhhhhh. A mustang dyno and what def does sound like very very little back pressure could explain the low torque numbers. On a dyno jet with a 6LB lower I put down 430RWHP and 558RWTQ. So your HP is gonna be well over that and torque should be very close since you did it on a mustang dyno. Do you plan on going on a dynojet in the future>??? -Mat-
 

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ok here's the last dynojet i was on with my diablo

and here is the mustang dyne with the same diablo (390 hp) see how it was fallin' off at 4700 basically that is were it was spiking up to 24 degrees of timing and basically it started pulling timing cause it didn't like it. now the second set is an autologic dyno tune and basically he was able to get me about 10 hp and 18 tq more so if you dynojet math that would put me around 438hp and 516 tq now i have since had sal change a few things and have dropped 2 tenths of my 60 and ran almost 2 tenths faster than i have ever ran in hotter and more humid weather.
 

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Discussion Starter · #14 ·
rdy2rac are you not still using a jlp tune or are just experimenting with other chips.
 

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well we're still playin with chips. as you may or may not know i have my own diablo programmers but the way the diablochips work you basically call, im or e-mail them for the specs you want. i had the autologic chip already so i worked out a deal if i ran there name on the truck (detroit speedworks) dyno time and tune at no charge. they do alot of lsi(f-body) turbo kits and they are trying to work a deal for a turbo to put on my truck and would be their test truck. :D
 

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Discussion Starter · #16 · (Edited)
great hope it works out for you I'm pretty sure I can get a better tune than what I have now I think it is set at 16 degrees of timing in my old 99 lightning I had a Jdm tuned chip and 4pounder that's it for mods and it ran 12.60's all day but the timming was also at 22 degrees it's all in the tune .
 
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